Bucket Indexer tips

[Brandon_L]

Heyoh All-

Today was quite an experiance for the team, we've got a bucket indexer/hopper on the back end of our arm where all the frisbees stack then get pushed via pneumatics into our shooter. We had rediculous problems with jamming all day and it isn't looking too good. We were just wondering if anyone else with bucket indexers would like to toss some tips around.

Specific issues were having:
The frisbees seem to enter the bucket alright - usually. sometimes they enter at a weird angle I guess from our conveyor and don't really enter it right until the next frisbee comes in. Probably nothing you guys can help with on this without seeing the specific setup but worth a shot.

When the frisbees do stack, we have an issue where sometimes the frisbee above the bottom frisbee will not sit right, because the bottom frisbee will be slightly leaving the bucket causing our pusher to push the frisbee above the bottom frisbee into the bucket wall instead of pushing the bottom frisbee into the shooter. (because the 2nd frisbee will be leaning at a slight angle from not sitting directly on top of the bottom frisbee)

Overall shape of the bucket, we actually switched to curved sheet metal and we were bucketwrangling with this all day. Everytime we fix one issue an old one pops up, then we fix that and the other issue pops back up.

So yeah, just looking for some general bucket tips. Pitch in anything ya got.

[Aroki]

My guess is that you're having one (or more) of these problems
1. The backstroke of the piston is catching on the frisbee above, causing it to not load right
2. The bucket is slightly to big allowing the frisbees to load incorrectly
3. The slot cut for the frisbee to leave the bucket is to small

If you have time, switching from a piston to a motor with a cam-shaped arm would probably best fix you problems. For our one we used a KOP window motor with the plastic hub for it, and attached a 1/4in thick plexiglass cam-shaped arm. Having a motor and cam allows for some degree of error (the circular motion and rounded shape of the arm let it roll if it isn't lined up perfectly right instead of driving it into the wall.)

If you are short on time, I'd keep the piston but make the head that strikes the disc thinner and is smooth on the top so it doesn't hit the second frisbee (not sure if this is your problem). Also if you had a U-shaped head so the piston aligned the frisbee when it fired. You'll also want to make your piston fire relatively slowly, so the head has time to align it. Also if your design allows it, increasing the exit slot for the frisbee may help.

Either way checking to make sure your bucket stacks the discs nicely will probably make the biggest difference, a slight funnel (like a 1/2in from the top diameter to the bottom diameter) can help with this.

*Please note that much of the above advice (especially regarding the piston) is untested speculation on my part, and may be completely wrong. Also it's 12:30am my time and I'm sick so I'm probably not thinking clearly

[Steven Donow]

Brandon

We had a similar issue with our bottom discs not sitting right, and we made some cuts to it and now everything sits just about perfectly. You're more than welcome to stop by our pit tomorrow to take a look, and hopefully you can get it all solved out.

Originally Posted by stevend1994

Brandon

We had a similar issue with our bottom discs not sitting right, and we made some cuts to it and now everything sits just about perfectly. You're more than welcome to stop by our pit tomorrow to take a look, and hopefully you can get it all solved out.

Would you happen to have pictures of this for those of us who can't see it irl?

[waialua359]

We had exactly the same problems you described and spent two weeks of build season trying all kinds of methods to fix the jamming.
It came down to a simple thing for us....we cut a strip of 1/16" lexan and cut it like a comb. It is duct taped to our bucket where the frisbees leave.

It has enough force to hold it in place and flexible enough to have a piston push it through. The teeth will eventually break, but making 20 spares is easy.

[jblay]

Originally Posted by waialua359

We had exactly the same problems you described and spent two weeks of build season trying all kinds of methods to fix the jamming.
It came down to a simple thing for us....we cut a strip of 1/16" lexan and cut it like a comb. It is duct taped to our bucket where the frisbees leave.

It has enough force to hold it in place and flexible enough to have a piston push it through. The teeth will eventually break, but making 20 spares is easy.

We did something similar to this at NYC. We took a piece of flexible plastic that wasn't lexan and used it to essentially shim out our bucket to fit the frisbee better and prevent the discs from riding up onto each other. We are still having a few jamming issues and withheld our hopper to work on it so I'll post anything we come up with, hopefully this thread stays alive because I know this was a problem for a ton of teams at NYC.

[Ultimatum]

You might be having the same problem we were. In driving around a lot, the bottom frisbee can occasionally move forward, causing the second frisbee to fall back, and thus making your piston hit the second frisbee instead of the one on top. I would recommend some sort of grip tape on the bottom of your hopper, so that the frisbee on the bottom of the stack has a hard time moving forward except with your piston hitting it. We were not able to fire in teleop in a large number of our matches, and after one piece of grip tape we shot fine, and put up 60 points of frisbees in teleop.

Unfortunately I don't have any pictures right now of our setup. But if your problem is the bottom frisbee sliding forward, grip tape works wonders.

[Brandon_L]

Thanks for all the replys guys

Were going to try to pull the frisbee from the bottom lip instead of push it from the back. Theory being that the disks sitting improperly above would have no effect on this type of system, as long as the disk doesn't slide out of the bucket early by itself. We currently have a few strips of tape meaure we cut and taped to the inside of the bucket that act as our gate, and thats been working.

Will update.

[THE DYNAMO]

we discovered an easy solution to all of this: put a bolt or other kind of 'nub' on the inside of the bucket near the bottom. the 2nd frisbee will rest on this bolt and the bottom frisbee until the botomm one is ejected, at which point it will fall down and the cycle will repeat.