Do you need some simple spacers? This product might be just what you're looking for. The entire printing process takes less than a minute, and you can easily integrate multiple spacers into a single print job at once.

I've customized a new end effector for my Delta 3D printer, and I just needed some shims, which are perfectly capable of doing the job.

Outer diameter: 7.5 mm
Inner diameter: 3.0 mm