Gears Not Meshing Well Solidworks

So I’m in the process of making my drivetrain gearboxes and currently i’m looking at the configuration I want it in but the 40 tooth that is being driven by the 12 tooth pinons is not mating correctly(ie keeps using a tangent mate). Can anyone help?
GrabCAD link:

I tried opening the assembly, but the Falcon 500 file doesn’t load properly. Try pack and going, and re-uploading; I may be able to help out then.

Regarding the tangent mate, what exactly are you trying to mate? If you’re trying to select two faces on the gear and it defaults to tangent, chances are that the faces (even if it doesn’t look like it) are arcs. Try going into the gear file and starting a new sketch, and pressing “convert entities” with the profile of the surface selected. If it is indeed an arc, a centerpoint will appear somewhere. If you don’t want to modify the gear file, mate each gear onto a pinion of some sort (motor output and Thunderhex in your case), and mate the pinions relative to each other.

What do u mean by mating the pinons relative to each other. By mating the motor shafts and thunder hex?

Yeah. Do you know how to do distance mates?


Awesome. I’d calculate center distance and then do a distance mate between the center of the output shaft and Thunderhex. Assuming you’re using Thunderhex with a hole in the center, it should be easy. If you’re not, make an axis and mate it.

Aight will do. Thanks!

Welcome. I’ll try to check CD relatively frequently today, feel free to reply to this thread or DM me if you have any more questions. Good luck with the gearbox!

This is my favorite site to calculate gear center center distances. Maybe someone with a little bit more knowledge of this can tell you how much center add you want.

Edit: also be careful that certain pinions have different center spacing then their gear count

My advice is to make the gearbox plate first. This will allow you to set all your distances so assembly is a piece of cake. What I like to to do is make 2 construction circles for each gear’s pitch diameter and constrain them to be tangent. Then, I add .004"-.006" to one of the circles. Once you do this, put a bearing hole concentric to each of these, so in the assembly you can put the bearing right into the plate, mated concentric, and the shaft with the gear right into the bearing. Assuming you’ve done all this right, you should end up with perfect gear meshing. (don’t worry if it looks like the teeth are inside of each other, as long as they aren’t in the main body of the gear you’re good)


Yeah I realized that was a smarter idea. Really wish that I started this project earlier. Definitely showcasing the gaps in my knowledge. But thats a good thing cause now I know what to work on in the small sliver of time I have till build season.

Here is an excellent video by Patrick from 2910 on designing a gearbox. It is the video I followed when I designed my first gearbox.

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Yep! Once you get the first one done, they get a lot easier.

There is a function called repair sketch that you can use to find gaps.

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