Multibellow Suction Cup

Hi All

This is a ABS/TPU printed suction cup that can be done with a single extruder by pausing and switching filament. The suction cup can be used on the end of a robot arm for Picking and Placing stuff. This design is meant to be a general example/starting point. No hookups are provided for a particular vacuum source. Add what you need or your own setup.

Things that worked well:
1. Bellows walls are 0.4mm thick, any more and the cup is too ridged.
2. No more than 45 degree angle.
3. 6mm long on the "Increasing Diameter" half of the bellow is about as long as you want, and even at that length the upper part start to bend inward a bit due to plastic contracting. The decreasing diameter section of the bellow prints just fine.
4. Sticking with .1mm layer height on the bellows worked out better than 0.2
5. Upped the TPU temp to 230 for better layer adhesion.
6. You want more (AKA thicker) material on the inside of the cup lip. This provides a spring force to pull the lip back