RC Spring Cups, Crawler, Stoßdämpfer, Federteller

This is my first customizable Part.
I printed it with ABS and it fits well...
There is some finsh-grind to do with the Dremel or carefully with your drilling machine.
For example:
I drilled the blind hole with 6.0 molding cutter on a drilling machine (slowly!) to get a better cylinder form.