Catch Push or Pull?
I'm designing a printed stringer that uses a sled rather than direct string contact, and I'm trying to decide on whether the trigger should pull or push on the catch mech to release. In a direct contact stringer, the catch mech just pushes the string directly upward, so this is all new to me.
The sled is already pushing forward against the catch, so a pulling trigger would press the catch harder into the sled and pull it back further before releasing. A pushing trigger would instead move in the same direction as the string tension, temporarily reducing the load on the catch before releasing.
Is there a significant difference between these two methods? Should I just use a pivoting catch instead? Bear in mind that stringer springloads can get a lot, lot heavier than springers if desired, so I'm thinking in terms of what will be best for these printed parts as they produce constant lateral friction against each other.
2 replies
I'm not entirely sure what you mean here, but it sounds like the mainstring's tension could actuate the catch and fire the blaster without a trigger pull under this setup.
Perhaps pictures would help?
More generally, there's multiple ways to set up a catch and all of them have advantages and disadvantages. We'd be in a better position to answer this question if we had a clearer idea of your design goals - do you want to minimize parts count, have heavy string loads, have a good clean-feeling trigger pull, or some balance of all of these?
If you're worried about the friction on 3d printed plastic, having a pivoting catch which uses a bearing as the sliding contact between the catch and the notch on the sled is an option. This is normally not necessary - Caliburns can have decent spring loads with pure plastic pivoting catches - but could enable string loads far above what conventional springer catches handle.