Hello, team 40994A here. I was just wondering what you guys would say to this question. What should we do in order to keep the inserts for the motors in on our drivetrain? We have been having this issue for awhile, and we might’ve found a solution, but I still want to see what you guys would say about it.
what inserts for the motors i never put inserts in motors only wheels
could you not just put a shaft collar or spacers that hold the insert in the motor between it and the C-channel
like this (sorry CAD model is a little scuffed)
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So that the axle can go into the motor easily.
Due to the amount of pressure and speed from gear ratio, the insert itself comes out regardless of whether there is a shaft collar or not. We have began putting spacers on to try to solve the issue, but I want to check if anyone else has a different way of solving.
You only need one collar in your example, the one between the c-channel and the motor.
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Ok thanks. We will try that.
The small grub screws are hard to tighten and strip easily so if you want to get a really strong collar you can take out the grub screw and replace it with a short regular screw as they have the same thread size.
I do this on rubber band rollers as regular collars couldn’t hold the sprockets in place with the force of the rubber bands.
Also, make sure to put a spacer between the c channel and collar so you don’t have metal rubbing on metal.
Hope this helps 
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@lacsap Yep noticed that after I made it the model still gets the point across I hope.
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This helps a bunch! Thanks for sharing, we will switch the collar screw. Do we need to use a motor screw, or should a 0.25 screw work fine?
Indeed it does, I think it is a clear illustration of a typical assembly. Looking forward to future ones to share with our teams.
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Any screw from the vex line should fit but I would recommend using the shortest possible as it may hit the motor attachment post.
If this happens you can always file down the screw to the right length.
It’s not necessary but as it’s probably in a hard-to-get place and an important part of the robot that experiences a lot of force and vibration from the motor it might be smart to add some lock-tight to the screw. I have had problems where a collar berried in my robot came loose and it took 30 minutes to fix as I had to remove parts to get to it. Luckily not at a comp.
It’s annoying that some of the most critical parts of a robot experience the most vibrations and force can’t be nylocked. Motors, Collars and Standoff.
If you need any more help feel free to post a picture of the mechanism as this would help give us a better idea of where you could place a collar.
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make sure to use a berring flat so the collar is not contacting the metal.
A bearing flat is unnecessary as the motor supports the axle better than a bearing flat so a spacer should suffice.
A bearing flat is only needed on the other side of the drive train to support the other end of the axle.
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I agree, just make sure there is a spacer to prevent the collar from rubbing on the metal.
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We put a bearing flat on the side of the c channel without the motor. On the other side with the motor, we just kept the shaft collar close to the motor insert.
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a very easy way to do it that i love doing is to use shaft adapters, I see lots of teams not really using these but if you want less tension overall from the collars and you arent using bearings, I highly recommend them. You most likely already have some lying around somewhere.
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Do you mind if you tell me what CAD modeling software is this? I’ve been looking for the software, just haven’t been able to find it yet.
The website I use is called Onshape, it’s really nice because they have vex parts that you can download and port into your projects. There are also a lot of walk-through videos on YouTube I suggest watching first here. I am by no means an expert CADer so I suggest talking to people on this forum post if you want to learn more they know much more than I do. There is also a discord server dedicated to CADing ( I’m not in it I should probably join it) but here is the link. Hope this helps!
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I’d say a Bering so that the Axel isn’t rubbing also, it would also stop the collar from rubbing too (if put on both sides)
Also if you only use spacers, and have to much pressure put on that axle then the Axel will still rub and ruin the c-channel and Axel.