I’m not sure what motor to use for a ball shooter. We already have the fisher price motors reserved for a different function. I thought about using a CIM motor, but I wasn’t sure how to mount it or what gearbox to use. Any help would be great thanks. Pics would be nice to if you have link to some of your old robots.
CIM will work great, two even better. Try a six inch wheel direct drive. If you tie the two together with gears or belts it will stablize the shooting force. When the ball hits the two spining wheels it will be gone…
ok great, thanks for that. So if I just connect the wheel directly to the motor without any chains, and I only use one motor, do you think that would be ok to. I don’t really need it to go that far.
a direct drive from the CIM motor should be sufficient.
One may not have enough power, it may stall out the motor or slow it down unless you are spinning two wheels. But two will do a great job. 2006 we used one large cim which is about 2500 rpms (35ft no problem) and it did the job, the small CIM is about 5300 rpm (less power & more speed) & with two you will have the power and speed.
With these lighter balls one may do it.
We are using two CIM’S this year and the 6 in skyway wheels. Remember you can only shoot as far as your camera can see.
Just a suggestion, it seems you are all assuming that he is using the motor for a softball style of shooter. If he is using it in a different way, then the advice you gave him will be of little help.
We were able to fire poof balls the maximum permissable distance in 2006 using an FP geared 5:1 using a banebots planetary gearbox and a single 8" wheel. So far we have found that an 8" wheel spinning at about 1000-1500 rpm puts a nice bit of velocity (and backspin) on the orbit ball. The downside was that the 2006 shooter would slow down after two shots and would take a second or two to come back up to full speed.
Jason
We’re coming to similar findings as well. Our prototype (here) spins an 8" wheel at 1300 rpm and spits an orbit ball a good distance with a ton of backspin. The time it takes to spin back up looks short enough to possibly shoot 3 or 4 balls a second. This is with about a 4:1 reduction off of a single CIM motor.
I don’t see the need to shoot the ball any further than 10 feet or so, but I may be wrong (it’s happened before…).
I reccomend rollers not wheels, or at least multiple wheels next to each other. 6" diameter wheels opposite each other tend to catch the ball in the holes which slows it down significantly.
In 2006 we used 2 of the CIM motors directly driven into a 6" Skyway wheel (similar to this year’s wheels, but with a much more grippy surface on them.)
They threw the Poof balls very far that year at a nice speed, but your main factor with shooting this year’s balls will be how the shooter wheel or other surface will interact with the “not-so-solid” ball.
Should be interesting seeing the shooters that teams come up with this year.
I know I want to see some in action!
I’ll try to get a nice up-close pic of our shooter mechanism from 2006, as all of the pics I’ve located so far of that bot are not close-ups.
Oh oh. What do you think the chances are of that rule coming back in a Team Update?
IMO a single CIM motor will have plenty of power for what you’re doing. A CIM is roughly as powerful as 2 FischerPrices, and it is more resilient to stall/heavy usage. If you don’t need any reduction, just direct drive the CIM. A rather small transmission for the CIM that can provide decent reduction would be the DeWalt planetary transmission (see CD Whitepapers, All About Dewalts, if I recall the name properly)
Depending on how your shooter works, a single RS545 (Banebots) might also be enough, geared properly. Banebots sells 4:1, 5:1, 16:1, 20:1, 25:1 (?) 36mm transmissions for this motor. Be careful, however, since these motors do not like being stalled and will heat up rather quickly if they’re forced to work hard. They will die on you if overworked.
We’re looking into using the toothed belt for the small amount of speed reduction we think we want for a CIM powered shooter. Or possibly even a V belt, pulleys and belts available at your local hardware store.
Elgin: see the ball cannon thread
for videos
Is there a limit on cim motors this year?
I have a hunch that it’s four like last year (and because I read the rules)…
So I’m guessing that teams using cim motor for a shooter/cannon will only be using a total of two cim motors for their drive train
Fischer Price or CIMs are really your best bet. We’ve been prototyping all week in different configurations using last year’s kit wheels. We were able to get a ball shooting beyond 15 feet, however, we don’t really think we’ll be going for that kind of distance in our final design.
As others have said, a direct drive from the small CIM would do just fine for shooting 5 - 10 feet. I would advise everyone to try out different materials as we’ve found that some materials react much better with the ball than others.
I always like the design MARS 1523? used for their shooter in 2006. It would work great with these balls I think. A design like this would allow you to use a less powerful slower spinning motor like a bane bot.
Thanks for the kind words about our 2006 robot design, Ball-istic.
MARS, Team 1523, accomplished that with a one-way bearing, a little bit of surgical tube, and a window motor. It wasn’t a winning design of the season, but it was gentle on the game pieces and worked very well for us. It would even throw balloons without breaking them!
I’m not sure we need that kind of power in this year’s game. 30 ft into the upper goal is a little too much. That center post on the trailer is going to prevent many a ball from staying in the trailer.
We just made a test stand using two CIM motors direct drive with 6 in Skyway wheels. They were set at about 35 degrees (low ceiling) and were 4 ft off of the ground and we were able to land a ball in a trailer located 13 ft away. These were mounted horizontal and our final design will be vertical. I did notice that if a hole portion of the ball happened to hid the spinning wheels the distance was greatly reduced. We will be using four wheels to contact the ball to reduce this problem and may use 8 inch wheels instead of 6 inch. The CIM motors seemed to come back up to speed very quick with out gear reduction and a well balanced wheel.