How to add range

My team is prototyping a hooded shooter, however we can’t get the range we want as we keep landing about 5 ft short. We have tried larger wheels, increasing compression, and using a 1:1 versaplanetary instead of a 4:1, and we are about to try adding a second motor. Is there any other ways to increase the reange of our shooter.

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Need more info about your motor, compression, wheel type etc to be able to comment.

You could add more mass to the flywheel so that the system has more inertia proportional to your projectile. Adding more motor/motor power should also work though.

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Additionally how far is it going? If your shooting 300 feet and your 5 feet short then not much we can do. But if your only shooting 5 feet now and are 5 feet short we can help a lot.

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At the moment we are using 2 6 inch smooth grip wheels powered by a 1:1 versaplanetary with a 775pro and an inch of compression.
We are trying to go 35ish feet and can hit our target from about 30.

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If you add a motor and gear them at the same speed you will double your torque. This can decrease how much the flywheel slows down during the shot and drastically increase range. In the end all that matters is how fast the ball and the wheel are going when the ball exits the shooter.

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There is so much going on in a shooter system that we can’t just use this information to diagnose your mechanism.

Some various factors:

  1. All other things equal (and this is a lot of things!), a two axle shooter will shoot twice as fast as a one wheel shooter (rolling vs tossing)
  2. If you are not noticing any increase in length as you change the speed of the wheel (gearing), your wheel may be slipping on the ball. This is one area where high speed video would help dramatically. Consider a different wheel, adding traction tape to the wheels, etc.
  3. Sometimes you can also notice improvement by adding grip to the backplate, but this is usually less about range and more about consistency.
  4. If your system doesn’t have enough inertia, your wheel may be slowed down too much when it is loaded by the ball.

Edit: From your most recent comment I would say you are likely spinning the wheel faster than is appropriate. If it is really 1:1 you are spinning at well over 10,000 RPM? Speed is not a 1:1 correlation with distance here. Go back to the 4:1 gearing for now (maybe 3:1) and try other factors, especially since you said the distance didn’t noticeably improve when you removed the gearing.

For a single shot the number of motors isn’t the absolute most important thing as adding motors is mostly about recovery time really. So I wouldn’t change the motor yet if you are still working purely on range. Inertia is far more important to maintaining speed in the very small amount of time the ball is touching the shooter wheel.

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On Tuesday our shooter prototype (we did a 1:1 775pro as well) shot a single power cell insanely far (at least 30 feet, maybe more). We had a slight mechanical malfunction related to the prototype itself, but once we’re in tonight I’ll try and get some specs/video on what is working for us, as well as some measurements hopefully to compare to what you’ve got.

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Add ~1” more compression, made a massive difference for us

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Moving from 1 inch to 3 inches of compression added ~7 feet to our somewhat-unscientific testing. This was witnessed on both a hooded flywheel and a 2-horizontal wheel shooter.

Would 250 grit sandpaper be an effective grip material for the wheel?

That might be too rough and could damage the balls if it were to slip for whatever reason. I’d suggest traction/grip tape instead. 250 grit is small, but it can cause damage to the ball at high speeds

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We shot a ball and the ball was fine.

I would still be cautious, but thats just me.

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I think you would have trouble passing inspection using a traction material that is specifically designed for the purpose of damaging materials. Consider some other kind of grip tape; there’s many different kinds out there that could work.

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Our team has gone through 7 motors already

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In addition to the other suggestions here, at some point if you tune everything else right, you’ll just have to add more wheel speed.

That being said, if you’re running a 775pro 1:1, you’re nowhere near needing more wheel speed. That’s ~490ft/sec (~330mph) surface velocity! In fact, I would recommend going down to 2:1 if you can make that happen. You’re likely slowing the motors WAY down as soon as the ball contacts the wheel, so you’d be much better off trading off speed and getting more torque to maintain wheel speed.

Also, as other people have mentioned, MORE COMPRESSION. I always tell my students that a shooter needs “way more compression than you think it does”. Figure out how much compression you think it needs and then compress it another inch.

Fair warning, if you increase compression and don’t gear down the motor, you’ll probably start burning out 775pros.

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I haven’t heard this term before. Can you elaborate? Or point me to an example?

The projectile passes between two sets of wheels.

facepalm
Sorry. I’ve only had one cup of coffee…clearly cutting back my caffeine was a bad idea…

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