8-1 from Omni-Wheel to Omni-Ball.

I made "Omni-Ball(s)" for my final project in last week. These are important parts to move a plant-pot in any directions.
Although "Omni-Wheel(s)" is one choice, it's too expensive and complicated. I had been looking for good alternatives.

One day, my friend Ken Endo (MIT Media Lab) thankfully advised me to check out a paper as follows:

"Development of holonomic omnidirectional Vehicle with “Omni-Ball”: spherical wheels
"Tadakuma, K. Tadakuma, R. Berengeres, J.
Massachusetts Inst. of Technol., Cambridge
http://ieeexplore.ieee.org/Xplore/login.jsp?url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F4398943%2F4398944%2F04399560.pdf%3Farnumber%3D4399560&authDecision=-203

Images above from a paper
http://ieeexplore.ieee.org/Xplore/login.jsp?url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel5%2F4398943%2F4398944%2F04399560.pdf%3Farnumber%3D4399560&authDecision=-203

 

8-2: Modelling

I designed the basic model by Rhino. (Actually, SolidWoks are more useful and popular for mechanical design).

8-3: Molding and Casting


urethane 60 (A+B)

I made my basic cast with wax (fabricated by Modella) , and bought "urethane 60" as molding material at Raynolds.
The hardness of material is critical for this part to work efficiently.
The instruction said that we had to wait for 48 hours! I couldn't wait such a long time.
So I used an oven for acceralating the molding.

 

Beautiful! Perfect!
A couple of semi-sphere tires and shalts
It worked!

8-4: Assembling

8-5: Finish! Omni-Ball (no bearing inside)