We are having trouble with our flywheel. It keeps cutting out after ~5-7 shoots, and when we feel the motors after the shooter cuts out, they are not warm/hot (tripping the PTC). Our shooter has two flywheels, one using a 2.75" traction wheel and the other wheel is a 5" traction wheel, both using a 15:1.
We think that there is friction somewhere on the shooter, but it might not be. Do you guys have any ideas?
I have attached pictures so it is easier to visualize the shooter and our problems.
Even if the motors are not warm/hot, you may still be tripping the PTC. Its purpose is actually to keep the motors from getting hot to avoid damage.
Reducing friction is very important, and that is not an exaggeration with the high speeds that the flywheels are running at. Your wheels should be able to spin freely for at least 5-10 seconds without motors attached.
If you have too much friction, make sure everything is aligned perfectly and make sure you’re using washers between rotating parts and metal. Also make sure none of your shafts are bent. Basically check everything, and then double-check everything that moves.
Consider the brackets you have holding the gears in place. You may want to add another spacer or two so there’s a little wiggle room. Consider lubricating your gears with white lithium and adding liquid graphite inside the bearings. Also using the low strength 24 tooth gears could potentially reduce friction so maybe try that. Also spread your motors on different fuses on the cortex. This will disperse the power equally and not over heat one fuse.
From looking at the picture, it seems like you may have your spacing too tight between the c channels and the gears. they need to be able to barely move back and forth on the axle to have low friction. Also make sure that all of your axles are completely straight, any axles that are even barely bent will cause a lot of friction at high speeds. Also try graphite to lubricate the axles to reduce friction. Try not to run your flywheels at full motor power to keep the load on them down to prevent stalling and overheating.
Try to space your gear box out a little more. It looks really cramped, those gears need some room in there. Also, try using a different speed on your flywheel. You might still be able to shoot your wanted distance with a much lower speed.
My team has a flywheel similar to yours, but only one wheel. We were experiencing a problem identical to yours, but before i get into how we resolved that issue, first i will address the issue of the PTC.
When that trips and shuts your motor off, you will not always be able to feel the heat on the outside of the motor right away. Your PTC can trip when the outside feels cool to the touch, because the motor inside is actually too hot, but the heat has not transferred to the outside motor.
Now, for the actual problem that we found. We ran our shooter, and we hooked it up in series with a volt meter. We set the volt meter to measure the amount of amps the cortex was drawing from the battery, and at an idle it draws about 4 amps running top speed. When we place a ball in the launcher, the motors get stressed and will spike up to 6.5 Amps. This is way too high for a motor to be able to run at for extended periods of time, they burned out after about four shots, and the motors did not even feel hot to the touch. So basically what i’m saying is that if you can, you need to see what kind of amperage the shooter is drawing, and if it is too high or if it spikes to high, your motors will burn out so fast that the heat wont even have time transfer to the plastic outer casing.
While the shooter was running in series with the volt meter, we tested something. We added grease to the system, reducing friction, and the amperage draw dropped from 4.1 amps to 3.5. We lowered the speed of the motors from 100 to 70 and it dropped done to a much better level of 2.6 Amps, and only spiked up to 4 when we launched a ball (and it still made it full court)
Measuring the amount of amps it draws is a great way to see how much strain is getting put on your system, and it allows you to see if you have improved or made worse your launcher in the end. I hope this helped, and if you do not have the means to measure the amperage draw, at least you understand the concept at hand hopefully (i’m not the greatest at explain sorry).
Noah, bud, be careful when using the flat plates because those tend to flex quite a lot. My shooter had issues with c-channels being bent so I had to force them together using additional structure to keep them straight.
Also, is your shooter plugged into a power expander? I have 4 motors on my shooter and Have them y-cabled together. I had put intake and shooter on the power expander and the drive train on the cortex and I had the same problem. So I directly plugged the shooter motors into the cortex and now I don’t have stalling issues.