Posted by BillS on May 04, 2012 at 09:00:00:
In Reply to: Re: Barber Coleman No. 3 question posted by Tom Ramsey on May 03, 2012 at 15:25:37:
Tom,
I like the idea of renewing the feed table screw. As you are aware, this screw gets a "saddle" section worn in it, and the slack can't be adjusted out.
Yes, you can adjust wear out of the two-piece nut if the screw is uniform in fit (end to end), but the screw cannot be adjusted without regrinding or replacing it.
Do you have a complete range of change gears?
Are you cutting small helix angles?
If you are not using the differential, are you locking it out to prevent creep?
These 3 things are common contributors to excess lead error.
I don't see why you would typically need 6 gear sets, unless you need extreme accuracy. 4 feed gears (or 4 diff gears) will usually get you to within .00001 inch/inch lead error. What is the allowable lead error you typically want?
If you would be willing to try a setup from me (either using or not using differential - your choice), I would really like to provide one to you based on your gear specs. I would need to know the missing sizes in your change gear inventory.
We can do this off-forum if you wish. Email usually works better for keeping track of responses, data, etc.