Printrbot Simple Metal Guide
For the DAMlab Tinker Thinker Trailer we use different software and printers than those used in the DAMlab Makerspace. Most of the information from the previous page will still apply to this page, such as filaments and the basics of 3D printing.
Open the Cura engine on your computer and click the "Load File" button. After selecting your file, allow the computer to render a 3D image.
Editing Model in the Cura
Click on your model to bring up three options for editing your model in the Cura engine.
Use this tool to rotate your model in any XYZ direction. Use this to reduce any overhangs present in your model. The lay flat option is a good starting guide as Cura will determine what is the flatest side and orient your model as such. This will sometimes result in more overhangs than necessary and shouldn't always be regarded as the perfect orientation. If at anypoint you with to return to the loaded in orientation, just click the "Reset" option.
Because of the layer by layer basis by which 3D Prints are made their strength is similar to other layered materials like plywood. When designing your prints it is often a good idea to determine the orientation before beginning the design process so that strength as well as the effects gravity will have on the part as it is printed can be accounted for.
As each layer is printed it must be supported. When parts extend out over the air a printer can either print support material that will be broken off once the final part is finished, sometimes the part orientation can be changed to minimize the overhang, or the design itrself can be modified to reduce the overhang. In general, it is a good idea to follow the "45 degree rule." Simply put, don't design or orient models with overhangs steeper than 45 degrees.
Use this tool to directly scale your model in relation to the printbed. Use the scale to maxium option to have Cura determine the maximum dimensions possible for your model.
Note: for objects that are taller than wider, rotating your model and then scaling to maximum can result in a larger final print.
The mirror tool can be used as a shortcut for the rotate tool. For simple XYZ orientation, use this tool. Otherwise, stick with the Rotate tool.
Slicing Your Model
On the left side of the program window under the "Basic" tab, you will see a list of settings that can be adjusted.
Layer Height: determines the height of each individual layer of the print. The smaller this height, the better the quality. With this however, comes increased printing times. For higher quality and longer prints, use 0.1mm layer height. For general use, use 0.2mm. For quicker prototype prints with minimal detail, use 0.3mm. Do not go above 0.3mm layer height or below 0.08 mm.
Shell Thickness: determines the thickness of the model's outer layer. Similar to layer height, reducing this will reduce printing times, however 0.8 mm is advised for printing with Simple Metal machines.
Fill Density (%): The basic idea of infill is that your print does not need to be solid plastic. For general prints of all kinds 10-20% infill is plenty. For large prints with minimal detail, 5-10% is good. Even for high strength parts, 100% is not necessary and is just wasteful. 60% infill is the highest you should ever print at for high strength pieces.
Speed and Temperature
Print Speed: To avoid jams the printing speed should never be set above 50 mm/s.
Printing Temperature (C): Printing temperature is determined entire by the filament being used at the time, check the role for a white sticker with the correct printing temperatures.
None: There will be no additional adhesion between the bed and the model, it will only touch the bed where the model touches the bed. Most of the time you will use this option
Brim: A one-layer tall outline will be built around the model to help with stability. Use this when worried about the model tipping during the print phase.
Raft: Like a life raft for your print, this layer of plastic is printed first and sits under your print and keeps it from peeling off the build plate during printing. If can be removed when the print is complete. The raft is useful if your print is long and flat because some warping may occur during printing due to temperature fluctuations.
None: Supports are only needed if there any overhangs that have an angle over 45⁰ above the bed. If your model doesn’t contain any overhangs, it does not need supports.
Touching Bed: Supports will only be built in places where the model hangs over the bed, if there are overhangs that are located above more of the model, it will not create supports in those locations.
Everywhere: Supports will be placed anywhere the engine determines supports are needed, these can include places that really don’t need supports, so keep this in mind.
The filament tab should be left alone as these settings are determined by the size of the filament. These shouldn't need to be changed as the filament provided will always be 1.75 mm in diameter.
After changing your settings appropriately, click the print file button. Allow the program to load your settings, then confirm that the temp setting is correct in the pop-up window. After all of this, click print and wait for the printer to heat up.