Truing flywheels

[DANPATCH]

Has anyone ever trued a set of flywheels in there lathe .I am going to use the 5C collet and dead center on the tail stock. I will install the sprocket and pinion shafts in the collet so I can check run out while I am tightening them. thanks

[junkyarddog]

I have, but you don't want the do any heavy hammer work while in the lathe. Hard on spindle bearing.
Jim

[exeric]

I've trued many wheels in my lathe. I trued my Excelsior wheels last Sunday and they ran out within .001" I made a fixture, similar to what H-D supplied and it uses the holes in the flywheel to to hold the wheel while you tighten the nuts. This fixture works for my Excelsior wheels but will not work on Indian flywheels. I don't think you will get the torque you need by holding the shafts with your collet so you may want to consider making a fixture similar to mine. I just make sure everything is surgically clean and tighten the pinion, and sprocket shafts, then tighten one side of the crankpin. I leave the other side just tight so I can "move" the wheel as needed. I use the all-thread and 1-2-3 blocks to bring the wheels close. Always take the wheels out the centers before striking them and only use a lead, or brass hammer.

[T. Cotten]

Dan!

Your lathe should do fine, as the centers are only for inspection.
All "massaging" of the assembly should be performed on the bench anyway.

I strongly suggest lapping all tapers, and inspecting the shafts' end centers before you begin.
And by all means, spare the hammer as much as possible!
(Brass hammers WILL mar flywheels! Babbit rules.)

Many assemblies can be trued using only a large C-clamp, plus a pair of prybars, once the wheels are roughly parallel and aligned.
Rather than an awkard jig or clamping devise, I just use a press (attached).
If everything is hygienic, the mainshafts should set into their tapers snugly, and the nuts act as an assembly aid to pull them into their tapers with a squeeze like a nail into an oak timber. I merely put the wheel in my press to hold it as I bring the nut up snug. The wheel sits upright directly on the parallel members of the press table truss, with the ram gently pressing upon the outer circumference. Then it's off to the centers to read the wheels' wobble.

Please do not assume a previously installed shaft is true to its wheel!
Each main must be trued separately, before the assembly is trued. Beyond that point, the sides of the wheels are to be ignored.
With the complete assembly held true in the press for tightening, it is quite common to find them aligned very well, but tight at the crankpin, and splayed opposite the pin. Thus clamping at the pin, or prying apart opposite will bring the mains into 'square with each other".

Aligning and re-tightening several times will eventually allow the nuts to be drawn up to full torque without sqeezing it out of true again.
Many details can be found at http://virtualindian.org/1techflywheel.htm, with a discussion of taper lapping at http://virtualindian.org/10techfly.htm. (I have yet one more installment that was not published.)

Good luck!

....Cotten

[DANPATCH]

Thanks for all the great advice Dan