Fixing an X-Drive Drifting Issue

VEX V5 General Discussion
#1

Me and my team decided on making an X-Drive, which we made. But recently I’ve noticed that there is some drifting when the robot is moving. So I took off the main part of our robot and have been trying to figure out the problem. I checked everything I possibly could, I even switched the motors that were in the base for different ones. https://photos.app.goo.gl/5MZM4itKzb2b9qaF9
https://photos.app.goo.gl/UG2zfmdp4oweqUkT7

Those are the videos of it drifting, and first one is something else I have noticed, there is also no autonomous.

So could anyone tell me what is going on? And how could I fix it?

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#2

i get a 404 error when i click the links, might need to enable link sharing

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#3

Ah ok, thank you for letting me know.

#4

my guess though is that the way you built it made it so the wheels were not the same distance apart. it’s a common error and is best rectified with custom lexan gussets or drilling holes (the reason for this is vex holes dont line up properly at 45° angles, even with the vex 45° gusset)

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#5

anyways i could be way off but if it’s a mechanical issue that’s my best guess until i see the vid

#6

I just made it so you can view the video.

#7

what’s going on with the code? whatre you trying to have it do

#8

For which video?
I the one where it is moving on it’s own, I have no idea how it is moving. The one where I am controlling it, i just have strafing on Axis 1, forward and back on Axis 2, and turning on Axis 4. I hope that’s what you needed

#9

both

#10

can you send your code for the first one? i’m more of a mechanic than a coder but if something’s moving by itself i can only assume it’s something wrong with the program

#11

Sure, just give me a minute.

#12

code picture help

#13

ah i see the problem

main issue- in the first vid your wheels are cantilevered. this causes monstrous frictional losses and is probably why it was going as slow as it was. in the second vid, your wheels supports were at different angles so there was friction added there as well. these two issues were why in both cases, the bot couldn’t drive straight- each wheel had different power losses than the next because of how much friction there was

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#14

did you have any bearing blocks on them in either vid? a closer pic would of the wheel hubs would help

#15

By bearing blocks, do you mean bearing flats? And I can get you an up close picture.

#16

yeah

#17

Ah ok. I have then on them.

#18

Google Photos
Google Photos

#19

ok that’s a lot to fix ngl

main thing, add a channel on the other side of the wheel and make sure you have bearings there too. after that, fix the shaft collar that’s next to the motor- it’s way too close to the channel ( and even if it isn’t too close, you need to add a teflon washer between the shaft collar and the channel. never ever ever let metal rub on metal- that’s how you get massive friction losses)

the reason for all of this is because the shaft is bending (or going to bend) because you only have the wheel supported on one side. cantilevered wheels don’t work well in vex

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#20

once all that is done lemme know. friction is your biggest problem in both vids