I know there are other threads out there about this, but I couldn’t find a clear answer(Chances are I was just being dumb). For 60A fairlane wheels, what is their max safe rpm, and does safety wire increase this or does it act as a safety feature in the event the wheels delaminate? Are there any wheels that have a higher safe rpm? What is the highest rpm you are comfortable running your shooter at, and why?
You might be interested in some of these threads:
Not specific to 60A fairlanes, but general flywheel safety and safety wire.
Thank you. From what I’ve seen, it is not safe to run a fairlane wheel at more than ±9500 rpm. Our team wants to safely run a flywheel at 20000 rpm. Is there any safe way to do this?
This sounds way above what a shooter would need to go (most hit 3-10k accounting for PID), and would be wildly unsafe to do on the field.
Is there a reason you want to go that high? Chances are a better solution can be found that doesnt risk blowing out the whole shooter.
We want to be able to shoot from across the field somewhat accurately.
Have you run a trajectory analysis that says you need that flywheel speed? We ran some fairly simple trajectory analyses early on to set our shooter speed ratio and those calculations turned out to be fairly close. Although we were not looking at shooting from across the field, we were looking at some fairly long shooting capabilities and the fleywheel speeds we needed were not nearly as high as what you are proposing.
Also, keep in mind that if you are shooting from the loading station initiation line, you will need a high looping shot to get over the shield generator structure.
The speed of your shooter wheel does not have a large effect on your accuracy. The only way RPM increases accuracy is in the increase of KE that comes with an increase in RPM, however there is a threshold at which your shooter does not need more KE, and plenty of teams have high KE shooters with much lower RPMs. If you really want to increase accuracy a bigger diameter wheel can help, but realistically you do not need to go over 10000RPM on your shooter. Our shooter is at about 5000 RPM and we can shoot a ball from our feeder station over the opposing driver station so shooter design has a much greater effect on power than RPM.
Thank you. We weren’t planning on shooting directly from there, we were going to use the line of sight a couple of feet to the side. With the testing we did, we had our flywheel spinning at around 5000 rpm and we had difficulty shooting from a couple meters from the goal, though that is probably just because of a badly designed shooter. What would be the maximum rpm you would feel comfortable shooting with?
Alright, thank you!
What angle was the shooter at? at that distance, 5k is a bit overkill for most applications with a normal release angle.
This was just during testing for our shooter, I don’t remember the angle but I’m guessing that the issue was with how little compression we had.
Shooting that far with such a small flywheel and various wear conditions on power cells isn’t going to work, regardless of how fast you spin it. If you want a long range shooter, you need to focus not on how fast you spin, but rather on how to eliminate the variance created by wear and tear on power cells.
I asked in the thread about flywheel safety and one of the mentors from citrus responded by saying somewhere around 5-6k. Don’t quote me on that. Look through the thread. It has a lot of useful information.
Alright, thank you. Do you know if there are any other flywheel materials that could handle maybe 8000-9000 rpm, or where I could find information on something like that?
Our robot never went past 7000 rpm, and at 7000 rpm we hit a shot (in our space) from across the field.
Ok, if you would be comfortable with sharing how much compression did you have on balls going through your shooter?
I’m not an expert but if you really want a super high RPM wheel for your shooter, your best bet is to turn one using aluminum tubing or a solid chunk of aluminum. And then adding some sort of grip spray to the aluminum. You’d have to experiment with different types of grippyness and what not
Our compression was 1.5" according to our mech lead.
Alright thank you! We will look into having a less obnoxiously dangerous design for our shooter.
We are running a flywheel on 4 inch hiGrip wheels, running at ~10k rpm on the high end (36:18 belt off NEOs). We have had no problems so far shooting from behind the control panel in the little testing time we had. From our tests compression on the ball has a much larger effect on how accurate our shots were. For our tests after week 1 we only even ran the flywheel up to 6k for close shots from inside the trench.