Robot problems D: HELP!!

[Warrior5]

ORIGINALLY POSTED BY JMS95

Hello;

My team and I have been building our robot for the new sack attack competition and we have been encountering problems driving our robot with the Remote Control All we want to know is how to fix it because we tried many things to then get the same results. When driven, some or all of the motors on the chasis stop. The robots original design had mecanum with 393 motors on speed mode. We changed the Mecanum to omniwheels to see if the friction was causing the situation, but the problem continued. We then checked all the motors, they were all fine, but we changed them anyway, no luck…we also checked if the R/C was making the problem, but We changed it and it was doing the same thing. We changed the Cortex, having the same results. What angers me is that the robot works fine with te online window on the computer. So, is there a way to fix this???

Could we see your code and which program you are using (ROBOTC or EasyC)?

[LegoMindstormsmaniac]

If you lift the robot off of the ground after the motors stop, do they run at all? Have you checked to see if there is a lot of friction in your drive between the bearing flats and shafts? If your robot very heavy?

I’m asking these questions because it sounds as if the motors are overheating, due to being pushed too hard. Solutions would be to strengthen the rigidity of the drive, lubricate the moving parts so that shafts spin more easily in the bearing flats, and/or simply lower the speed of the motors by putting them into the factory lower-speed setting.

~Jordan

[devinc]

How many 393s are you using and how long are you using them for? you could be tripping the circuits.

[JMS95]

@LegoMindstormsmaniac

If you lift the robot off of the ground after the motors stop, do they run at all? Have you checked to see if there is a lot of friction in your drive between the bearing flats and shafts? If your robot very heavy?

I’m asking these questions because it sounds as if the motors are overheating, due to being pushed too hard. Solutions would be to strengthen the rigidity of the drive, lubricate the moving parts so that shafts spin more easily in the bearing flats, and/or simply lower the speed of the motors by putting them into the factory lower-speed setting.

~Jordan

When I lift the robot of the ground they shake. I’ll check the friction when I get to school, and the robot is light in weight, the four Mecanum weight more than the structure of the robot. But I’ll lubricate it anyways to see what happens. Thanks!

[JMS95]

@devinc

How many 393s are you using and how long are you using them for? you could be tripping the circuits.

I use 4 393s, one for each wheel, I divided the motors between ports 2-5 and 6-9. I tried new motors in their 100RPM mode and they were not mounted on the chassis and they did the same thing.

[JMS95]

@Warrior5

ORIGINALLY POSTED BY JMS95

Could we see your code and which program you are using (ROBOTC or EasyC)?

It’s EasyC, I’ll post the code later. I don’t have my laptop with me :o

[JMS95]

This is the code:

while (1) // Insert Your RC Code Below
{
Arcade4 ( 1 . 3 . 4 . 8 . 2 . 9 . 3 . 1 . 1 . 1 . 1 ) ;
JoystickDigitalToMotor ( 1 . 6 . 2 . 127 . 1 . -127 . 8 ) ;
JoystickDigitalToMotor ( 1 . 6 . 1 . 127 . 2 . -127 . 9 ) ;
JoystickDigitalToMotor ( 1 . 6 . 1 . 127 . 2 . -127 . 2 ) ;
JoystickDigitalToMotor ( 1 . 6 . 2 . 127 . 1 . -127 . 3 ) ;
JoystickToMotor ( 1 . 2 . 4 . 0 ) ;
JoystickToMotor ( 1 . 2 . 7 . 1 ) ;
}

Its a simple code to just drive and strafe with the mecanum. Arcade for driving, joystick digital to motors are for strafing, and joystick to motors are for the arm motors.

[tabor473]

That code might have issues if you try to straif and arcade drive at the same time. I would suggest using the new holonomic block and see if that fixes your problems

[LegoMindstormsmaniac]

@tabor473

That code might have issues if you try to straif and arcade drive at the same time. I would suggest using the new holonomic block and see if that fixes your problems

I agree.

After what you have described, it sounds like it is a software problem. I would do as tabor suggested.

~Jordan

[JMS95]

@tabor473

That code might have issues if you try to straif and arcade drive at the same time. I would suggest using the new holonomic block and see if that fixes your problems

Thanks Alot!!! That was the problem all allong!

[josemanuelpagan]

I told you… The people in the VEX Forum are the best.

[tabor473]

I am amazing. Glad I could help next time maybe try to be a little more descriptive when exactly and issue happens because I was just saying holonomic block as a side note and was going to go into more complicated bugs next.

[JMS95]

@tabor473

I am amazing. Glad I could help next time maybe try to be a little more descriptive when exactly and issue happens because I was just saying holonomic block as a side note and was going to go into more complicated bugs next.

Ill keep that in mind. Thx again!

[jgraber]

I’m late to the party, but didn’t see a clear description/analysis of the reason for the problem, so I’ll add this one.
This is a typical “Multiple assignment to motor” problem,
where Arcade4 and 4 JoystickDigitalToMotor commands
all are trying to control the same motors 8,9,2,3.
Its like your mum telling your to wash the dishes,
and your da telling you take out the trash,
back and forth, every millisecond, and you end up just standing there quivering.

[tabor473]

Very good analogy but i dont think you explain how bad it is for the motors.
More like sprinting back and forth to start each task.