Best way to align the tailstock

K

kiinstructor

AzB Silver Member
Silver Member
I have an older Enco lathe and it seem like the tailstock is not in line with the lathe. What happening is when I drill holes, they seem to bind and are always larger than the bit. Put a pin in the chuck with a sharpend point and the same in the tailstock. Butted them together and adjusted the tailstock so they were close as far as I could see but I dont think that good enough. I also concerned that not only left and right, the barrel might be off up and down. I have a bar that I took a pass on and checked the diameter with caliper and found a difference of .003. The bar is about 10 inches long. What I was thinking was to measure the bar with a dial indicaor mounted to the tool post at the chuck and then turning the bar end for end and taking the reading at the tailstock and adjusting accordingly. If you guys have other ideas please chime in. Id hate to have to get another tailstock, even for an older 90s lathe like this, I think the price is quite hefty. Thanks in advance for your help.

Mark
 
Chuck up a dead center.
Put another dead center on a drill chuck.
Align the tailstock for tthe two tips to meet dead-on.

Make sure the bed is dead nuts level.
 
The only way to really know if the tailstock is right on is to tape at least a 6 inch long piece chuck it up and support the end with a center in the tailstock. Take a skim cut off of the whole piece and measure both ends. Too big at the tailstock move it toward you. Too small move it back. Put an indicator on the tailstock to see how much you are moving it. Check and repeat as necessary. It may take you a little while but this is the only way to know it is right on. Also make sure the headstock and tailstock are level front to back. If the bed is twisted what I told you to do will only work where the tailstock is positioned.

John
 
Make sure the bed is dead nuts level.
Click to expand...

Start here using a machinist level before you do anything else.
After you have leveled, don't assume anything and check to make sure the tail ram is parallel to the bed.
You may have to shim the tailstock to get it parallel.
 
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RocketQ said:
The only way to really know if the tailstock is right on is to tape at least a 6 inch long piece chuck it up and support the end with a center in the tailstock.
Click to expand...

John, pardon this possibly dumb question, but why wouldn't you turn a test bar between centers (ie use a dead center in the headstock, turn with face-plate-driven dog) rather than between a chuck-and-a-center ?

Dave
 
its an Enco, theres a good possibility that if you have center to center lined up then the chuck is where the runout is! chuck a ground dowel or your drive center and indicate it. Had the same problem with HF lathe
 
alignment

take something you know is round and straight. put it between centers and use a dial indicator run it from end to end and adjust until it reads the same number from end to end. this is how we set up lathes and mills i hope this helps.
rh
 
kiinstructor said:
I have an older Enco lathe and it seem like the tailstock is not in line with the lathe. What happening is when I drill holes, they seem to bind and are always larger than the bit. Put a pin in the chuck with a sharpend point and the same in the tailstock. Butted them together and adjusted the tailstock so they were close as far as I could see but I dont think that good enough. I also concerned that not only left and right, the barrel might be off up and down. I have a bar that I took a pass on and checked the diameter with caliper and found a difference of .003. The bar is about 10 inches long. What I was thinking was to measure the bar with a dial indicaor mounted to the tool post at the chuck and then turning the bar end for end and taking the reading at the tailstock and adjusting accordingly. If you guys have other ideas please chime in. Id hate to have to get another tailstock, even for an older 90s lathe like this, I think the price is quite hefty. Thanks in advance for your help.

Mark
Click to expand...
had a similar situation
butt the dead centers up point to point , with a razor knife blade between them
that'll give you a damn close if not perfect alignment left to right
then rotate the blade as to point the tip of blade towards ceiling, step back and look to see if blade is not tilted
that'll tell you if tail stock is low or high

you can make any adjustments if needed after taking a pass on something
your .003 in 10" translates to .009" on a 30" cue
i offset my tailstock alot and have to recenter it alot, several times a day
this method usually gets me either dead on or out maybe 3 at the most at end of lathe
i beleive it was someone on here that suggested that method to me way back when
just passin it along


however that method will not help with making sure the tail stock is level/parallel with the bed
get that resolved first or the stuff i mentioned wont help
i just did all this too, a shim under my tailstock had shifted tilting it down in the front
 
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All the different ways mentioned so far will work. If you have precision ground dowel pins, chuck one up in the tailstock and one in the headstock chuck. Place a dial indicator on your tool post and run it across both. Adjust the tailstock until both read the same. If you have a tailstock that is out .005" one inch from the headstock it will still be .005" out 30" from the headstock provided the bed is true. That type of offset does not change with distance. If you have something cocked in the headstock at .005" for say five inches then face it off. That will give you .030" run out in 30 inches. That is why it takes special care to work on shorter pieces in lathes with long headstock spindles.
 
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ok

DaveK said:
John, pardon this possibly dumb question, but why wouldn't you turn a test bar between centers (ie use a dead center in the headstock, turn with face-plate-driven dog) rather than between a chuck-and-a-center ?

Dave
Click to expand...

Test bar = expensive.
also if you re-cut your dead center in the headstock to ensure it is right on. Chuck or center doesn't matter you still need to cut the piece in question.

John
 
Hi,

I have an Enco and here is what I did to tune it in. I don't know if this is the best way but it worked for me. If you do this you will be very happy as far a cue making tolerances are concerned.

1. Disassemble jaws and clean everything with brake cleaner.

2. Zero in the chuck via boring using livetooling/ grinding. Indicate a dowel pin for checking run out. Make sure you have a machined shaft collar and chuck up the ID during so that the chuck is locked with pressure while you grind jaws.

3. Make sure bed is level.

4. If you get it to .001 run out that's plenty good for cue making. If you have an old lathe this procedure will verify the bearings condition.

5. For tailstock checking get a 36" Thompson rod with 60 degree centers on each side. Place rod between centers on the lathe and with a mag based indicator mounted to the saddle, indicate the rod.

If the rod is out up/down or in/out you must shim the tailstock to get as close to zero as possible.

Remember that Enco Lathes are not toolroom quality. I have an Enco and have done this procedure. I got my numbers pretty close but not perfect on the tailstock. This is why final hole diameters should be bored.

You can buy a 3/4" Thompson rod at Mc Master Carr for about $ 100.00.
The T Rod is hardened on the outside but the ends are softer for machining. You must take your rod to a machine shop with high precision equipment and have them put the 60 degree centers on the ends. Don't use your lathe to drill the centers because this rod will be the standard for truing your stuff.

Before I did this my pins were not very accurate and since then my joint concentricity is repeatable every time. I usually check my machine every couple of months.

Good Luck,

Rick G
 
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RocketQ said:
Test bar = expensive.
also if you re-cut your dead center in the headstock to ensure it is right on. Chuck or center doesn't matter you still need to cut the piece in question.

John
Click to expand...

cheap-assed-DaveK-test-bar = an old chunk of something, not a purchased precision ground test-bar :thumbup:

Yes, you need to cut the bar to see what taper (if any) you have.

My 3-jaw has runout. A dead-center in the spindle has way less. It seems more appropriate to me to use whatever indicates the true position of the spindle.

Dave

<edit> John cleared up my misunderstanding by PM, thanks sir ! I had missed the part about re-cutting the center while it was in the chuck, thereby ensuring it is dead-on.
 
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Tailstock Alignment

If you have a dial indicator with a magnetic mount stick it to the chuck and sweep in the live center this is one way to do it.But if the ways are worn or the lathe is not level the tail stock will only be inline at the point you sweep it in at.
 
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