m&m sorter #3

Sorts m&m's by color
DeltaRobot-0.02.zip3.44 KB

Videos: http://www.youtube.com/watch?v=Pbb9GOWaL4g and http://www.youtube.com/watch?v=mPakG8p3MHE

Update: Added schematic for the vacuum system

Code word were: CHEAP!

Cheapest RC servos I could get, Cheapest Arduino, almost. Straws from mc donalds, icecream sticks, rubber bands, Lots of scrapped stuff just waiting to be used in the workshop. Solenoids in the valves were from old tapedrives, and the valves them selfs were from old bicycle tubes. Vacuum and pressure comes from an old aquarium pump, reshaped to make vacuum too.

The dark disk is a sun shade, had to add that before filming outside, othervise color detection made too many mistakes.

"Exploded view" of lower arm:

"Exploded view" of lower arm

Lower arm:

Lower arm

Lower arm about to be connected to bolt on upper arm

Lower arm about to be connected to bolt on upper arm

Lower arm and the moving platform:

Lower arm and the moving platform


Two valves, the lower one disassembled

The pin visible at the end of the yellow tube pin of the bicycle valve. The brass tobe above goes over the pin. Since the pressure uses in the robot is low, +/- 0.15 bar, I could go with these simple home made solenoid valves.

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This is really cool!!

I've seen the three arm design before, but it was on a 3-D printer. I didn't think of using it for moving physical objects!

This is really inspiring, I might try making one... when I have finished 4WD! (that's a thought actually...4WD with one of these stuck ont the front - put a grabber on the end rather than the m&m sorter and you would have a very dextrous 'hand' for your bot...)

well done mogul!

I would say make it again, if only to gaze at it goes about it's sorting, moving in such a futuristic way...


when they are moving low mass. If you start trying to move more massive objects, you will likely run into any number of problems.


Cool stuff there!

Thanks man, I'm also really proud of that build, and somehow regret I took it apart shortly after completing it.

Great project. I just works it's butt off. very nice

Yes it indeed did. Unfortunately I took it apart shortly after I filmed it, which I regret now. Perhaps I should build me a new one.


I put this question to the youtube link, but to be sure u will find it, and answer it, I ask here to...it is very important for me.

I want to build a similar robot and I have to choose a motor, but I don't know how strong and fast must it be?

What do you think about this motor?


As you see in Moguls writeup he used cheap servos. I made a light weight delta like his (out of sticks & straws) and cheap 1.6kg torque servo worked fine.I decided to remake the robot with metal components & used the same servos. Disaster! When you calculate the torque required you find you need much gruntier servos. I have now used MG996r 19kg servos & it all works smoothly.I don't think speed is all that important but you must have enough torque to drive your system otherwise you end up with a jittery mess. The more powerful servos often draw a lot more current though!


So much fun to see your creations.

If you ever get a 3D printer- You will be the the most dangerous man alive.

Thank you,


P.S.-So how about those pesky unsorted peanut M&Ms?

Thanks for your kind words.

I have thought about a 3D printer multiple times, but it always boils down to the following:

  • The plastic filament seems expensive and not easy to reuse
  • I would hate to designing parts in a CAD program, perhaps OpenSCAD could be acceptable to me
  • It would go against my overall design philosophy: break a stick, hot glue it and compensate for the crappiness in software

And about the m&m's with peanuts, well, I'm not a big peanut fan, and my daughter is allergic to them. I think I will leave that challenge for somebody else.