MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.

Download Now

Report as inappropriate

I ended up using two springs pulled from a pen, with little metal nails slid into them to keep them moving the right direction. I had to drill an extra hole into the inside of the trigger.

It works reasonably well, but does not feel great, the whole trigger moves and grinds a lot despite a shitload of filing and sanding. The single hole on the bottom is placed in a bad location, it pushes the trigger at an odd angle so it doesn't want to return easily.

If you could find a long, but narrow flat spring, like the follower spring from a rifle magazine, that would be ideal because it would push evenly against the whole back of the trigger.