How much saddle wear is too much?

Ray,

If you shim the rack , and a small shim there is not a bad thing, you want to use a full strip of shim under the entire rack surface and it won't be very thick. Do not try to just shim under the bolts. ( I've known someone who tried that and it is not nearly as good.) You will always have a little play. It can't be too tight or you will get spots that bind.

Mark


Thanks for the info Mark.
My common sense thinking tells me that a full strip shim is the way to go.
I've never considered shimming just under the bolts, doesn't make sense to me.
Thanks for the confirmation.
Ray
 
When the carriage casting rubs against the top of the bed v-ways. Remove the wiper retainer and look for a slight gap between the casting and the top of the bed vway. If you have a long bed, you can slide the whole heastock up a foot or so.

If one slides the headstock up a foot or so where does the banjo set up sit?
And what about the quick grange gear box ?
Thanks
Joe
 
Banjo and QCQB stay in their original locations, the extension shaft connects the gear train to the headstock:

shifted.jpg shifted2.jpg
 
Large machine tools use epoxies bronze and just fill under the saddle
There other types of epoxies work today
Works great I have use mills and lathes with epoxies and just like running new machine

Dave

In attempting to get rid of most of the backlash and slop in the various parts of my SB 9A, I removed the saddle to inspect wear on the underside. The rear "V" grove of the saddle has a raised ridge on the lower edge (the edge that runs OFF the ground surface of the Way), that measures .017" above the ground surface of the saddle. Both sides of the V have the same .017" ridge. The front V grove measures approx. .007". My reasoning is that this saddle wear has caused the entire carriage/saddle assembly to sit lower in relation to the rack, causing the pinion gear not to mesh with the rack as snugly as it should. The pinion gear does have it's own wear, but I can eliminate nearly all of the backlash by gently lifting the saddle/carriage assembly slightly off the ways.
Should I be concerned about this saddle wear and what can I do about it.
Needless to say, wear on the ways is my next concern.

Thanks for your valuable input.
Ray
 
Something else to look at perhaps with bed wear, does the tailstock line up with the headstock? On my old 12" Utilathe, I discovered my tailstock was lower than center of axis on my headstock because of wear on the bottom of the tailstock. Eventually I was able to bring it back into alignment by leveling the bed and a bit of shimming. Not an ideal fix, but it works fine now. Also have started turning between centers for longer work if I notice misalignment problems that I can't live with.

At some point I may try building the tailstock back up with brass shims or turcite. But the ways need grinding and scraping, which is more expensive than buying a new machine. So oh well, I keep learning how to do work arounds.

Glenn
 
Back
Top