Hi Everyone, My team struggled last year with friction in the drivetrain causing our motors to overheat and not work. What have other teams done to solve this problem? is it changing the motors or gearing. looking for help. Thanks
Make sure that nothing is heavily rubbing against metal or other parts. Also Try screw joints as they do not have as much slop as shafts due to the circualar structure rather than a square. There are plenty of examples if you search around on the forum using the magnifine glass on the top of the page.
(welcome to the forum) Can you take a photo of your robot?
Do you have any pictures? Typically it is very easy to find the problem with pictures but without them we would just be guessing.
there are quite a few ways! first, if you havent already, screwjoint all of your wheels. There are plenty of videos online on how to do this. Second, run bearing flats on motor axles. you can drill them ut a little bit if you want to reduce friction further. third, try to make sure that the c channels in your drivetrain don’t clamp together super hard. fourth, use white lithium grease sparingly wherever you see fit.
Welcome to the VEX Forum!
Do you have any pictures of your drivetrain? There are a few things teams do, such as using more motors in a drivetrain, using screw-jointing whenever possible (Look this up, it is seriously an important concept), and using the correct motors and gearings for a drive (EX: Green motors for a 2 motor drive), and even looking for bent axels in your drive, and using an appropiate drive considering the weight of your robot.
It is important to know, however, 4 motor drives and especially 2 motor drives are going to overheat fast no matter what you do. A picture (or pictures) or general info on what your drivetrain is would help a lot here though.
As someone who struggled severely season before last with overheating, I found that the frame had a lot to do with it. I know, it is not easy, but having a different frame type, (mine last season was quite open in comparison) helped almost unbelievably with overheating. Flipping your motors may also help, so that the main vents face the floor; the air flow could help, especially if you have a higher set chassis. Sorry if that does not help.
Most of it boils down to:
- Using bearing flats (a lot of teams forget this)
- Not cantilevering your drive axles
- Properly squared drivetrain (meaning everything is aligned, so your axles arent haivng to go diagonally to reach the other side) and not overtightening braces
- Screwjoints on wheels and non-motor powered gears
One big thing that our team didn’t realize until the middle of our first season is over-spacing the drive. If you have too many spacers in between two c-channels, then they end up rubbing against each other which causes a lot of friction.
Also remember to use washers!
Could you elaborate on no2. I was under the impression that cantilevered/ie skewed/titled drives were a bad thing!
Sorry for being unclear, you are correct in that interpretation.
The list was meant to be read as things one should do (as in one should “use bearing flats” or one should “not cantilever drive axles”).
There is ALOT you can do to optimize drive friction so ill list all I can think of here
1:Cad your spacing-if your spacing is off you will have friction especially if you re oversized.
2: square your drive-if your drive isn’t perfectly parallel in perpendicular you will experience more friction
3: make sure your metal isn’t bent
4: make sure your bearings are loose drill out if needed: if your bearings aren’t loose and free spin you have a issue
5: don’t put bearings on motors
6: screw joint wheels and idler gears: anything not powered=screw joint
7: support your drive- you honestly need 2 full cross braces make sure they are there
I assume 2. is by using standoffs across the drive but not exactly sure by what you mean in points 4 and 5!
Bearing flats are what you use on the axles on the drive. Sometimes they can be too tight on the shaft and increase friction so you have to expand the bearing hole a bit to loosen the fit to reduce friction. For the other one a common mistake teams will do is mount a motor on a bearing flat increasing friction and making motor mounts less secure