I’m looking to build a compact ball and/or puck throwing machine for the kids I coach, and need some design ideas.
When I was a kid, my dad took an electric lawnmower motor, jerry-rigged a pulley-drive system to a couple of lawnmower wheels, and built a 2 foot x 2 foot x 3 foot box around it: made for a great, cheap, ball-shooting machine. Used to for hockey and baseball practice. The neighbourhood kids and I loved it. (hmmm… I remember he made me promise to later do similar stuff for my kids… for now, that’s these boys and girls.)
I could do something similar, but where I’m coaching (out on the ice, and at a riverside park) there’s power supply issues. I can’t be sure of finding an electrical outlet in the park, and don’t want to string cords around the rink. Nor do I want a gas-powered motor: 1. too heavy to move around easily, 2. those fumes aren’t great indoors.
So, I’m looking for something that can throw a ball (tennis or hockey) or puck with reasonable accuracy and force, but will be manually powered. I’ve been playing around with some crank designs using bicycle chain drives, but I’m not yet happy with what I’ve come up with. My old man back home’s working on ideas that involve a stripped down bike that you’d sit on, but I think that’d be too bulky. I’d like to keep the bulk and weight of this thing to a minimum. Ideally it’d fit in the back of a van (along with many bags of gear), and could be operated by kid power.
Anyone got bright ideas? Places to look?
How many pucks must it release and how often? Must it be fully automatic loading or will manual do?
Say 2 dozen shots. At a rate of one every 3 ~ 5 seconds. (Any faster gets silly, and a little dangerous.)
At that rate, it wouldn’t have to be automatic.
The one I had as a kid didn’t even shoot pucks, and if this one doesn’t, I won’t worry about it too much. On ice, when pucks get wet, they stick together, and so far a solution to that issue has entirely eluded me. (Toweling off ever puck before feeding it in isn’t realistic.)
If it’s handling only balls, a ramp delivery system could send out balls fairly automatically without problem.
My dad set up a ramp with a spring-loaded door. A string ran from it to my goal post. If I was playing alone, I could stand in the net and give the string a tug with my goal stick, and a couple seconds later a ball would fire. But if this is manually driven, nothing like that will be necessary (or possible).
I’m thinking a car’s starter motor hooked up to a car battery and the pulley drive system that your dad had before. It could be triggered by a switch like you had before as well. I think you could get a few dozen throws out of it before the battery got weak. It wouldn’t take too much space and you could buy a charger for it that you plug in a few hours before class. It would take a lot of fiddling to get the speed and gearing/ pulleys right, though. The guys in my shop class made shop stools that zoomed around on starter motors. Pretty cool at the time and more range than you think.
Oh, sorry, you said manually powered. I’m not so sure about it being bike part made. I think you would need some sort of flywheel that would have to get up to the correct speed before everything could generate enough force to chuck the puck properly. if you want, I have an old exercise bike you can have. I just don’t have the energy to pack it downstairs and leave it on the street. Maybe the lightweightish “wheel” on it could be modified to be heavier and somehow squeeze the pucks out at the right velocity. The bike operator could manually feed while pedaling.
Would it be dangerous to spray the pucks with wd-40, or spray olive oil or something like that? I’m not a hockey guy so I don’t know.
I don’t think it’d be dangerous to spray the pucks, but it’d make a mess of the kids’ gear: oil on (expensive) leather; I think I’d catch some grief from the parents.
Your exercise bike might be useful. I had been thinking of using a few gears to get the proper speed/force, but an exercise bike… hmmm…
I briefly considered a car battery driven contraption, but weekend practices (different ages/ classes) run around four hours. When kids aren’t on deck, I’d like them to be able to goof around (practice). Plus, there’s a dad’s team, and I’ve no doubt that they’d also get a kick out of it. I figure this thing would easily burn through several hundred shots over those four hours.