More Wheels?

My current launcher is a 1 wheeled-launcher but with two 5" wheels put together. I have to wait 5 seconds before each launch. Would adding more wheels increase my fire rate?

My first launcher used the same two 5" wheels at first, and we had the same problem. but moving to a single 5" wheel halved the weight on the motors, and thus the time to spin back up to speed. But it wasn’t until we moved to a 4" wheel that we got down to a ball per second. On the other hand, More wheels won’t slow down as much when a ball goes through, but that was not my experience.

Search the forums, there’s lots of threads on this. Pretty much, more wheels = more mass = more momentum = less speed loss between shots. On the other hand, a lighter flywheel is quicker to spin up at the beginning.

When we have a single wheel spinning, it becomes very inconsistent.

We’ve had lots of success with a single very heavy flywheel (using sprockets, tank treads, and nylocks). Once we reduced friction enough is became very accurate and took a long time to slow down, when it does start losing speed our velocity control kicks in. So far in recent tests we got about 2 balls per second. It does take 4.3 seconds to get up to speed though.
I think I’ve seen a launcher with 2 5" wheels that worked really well, maybe its friction?

I’ve got a 2 5 inch wheels on my flywheel and once I get rid of some friction I think I can get a 2 or 3 second reload time with awesome accuracy. I have a 25:1 gear ratio and 4 regular motors, it is a single flywheel that is shaped like o) where the bottom of the closing parentheses is hitting the ground. Should I go to one 5 inch wheel?

We have a 35:1 ratio on ours and our launcher looks exactly like that " o)" parentheses thing, the balls are pulled up using the flywheel. It seems to work well with the 4" sprocket wheels. I guess the issue with moving to a 5" wheel is having to change the compression, more annoying then hard I suppose.

With 5 inch wheels and 35:1 gear ratio your going to over shoot a lot (hopefully). you should just keep it and get a faster wind up

Indeed, we will be keeping the 4 inch wheels for that reason. (Also bigger wheels would apparently make us illegal without further redesigns.) We overshoot at 85 power, so it gives us some room the velocity control. I wonder what 5" wheels would do though.

I also have a 35:1 gear ratio on my flywheel, but I am using a 5" wheel. The flywheel currently coasts at about 55-65 power depending on the battery. It has really fast speed up time and fire rate as well.

Maybe if you’re firing full court with 55-65 power, you should use a lower ratio. It might just put less stress on your motors, and you might get an even higher firing rate.

Redoing this. I should read the team numbers before I reply to a post.

What’s your currant fire rate? I’m afraid I don’t know ours exactly, we can’t feed it fast enough. (Note that’s not because its infinity fast, its just because its hard to load without an intake.)

5 hours ago, I took off 1 wheel. For some reason, switching the high strength gears to normal gears, made the flywheel slower. It takes us two seconds to start up our flywheel now. 25:1 gear ratio run by 4 motors cannot shoot across the field now. Any ideas of how to make it fast without changing gears or wheels. The speed is at 127.

This is definitely friction. Check for bent metal and axles, as well as over tightened or overspaced axles. I had this issue with mine and it had six motors on, but the whole launcher was bent. New metal and a new axle made it break the net it flew so hard. Reduce the spacing by about a washers distance so there is some flop, make sure all the holes are lined up, and make sure the teeth have no bevels, burrs, or bends in the teeth. Getting a flywheel right is hard, but very rewarding.

Okay thanks.

Impressive, how many motors are you using? Have you thought of increasing speed to 127 in between shots then back down to 55-65 to get a faster fire rate?

just make it one 5 inch wheel that should put half as much stress on the motors so therefore should spin up faster.

I have 4 motors powering the flywheel. It currently shoots just under 1 ball per second with a PID program I wrote a few days ago, and am hoping to get it down to less than 1.5 balls per second when I get more time to tune the program.

Will that increase fire rate?

If anyone’s curious as to the actual physics of the flywheel, and why it matters, here’s a useful thread. For the answer to this question, see the graph in the last post, as well as the accompanying explanation (note: the graph’s y-axis is actually recovery time, so lower is better). If you’re confused about the physics of it, then just ignore that part. All you really need to know is explained under the graph. The rest is there for fun and engineering notebooks, if you can understand it well enough to explain it to judges. Thanks to @technik3k, who led that particular discussion, all 100-something posts in it.

Actually, it will either slightly decrease the rate of fire or do nothing to the fire rate. The only improvement you might see is in the spin up time of the flywheel, as well as current drawn by the motors during flywheel acceleration (both will decrease, neither is particularly great).