I'd be checking the true alingment of the turret first. Pull a tool, and clock the mounting face in the Z direction. It's a folly to be checking anything over the lands of a U-drill. That's what I think you are seeing when you measure 0.1" per 5", over a drill. That 2.5mm over 125mm in Heathen meausurments.* You'd be lucky to push a U-dril 2x before its rubbing I wouldn't trust a check over a measured drill. You have relief, land wear, most drills will have back taper for clearance. Go to gospel, and clock the raw face you mount the tooling blocks to. Get the Turret gospel, anything you mount on them after that, its only the manufacturing tolerences of that tooling block you have to live with. You have 12 of them to live with. MAKE THE TURRET DATUM.
You can clock the face of the turret in the X direction, Its normally good enough. Its a Hyundi. Turret will be pression ground all over. Other option is too high or too low. As if you had a Y axis, weather you had it or not. Most common cause or turret mis-alignment, is a crash, generally knocks the turret high with an upper turret like yours is you're are turning C.W, Lower turrets go down. Dont believe this is your problem. Buts it's remarkably common. There usually only 8 M12 bolts holding the turret drum to the centre axle. Bolts and 2 case hardened taper pins. Which bend. They are in under your number plate, way smaller P.C.D, which is why they let go
I'd clock your raw turret up, get that gospel, The entire turret assembly can rotate on top of the Z axis slide. When you are looking at it from the operators door, it can slew C.W or C.C.W, There hasn't been a holder built that is 0.100 per 6". Brick layers do better than that.
I dont know how many Hardinges I've tuned up over the life time. But be assured the entire turret can sit cock eyed to the Z saddle. So your turret is sitting cock eyed to the spindle centre line. At 0.1" / per 5" (100 thou in 5 inches). Thats pretty shit house, spec is 0.020mm per 150mm for every machine builder on the planet, past WW2 when Schlinger drafted the standard. Nothing in magic adjustable tool holders will accomadate that. I personally hate adjustable tool holders. Operators just bring my VooDoo down
And it doesn't have to be a big crash, decent broken tool can cause the turrent drum to slip, or knock the turret out of parrallel alignment. Some thing has to give. In preference to your spindle bearings.
Wouldn't it be a case, that the holder you are haviving issue with, is the one that has to be on centre line.? You wouldn't necesarily know if a turning tool was off centre apart from the Tit it might leave. And that get's negated by passing though way past centre.
As always, regards. Phil.
* Bloke I had an enmourmous amount of time for, but did his craft in the 60's. Described Imperial as Christian. Metric as Heathen
