[Bob Steele]

On our robot this year we used several water-jet machined gears.
Specifically we used a hard plastic 6" gear which was approximately 1" thick and was used to operate our arm. The small gear which was attached to the Van Door Motor was also cut on the water jet and was made of aluminum.

These gears performed flawlessly for us after we figured out that we could not use softer plastic gears because of the stress on the teeth. The cog is quite handsome. I would add a picture but I don't know how to attach it here.
The actual gears are skeletized with a webbing of titanium plate that holds the aluminum hub inside...very striking as the plastic is blue.

We were lucky enough to gain a waterjet cutting company as a terrific mentor this year. It opened doors for design that we didn't have before and we are very grateful that he chose to join with us.

By the way, the taper can be compensated for, one of the waterjets that is owned and operated by Rolls Royce has this compensation. The one we were able to use did not. We did not have any problems though with the gear.
I would expect that if you chose to drive a gear more stressfully (IE in a drive train...) that you might see some problems. For our application it worked admirably.

I will post a picture in the gallery if anyone is interested.
One of our mentors also designed omni-wheels which were entirely cut on the waterjet as well. The only additional machining that was necessary were some grooves for the small wheel axles (millwork) and tapping the holes for the screws used to hold the assembly together.

Like any piece of equipment, the waterjet is not a complete answer.
I only know that it opened doors for us this year that helped us immensely.
Thank you ... Mike Trapp and WaterJet Cutting of Indiana.

thanks
Bob