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.
A pushing trigger would instead move in the same direction as the string tension, temporarily reducing the load on the catch before releasing.
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.
