Thread: Realigning the tail stock QT8

The tailstock is out of position by .008” and wanted to get some info on realignment procedures. There are 4 bolts holding the ways nearest to the chuck and 2 more at the other end. My question is how do you adjust the ways to ensure that it’s parallel to the chuck so it will be on center line regardless of tailstock position?

Thanks for your input

Have you checked your "Head Stock?"

Is it straight or did it take a hit and needs to be trammed in? Was there a crash recently? When was the last time the Tail Stock was used that it was fine?

Personally, I'd check the Head Stock out first, but then again that's me

All good points Steel cutter. There haven't been any crashes and tailstock hasn't been used since I've owned the machine so I have no idea of it's history or performance. There is a small mark in the paint on the turret side of the tailstock where there was some contact in the past but looks very slight. I have never check the head stock for squareness, I'll chuck up a piece of drill rod, mount an indicator on the turret and sweep the length.

Is there a better method to check the headstock for squareness?

Thanks for your reply.

Yes!
*The way to check it is to chuck up a piece of some type of "Anything / 1.5 to 2.0" diameter Bar" (( Aluminum is perfectly acceptable )) take a cut on it, preferably no less than 6.0" long, I prefer 10.0" to 12.0" length of cut myself (( but that's just me once more ))

>Once you take the cut to a full clean up, Mic the diameter on each end, this will tell you if / how much, if any, your head stock is out, go from there to tram it in as / if needed (( there should be 4 bolts behind the spindle / chuck to make your adjustments CUT / MIC / TRAM IN, 'til you got it!.

( a few tenths taper ocer this length would make me happy )


It's a fun exercise

to your original question
there are 2 adjustments
one is an eccentric adjuster that's under a plug in the area of the front four bolts
you pull that plug and turn it with a big screw driver (i believe there is a locking set screw that comes in from the front of the machine) it's behind one of those plugs you have wondered about.

there is also a set of opposing adjusters in the neighborhood of the back two hold down bolts just like on an old engine lathe,(one of which also comes in from a plug in front of machine).

getting that rail dead straight so the tail stock is right on in any location is pretty tough
but you could do it by sweeping the rail in the -z- axis plane with an indicator
once it was straight you would then have to move it in parallel to the proper center point

all more than i have ever had the patience to do

after any other checks the real confirmation of the headstock (and tail stock) is a test cut


QT8's are so compact and rigid i have rarely had any head stock alignment issues

3 times diameter is about a max for lenth of an unsupported cut
a piece of 1.5" diameter about 3 and a half inches long will tell you what your up against

.015 max depth of cut on your "test cut"(after part is round)
sharpest (small nose radius) tool you got

Everything wippin' boy says I agree with, except that Why start loosening things up to align the tail stock when it may be the head stock that is out, I have seen not only QT-8's but QT-15's, Super-18's and even QT-35's where the head stocks have gone out of alignment!

>A simple cut on a piece of chucked bar stock will tell you in a couple of minutes if the head stock is properly aligned or not, if it's OK, then go into what wippn' boy classifies as

all more than i have ever had the patience to do

(( I couldn't agree more, it's a bitch to align the damn tail stock! )) I'd rather align the head stock any day myself!!!

>>Just the way I'd tackle this problem wippn' boy not contradicting what you state!

It's your decision to make on which way to go captdave
*Furthermore, you need to turn up a piece of bar and put a center on it before checking the tail stock anyway, correct?"

Great advice guys, I'll run some test when I return.

you do allways check head taper before adjusting tailstock
.015 depth, 2" long test cut on 1" diameter bar will tell you what you need to know on that

Had some extra time today to check the headstock for squareness. 9" length of cut 1.5" 6061 and had .0002" larger at the tail end. I did it manually and since it came out that good I didn't bother writting a program to get a perfect (SFM) and I'll attribute the .0002" to lazyness. That's good enough for my work!

The shaft job has long since gone so I'll have to wait till I have some more free time to mess with it further.

Now off to install that new Royal combo bar puller!

Thanks for your advise and thoughts all.