Does anybody know why my motors are so slow? For some reason whenever I drive in driver control (I haven’t coded anything yet) all the motors move slowly compared to other people’s online. I checked in the device info and the motors are able to get 110+ RPM. Do I need a software update or something? There’s nothing wrong with how I built it, I checked many times. Also, is there anyway to sync the two motors that I use for the drive train so that they move at the same speed? (One moves faster than the other.
Step 1 take them off the robot, mount a gear with a marking pin on the gear to a motor. Run it, count the revolution per min for each motor and report back on your findings.
This elimates a problem with your motors.
Is that different than what the device info tells me?
By doing it off the robot you elimate issues with the robot. By counting you eliminate an issue with th onboard sensors.
Ok, I will try it out
In my experience, this sometimes occurs when you have old/much used motors or new and old motors together. VEX IQ changed their motor manufacturer midway through the Next Level season, introducing the “same” motor by a different manufacturer. I don’t know what happened with the manufacturing, but the end result was that we bought some of these new motors, and were surprised when our robot couldn’t climb anymore. We tried the old motors, and it climbed perfectly. From that and other tests, we concluded that the new motors were less powerful then the old ones. This could explain your drivetrain issue with one motor moving faster than the other. Another solution to your issue would be to buy new motors (I know this is expensive).
I am not sure why the new motors are different as we couldn’t find a way to take one apart so we could get it back together, but if find a way to take one apart, you could try lubricating the gears inside.
IQ motors are ultrasonic welded together, no way to take them apart without permanent modification/damage.
Note that any motors you take apart and put back together would no longer be competition-legal under <R13>, since disassembly would require permanent modification.
@Foster @FRC973 Update: I tried the RPM test and the motors did fine, getting around 120 each. However, if I attach them to the robot I’ve got one that works well with the rest being pretty bad. The ones that don’t work function fine by themselves, but after putting them onto the robot you can tell that they move slower, especially compared to my good motor. And then under the weight of a couple risers? They barely move. By the way my drivetrain ratio is 2.5:1 and is a similar weight to the 210 skills robot.
Is calling the VEX support thing an option or is that only for getting refunds and stuff?
It’s hard to get refunds on motors that work just fine (as you just proved). Support doesn’t do robot debugging, but we are a source of help.
Next step is to take some pictures of the side that is failing and let us look at that?
Actually, I tried switching the motor that worked and the motor that didn’t work and had the same results. So I know that the side isn’t the issues, it’s the motors.
I find this really hard to believe, maybe @Grant_Cox can shed some light on this?
@FRC973 do you have some sample serial numbers from motors you can supply?
So do you think that the best choice is just to buy some new motors?
No, I think the best thing is for you to take some shots of the drive train you are having problems with and let us see if we can see something that you can fix.
Sorry, I had missed this post, so you did switch sides and the issue traveled with the motor.
Can you do us a favor and post the serial numbers of the motors that work and the one(s) that don’t. At this point you need to call support and let them sort this out for you.
Alright. Where’s the serial number of the motors? I’m new to Vex (this is my 2nd year) On the motors on one side towards the bottom I see 228-2560 and on the other side I see 5191DD
The one that works is 5151DD and the font looks different than the others.
All the others are 5191DD
The 5191DD is the serial number. It’s either under the part number 288-2560 or on the dark gray material on the opposite side of the part number.
So 5191DD do NOT work and the one that does is 5151DD. Can are both sets of serial numbers printed on the dark gray material?
The ones that didn’t work were all 5191DD. The one that worked was 5151DD