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lapping arbor - Printable Version

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lapping arbor - B34VD - 06-22-2012

Since I've been banned from the premier site for the machine arts I guess I'm forced to post this here. I'm having trouble truing a pair of flywheels for a 53 Indian Chief motor I'm building so I'm following the instruction of an old pro that suggested that I lap the tapered bores of the flywheels to correct any imperfections. The following is the process that I followed.


RE: lapping arbor - B34VD - 06-22-2012

I used an old crankpin as "donor" arbor. Using a 1/8" aluminum oxide disc I ground reliefs around the pin


RE: lapping arbor - B34VD - 06-22-2012

another angle


RE: lapping arbor - B34VD - 06-22-2012

The arbor set up in the lathe.


RE: lapping arbor - B34VD - 06-22-2012

I turned down a simple bushing out aluminum and pressed an MT2 arbor into it to stick into the tailstock. This will be the press that forces the flywheel into the lapping arbor.

Note: the lapping arbor is coated with a grinding compound.


RE: lapping arbor - B34VD - 06-22-2012

The flywheel in position to be lapped. The bushing & taper should keep it aligned properly.


RE: lapping arbor - Bill Gruby - 06-22-2012

Being totally in the dark here could you please elaborate a little more on what you are trying to accomplish. I have no knowledge of the Indian Motorcycle other then they were made. The pictures are awesome.

"Billy G" 17428


RE: lapping arbor - TomG - 06-22-2012

The lap in your set up will tend to follow the tapered bore rather than correct it's misalignment. It looks like this lapping operation is normally done on a vertical mill with the spindle being dead perpendicular to the table. I don't know if you've seen this site, but here's a guy demonstrating it:

Cannonball and the Beast

There is also a ton of other info on flywheel alignment on the site.

Tom


RE: lapping arbor - B34VD - 06-22-2012

The motor is a v-twin flathead similar to what you see in today's modern Harley-Davidson. Both connecting rods ride on a common crankpin that spins between two flywheels. These flywheels turn on 2 pins called a drive & and a pinion pin. The whole thing is bolted together and before assembled in the cases need to be true in a truing stand. The same as putting a shaft on centers in a lathe. The shafts are the persuaded to run true with a lead hammer. Hopefully this explains what's going on.


RE: lapping arbor - B34VD - 06-22-2012

(06-22-2012, 08:12 PM)TomG Wrote: The lap in your set up will tend to follow the tapered bore rather than correct it's misalignment. It looks like this lapping operation is normally done on a vertical mill with the spindle being dead perpendicular to the table. I don't know if you've seen this site, but here's a guy demonstrating it:

Cannonball and the Beast

There is also a ton of other info on flywheel alignment on the site.

Tom

I have and the problem with it that he indicates the bore of the taper but then does not fixed the wheel to the table. It's allowed to wander and seek it's own true.