# catapult release

Our catapult releases of an angle about 45 degrees. However, when we shoot at the flag, it only reaches the middle and bottom flag. Keep in mind running a double catapult. Any ideas on how to fix this excluding increasing tension?

You could make the arm longer and you can experiment with the release angle (changing it to 50 or 55 degrees).

Seems like the only way to do this, if I’m understanding the issue correctly. Just change the release angle. If youcan’t see an easy way to do so, a picture might help us help you.

Changing the release angle a little is not going to have a huge effect, and if you can’t reach the upper flag, you need a pretty significant shift. Why do you have to excluding increasing tension?

The best way to do as you ask, though not necessarily very easy, would be to use weaker elastics but stretch them further. For simplicity, assuming they obey Hooke’s law, with half the spring constant you could stretch them twice as far without increasing the tension, and then they would provide twice the energy. But being able to stretch the bands further and using bands with a fraction of the spring constant may well not be viable.

Idk how well this would help but I found that different sized standoffs which hold the balls help. So if the stand-off farthest out and nearest to the top flag ball is shorter, the ball goes higher but if it is longer the ball shoots shorter

Yes, that’s the kind of release difference seen in trebuchets.

+1 especially the farthest standoffs from the vertex of the arm. if you make these shorter, your ball should go higher. but this really depends. does your ball go far, but not high? or does it just have a generally weak shot, not high or far?

Thanks for the suggestion on the standoffs. We reduced the length of the standoff as well as well as tampering with the tension and changing the degree of release.

Ps. Sorry for the late response

It sounds like you need more hight so try making the release angle shallower, if this doesn’t work go for power by making the arm longer and increasing the amount of elastic bands, you might have to add a gear ratio for this