Hopper Design
 

After last weeks TCNJ FRC District Competition. a few other team member and I had a though about changing our hopper design and adding a new human player feeder. and we came up with a design of a square hopper because it would have less areas of contact with a frisbee than a circle but still does its job of holding the frisbees in. It also solves many other problems we have been having with a circle hopper. How do you guys think about this? :confused:

Re: Hopper Design
 

Just go to Home Depot/Lowe's and buy a bucket like everyone else is. It's a solid solution that is cheap and easy. Also if you cut it wrong it just costs $5 to get a new one.

Re: Hopper Design
 

What problems have you had with the circular hopper?

Re: Hopper Design
 

We switched from a square hopper to a circular hopper after running into a lot of issues with frisbees not stacking particularly well in the square hopper and jamming the feeder. Square wasn't the way to go for us. I think the more sides you have keeping it centered the better, and a circle has infinite sides.
Drawbacks: the circular hopper is tempermental to any pinching, so you have to be careful to keep it round with any attachments or fastening.

Re: Hopper Design
 

Get a five gallon bucket from Lowe's/Home Depot. (I recommend getting several...so you don't hesitate to experiment/screw up...they cost us less than $3 each.) The buckets are great because they taper only slightly, almost imperceptably from the top to the bottom. Put a disc into the top....and it stops about 6 inches from the top. Draw a circle around the bucket where the disc stopped. Slice the bucket at this line or just above it, to establish the bottom edge of the hopper. (We used a Dremel with a metal disc cutter or sharp box cutter to cut the bucket.)

The slight taper in the bucket is nearly the perfect shape to keep the discs stacked, yet not nested so much that they do not separate or jam, and not so tight that they jam in the cylinder as they drop.

From there, experiment with an exit slot in the bottom (needs to be 1.4 inches high), a means to transition from the hopper to the chamber/shooter barrel (we use a pneumatic piston, without any clevis attached), and a means to feed it. For feeding, we cut about 225 degrees around the uphill and top edge of the bucket, cutting down about 1" from the top. With the sloped cover to the shooter, we have a good backstop for discs to hit, and drop into the hopper.

Dozens of examples are shown in the reveal videos. Your own geometry will vary, depending on you shooter configuration and space available on the robot.

We have been using a circular hopper made out of a 6 gallon bucket we found. We went through our district competition with one. And it had issues of the frisbee getting stuck and not falling in straight. So I was wondering if a square would be better.

Re: Hopper Design
 

Use a 5 gallon bucket from home depot / ace.

We prototyped square and it was a mess. Two days later we were back at a bucket. Rember that you can't use the whole bucket, only the top 6 or 7 inches is wide enough to pass a frisbee without binding.

Re: Hopper Design
 

4343 and 1114 went the 'dont stack the frisbees' route, which seems to be less jam-prone, provided you only index a single frisbee at a time into the pre-launch position of the shooter.

4343's design made human loading quick, and prevented the frisbees from jamming up their hopper by falling in sideways as is possible on many robots I've seen.

Alright. thanks for the advice guys :)

Re: Hopper Design
 

They only fell out the top :rolleyes:

Re: Hopper Design
 

Well, yeah. The indexer motor needed to be about 3" further down the hopper, and that problem would have been entirely alleviated.

Re: Hopper Design
 

we have a custom made sort of square shaped hopper, with "stairs" that we built out of polycarb. here's a video where u can see how it works and stacks Frisbees... altho i'm not sure i'm supposed to be sharing it :P

http://www.youtube.com/watch?feature...&v=f_v3UbFI_6U

Re: Hopper Design
 

We had a square hopper, but in order for things to work perfectly, it became very complicated. It also became very finicky, working one day and not the next. We're currently switching to a round hopper.
Good luck with what your trying!

Re: Hopper Design
 

We've been using a square hopper and it's been working pretty well for us--we tried the bucket method briefly, but decided it wasn't really worth it for what we were trying to do. However, we do collect and shoot from the bottom (we built it for floor collection, but after Lone Star we decided that it might be better to human feed through the bottom slot, and it's working quite well for us) and it's powered, which helps make collection quick and reliable.

What are your dimensions for ur hopper?