How-To Tutorials - 3D Printing News

In this article by Joe Larson, the author of the book 3D Printing Designs: Octopus Pencil Holder, we are going to look at some of the basics, while setting the project for 3D printing. In this article we used Blender as our 3D editing tool. (For more resources related to this topic, see here.) Editing the basic shape This project is going to take advantage of several powerful editing tools that Blender provides. The first one is going to be the Extrude operator. Extruding takes its name from the process of creating things in real life, but in 3D modeling, extruding takes a selected part of an existing model and creates new geometry on the edge of the selected parts so that the original can be moved away but remain attached to where it came from. The result is a new shape that can then be edited. Extruding is a very powerful tool that's used to alter the shape of an object and create new faces that can be extruded themselves: Enter Edit Mode (Tab) and switch to face the select mode (Ctrl + Tab). Deselect all faces (A). Then, select one of the vertical sides of the cylinder. Extrude it either by navigating to Mesh | Extrude | Region in the 3D View menu or pressing E on the keyboard. Extrude the face about 40 mm by moving the mouse or typing 40 on the keyboard. Press Enter or click on the select mouse button to complete the extrude action. Like all actions in Blender, if a mistake is made in the process of extruding, pressing Esc or click on the right mouse button to cancel the action. If a mistake is made after this, undoing the action with Ctrl + Z is always possible. Then, scale the face (S) down to about 20% (0.2) in order to create a tentacle. Repeat the extruding and scaling process with the other seven vertical faces of the cylinder to create all eight tentacles. Select the top face of the cylinder and extrude (E) it about 30 mm. Then, scale (S) it up just a little bit to make the head bulbous. Extrude (E) the top again—this time, about 20 mm and—and scale (S) it in order to give the top a more rounded shape. Now, the cylinder has been changed into something more of an octopus-like shape. And it was mostly accomplished with the Extrude command, a truly powerful tool used to modify the shape of an object. Summary In this article we learned the basics of 3D editing and setting the project for initial stage. We learned basics of 3D modeling and used Octopus Pencil holder as our project. We also come across various keyboard shortcuts. Happy designing! Resources for Article:   Further resources on this subject: Build a First Person Shooter [article] Audio and Animation: Hand in Hand [article] Metal API: Get closer to the bare metal with Metal API [article]

(For more resources related to this topic, see here.) Simply scaling the model is easy to achieve with other programs like Netfabb (www.netfabb.com) or your desktop printer's slicing program. Scaling would make the handle longer, but would also proportionally increase the size of the wrench head, making it too large for its purpose. Using SketchUp she easily lengthened just the handle. She downloaded the .stl file and opened it in SketchUp. Since she prefers using SketchUp 8, she didn't have the option to merge coplanar faces; the model came in triangulated, which is normal for .stl files. It looked like the following diagram: Kim checked the dimensions of the imported wrench right away, to see if they made sense with the size of her GoPro. Fortunately, they were correct. If not, she would have gone back to ensure the units were correct in the Import Options, or scaled the model using the Tape Measure tool. Since it's harder to work with triangulated models, Kim used the CleanUp extension to remove the unnecessary lines. The link to CleanUp is http://extensions.sketchup.com/en/content/cleanup%C2%B3. After running the extension with the Erase Stray Edges option checked, the model looks like the following diagram: To extend the handle, Kim selected all the edges and faces that form the handle end. This is quickly achieved using the Select tool and a left-to-right selection box, as shown in the following diagram: Next, Kim got the Move tool and moved the selected entities along the Green (Y) direction until the handle was as long as she wanted. She used the Tape Measure tool to check the length. The following diagram shows the lengthened handle: Kim noticed that she can save some weight in the final part by removing some material. Using the Offset tool, she creates a new face in the center of the wrench head, as shown in the following diagram: She also used the Eraser tool to clean up the extra lines created by the Offset operation, as shown in the following diagram. Leaving the extra lines would prevent her final model from becoming solid. Using the Push-Pull tool to push the new face through to the back of the model, a neat hole is formed as shown in the following image: Kim noticed the opportunity to reduce material in the handle as well, so she used the Rectangle tool to create two faces on top of the handle, and the Push-Pull tool to create the holes. Kim was happy at this point, and exported the model as .STL for 3D printing. The following diagram shows how the final model looks: Summary In this article, we learned some time-saving techniques such as how to save components for later use and how to use different tools in 3D printable models. We also discussed the editing of downloaded models to perfectly suit your needs. Resources for Article: Further resources on this subject: 3D Printing [Article] Walkthrough Tools within SketchUp 7.1 [Article] Creating a 3D world to roam in [Article]

(For more resources related to this topic, see here.) Function The software starts by taking a .stl or .obj file along, with all our settings, and converts it into GCode. Think of the GCode like an instruction set to our printer, which includes where to move, how fast to move, whether or not to extrude material, extruder temperature, lower platform, and so on. The following screenshot shows an example of GCode produced by the ReplicatorG slicing engine Skeinforge at the start of a print: Start of GCode The slicing engine is what tells your printer what to make and exactly how to make it. The algorithm involved directly relates to print quality, and thus gets the most attention from developers. It's at this stage we can see the tradeoff between software and hardware: maybe the printer has the capability to print with greater resolution but current software might only break the model down so far? Or perhaps it's the opposite, where the software can break down the model finer than the hardware is capable of producing? It turns out this is a major factor in what separates personal and commercial printers, and even a $200 and $2,000 printer—precision. More precision costs more money in both hardware and software development. The hardware must be able to handle the precision calculated in software, and where it cannot, and then software solutions must be implemented in circumvention. It's these reasons why algorithms improve by leaps and bounds with every software update, and why newer released printers outperform their predecessors. To make it easier on the microcontroller, in the printer the GCode is converted into the .s3g or .x3g code, which is essentially just optimized GCode. From here it is used to generate motor steps and direction pulses, which are sent to the motor controller and then to the motors. It's at this stage we realize that the process of 3D printing is just a handful of motors moving in a set pattern combined with a heater to melt the plastic material. The magic of 3D printing happens behind the scenes inside the slicing algorithm in order to create those explicit patterns. MakerWare You may be thinking, "This software is made by MakerBot and is intended to use with MakerBot printers that sounds like the best option"; well, you are mostly correct. MakerWare is currently still in beta, but is released for general use. The software is always in revision, and has made major improvements in a very short period time. Logically, it would make sense to use the software explicitly designed for use with your printer, but up until MakerWare v2.2, the ReplicatorG software had been superior. With all the improvements made in MakerWare's latest release v2.3.1, I would argue that the MakerWare software surpasses the ReplicatorG for use with a MakerBot 3D printer. This is one of the joys of being involved with MakerBot and the 3D printing environment- The products are always evolving and always improving. In a period of five years, MakerBot went from an idea to being acquired by Stratasys for $403 million. This speaks for how fast the industry is moving, and how fast the technology is advancing. For those interested, visit http://www.makerbot.com/blog/category/makerbot-software-updates/ to see a detailed description (lots of pictures) of the improvements in each MakerWare update. ReplicatorG You might be wondering why we would even consider the ReplicatorG software. The simple answer is with the release of MakerWare v2.3.1 and the purchase of a MakerBot, we wouldn't. The ReplicatorG software undoubtedly served as a building block for many of the features in MakerWare, and was the leading software for personal/hobbyist 3D printing for many years. The MakerWare software will meet all the needs for our designs, but if you are interested in learning more about open source 3D printing, I would suggest checking out this software. We have chosen to use MakerWare (v2.3.1) for the examples in the article, as this software is most tailored to our needs. Visit http://www.makerbot.com/makerware/ to download your own beta copy. MakerWare options and settings The first step after opening MakerWare is to add a model to the build platform by clicking on the Add button. Let's add Mr Jaws (by navigating to File | Examples | Mr_Jaws.stl) to our build platform. Once the model has been added, it needs to be selected by left-clicking it. This should highlight the model in yellow as shown in the following screenshot: Mr Jaws is selected Notice the buttons on the left-hand side, which are intuitively labeled Look, Move, Turn, and Scale. Clicking these buttons allows us to orient our model. Let's move Mr Jaws to the top-right corner, spin him 180 degrees in the Z-plane, and scale him to 110 percent. The result can be seen in the following screenshot: Mr Jaws is moved, rotated, and scaled Once we are satisfied with the orientation, click on Make located at the top of the screen to open up the print options. Ensure that your model is sitting on the platform by hitting the On Platform button (by navigating to Move | On Platform); else, you will print many layers of supporting material before finally reaching your part (if your part is floating above the platform), or you will damage your nozzle and platform (if your part is floating below the platform). Print options The default options are fairly straightforward, and will modify all the advanced options automatically. We will use the following table to describe each of the default options: Option Description I want to: This gives the option where to save the file or to send it directly to your MakerBot, if its plugged in by USB. Export For: This helps you select your MakerBot. Material: This helps you select the PLA that is recommended. Resolution: MakerWare has 3 quick set profiles which are Low, Standard, and High. These profiles reference the desired print resolution and directly control the Z-layer height. Remember that higher resolution requires longer print times. Raft: A raft is a surface slightly larger than the part which is built between the bottom of the part and the build platform. Rafts help reduce warping by having more surface area adhered to the build platform. Once a part has been printed, the raft is easily broken away. We will always be using rafts to help reduce errors in our models brought about by poor adhesion and warping. Supports: Supports are used to support sharp overhangs. We will always have the support box checked, as the software will determine when and where to use supports and will not print them if they are not needed. This ensures we will never run into errors from floating layers. By evaluating the advanced options, we are able to observe the result from changing the default options and gain a little more insight into settings that influence our print. The following is a table describing these advanced options: Advanced options Description Profile: Profiles handle all the settings of a print. Profiles are a grouping of preselected options. By default, there are 4 profiles: Low, Standard, and High but you can create your own custom profiles. Slicer: The options are between MakerBot Slicer and Skeinforge slicer, and can be changed by creating a new profile. It is recommended that we use the MakerBot slicing engine because it has been optimized for use with MakerBot printers as mentioned earlier. Quality | Infill: Infill is the density of the object measured by a percentage. By default, the amount of infill is low (less than 20 percent) to save both time and material. The slicing engine will automatically create a pattern for the infill (most commonly honeycomb). Quality | Number of Shells: The number of shells will represent the perimeter thickness of your model. One shell corresponds to one layer (which is approximately 0.4 mm the width of the nozzle opening in XY, and will depend on the next property, Quality | Layer Height, for the Z thickness). All the profiles default to two shells. If strength is a concern for your model, it is suggested to increase the number of shells rather than infill. Adding shells will also increase print times. Quality | Layer Height: Layer height is the height of each individual cross-sectional layer. MakerBot Replicator 2 is capable of heights as low as 0.1 mm. This corresponds to 10 layers for a model of 1 mm in height. Lowering the height will increase print times. Temperature | Extruders: The temperature for the extruder by default sets to 230 C. Greater temperatures can improve adhesion but may require slower printing. Every individual has their own "magic number" for temperature, which they feel works best but its best to say within +/- 10 C range of the default. For our models we will be using the default 230 C. Temperature | Build Plate A heated build plate is only required if we are printing in ABS, in order to reduce warping. The default is 110 C, and slightly higher temperatures will improve adhesion but also risk greater warping upon cooling. Speed | Speed while Extruding: Extruder speed and temperature are directly linked to one another; the speed needs to be slow enough to allow the layer currently being extruded to bond with the layer underneath. Greater speeds have the potential to reduce accuracy but will decrease print time. Be extremely cautious while modifying this parameter, as it takes experience to match increased speed and temperatures properly. Speed | Speed while Travelling: When not extruding, the extruder head is capable of faster travel. It is recommended to leave this parameter as set. Preview before printing This is an amazing tool and you should check it off every time. Preview before printing allows you to see an approximate material use and time estimate to print the given model. Summary This article thus explained some basic steps to build a 3D model in MakerBot and to get it ready for 3D printing. Resources for Article: Further resources on this subject: Design Tools and Basics [Article] Materials with Ogre 3D [Article] Importing 3D Formats into Away3D [Article]

(For more resources related to this topic, see here.) How a 3D printer works A 3D printer needs to take a description of a three-dimensional object and turn it into a physical object. Like Blender, a 3D printer uses values along the X, Y, and Z axes to determine the shape of an object. But where Blender sees an object as perhaps cylinders, spheres, cubes, or edges and faces, a 3D printer is all about layers and perimeters. First, a slicing program opens the object file that you made and it slices the object into vertical layers as seen in the following screenshot: Then, each layer is printed out one by one in a growing stack as seen in the following screenshot: But you can get a better idea of how these layers stack up if you can see it interactively. I have provided an interactive illustration that allows you to see the dragon slice by slice. Scrolling through the frames, you can see how the walls of the dragon's body are built: Open up 4597OS_01_LayersDisplay.blendin your download packet. Examine the thickness of the body at each layer. Press Alt + A to play the animation. Press Esc to stop playing it. You can also drag the current time indicator in the timeline back and forth to look at individual frames, or use the right and left arrow keys. Note how the dragon starts as a series of islands. Look at the dragon's hands. The fingers start off floating in space until they are joined to the arms. The exact method a 3D printer uses to print a layer varies. Some printers work like a pencil, drawing an outline of the shape on that layer and then filling in the shape with cross-hatching. Look at the left side of the preceding screenshot again. The printer would first outline the tail, then fill it in. Next, it would move to one haunch, outline it, and fill it in, and then the other. And finally, it would outline and fill each foot. You can get a better idea of how this happens with this 3D printer's hot end simulator. The hot end is the printer's nozzle where the 3D printing material is extruded. Other printers may use a print head much like an inkjet printer. The print head moves across the printing bed and deposits material where needed. Types of 3D printers So what kinds of printers are there? How do they print and how are they different? The terminology is still a bit confusing. The American Society for Testing and Materials (ASTM International) recently came up with the following categories: Material extrusion is also known as Molten Polymer Deposition (MPD), Fused Deposition Modeling (FDM), or Fused Filament Fabrication (FFF); these extrude a gooey material out in layers to build up the proper shape. This is the class of printers that includes most hobbyist 3D printers. They work like the simulator you just used. These can use plastic, metal wire, wax, sugar, frosting, chocolate, cookie dough pasta, pizza, and even corn chips. Material jetting is also known as photopolymer jetting. Like an inkjet, this printer squirts liquid photopolymers at the right moment, which are cured immediately with ultraviolet light, layer by layer. The object being built is supported by a layer of gel that is also applied by the print head, so overhang is not a problem. Binder jetting uses a two part system. A thin layer of composite material is spread across the print bed. Then, an inkjet-like printing head sprays a binder fluid and possibly colored ink, which combine with the composite material to produce solid colored and sometimes textured objects. This can be plastic, gypsum, or metals, such as copper, tungsten, bronze, and stainless steel. For metals, a second step is needed to make them solid. The binder is removed and metal is infused where the binder used to be. Sheet lamination printers may use materials, such as paper or metal, and will color, cut out, and glue layers together into objects. Vat photopolymerization is also called Stereolithography (SLA). Photopolymerization printers use light to cure liquid material into the right shape. This process uses resins, wax, or liquid plastics for the material. It may use a laser or a high resolution DLP video projector similar to one you would hook up to your computer to give a PowerPoint presentation. Powder bed fusion is also known as Granular Materials Binding. These printers use a laser or heat to fuse layers of powder into the right shape. These can use metal, ceramic, gypsum, or plastic powder. There are several subtypes of powder bed fusion printers. Selective Laser Sintering (SLS) is used with thermoplastics, wax, and ceramic powders. A thin coat of powder is spread across the printing bed. Then, the printing head prints the layer by fusing selected areas with the laser. The printing bed then drops down. Another coat of powder is added and the laser prints the next layer. Selective heat sintering (SHS) uses heat instead of a laser and can be used with thermoplastic powder. Direct Metal Laser Sintering (DMLS) or Selective Laser Melting (SLM) is a subcategory of selective laser sintering. The laser beam melts the metal and makes solid parts with metal alloys like aluminum, iron, stainless steel, maraging steel, nickel, chromium, cobalt, and titanium alloys. In theory, it can be used with most alloys. Directed energy deposition, also known as Electron Beam Melting (EBM), is similar to SLS, but uses an electron beam instead of a laser. The high heat generated by the electron beam allows use of pure metal powder such as titanium alloys, and can make high-detail, high-strength objects that do not need any postmanufacturing heat treatment. Question: Earlier, I mentioned a company named Made In Space, which is making a 3D printer to be used in zero gravity. What kind of printer is it making? Directed energy deposition Vat photopolymerization Material extrusion Powder bed fusion Answer: Option 3, material extrusion is correct. Extruding a material avoids liquid or powder floating around in zero gravity. Basic parts of a 3D printer As you have observed, there are a wide variety of 3D printers. But there are some parts they all have in common. The printing bed is what the 3D object is built upon. The printing head holds the laser, the printing jet, or the hot end of the extruder. And then there are controls to position the printing bed and the printing head in relation to each other; one control for the X dimension, one for the Y dimension, and one for the Z dimension. There are no hard and fast rules for which controls the printing bed and printing head have. The Cube printing head is controlled in the X dimension only and the printing bed is controlled in the Y and Z dimensions, whereas the MendelMaxPro puts X and Z controls on the printer head and controls the printing bed only in the Y dimension. How is a 3D printer controlled? Generally, the answer is stepper motors. Stepper motors are motors that move in small discrete angles of rotation instead of spinning like most regular motors. This allows you to make definite, easily repeatable motions. It is also one reason why there are minimum sizes on the detail that you can make. A 3D printer can't make detail smaller than one step of the stepper motor. Then, through wires, drums, gears, and threaded rods, the motion of the stepper motor is scaled to fit the medium that the printer uses. A hobbyist printer that uses a filament of the ABS or PLA plastic that feeds off of a reel will provide the kind of detail that those plastics can support. A high-end stereolithography printer may get much finer detail. The next graphic is a diagram of the insides of a stepper motor. The rotor is in the center. It rotates and is attached to a shaft that pokes out of the motor. The stators are attached to the outer shell of the motor. They are wrapped with copper wire and an electrical current is run through the wire to give each stator a negative charge, a positive charge, or no charge as indicated in the next graphic. In the graphic, red represents a positive charge, the blue is a negative charge, and the grey has no charge. The rotor in the center has 50 teeth. The stators around the outside have a total of 48 teeth. It's this imbalance in the number of teeth that allow the stepper motor's rotor to walk around step-by-step. The positive charge of the rotor is attracted to the stator teeth that are negatively charged. In the following screenshot, you can see that the rotor teeth aren't well aligned with the uncharged stator that is counter-clockwise from the blue stator. To do a single step, the stepper motor controller changes the negative charge from the blue stator in the following screenshot to the stator just counter-clockwise to it. Then, the teeth in the rotor try to align with that stator. So, the rotor moves just a little, a step. To continue moving more steps, the stator with the negative charge keeps moving to the next stator, as follows: The stepper motor is then attached to a control belt or a shaft with a screw thread to give the printer precise control of the print head and the printing bed. There may be one or more stepper motors controlling a single axis. Summary In this article, we covered the fundamentals of how a 3D printer works and the different kinds of printers that there are. And you discovered that 3D printers can handle a wide variety of materials from wood, to plastic, to titanium. We also covered how to control a 3D printer by a stepper motor. Resources for Article: Further resources on this subject: Introduction to the Editing Operators in Blender: A Sequel [Article] Getting Started with Blender’s Particle System [Article] Blender 3D: Interview with Allan Brito [Article]

(For more resources related to this topic, see here.) Getting ready Open up Slic3r and go to the Print Settings tab. We're staying in the Simple mode for now, because it's easier to track the changes we make to the changes in our final print. A good thing to do when making setting changes is to only make one change at a time. This is so that if something goes wrong, or right, we know exactly what change did it. How to do it... The Print Settings section is where a lot of changes will happen as we print. Let's go down the list of options in this section so we know what they are and why we might want to change them, sometimes from print to print. First up is Layer height option. The default layer height of 0.4mm is ok, assuming that we have a 0.5mm nozzle. So we can leave that for now. If our nozzle is more than 0.5mm though, we will have a lot of squeeze out of our filament. So if our nozzle is larger, increase the size of the layer. 80 percent of the nozzle diameter is a good rule of thumb. This also means that if we have a nozzle less than 0.5mm, we can make our layer height default smaller. Again, 80 percent of the nozzle diameter is a good starting place. Depending on our object we are printing, the Perimeters (minimum) setting of 3 is good. If there are gaps in the walls, especially of sloped surfaces, increasing the number of perimeters is something to try. Next, Solid layers is the setting of how many layers Slic3r will tell the printer to fill completely at the top and the bottom of the print. For the bottom layers, this will give the object a stable base that is less prone to warping. For the top, the default of 3 layers is based on the extruded filament width, and how much coverage the filament will give as it gets to the top of the object. For the Infill settings, a value of 0.15 for Fill density should stay, but change Fill pattern to honeycomb. It's a bit slower, but more stable. This is how the inner part of the object is filled with plastic. Since filling the entire object uses a lot of plastic, and isn't needed, we set the infill settings. How it works... Layer height, infill settings, perimeters, what does it all mean? Let's look into those settings and what they stand for, in more detail. Layer height The layer height of the print means how thick each layer of plastic is deposited on the model. The thinner the layer, the smoother and more detailed the print can be. We don't always want thin layers though. Some prints, such as for mechanical parts, or parts that will not be seen, can be done with thicker layer heights. If we're printing parts for a RepRap or another printer, the layer height can be thicker for the structural elements. It doesn't directly relate to the structural strength however. That would be covered in a moment when discussing the Perimeters and Infill settings. For thicker layer heights, it's usually a good idea to have layers at or under your nozzle size. This is so the extruder will press the plastic into the layer below. If the layer height is higher, the plastic will have a chance to cool before touching the foundation layer, and also only have gravity to help weld the two layers together. If we're printing objects for viewing, such as a statue or a decorative item, we'll usually want to go with thinner layer heights. This comes at the expense of printing speed, because the printer will now need to lay down more layers to complete the model. So finding a balance between looks and speed is something we will constantly juggle. For very detailed objects, resolutions as low as 0.1mm have been achieved by some printers. Perimeters These make up the walls of the object. They are also important for adding stability to the object being printed. The Slic3r developers recommend a minimum of two perimeters for printing. Having at least two will help both the structure of the outside, and help to cover up imperfections in the print. There is also a setting for solid layers. It is related to Perimeters, in that, it determines the number of solid layers at the top and the bottom of the print. The default setting for this is three perimeters. For models that are not solid, set them with the Infill settings; having more than one top layer will help bridge any gaps in the model and will result in a better fill for the top of the model. The default setting for Slic3r is for the three top and bottom layers to be solid. Depending on our model, and what we want to do with it, we can change this. Coming up is a hack for making hollow objects such as vases from normally solid objects. Infill settings Infill in our objects gives them stability. Too much infill, however, such as making our object solid, can not only cause printing issues, but also is a waste of plastic. The Fill Density setting ranges from 0 to 1, with 0 being 0 percent, and 1 being 100 percent. The default setting for Fill Density is 40 percent, or 0.4 in the preference. This is a decent setting to start with, but for structural components, or ones that will depend on being rigid under stress, raising that up would be a good idea. The developers suggest a minimum of 0.2 as the setting to support flat ceilings. Any lower, the top of your model is likely to sag inward. The Fill Pattern is interesting. This setting is how Slic3r will tell our printer how to fill in the inside of our model. The honeycomb option is good for structure, but takes longer to print. The developers also recommend rectilinear and line for infill, but there are several others to choose from. A bit of experimentation will reveal what is best for what models we want to print. There's more... Settings can be more than just settings. More than just a tool for making nicer quality prints. We can use some settings to alter the objects themselves, to make changes to the objects, and have it come out as what we want without having to touch the modeling software. Vases and other hollow objects There are some interesting things you can do while printing models and changing these settings. For instance, if you set the Infill Fill Density to 0, and the Top setting of Solid layers to 0, you can make any object hollow with the top open. We'll need to make sure the model can actually print this way, structurally. If it can, it is an interesting way to make custom vases or other open cupped objects. Having a higher setting on the Perimeters (minimum) will help some prints with this. Summary This article talked about some of the most important settings for printing your objects. It delved into how each setting works, and how changing it affects your final printed object. Resources for Article: Further resources on this subject: Learn Baking in Blender [Article] Getting Started with Blender’s Particle System- A Sequel [Article] The Trivadis Integration Architecture Blueprint: Implementation scenarios [Article]

(For more resources related to this topic, see here.) Owning a Makerbot 3D printer means being able to make anything you want at a push of a button, right? 3D printer owners quickly find that while 3D printers have no end of things they can produce, they also are not without their limitations. Designing an object without 3D printing in mind will result in a failed print that more resembles a bird nest or a bowl of spaghetti. Making a 3D printable object requires learning a few rules, some careful planning, and design. But once you know the rules the results can be astounding. 3D printers can even produce things with ease that traditional manufacturing cannot, for example, objects with complex internal geometry that machining cannot touch. There are many places online such as Makerbot's own Thingiverse that hosts a daily growing library of printable objects. Printing out other people's designs is all well and good for a while, but the most exciting part about 3D printing is that it can produce your designs and models. Eventually, learning how to model for 3D printing is a must. Can you learn 3D modeling? If you've ever won a round of Pictionary you've got all the artistic skill it takes to get started. If you've ever gotten past level 1 on Tetris then you've got spatial reasoning. If you've ever played with modeling clay then you know all about designing in three dimensions. Design basics There are some design rules and basic ideas that will be true regardless of the modeling software used. The working of 3D printing 3D printing has come a long way in terms of technology and cost allowing home 3D printers to be a reality. In this process there have been choices that will limit what can be printed. Seeing a 3D printer in action is the best way to learn about the process. Fortunately there are many 3D printing time lapse videos online of printers in action that can be found with a simple search. 3D printers build an object layer-by-layer from the bottom to the top. Plastic filament is heated and extruded, and each layer is built upon the last one. Usually the outside of the object is drawn and sometimes additional shells are added for strength. Then the inside is usually filled with a lattice to save plastic and provide some support for higher layers, however the inside is mostly air. This continues until the object is complete as shown in the following screenshot: Because of this layer-by-layer process, if a design is made so that any part has nothing underneath it, dangling in the air, then the printer will still extrude some plastic to try to print the part which will just dangle from the nozzle and be dragged into the next area where it will build up an ugly mess and ruin the print: Building for supportless prints One way of fixing the dangling object problem is to configure the preparing software to build the model "with supports". This means the slicer will automatically build a support lattice of plastic, up to the dangling part so that it has something to print on. Higher-end printers can actually print with a different material that can be dissolved away, but so far most home printers only use break-away supports. Either way after the print is complete it is left to the user to clean up this support material to extract the desired part. While supports do allow the creation of objects that would be impossible any other way, the supports themselves are a waste of material and often don't remove cleanly leading to a messy bottom surface where they contact the print. If a part is designed needing supports that are hard to remove, such as if they're internal and partially obscured, it can be difficult and frustrating to completely remove the support material (this can be true for even the higher-end 3D printers). The process of removing it may actually damage the print. It is possible and very easy with just the slightest application of cleverness to make designs that are printable without the need for any supports. So the blueprints in this article focus on making designs that print without supports. The limitations imposed by this demands just a little more effort but allow for the teaching of principles that are generally good to know. Designing for dual extruders Some models of Makerbot and other 3D printers have the ability to print in multiple colors at once using two different extruder heads feeding plastic from two different spools. There are some fun prints that come from this process. But as most Makerbots and other brands of home 3D printers do not have dual extruders at this time this article will not explore this process in detail. The basic idea of the process is creating two files that are aligned to print in the same space and combining them in the slicer. Designing supportless – overhangs and bridges When designing for supportless printing the rules are simple: Y prints, H prints okay, T does not print well. Branching out with overhangs It is possible to have the current layer slightly larger than the previous layer provided the overhang is not more than 45 degrees. This is because the current layer will have enough of the previous layer to stick to. Hence a shape like the capital letter Y will successfully print standing up. However, if the overhang is too great or too abrupt the new layer will droop causing a print fail, hence a shape like the capital letter T does not print. (If the T is serif and thus has downward dangling bits, it will fail even worse, as illustrated previously.) So it is important to try to keep overhangs within a 45 degree cone as they go upwards. Building bridges If a part of the print has nothing above it, but has something on either side that it can attach to, then it may be able to bridge the gap. But use caution. The printer makes no special effort in making bridges; they are drawn like any other layer: outline first, then infill. As long as the outline has something to attach to on both sides it should be fine. But if that outline is too complex or contains parts that will print in mid-air, it may not succeed. Being aware of bridges in the design and keeping them simple is the key to successful bridging. Even with a simple bridge some 3D printers need a little bit more calibration to print it well. Hence a shape like the capital letter H will successfully print most of the time. Of course this discussion is purely illustrative of the way overhangs work or fail. In real life if a Y, H, or T needed to be printed the best way to do it would be to lay them down. But for purposes of illustration it still stands that Y prints, H prints okay, T does not. Choosing a modeling tool There are many choices of modeling programs that can be used to produce 3D printable objects. There are many factors including versatility, simplicity, and cost to take into account. A tool with too steep a learning curve can turn off new users to the idea all together. A tool with too limited a set of tools can frustrate a user when they hit the limit. Investing a lot of money into something that doesn't end up going anywhere can be extremely disappointing. So it is important to explore the options. SolidWorks (www.solidworks.com) and other drafting oriented programs can do technical shapes with extreme precision. They include the necessary tools to accurately describe a shape that can be brought into the real work with high fidelity. However these sorts of tools tend to be costly and don't do artistic or organic shapes very well. Their highly technical nature also gives them a steep learning curve. OpenSCAD (www.openscad.org) is free and famous among the people who make 3D printers and can make technically accurate models as well. OpenSCAD also allows the models to be parametric, meaning that by changing a few variables and recalculating a new shape is generated. But OpenSCAD is difficult to use unless the user has a very technical and programmatic mind since the shapes are literally built from lines of code. Zbrush (pixologic.com/zbrush), Sculptris (pixologic.com/sculptris), or Wings3D (www.wings3d.com) are great tools for modeling organic shapes like the kind used in video games or animation. Sculptris and Wings3D are free and are very easy to pick up and use. But these tools lack when precision is necessary. Sketchup (www.sketchup.com) is a great free program with a library of shapes built in ready to import and play with. Its modeling tools are great for precise or architectural models. Sketchup doesn't do organic shapes well either and it can be tricky loading the plug-ins necessary for Sketchup to export their models to something printable. Even then models from Sketchup often have to go through an extensive clean up phase before they'll be ready to print. Autodesk 123D (www.123dapp.com) is not one but a whole suite of free programs designed around 3D modeling with specific focus on 3D printing. There are programs to design creatures or precise shapes. There is even an app for converting pictures of real life objects into 3D models. Some are programs that run in browser, some are downloads and some are apps for Apple devices. It's an eclectic and powerful group of programs. The Autodesk 123D suite's weakness is in its general immaturity. Autodesk is making great efforts to make modeling for 3D printing accessible for everyone but its tools still need to mature somewhat before they'll be ready to explore in depth. Blender (blender.org) is a 3D animation program that features a robust set of modeling tools. Good for artistic and organic shapes, it can also be used when precision is needed. On top all that it is free and open source, so it is still in constant development. If Blender doesn't have a particular feature it is only a matter of time until it will be added. If fact by the time this article is published chances are the version of Blender used to make it will already be out of date, but most of Blender's functionality remains unchanged version-to-version. Blender is also completely customizable so that every feature, from the key strokes used to the overall look, can be changed. The downside of Blender is that its user interface is somewhat unintuitive. This causes Blender to have a famously difficult learning curve. Because of Blender's versatility and availability it is the tool of choice for the beginning 3D designer and this work. Installing Blender This will be the first project in the article. Fortunately downloading and installing Blender is as easy as 1-2-3-4. Go to www.blender.org. Click on the Download link. Choose and download the installer for your system: Windows, Mac, or Linux, 32 bit or 64 bit. Run the installer. The installer will guide the process of loading Blender and adding icons to the system. Windows Blender.org offers installer executable and ZIP files. The zip files are for advanced users who want a portable version of Blender. When in doubt choose the executable since it will set up icons making for easy access. If in doubt whether to use the 32 or 64-bit versions picking the 32-bit will insure compatibility, but it is a good idea to find out what type of system it is being installed on as 64-bit offers significant performance improvements. Windows 7 or greater will confirm that the installer should be run. Click on Yes to assure Windows that it's okay to install Blender. Then the installer will run. The install wizard's defaults are fine for most users. Simply put the mouse over the Next button and click on every button that appears under it. On the second screen read over the Blender Terms of Service and click on I Agree to proceed. Unless you manage your installed programs directories yourself it is best to leave the defaults on the third screen as it is. Then click on Next and the install process will start. When the install process finishes leave the check box check and click on Finish to exit the installer and run Blender. Getting acquainted with Blender When Blender starts up, the Splash Screen can be dismissed by left-clicking outside the screen. The screenshots in this article use a custom color palette for print and a smaller window to minimize wasted screen space. Customizing the color palette will be discussed briefly later but these cosmetic changes will not affect the instructions presented at all. The Blender interface is broken into several different customizable panels to keep things organized. Each panel has resizing widgets in the upper-right and lower-left corners. By clicking on these widgets the panels can be split to add more panels or expanded into the territory of another to collapse panels at the user's preference. However, for now the default panels will be discussed as they provide the most common functionality for beginners. The 3D View panel The main window where things will be happening is the 3D View panel. The largest portion of the 3D view consists of the viewport where most of the work will take place. On the left-hand side of the 3D View panel is a tool bar that consists of tools relevant to the selection and mode. If the tool bar is ever not visible it can be revealed (or hidden again) by pressing Tor by clicking on the plus icon on the right-hand side that will appear when the toolbar is hidden. The specific tools in this bar will be explored as they are needed in the projects. There is another plus icon on the right that will bring up the viewport properties with properties relevant to the current selection or the viewport. This can also be revealed or hidden by pressing the Nkey. Again, the specifics will be explored further as needed. At the bottom of the 3D View panel is the 3D view menu bar with additional options followed by menus and icons related to editing and views. Hovering the mouse over each button will show what they are for. The Outliner panel The Outliner panel contains a hieratical view of all the objects in the scene. Each object can be selected by clicking on their name or the object can be hidden, locked, or excluded from rendering. Rendering means making a high quality picture from a scene for things such as animation or presentations. Doing a proper render includes setting up scene lights, cameras, textures, material properties, and many other functions that will not be explored in this article as it does not do anything that helps produce models for printing. However, exploring this functionality outside of this article can be good when trying to show off the models if printing them is not an option. The Properties panel The Properties panel is broken up into many tabs indicated by small icons. Hovering over the icons will show the name of the tab. For modeling the two tabs that will be used the most are the object and modifier tabs. Specific exploration of the tools contained therein will be done as needed. The Info panel On the top of the Blender windows is the Info panel. On the left-hand side of the Info panel there is an easy to navigate menu similar to the menu in most applications. This menu can be collapsed by clicking on the + button next to it and expanded by clicking the same. On the far right of the Info panel there is data about the current scene. If the data cannot be seen, hover the mouse over the panel, and use the middle scroll wheel or click-and-hold the middle mouse button (pressing the wheel like a button) and moving the mouse to pan the panel until the desired data is visible. The Timeline panel The Timeline panel is only relevant to doing animation and can be effectively ignored or collapsed for the purposes of this article. Because this article is only using a limited subset of Blender's functionality some things such as the Timeline panel could be customized away. However, since it is not the focus of this article to tell the reader how to customize their version of Blender, and because Blender has a much broader application, the screenshots that follow will have the Timeline panel visible. The reader is encouraged to explore Blender's other functionalities such as rendering and animation at their leisure and desire. Proper stance While all of Blender's functions are available from buttons and menus on the screen, typical Blender users rely heavily on hotkeys and shortcuts. Already the T and N keys have been discussed to bring up or collapse the Tools and Properties tabs in the 3D view. For this reason it is recommended that to use Blender have one hand on the mouse and the other hand on the keyboard at all times. This tends to be a common stance for many people but is mentioned for the few for whom learning this will be of great help. Blender customization One of Blender's strengths is its customizability. Almost every feature from the look and color, right down to the keystrokes and hotkeys are used for every action in Blender. Customization is accomplished in the Properties menu accessed from the File | User Preferences menu. The buttons across the top, switch to the various categories. Each category is packed with options. A full exploration of these options is beyond the scope of this article but the reader is encouraged to explore these options and make Blender their own. For instance if the reader is using a setup where a middle mouse button is unavailable, Blender contains an option to emulate the middle mouse button by pressing Alt along with left-click. Other systems may require other accommodations many of which are available in this menu. Setting up for Mac OSX Mac OSX users require special consideration. Blender is made for a three button mouse. If a single button mouse is all that is available, click when the instructions say Left-Mouse Button, use Alt with click for Middle-Mouse Button, and press command with click for Right-Mouse Button. General Blender tips Blender employs some conventions that are unique to its environment and as such getting acquainted with its most common quirks early can avoid frustration. First and perhaps most importantly, Ctrl+ Z for undo works in Blender will undo a multitude of mistakes. Undo in Blender remembers many past steps allowing backing up to a point before a grievous error was made. Remembering this when following along with the blueprints that follow will save the reader much frustration. Next, the location of the mouse pointer is important when using hotkeys. For example the T and N keys for the Tools and Properties tabs do not bring up those tabs if the mouse pointer is not hovering over the 3D View. If the mouse is hovering over a different panel the reaction could be unpredictable. Pressing the A key with the mouse over the 3D View will toggle selection of all objects in the scene. Pressing the A key with the mouse over the Object Tools tab will collapse the expandable menu hiding all the options of that menu. Blender uses the right-click on the mouse to select objects by default. This is perhaps the most counter intuitive thing for first time users, particularly because it will be encountered so frequently. But not everything has been swapped, just object selection. This behavior can of course be customized. If the reader would like to customize selection to the left mouse button then it is left to them to adjust the instructions accordingly. Finally, the relation of Blender units to real life units is not by default defined in Blender. Generally it is just easier to remember that 1 grid point will translate to 1 millimeter in the printed object. As the scale is increased Blender inserts darker grid lines every 10 grid lines by default which correlate to centimeters. So the default cube in the default scene would measure 2 mm on each side, which is less than 1/10 of an inch, which is very small. Suggested shortcuts In the projects in this article, when a new idea is introduced it will first be introduced with detailed steps. Once a process is taught the next time the name of the operation and the shortcut for that process will be all that is given. This does not mean that the keyboard shortcuts are the only way to do an operation but they are often the preferred method for experienced Blender users. The reader is free to accomplish the operation in any way that is comfortable for them. The blueprints This article has been designed to teach 3D printing design in a hands-on approach. A series of projects or blueprints will be presented and each one will introduce new tools and techniques. Each one builds on the last. Despite being a "virtual" process, 3D modeling has a surprisingly muscle memory aspect to it. The movements and processes need to be more than a mechanical process being executed, they need to be practiced so they can be fluid and eventually seamless. To that end the reader is advised not to skip any of the blueprints and follow along actually doing each one. The objects being designed in this article are, most of them, very small so that they can be printed without taking too much time or producing too much waste. The reader can make larger versions if they like but that is left for their own challenge activities. Summary 3D printing is cool. Learning to design your own models is the best way to take full advantage of 3D printing today. This article will teach 3D modeling by a series of hands-on activities so it's a good idea not to skip and actually follow along with each blueprint. While home 3D printers have the capability to do break away supports these are messy and wasteful. It is possible to design things to be able to print without the need of any supports. When designing things for support-less 3D prints remember Y prints, H prints okay, T does not print. Keep outward inclines gradual and no more than 45 degrees to be safe. There are many 3D modeling programs to choose from. Some are expensive, some are free. Some are better for technical works, others do artistic or organic shapes better. Some are easy to learn, some take more practice. This article will use Blender since it is free and open source, has tools for modeling technical and organic shapes and is not too difficult to learn if you learn by doing. Blender can be a bit tricky to get started with since it employs some conventions unique to its environment. Blender can be customized but this article will stick with the defaults so everyone is on the same page. Generally remember that Ctrl+ Z undoes a multiple mistakes and can get Blender back to the state it was before, useful in tutorials to get back on track. The location of the mouse pointer is important when using Blender's hotkeys, which is the best way to learn to use Blender. Blender uses the right-click on mouse for selection by default. Finally, Blender's units translate to real life by 1 Blender grid space = 1 millimeter. Resources for Article: Further resources on this subject: Building Your First Bean in ColdFusion [Article] Designer Friendly Templates [Article] The Trivadis Integration Architecture Blueprint [Article]

Configuring Printer Classes By default there are no printer classes set up. You will need to define them. The following are some of the criteria you can use to define printer classes: Printer Type: Printer type can be a PostScript or non-PostScript printer. Location: The location can describe the printer's place; for example the printer is placed on the third floor of the building. Department: Printer classes can also be defined on the basis of the department to which the printer belongs. The printer class might contain several printers that are used in a particular order. CUPS always checks for an available printer in the order in which printers were added to a class. Therefore, if you want a high-speed printer to be accessed first, you would add the high-speed printer to the class before you add a low-speed printer. This way, the high-speed printer can handle as many print requests as possible, and the low-speed printer would be reserved as a backup printer when the high-speed printer is in use. It is not compulsory to add printers in classes. There are a few important tasks that you need to do to manage and configure printer classes. Printer classes can themselves be members of other classes. So it is possible for you to define printer classes for high availability for printing. Once you configure the printer class, you can print to the printer class in the same way that you print to a single printer. Features and Advantages Here are some of the features and advantages of printer classes in CUPS: Even if a printer is a member of a class, it can still be accessed directly by users if you allow it. However, you can make individual printers reject jobs while groups accept them. As the system administrator, you have control over how printers in classes can be used. The replacement of printers within the class can easily be done. Let's understand this with the help of an example. You have a network consisting of seven computers running Linux, all having CUPS installed. You want to change printers assigned to the class. You can remove a printer and add a new one to the class in less than a minute. The entire configuration required is done as all other computers get their default printing routes updated in another 30 seconds. It takes less than one minute for the whole change—less time than a laser printer takes to warm up. A company is having the following type of printers with their policy as: A class for B/W laser printers that anybody can print on A class for draft color printers that anybody can print on, but with restrictions on volume A class for precision color printers that is unblocked only under the administrator's supervision CUPS provide the means for centralizing printers, and users will only have to look for a printer in a single place It provides the means for printing on another Ethernet segment without allowing normal Windows to broadcast traffic to get across and clutter up the network bandwidth It makes sure that the person printing from his desk on the second floor of the other building doesn't get stuck because the departmental printer on the ground floor of this building has run out of paper and his print job has got redirected to the standby printer All of these printers hang off Windows machines, and would be available directly for other computers running under Windows. However, we get the following advantages by providing them through CUPS on a central router: Implicit Class CUPS also supports the special type of printer class called as implicit class. These implicit classes work just like printer classes, but they are created automatically based on the available "printers and printer classes" on the network. CUPS identifies printers with identical configurations intelligently, and has the client machines send their print jobs to the first available printer. If one or more printers go down, the jobs are automatically redirected to the servers that are running, providing fail-safe printing. Managing Printer Classes Through Command-Line You can perform this task only by using the lpadmin -c command. Jobs sent to a printer class are forwarded to the first available printer in the printer class. Adding a Printer to a Class You can run the following command with the –p and -c options to add a printer to a class: $sudo lpadmin –p cupsprinter –c cupsclass The above example shows that the printer cupsprinter has been added to printer class cupsclass: You can verify whether the printers are in a printer class: $lpstat -c cupsclass Removing a Printer from a Class You need to run lpadmin command with –p and –r options to remove printer from a class. If all the printers from a class are removed, then that class can get deleted automatically. $sudo lpadmin –p cupsprinter –r cupsclass The above example shows that the printer cupsprinter has been removed from the printer class, cupsclass: Removing a Class To remove a class, you can run the lpadmin command with the –x option: $sudo lpadmin -x cupsclass The above command will remove cupsclass. Managing Printer Classes Through CUPS Web Interface Like printers, and groups of printers, printer classes can also be managed by the CUPS web interface. In the web interface, CUPS displays a tab called Classes, which has all the options to manage the printer classes. You can get this tab directly by visiting the following URL: http://localhost:631/classes If no classes are defined, then the screen will appear as follows which shows the search and sorting options: Adding a New Printer Class A printer class can be added using the Add Class option in the Administration tab. It is useful to have a helpful description in the Name field to identify your class. You can add the additional information regarding the printer class under the Description field that would be seen by users when they select this printer class for a job. The Location field can be used to help you group a set of printers logically and thus help you identify different classes. In the following figure, we are adding all black and white printers into one printer class. The Members box will be pre-populated with a list of all printers that have been added to CUPS. Select the appropriate printers for your class and it will be ready for use. Once your class is added, you can manage it using the Classes tab. Most of the options here are quite similar to the ones for managing individual printers, as CUPS treats each class as a single entity. In the Classes tab, we can see following options with each printer class: Stop Class Clicking on Stop Class changes the status of all the printers in that class to "stop". When a class is stopped, this option changes to Start Class. This changes the status of all of the printers to "idle". Now, they are once again ready to receive print jobs. Reject Jobs Clicking on Reject Jobs changes the status of all the printers in that class to "reject jobs". When a class is in this state, this option changes to Accept Jobs which changes the status of all of the printers to "accept jobs" so that they are once again ready to accept print jobs.    

The Common UNIX Printing System (CUPS) is actually a printer management tool, and thus monitoring CUPS always remains a very essential activity to to make the best use of the resources available. Monitoring CUPS will allow us to take action quickly should something go wrong. Using the lpstat Command The lpstat command displays the status of the CUPS service, printers, classes, and jobs. It supports a number of options. If the command is used without any options, it displays the job queues for the current user: $lpstatcupstest-3 kajol 8192 Tue Aug 05 13:24:43 2008cupstest-4 kajol 8192 Tue Aug 05 13:25:34 2008 To check whether the CUPS server is running, use the -r option. $lpstat -rscheduler is running$lpstat -dsystem default destination: cupsclass The above command gives information about the default destination printer or class. The output following the command shows that the default destination of the system is cupsclass. $lpstat -c cupsclass This shows the printer class and the member printers belonging to that class. If a particular class is not specified, then the output shows all classes along with their member printers. members of class cupsclass:cupsprinter1cupsprinter2$lpstat -v cupsprinter2 The command above will show the device to which cupsprinter1 is attached. If no printers are specified, then the output will list all printers along with device-uri information. device for cupsprinter2: ipp://cupsserver.cupsgroup.org/printers/cupsprinter2$lpstat -s This shows a status summary for all printers and classes on the network. The summary includes the default destination, a list of classes and their member printers, and a list of printers and their associated devices. The output is equivalent to using the -d, -c, and -v options simultaneously. system default destination: cupsclassmembers of class cupsclass:cupsprinter1cupsprinter2device for cupsprinter1: lpd://192.168.0.11/printers/cupsprinter1device for cupsprinter2: ipp://cupsserver.cupsgroup.org/printers/cupsprinter2$lpstat -a This command shows if printers are currently accepting jobs. If no printers are specified, then it will list all printers. cupsprinter1 accepting requests since Mon 16 Jun 2008 02:28:14 PM ISTcupsprinter2 accepting requests since Wed 18 Jun 2008 11:07:23 AM IST$lpstat -p cupsprinter1 This shows whether the printer cupsprinter1 is enabled and if it is currently printing a job. If no printers are specified then all the printers are listed. printer cupsprinter1 is idle. enabled since Mon 16 Jun 2008 02:28:14 PM IST$lpstat -o This shows the job queues on the specified destinations. If no destinations are specified then all jobs are shown. $lpstat -t This displays status information for all printers, which is equivalent to using the -r, -d, -c, -v, -a, -p, and -o options. scheduler is runningsystem default destination: cupsclassmembers of class cupsclass:cupsprinter1cupsprinter2device for cupsprinter1: lpd://192.168.0.11/printers/cupsprinter1device for cupsprinter2: ipp://cupsserver.cupsgroup.org/printers/cupsprinter2cupsprinter1 accepting requests since Mon 16 Jun 2008 02:28:14 PM ISTcupsprinter2 accepting requests since Wed 18 Jun 2008 11:07:23 AM ISTprinter cupsprinter1 is idle. enabled since Mon 16 Jun 2008 02:28:14 PM ISTprinter cupsprinter2 now printing cupsprinter2-5711. enabled since Wed 18 Jun 2008 03:12:55 PM ISTPrinter is now on-line.cupsprinter2-5711 kajol 1449984 Wed 18 Jun 2008 03:12:55 PM IST$lpstat -l This command displays printers, classes, or jobs in a long list. $lpstat -u This shows a list of print jobs queued by the specified users. If no users are specified, it lists the jobs queued by the current user. cupsprinter2-5711 kajol 1449984 Wed 18 Jun 2008 03:12:55 PM IST$lpstat -h 192.168.0.11:631 The above command specifies an alternative server for CUPS. It uses the port number that is specified along with the server. If no port is specified, then it will connect to the default port 631. $lpstat -U username You can specify an alternative username with the -U option $lpstat -R : $lpstat -W all This shows the ranking of print jobs. This command specifies which jobs to show, complete, incomplete (the default), or all. This option must appear before the -o option and any printer names: $lpstat -W completed -o cupsprinter2 The output will be as follows cupsprinter2-5709 kajol 483328 Wed 18 Jun 2008 03:10:45 PM ISTcupsprinter2-5710 kajol 97280 Wed 18 Jun 2008 03:12:18 PM ISTcupsprinter2-5711 kajol 1449984 Wed 18 Jun 2008 03:12:55 PM ISTcupsprinter2-5712 kajol 8192 Wed 18 Jun 2008 03:22:31 PM ISTcupsprinter2-5713 kajol 9216 Wed 18 Jun 2008 03:23:38 PM ISTcupsprinter2-5714 kajol 9216 Wed 18 Jun 2008 03:24:23 PM IST$lpstat -E This command forces encryption when connecting to a print server.

How SNMP Behaves in the CUPS Web Interface In the CUPS web interface under the Administration tab, the option Find New Printers is used to discover printers that support SNMPv1. This will search and list the available network printers. The discovery of printers is based on the directive configuration done in the /etc/cups/snmp.conf file. On the basis of the search list, you can add a printer using the Add This Printer option. The process is very similar to the Add Printer wizard. Overview of Basic Debugging in CUPS-SNMP In the snmp.conf, we started discussion about various debugging levels in CUPS support. If the directive DebugLevel is set to anything other than 0, you will get the output accordingly. The debugging mode can be made active using the following command. As the SNMP backend supports debugging mode, the command for setting up debugging mode changes depending on the shell prompt. The SNMP backend is located at /usr/lib/cups/backend/snmp when using the Bourne, Bash, Z, or Korn shells. The following command will output verbose debugging information into the cupssnmp.log file when using those shells: $CUPS_DEBUG_LEVEL=1 /usr/lib/cups/backend/snmp 2>&1 | tee cupssnmp.log On Mac OS X, the SNMP backend is located /usr/libexec/cups. The following command will be used: $CUPS_DEBUG_LEVEL=1 /usr/libexec/cups/backend/snmp 2>&1 | tee cupssnmp.log If you are using the C or Tcsh shells, you can use the following command. $(setenv CUPS_DEBUG_LEVEL 1; /usr/lib/cups/backend/snmp) |& tee cupssnmp.log An example of the output might look like this: DEBUG: Scanning for devices in "public" via "@LOCAL"... DEBUG: 0.000 Sending 46 bytes to 192.168.0.255... DEBUG: 0.001 Received 50 bytes from 192.168.0.250... DEBUG: community="public" DEBUG: request-id=1213875587 DEBUG: error-status=0 DEBUG: 1.001 Scan complete! The above output shows that doesn't find any printer at the specified DeviceURI. The above shows the output at the basic debugging level; more information can be found if we use level 2 or 3. Overview of mailto.conf The CUPS provides the facility to send notifications through email. It can be done by integrating the local mail server with CUPS. The configuration file is /etc/cups/mailto.conf, and contains several directives and the characteristics and behavior of the local mail server and email notification for CUPS. We normally use each of the following directives in our daily communication done through mail. The Cc Directive The directive Cc (carbon copy) is used to specify an additional recipient for all email notifications. By default, the value directive is not set and the email is sent only to the administrator. The following examples shows that how email IDs can be specified with this directive. Cc kajol@cupsgrp.com Cc Kajol Shah <ks@cupsgrp.com> The From Directive This directive is used to specify the sender's name in the email notifications. By default, the ServerAdmin address specified in the cupsd.conf file is used. The following are some examples that show how the sender's email is specified with this directive: From cupsadmin@cupsgrp.com From Your CUPS Printer <cupsadmin@cupsgrp.com> The Sendmail Directive The directive Sendmail specifies the command to run and deliver an email locally. If there is an SMTPServer directive, then this directive cannot be used. If both directives appear in the mailto.conf file, then only the last directive is used. The following example shows how this directive can be specified. The default value for this directive is /usr/sbin/sendmail. Sendmail /usr/sbin/sendmail Sendmail /usr/lib/sendmail -bm -i The SMTPServer Directive This directive is used to specify an IP address or hostname of an SMTP mail server. As we have seen previously, this directive cannot be used with the Sendmail directive, and if both Sendmail and SMTPServer directives don't appear in the mailto.conf file, then the default Sendmail will be considered. The following are examples of the SMTP server: SMTPServer mail.mailforcups.com SMTPServer 192.168.0.17 The Subject Directive The Subject directive is used if you want to prefix some text to the subject line in each email that CUPS sends out. The following examples show how a prefix can be specified with this directive. By default, no prefix string is added: Subject [CUPS_ALERTS] Subject URGENT CUPS NOTICE Monitoring SNMP Printers As discussed, CUPS supports SNMPv1 for discovering SNMP enabled printers. This Simple Network Management Protocol-SNMP is used for managing networking printers. We can use any network monitoring tools that supports SNMP for monitoring these SNMP-enabled printers. You can check various open-source network monitoring tools at: http://www.openxtra.co.uk/network-management/monitor/open-source/ I would recommend you to use Cacti, which is a frontend to an RRDTool (Round Robin Database Tool) that collects and stores data in a MySQL database. The frontend is completely written in PHP. The advantage of Cacti over other network monitoring tool is that it has built-in SNMP capabilities and like other monitoring tools such as Nagios, it has its internal mechanism to check certain aspects of the infrastructure. It also provides a frontend for maintaining customized scripts, which an administrator normally creates. But the most important factor is that it is much easier to configure than Nagios. RRDTool is a system that stores high performance logging data and displays related time-series graphs. You can get more information about RRDTool from: http://oss.oetiker.ch/rrdtool/ Downloading and Installing Cacti The pre-requisites of Cacti include MySQL database, PHP, RRDTool, net-snmp, and PHP supported web servers such as Apache or IIS. You can get detailed information about the pre-requisites for Cacti installation at: http://www.cacti.net/downloads/docs/html/requirements.html The current stable release of Cacti is 0.8.7b. You can download various versions of Cacti for different platforms from: http://www.cacti.net/download_cacti.php You can get installation information for Cacti and its pre-requisites on the UNIX/Linux platform from: http://www.cacti.net/downloads/docs/html/install_unix.html The following URL will help you install Cacti on the Windows platform: http://www.cacti.net/downloads/docs/html/install_windows.html You can proceed further by clicking on Next. The next screen shows two options for a new install or an upgrade. If you want to do fresh installation, use the option New Install and click on Next. The screen also displays some useful information such as database user, database hostname, database name, and OS that was specified while configuring Cacti. If you want to upgrade the Cacti, follow the instructions mentioned here: http://www.cacti.net/downloads/docs/html/upgrade.html And then select the upgrade from cacti-current-version option and click on Next to proceed further. The following screen appears, which shows the recommended path of the binary files such as RRDTool, PHP, snmpwalk, snmpgetV, snmpbulkwalk, snmpgetnext, and information related to the Cacti log file and versions for net-snmp and RRDTool. If you found any change in the path with your installation, it should be modified first. Otherwise, Cacti may not work properly. Click on Finish to complete the installation procedure. Once the installation is finished and the next screen will ask for authentication. You need to use the username and the password mentioned in your database configuration to log into a Cacti application: You can use default login information to log in for the first time. Once you click on Login, the next screen will force you to change your password. Once the password is changed, you can see the main page of Cacti that contains two major tabs: console and graphs apart from other generalized options. The console tab contains various options related to the template and graphs management, whereas the graphs tab contains related graphs.