FILENAMES: 

flywheel0.jpg
flywheel1.jpg
flywheel2.jpg
flywheel3.jpg
flywheel4.jpg
flywheel5.jpg

DESCRIPTION: 

These photographs show one satisfactory method of holding a 
cast flywheel for turning on the lathe.  Posted by Bucky 
Goldstein <bg@netcare.lucent.com> Bucky provided 
the following description:

===============================================================


There was some good discussion when I asked for advice on holding
a cast flywheel for machining.  A number of people seemed
interested, so I though they might also like to see how I edned
up doing the work.  

The issue was whether to hold the work in a chuck or on a
mandrel.  I wasn't sure that the mandrel would be able to hold
the work well enough for some heavy cutting.  I also didn't want
to use just the chuck because I was going to have to flip the
work several times.  Too much DTI time for me.  

Dave Baker of Puma Racing suggested that I chuck the work for
boring and to clean up one side, and then use the tailstock to
hold it agains a faceplate to do the other side.  This is pretty
much what I did, with minor variations.  

To those who discussed this with me: thanks for the help.  I'm
happy with the results.  

Comments on the pictures follow.  

	- flywheel0.jpg: The work is chucked and centered in the
	  four-jaw.  I've faced the edge and the hub, and cleaned up
	  part of the rim.  

	- flywheel1.jpg: Still in the four-jaw.  Drilling and boring
	  the center.  Note the half-machined rim: this flywheel gets
	  a crowned rim.  I have put the angle on with the compound.
	  The other half of the rim will get done after the flywheel
	  has been flipped.  

	- flywheel2.jpg: The tailstock center is holding the flywheel
	  against the faceplate, Puma Racing style.  This works out
	  very well -- simple, fast, accurate.  Note that I've
	  machined the second half of the rim.  The finish isn't
	  good, though, because I've had to hand-feed the tool.  I'll
	  correct this in flywheel5.jpg.  

	- flywheel3.jpg: Some oil has gotten between the faceplate
	  and the flywheel (leaky headstock bearing).  To keep the
	  work from slipping I have screwed a stud into the
	  faceplate, bearing on a spoke, to act as a dog.  This works
	  fine.  In the future I'll do it at the outset.  

	- flywheel4.jpg: I need to get the tailstock center out of
	  the way so I can machine the hub.  I've bolted the flywheel
	  in position before withdrawing the tailstock.  

	- flywheel5.jpg: To get a better finish on the rim (compared
	  to flywheel2.jpg) I have slipped the flywheel onto a
	  mandrel and have put the angle on by setting the tailstock
	  back.  That way I can use power feed to move the tool.  The
	  results are good; and since the amount of metal being
	  removed is small, I don't have to worry about whether or
	  not the mandrel can grip the work well.  All done.