We had a copy of the bellows 3D-printed in TPU on a HP Fusionjet. This material is quite a bit stiffer than the silicone we used (Shore 90 vs Shore 50) but this technique could provide an alternative solution to injection molding.
The bellows has been mounted in a test machine and is run through cycles in a longevity test.
Measurements show the motor needs to put out 25% more power to actuate the more rigid bellow, but the controller seems to behave identical to the blue bellows.
![](https://breathney.cc/wp-content/uploads/2020/08/IMG_20200731_122539-1024x768.jpg)
![](https://breathney.cc/wp-content/uploads/2020/08/IMG_20200805_173103-1024x768.jpg)