In Froggy World, the amusement park for adventurous plastic frogs, it became necessary to to move the frog from a train car back to the catapult.  Because I couldn't know whether the frog would be upright or sideways--and in what orientation--the gripper was a challenge.

I read about the "coffee gripper" developed at Cornell and used that technique for transporting the frog.

In the video, I cut out the "20 seconds of vacuum time--caused by my low cost pump" to keep from boring the viewers.

Step 1:

What do we need to build this?

Arduino motor shield
(2) Hitec HS-645MG ultra torque servo motors (amazon.com)
Vaccum pump  https://www.sparkfun.com/products/10398
Coffee (I used Maxwell house, original roast)
12" round balloon
Lazy Susan bearings  http://www.amazon.com/gp/product/B002TIKEQ6/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1
Cast Acrylic tube  http://www.amazon.com/gp/product/B0070ZQGRE/ref=oh_details_o02_s00_i01?ie=UTF8&psc=1
Two feet of 3/8 inch OD, 1/4 inch ID tubing

Various 3D printed parts, design and print files at:

12 volt 1 amp power supply
5 volt 1 amp power supply
These grippers are awesome! I first read about them in Popular Science I believe, and I like how so many people on Instructables have put it to use! Great job!
Thank you--I wanted to share what I learned so that it would be a little easier for the next person :)
Very nice! And I see you've got lots of 3D printed parts. You must be enthusiastic!
Thank you--I am enthusiastic! With the 3D printer, imagination is given freedom from many construction limits . . .

About This Instructable




Bio: I am an author and a maker. Current projects include Santa's Shop and Little Friend (ultracapacitor powered robot) on hackaday.io. I'm working ... More »
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