Have any of you come up with a fast and reliable way to sort a hopper full of balls into a single file feed for your shooter?
We have experimented with what the boiler mechanism is using but in the confined space of what we have for a hopper we are not having much success getting more than 2 balls/sec reliably. Spin the sorter to fast and balls just bounce around. Somtimes the balls bind against each other in the strangest of places and wreak havoc.
Thanks
I am sure some teams have, but I think you will be limited in how much info many teams want to share, this type of device/design will be a big differentiator.
I would recommend looking at some 2006 robots. 254 and 1114 (and their associated twins/triplets) had large hoppers that ran well without jamming. 217 also had a memorable system for sorting balls and feeding them individually, I heard it described as both a revolver, and a gumball machine, depending on your frame of reference.
thanks
if you look at hoppers of professional paintball guns that might be a good idea
Take a look at some of the Ri3D teams, specifically the Greenhorns, and how they did it. Many had to solve hte same problem.
I’ll be honest, we’re in a prototyping stage of 2 shooters, and a hopper that is a pyramid in the center, causing balls to go either right or left, with agitators on both so we don’t get a jam. Lowers our capacity a bit, but the speed might make for it.
Prototype! Always prototype, regardless how crazy!
I really think the best way to do this is to not have to sort your hopper into a single feed. In 2009, the last volume scoring game, lots of teams trapped themselves into this paradigm early on and found their scoring potential harshly limited.
The hoppers have a blender in them use a mini cim or bag motor to attach a verticle shaft and attach pieces of Lexan or metal and you have yourself a jam free hopper
This is a good approach to start with, but this is absolutely not the kind of thing you can be assured will be “jam-free” until you’ve thoroughly prototyped the exact geometry you will use on the competition robot.
Our plan is to start prototyping this week once we have our drive base done!
got an vids of this?
I’m happy for your enthusiasm, but before you’ve tested something, please don’t make sweeping statements that suggest something absolutely works. People may read your comment and assume a level of experience or rigor that isn’t there.
Many of those teams in 2009 did a sort of spray shoot that didn’t need to go very high in the air if at all. This is a completely different size and material game piece that needs quite a bit of accuracy to get into the goal. Introducing them in a reliable and consistent manner is going to improve accuracy greatly.
Compare the relative size of the goal and the game pieces in 2009 and 2017. It’s much closer than you think!
And, many teams did shoot high in the air, they just converted their shooters to shoot down so that the ball landed in the goal sooner after the shot was taken. Accurate repeatable arc shots with multiple ball wide shooters were clearly demonstrated, just suboptimal for that game.
Don’t knock it before you prototype it. If your shooter “wheels” and/or backboard are a uniform thickness / speed / etc, isn’t the shot consistent across the shooter width?
Shhhhhhh. 
We have been working on a design based off of a gumball machine. We are doing a 14" disk with 3 5" holes along the perimeter and rotating that at the bottom of the hopper. It feeds the ball into a channel under the hoper very cleanly and in a nice cadence. This is not a trivial issue. It’s much harder in practice than in your head. We have learned that the hard way
Do you mind providing an example or two of teams that did NOT have to sort their hopper into a single feed and were successful? I’m just not quite sure if I understand your point entirely.
We are using the same concept as a paintball power hopper. Using a small motor with a rotor mechanism to keep pushing the balls around. It works great in my paintball hopper, we’ll see if it works for this project. We’re prototyping this with a small motor turning a lightweight rotor (3D Printed). Who knows. I really am hoping my team doesn’t go obsessive/compulsive about this part of the game. I’d much rather spend time placing gears and hanging than wasting a load of time working on a shooter that shoots a ton load of balls for mediocre scores. Thank goodness the chassis, electricals, and gear delivery system is finished.
:ahh:
67, 971, and 111 are solid examples to start with.
unfortunately there is little match video, but our (1318) design in 2009 was 2.5 (ish) balls wide from intake to outflow. We won a regional and seeded #2 on Galileo.
I think his point was that once you commit to a singe stream shooter, you commit to a bottleneck mechanism, and if you skip the single width shooter, you may never need a bottleneck.
Part of the challenge is that most of these robots converted themselves into short-range dumpers before too long, since it was very easy for this style of robot to do that.
67 was a two ball wide shooter, but balls that came up in the middle shot just fine.
228 was not the greatest robot, but I’m very familiar with that example - a 3 inch diameter drum across the entire width shooter with a lexan hood allowed for those kind of shots.
Dumpers that had more of an active “shot” out rather than a slower puke could be argued to be this kind of shooter - 47’s rebuild, 254 / 968, etc. come to mind.
100’s shooter is pretty much perfect for this, but their hopper did divide into two single file channels (I’m not sure that was necessary, but that’s how it was).
The key design details tend to be the use of a roller of uniform diameter rather than spaced wheels, and the use of a curved backboard made from a single piece of plastic rather than separate “rails” used on some hooded shooters.