PiGraham
Posts: 4022
Joined: Fri Jun 07, 2013 12:37 pm
Location: Waterlooville

Re: First time poster! Multiple questions

Sun May 29, 2016 9:24 am

Cancelor wrote:Spot on video, but servos are so slow. If a solenoid could be used to 'fire' them in the right direction it could be so much faster.

I feel a whole new competition coming out of this. :P
Servos are easy to control.
I can see a continuous feed that carries beads past the colour sensor and past a set of ejetors that could be solenoids. It would be much faster, but rather more complex to build and control.

Competition?

"The Perler Challenge"?
Assemble a specified picture from perler beads given a container of mixed beads. Fastest wins, with time penalties for each bead in error in the picture.

epoch1970
Posts: 5424
Joined: Thu May 05, 2016 9:33 am
Location: Paris, France

Re: First time poster! Multiple questions

Sun May 29, 2016 10:05 am

Thanks for the physical description of the beads. Given the hole in the middle and their shape, is it possible to assume that in a steady flow of air the beads would align to show one of their hollow faces in the direction of the stream?
I am fascinated by this thing. (and I hope the OP is still there...)
"S'il n'y a pas de solution, c'est qu'il n'y a pas de problème." Les Shadoks, J. Rouxel

PiGraham
Posts: 4022
Joined: Fri Jun 07, 2013 12:37 pm
Location: Waterlooville

Re: First time poster! Multiple questions

Sun May 29, 2016 10:39 am

epoch1970 wrote:Thanks for the physical description of the beads. Given the hole in the middle and their shape, is it possible to assume that in a steady flow of air the beads would align to show one of their hollow faces in the direction of the stream?
I am fascinated by this thing. (and I hope the OP is still there...)
I think you'd have to try it, but I suspect the beads would tumble rather than align.

hanshjort
Posts: 1
Joined: Mon Mar 20, 2017 4:47 pm

Re: First time poster! Multiple questions

Mon Mar 20, 2017 4:51 pm

When I read 'competition' on the first page, I was really keen on seeing what people had come up with, but I guess this is a hard project to build. I'm also trying. Same issue as everyone else, how to get the beads to the color sensor in a safe and fast way. A funnel does not work, the beads jams up and things fall apart..

321a
Posts: 56
Joined: Fri Mar 17, 2017 11:07 pm

Re: First time poster! Multiple questions

Mon Mar 20, 2017 9:01 pm

Personally, I'd look for a kitchen funnel to act as a gravity feed hopper, then have a plastic tube which fits on the narrow part of the funnel/hopper which gets the beads into an individual line using gravity. Big enough in diameter so they dont block up but small enough sort them. It might also pay to have this bit vibrate to prevent any beads from jamming up as gravity takes them down the tube which could be flexible so that the end can then be married upto a switching mechanism which stops the beads from falling out.

This switching mechanism could be a couple of things, a simple rotating disc with holes in that one bead can fall through/into* at a time, or maybe a solenoid/piston which controls a flap that lets one bead out at a time. The latter I think could jam more often though.

*As the disc rotates underneath the disc could be another flat surface to stop the bead from the hopper falling through. As the disc rotates, you could have another mechanism which then does the sorting, moving tubes for different colours into position so that as the disc rotates the bead can fall through into one of the tubes moved into position for different bead colours.
The identification can be done by a camera looking at the bead as it rotates around the disc.
As ambient light ie daylight clouds passing in front of the sun on a summers day can affect the colour the camera would see, you could need to enclose the disc & camera into a box of sorts with a lamp inside to keep the lighting consistent. The for the software just position the camera so that it can see the bead, and then onscreen divide the camera feed into lots of small grids. Select the grids you want to watch ie where the bead comes into view, and then look for an avg colour for each of those grids. Set tolerances for a range of a each colour to allow for differences in dye strength when the bead is made and mixed. When a colour range is recognised, have some more software control the positioning of the tube the bead will fall into.
That should handle the overall operation of bead sorting, but variations of it could be used for anything really, sorting seeds or even small electrical components.

If you didnt have the rotating disc but a solenoid/piston moving a flap to allow one bead at a time out to fall through a transparent tube, you would need to be able to identify the colour in much the same way as before, ie divide camera input into grids, choose grids to watch and then id colour that way. Then you would need to have another device which could either stop the bead before moving a sorting tube into position, or make the tube long enough so that the machine can get the right sorting tube into position in time when considering the time it would take a bead to fall down a tube using the laws of gravity.

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