Gear’s teeth are slipping

We are currently having trouble with our catapult. It is just a simple catapult made with two 2x2 slip gears, two 4x4 gears, and rubber bands. It was working fine yesterday, but this morning, when we tested it, only one section of the slip gear geared. The other teeth just slipped. We don’t know why this is happening and have tried everything to fix it. Can anyone help?

Can you post pictures of your cata? I can’t help unless I see a picture to figure out the problem

60 tooth?

84 tooth?

Use teeth instead of the holes, because high strength and regular gears have different hole spacing and we get a bit confused.
Also, each build is usually unique in its own way, so we usually can’t infer the problem from just text. Could we have a picture of your mechanism?
(However, from what you’ve said, it sounds like your slip gear has worn down teeth; or your structure is flexing causing the gears to move away from each other)

Ziptie the axles together

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Please exercise a little bit more thought to your posts. Many of your recent posts err on the side of providing little to no tangible contribution to the conversations occuring on the forum. I encourage you to give the FAQ Section of the forum a good read, as it lays out a few rules regarding post content that you have tip-toe’d very close to violating numerous times.


Getting the topic back on track, A photo would be very helpfull as we dont have any understanding of the geometry or gear sizes, which we would normally need to help solve a problem of this nature. The solution that @Wesley13406D proposed is technically one that might work, however this is a pretty janky fix that can result in increased friction and risk of breakage. I would only advise that a team does this in an emergency.

As someone who has also had to solve a similar problem recentley, I found these bearngs to be extremeley helpfull, as they reduce friction by quite a lot, and have 4 points of contact rather than two

so that the shaft is less likley to wander within the hole since there are more points of contact than a traditional bearing flat.

These are also excellent because occasionally you may need to install a high strength shaft in the middle of 4 holes such as if you want to mesh a 12 and 48 tooth gear on a 5x C channel, and these bearing mounts can actually be fitted diagonally with just two holes to act as a bearing flat even though you only needed to drill one custom hole, rather than the three needed to install a bearing flat in a custom hole. This does stretch the part a little, however, which can cause cracking if not screwed in correctley.

I hope that helps!

Question for @bkahl

Just out of curiosity, since posts now need to be approved since the changes from a year back, how do posts such as

Get approved, because as you said, posts like these are

Im not trying to criticize, Im simply curious as to how these get through if they violate some aspects of the rules?


answer to your question, it should not have been and has been deleted.


I approved it to reply to it and highlight my concerns. In hindsight, I could have replied to the other post.