Quote:
Originally Posted by Brandon Holley
It's funny seeing your thought process throughout this thread. It's the exact same thought process I had when I was working on my little wheel. It all depends on how extreme you want to go on reducing that friction. Using Teflon or Delrin will be effective, but the urethane will not adhere to it, so doing some kind of insert mold is out. I looked at even purchasing tiny ball bearings to press into the rollers.
Ethers point of friction along the face should also be noted. I imagine this friction would be the harder one to solve elegantly.
Good luck!
-Brando
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That's funny, I too have investigated tiny ball bearings. While not one of my primary goals, keeping this thing cost effective is at least in the back of my mind. With 14 rollers per wheel and 4 wheels per robot, any additional components can raise the cost fairly quickly. Bearings at a few bucks each are almost out of the question.
Smooth-On customer service indicated that a dual-durometer pour is possible as long as the second material is poured while the first material is still tacky. They recommended PMC-780 DRY as the core and Vytaflex 40 as the outer material, or at least said that it is something they know has worked in the past for other customers. They also mentioned TASK 2 or 3, but noted that getting rubber to adhere to plastic is harder then getting urethane to adhere to another urethane.
A 40 durometer outer material sounds a little soft, as does an 80 durometer inner material. I'm fairly sold on at least attempting the dual-durometer casting, as it uses the fewest parts and creates an integrated solution. Any suggestions on which Smooth On products to start with, or at least which durometers to use?