We created this design for a simple racing bot, but it will only run for 10-15 seconds before locking up. Any advice?
#pragma config(Motor, port10, rightMotor, tmotorServoContinuousRotation, openLoop)
#pragma config(Motor, port1, leftMotor, tmotorServoContinuousRotation, openLoop)
//*!!Code automatically generated by 'ROBOTC' configuration wizard !!*//
//+++++++++++++++++++++++++++++++++++++++++++++| MAIN |+++++++++++++++++++++++++++++++++++++++++++++++
task main()
{
while(true)
{
motor[rightMotor] = vexRT[Ch2];
motor[leftMotor] = vexRT[Ch3];
}
{
arcadeControl(Ch2, 20);
motor[rightMotor] = 120;
}
{
arcadeControl(Ch3, 20);
motor[leftMotor] = 120;
}
{
arcadeControl(Ch2, Ch3, 0);
motor[rightMotor] = 0;
motor[leftMotor] = 0;
}
}
it’s kind of hard to tell from the picture, are you using 2 motors, with one motor on each of the large gears?
if so, your issue is simply a lack of torque. The 393 motors are pretty weak, and you definitely will not be able to run a 1:7 ratio with only 2 of them.
also I’m noticing a lack of bearings and proper axle support, which will create tons of friction and make your drive burn out very easily, even with a reasonable gear ratio
10 Likes
Sounds like a torque issue. You can solve this by adding more motors and reducing friction, as Xenon said. Additionally, supporting the wheels on both sides is common, since wheels being supported on only 1 side will cause excessive friction due to the way that pushes the shaft.
2 Likes
You could just complete the race in 9 seconds, before the gears lock up. If that doesnt work try what Xenon said and that will most likely work.
1 Like
can’t really see how the actual drivetrain is powered, can you send a pic from the side?
I’m not sure it is a 1:7 gear ratio, the motors may actually be driving the smaller gears, the larger gears may just be Idlers.
1 Like
yes it’s hard to see. even if it is a 1:1 ratio, the friction from the build here would make a 2 393 motor drive burn out in no time.
1 Like
either way that’s a lot of gears for no reason
1 Like
this should run fine, ive seen it happen. You need bearing flats for this because your getting metal and metal friction. Plus more pictures please
1 Like
It looks like your driveshafts are only supported in one spot. If this is the case, there is going to be a lot of movement in the shafts. When gears attempt to turn one another and they are free to shift a bit, rather than spinning, they will shift up/down and lock up. Coupled with a 1:7 ratio, those motors won’t move anything. We need more pictures to know for sure, but that is what it looks like to me.
1 Like