Friday, February 15, 2008

Finshed with the machining

I have finally finished the drive wheel for the ring lift I am making for my next project. The drive wheel is powered by a 10 RPM AC motor. The motor is attached to a shaft that rotates a rubber and plastic wheel, which in turn rotates the large wooden ring that will lift the marbles to the top of the sculpture. The drive wheel will contact the ring at the outer edge. The base and bracket are made from aluminum. The coupling from the motor to the drive shaft is made from stainless steel. The drive wheel itself is made from rubber (center) and plastic end caps. The shaft is stainless steel also. The motor is from McMaster Carr. $45 - I have at least 40+ hrs into this assembly.

This was a very complicated process for the beginner machinist, like me. I won't bore you with the details of construction. This drive wheel will be mounted at the bottom of the frame to support and turn the wood ring lift that Gene built for me. I didn't build the wood ring because I don't work with wood, just metal. Besides the motor and thrust bearngs, everything you see here was made from scratch with a Lathe and Mill. I learned a lot! I wish I could say that I knew what I was doing and just did it, but the reality is that Bill helped me the whole way. I did do all of the work but Bill helped me with the process and what tools to use when, and why. I will probably get Bill's lathe, as he is 80 years old, but I would be much happier with a few more years of experience under him. Bill told me today that if I had to take this design to a machinist he would charge me $3000 to $4000 to complete everything you see in the photo above. Ouch. That wouldn't be a problem if your customer is going to pay for it, but how do you get a quote on something you are not sure of how to make yourself? My answer is to do it yourself. Piece by piece. To be fair I used several tools I had no idea existed, let alone how to use them. But now that I know....well...knowing is half the battle...

This is the wood ring that will lift the marbles to the top. The drive wheel runs clockwise, so this wood ring will rotate counter-clockwise. There is a small groove inside each of the holes to keep the marble from rolling out. I will need to make a mechanical lever that pushes the marbles out when they reach the top. The steel frame is made from 1/2" stainless steel square tubing ($80 per 20 ft) which is cut at 15 degrees. (30 degree total)
I bought a book "507 mechanical movements" very informative. With it I will be able to find just the right movement to get the marbles out. I will put a pin in the inside of the ring to actuate the arm that will push the marbles out, but first things first. This is the mock-up of what the frame will look like. Actually it is missing one more circle that will go to the left and intersect the other two rings, the last circle being smaller by at least half. This will give me framing to connect the two idler rollers to as well as the supports needed for the track and elements.

4 tracks total, should be very nice. Josh, the buyer, wants it to be elegant and quiet. I will have to pay special attention to the tipping arms, and anything else that makes noise.

I will post again soon as I get more done. Back to the shop!

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