How to design suction cups for a very specific object

If you have a very specific object which isn’t a flat surface, you will probably have issues with finding a well suited suction cup. Instead of searching endlessly you should make them yourself.

First of all, some things you have to know before you start:
• Make sure you make as small 3D-testprints as possible. It will save a lot of time, because you will have to make some adjustments in the first versions of your suction cup. If you are 100% sure the design works you can figure out how to connect the suction cup to the end-effector.
• Don’t be afraid to make many test prints, it’s after all, R&D what you’re doing.
• Using PLA for the suction cups works perfectly fine, so you don’t have to use a fancy rubber (TPU/TPE) printer.

For explaining the steps we will use our example. We had to pick up ampoules at the tip.

  1. Measure all the important dimensions. For some objects there are standardized dimensions available. You can easily find them, just search ISO/NEN/DIN [Name of your object]. We used the syntax: “DIN Ampoules”.

  2. Try to make the area where the suction cup connects to the object as big as possible while maintaining a good seal, the bigger the area the stronger the lifting force will be. (p = F/A  F = p*A).

  3. Make sure there is a chamfer added to your suction cup to make sure you can get a good seal for the full range of your tolerance. In our case 2° was sufficient. For details look at the picture below.

If you want to discuss this topic or if you have questions, reply in the comments.

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