awdmoke wrote:
I think you are more than capable of making billet calipers, but why make the pistons when you could just choose an "off the shelf" spare part that is readily available?
Like all the things I make, use the best material for the job. The piston dia is 1 1/2" dia. This gives total piston area[one side] of 3.58 sq". Std cooper s is 2.08sq". Force =pressure X area.
The only ones this size are from a bike caliper. A honda or kwaka piston is around $100 each. They are only steel and chrome plated.
A piece of centerless ground 504 to make a piston is $5. The OD does not have to be machined, just set-up bar in lathe, drill one end to for the cup and then part off to length. The stainless will not rust, has a hard surface that work hardens with use.
The piston rings I am going to use a silicon quad ring [ used in hydraulic systems] that seal a lot better than a square section ring as pressure is increased. Again they are cheap about $4 each. The outer dust seal I am looking at a narrow series lip seal, cost about $7 .
I priced up all the bike bits and that was over $500. Typical bike spare part prices!!! With the parts I am looking at the seals can be obtained fron any hydraulic/ brg place. All up cost les than $70
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