Here’s an interesting resource for how to prep files for printing mechanical parts using Shapeway’s printing service. I’m highlighting the Clearance as I found the discussion pertinent to many forms of printing, with a special consideration for SLS.
Designing mechanical parts for 3D printing
What you need to know.
Through these pictures and explanations we hope to give you a better understanding on how to design mechanical parts for 3D printing.
- maintain a wall thickness of at least 1mm,
- accuracy is 0.1mm,
- always keep a clearance of 0.6mm
- and parts may have a deviation of 0.2mm.
When designing something mechanical that has to be 3D printed or when adding a mechanical feature to your model there are several main considerations.
Clearance, the distance between a door and the door frame when the door is shut. If you make a peg with a diameter of 3mm and a hole with a diameter of 3mm, the peg will not fit into the hole. There has to be some kind of clearance at play for it to work.
The amount of clearance would depend on the functionality of the part. The higher the clearance, the more likely it is to fit. When developing complex moving mechanical parts though, the more clearance the more inefficient the part. A good balance between clearance and efficiency is crucial for your design decisions. If you have a gear, gearbox or spring I would try to go for minimum clearance. When designing any other assembly I would go for more clearance. The minimum clearance is 0.6mm at all times. Do not go below this number or your parts will fuse.
The reason why clearance is especially important when designing things for White, Strong & Flexible(Selective Laser Sintered parts) is because the laser melts the SLS powder and then fuses it. This coupled with the shrinkage means that if you do not get clearance right your part will fuse. So not only will it not fit exactly right it will all get stuck together and will not work at all.
Every Thursday is #3dthursday here at Adafruit! The DIY 3D printing community has passion and dedication for making solid objects from digital models. Recently, we have noticed electronics projects integrated with 3D printed enclosures, brackets, and sculptures, so each Thursday we celebrate and highlight these bold pioneers!
Have you considered building a 3D project around an Arduino or other microcontroller? How about printing a bracket to mount your Raspberry Pi to the back of your HD monitor? And don’t forget the countless LED projects that are possible when you are modeling your projects in 3D!
The Adafruit Learning System has dozens of great tools to get you well on your way to creating incredible works of engineering, interactive art, and design with your 3D printer! We also offer the MakerBot Digitizer in our store. If you’ve made a cool project that combines 3D printing and electronics, be sure to let us know, and we’ll feature it here!