Tokyo Marui Spas-12 Trigger

thingiverse

I developed this trigger after being unable to find a reliable replacement part for years. The official part is made of poor quality metal and has a weak point between the lower and upper triggers. This seems to be a common failure point on these units, but I hadn't seen anyone else either offer better quality parts or any other alternative. While plastic is far from an ideal material for this part, I was able add some reinforcement is some areas to help it perform well enough. It should still be used lightly if made with plastic, but perhaps you could get it machined in metal for a longer lasting part. Some manual cleanup may be required to get the trigger to fit well. Some of the tolerances are very close and the modal is slightly larger than it needs to be. Primarily, you may need to sand/shave the lower trigger and at the top bar that actually triggers the release internally.