[SURFPROG1]

Although I program alot of Mill work have some trouble with lathe boring have a job of bushings that need to be bored out to .375 the hole in material is allready at .300 I have to boring tools a rougher and finish . taking .02 a pass leaveing .01 for finish pass part is 1.250 . Problem is I keep getting .001 taper from 1 end to other . The code does not show this any help? getting frustrated.Thanks Surfprog

Machine is Leadwell Ltc10 Lathe

[underthetire]

Take a test cut with some scrap. Just take about .005 doc, off a od, doesn't matter what size, larger the better though. Measure it and see if you still have a taper. If you do, the headstock needs alignment or the machine has twist in the bed. Either way, you will probably need a service guy.

[txcncman]

Take a test cut with some scrap. Just take about .005 doc, off a od, doesn't matter what size, larger the better though. Measure it and see if you still have a taper. If you do, the headstock needs alignment or the machine has twist in the bed. Either way, you will probably need a service guy.

+1

Your machine is probably out of line. You need to align it or have it aligned. Until then, you can probably compensate for the taper in your programming.

[miljnor]

could be tool deflection. especially with tools that small...what are the tools made from? steel? carbide? play-doh?

[fizzissist]

Before you bother with anything... LEVEL the machine!!!!!

... If your turret/toolpost is out of alignment, it'll give you the exact same taper on an OD as it will an ID.... Turning the OD the same exact Z distance and checking to see if the taper on the ID matches up will tell you whether it's alignment or something else.

Worst case, if you're in a bind for time, just program a G01 taper to compensate... ..... but I'm wondering if this isn't an obvious "... why didn't I think of that... "...

If the part already has a hole in it, and you're clamping down,,, you're squishing the hole at the chuck end. When you un-chuck it, it'll spring back and guess what... That end of the hole will be bigger. Check to see if that end is round also if you're using a 3-jaw, or even with a collet.

Squishing holes gives headaches. Check it on the machine, then off the machine.

[fizzissist]

If you're clamping on the whole outer diameter, with a 3-jaw, you could have uneven external pressure if the jaw faces aren't perfectly parallel with the axis of the spindle.. that is, you're getting distortion.

Either bore the jaws or back off on the chuck pressure. Or both.

[SURFPROG1]

Thanks all that gives me somewhere to start .I had missed posted the taper it was only .001 bt the tolerence is .0005 either way from nominal dim. will try the taper in post. Thanks again.

[juergenwt]

I don't know what the part looks like or the type of material being used. But-try boring to .360 and reaming to size.