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Old 03-28-2010, 09:40 PM
Creative Engineering Creative Engineering is offline
Join Date: Sep 2008
Location: Clearwater, FL
Posts: 1,668
Default re: 60 MPH...achieveable? Who cares?!? Let blueprint an engine!

Step #1 Post 3..."how to" precisely align the cases.

In the first pic, I am using a dial indicator that has a resolution of one tenth of one thousandth of an inch...split one of the hairs on your head 10-15 times and that would represent each division on the indicator.

Using shim stock, level the part to the mill table, and lightly clamp the case so that the indicator sweep around the outer bearing race is no more than .0002. This is time consuming and tricky as you will need to lightly clamp a thin casting just enough to take a skim cut without throwing the part off the table. This is an experience thing, and only a machinist familiar with precision set-ups will be able to do it.

Do this to both cases...yes tedious X2

Photos 2&3 show how to square the case half to the mill. Use a precision gauge pin in each bearing as a locator for the indicator. I used a .590" in the crank bearing, and a 589" in the countershaft bearing. Light lock the clamp shown to the right...finger tighten the clamp to the left.

Run back and forth across the pins until the 590" reads zero, and the 589" reads -.0005. clamp just a tad bit tighter to make sure nothing moves while drilling. Sweep the pins again to make sure nothing moved...repeat until perfect.

Photo #4...using the indicator: sweep the bore of the bearing until the indicator deflects no more than .0001. Set X&Y to zero. Now you're ready to drill the dowel pin holes. The location isn't critical...just find a nice open spot...but make sure you log your numbers so that you can put the holes in the exact same spot on the opposite case.

Don't forget, the cases are a mirror image...mentally, keep up with the orientation of the part when on the mill table.

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Last edited by Creative Engineering; 03-28-2010 at 11:02 PM.