Design Resource FilesBelow are the design files that we have used to create all of the designs shown in this resource. The include the CAD model of the memory stick itself and also the case design. Please feel free to download these files for use in your own designs and lessons (if you are a teacher).
- STL files (All cases)
- STEP files (All cases)
- USB memory stick Autodesk Inventor files
- USB memory stick STEP file
Working In CADAll the images and graphics shown on the page were created using Autodesk Inventor and Autodesk 3DS Max. This is available free to education establishments and students. Lots of other CAD packages are also available. One of the other advantages of working in CAD is that you can create fantastic looking animations like the one shown below.
Slide togetherThe key features of the slide together design are:
- A rail for one part to slide onto the next. You can see this in the left hand image below.
- A small bobble on the inside which pops into place and holds the case together. The recess into which this bobble engages can be seen at the top centre of the right hand image below.
- Keeping the angles of the rails at 45 degrees. This allows them to print well (as no severe overhangs) while still providing a good 'keying' between the two parts.
- Leaving enough space between the rails to make them not too loose and not too tight (around 0.3mm gap).
Screw togetherKey things that we took into consideration when modelling this case were:
- Not placing the holes too close to the inside or outside edges. This is to make sure the area the screws tighten into have enough mechanical strength not to break when they are tightened (see the 'bulged' area in the design above).
- Also make sure to know what screws will be used before modelling any holes to be sure they will not be too tight and break the plastic. If the the hole is too small in relation to the screw then this could easily occur.
- As this case has a chamfer (the 45 degree angle between the base and sides) it may be prone to warping. This is where the filament can 'curl' slightly on cooling. By modelling 'ears' (right image above) into the design the print will have better adhesion to the bed which can help prevent this. These 'ears' will need to be removed (cut away) one the print is complete.
Snap togetherKey things that we took into consideration when modelling this case were:
- Making sure the clips wall thickness is large enough to prevent print layers from snapping or peeling off.
- Using a 45 degree chamfer on the clips will also prevent them from breaking.
Push togetherKey things that we took into consideration when modelling this case were:
- To ensure the the two parts of the case are reliably connected we have used have slots (friction connection points) at the sides and back of the design.
- It is also important to make the slots slightly bigger than the studs to account for any inaccuracies during printing. We normally start with around a 0.2mm increase and then fine tube to get the desired results.
Other Useful Tutorials
- How to customize a USB case design using Autodesk Inventor. In this example we will show you how to write your name on one of the cases. Click here to download our guide.
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