For the past few months we have been working on a duel flywheel design to shoot full court. We are going to another competition in early November. However, whenever we design a prototype, the wheels will not spin up. Our current prototype is two sets of 84:12 tooth gears driven by a single high speed motor. Our flywheel looks a bit like 26 Iron Waves and has a similar structure for housing the shooter. When I get back to the robot on Monday I can include pictures. I am wondering how I should design the flywheel and if I should add more motors or more gear ratios for speed or torque. I would appreciate any ideas to get our robot back on track for the deadline before next competition.
According to some calculations, the 7:1 gear ratio you have will be good for shooting the full field if you use turbo gears in the motors. So when you say it “does not spin up” does it just not move the wheels at all? If so, check to see whether the motors are fighting against each other if the flywheels are geared together.
The wheel spins up to around 30-60 rpm on full power if speed up slowly. We are using bearing where our shafts are and washers everywhere we can. It will spin fine without the wheels on so I do not know if the mass is too much. Also it is a 7:1 gear ratio with another set of 7:1 gears outputting onto that shaft. I do not quite know the compound gearing of this yet, but I would have imagined that with the high speed motors we would have been able to shoot the ball like you guys. Does it have anything to do with having the gears in two C-Channels put together?
What size and how many wheels are attached to each motor? A 49:1 gear ratio with speed motors is probably way higher than you need, and might not have enough torque.
We have tried with all types of 4" wheels, single and double stacked. All had the same outcome as the others. What would you recommend me doing for the gear ratios if I was to use two high speed motors.
Did you try taking off the motors and spinning the wheels, they should spin for at least 5 - 10 sec. Also make sure that there are bearings on every hole in the metal that the shafts go through.
Try the 15:1 with 2 high speed motors, it shot the full field, but you may want to switch to 4 motors (to have a faster recovery time) to stay competitive during the season. Keep the 4" omni wheels for the launcher, they have the best grip.
Yes, I have been able to take off the motors and spin the gears, it spins for about 6 or 7 seconds, And yes, we used bearings and washers everywhere. Do you thing the high strength 12-tooth gears are doing this? Should we use 84 toothed gears to drive 12 tooth plastic ones, because I know I would eventually have to replace them because they would shred the teeth off at high speed.
By 15:1, what gears would I need to get that compound gearing to work?
Yes, keep the high strength 12 tooth gears. Did you test the motors to see if they were strong? Also, are the 2 sides of the flywheel geared together?
No we did not test the motors to figure out their torque, but if what your asking is if I know what motor is driving the gears it is a normal 393 motor with high speed gear replacements. We replaced all the gears of the motors and labeled them before we put it in. And no we have no geared the flywheels together.
For the 15:1 ratio use the fallowing gears:
http://www.vexrobotics.com/media/catalog/product/cache/11/image/296x/5e06319eda06f020e43594a9c230972d/f/i/file_61_7.jpg
http://www.vexrobotics.com/media/catalog/product/cache/11/image/296x/5e06319eda06f020e43594a9c230972d/2/7/276-2251-metal-12-tooth-pinion_1_1_1.jpg
http://www.vexrobotics.com/media/catalog/product/cache/11/image/296x/5e06319eda06f020e43594a9c230972d/f/i/file_64_3.jpg
And set them up in this order:
Question: Is that single low-strength plastic 12 tooth gear in the center of the two high strength 12 tooth gears on the bottom being driven by a motor on each side, if so what internal gearing are they?
and why are they on the malleable metal sheets instead of something like a large piece of C channel?
Ok so with the lack of friction of you flywheels, it must be something with your motors. When you get to your robot, make sure to test the motors of your flywheel, sometimes there is a bad motor or something. It also could be something in the program, are you using the normal button press so set the motor to 127?
The 12 tooth gear is a high strength gear cut in half. Yes, the gear is in between 2 motors on each side (i.e. 4 motor flywheel). The piece of metal that the motors and other things are mounted on is actually a 5 wide c channel with one side cut off.
We had a program to spin up and fortunately I have that now so I’ll include it here.
[ATTACH]9718[/ATTACH]
For some reason it would not work when we put it on the robot, After that we tried to use the controls for our wheels and ramp it up that way.
8686KZeus.c (2.74 KB)
Can you try a program that does not ramp up the motors. Like the one below:
#pragma config(Motor, port2, launchL, tmotorVex393HighSpeed_MC29, openLoop)
#pragma config(Motor, port3, launchR, tmotorVex393HighSpeed_MC29, openLoop)
//*!!Code automatically generated by 'ROBOTC' configuration wizard !!*//
task main()
{
while(true)
{
if(vexRT[Btn8U] == 1)
{
motor[launchL] = 127;
motor[launchR] = 127;
}
else
{
motor[launchL] = 0;
motor[launchR] = 0;
}
}
}Yeah, I think I could try doing that. I think the only problem with that is with stalling out motors for us, because I think we tried one when we made a flywheel with chain, we toasted quite a bit of motors in a matter of minutes.
The problem might be that the program is messing up, not the motors are stalling out.
Can you run the flywheel without the wheel attached to the end? Just the gears? Does the flywheel still stall (or toast your motors)? If it does still stall, somethings wrong with your code, or your motors! Otherwise, gear ratios too high 