Tailstock slipping

[Jason Matisheck]

I have a Delta 1440 lathe. When bringing up the tailstock to a blank, I lock down the tail stock and then advance the live center into the blank. After the live center engages the blank, turning the quill handle more will push the tailstock back along the ways. Is this normal? I would have expected the tailstock should stay in position and the quill to get harder to turn as the center engages the work.
I tried tightening the nut under the tailstock a little, but that just made it difficult to slide on the ways.

 

[Timothy Allen]

It's better if your tailstock doesn't move when you don't want it to (I had the same problem with my old Delta 46-700). If you have waxed or otherwise lubricated your lathe bed (or the bottom of your tailstock), you might try cleaning the lubricant off with a solvent.

 

[Mark Jundanian]

The tailstock should not move with reasonable quill pressure.

 

[John Torchick]

I agree with Mark J. The nut on the TS lock might need to be tightened. I have to watch to make sure my TS is locked down firmly or it will slip.

 

[robo hippy]

I remember hearing a long time ago that you don't want the tailstock to be able to lock down 'tight'. The talk about it was some thing like if it was too tight and you cranked the quill down tight, it put more pressure in the headstock bearings. Not sure about that, but I think the tailstock is more for holding a piece in place rather than driving the piece onto the spur drive.

robo hippy

 

[Mike Johnson]

You might check the locking nut under the tailstock to see if one side is cast smooth and the other rough, the rough side is what you want grabbing the bottom the ways.

 

[Dennis Weiner]

You've gotten good advice above, but if the problem still persists you may want to consider fixing the problem as follows:
I had a jet mini that did that. The clamp block provided with the lathe was round. There was not enough contact area with the bed to hold the tailstock properly. I switched it out with a traditional rectangular clamp that had tenons on both sides. The additional contact area did the trick.
The jet round clamp block was a design flaw. I looked at the delta manual online and it appears that perhaps the clamp block used is small and it is square. You may consider replacing it with a larger one that provides more surface clamping area. I obtained my replacement blocks from Monster LatheTools. I'm not sure if they are still in business. Given the bed gap size, a machinist can easily make you one.

 

[john lucas]

I agree with dennis. I have replaced the round block with rectangular blocks on a couple of lathes. Just recently my Powermatic tailstock started slipping unless I put a fair amount of pressure on the lockdown. Never really had that problem much before. I may put a rectangular plate under it.

 

[Bill Boehme]

I also agree with Dennis. I've had lathes with the round disk clamp plates and lathes with rectangular clamp plates. The rectangular plates are much better.

 

[Dean Center]

I believe the Delta 1440 is the "ironbed" and in the same 46-700 family as Timothy mentioned. The one I started with did the same thing, and Dennis has the issue nailed.

 

[Bill Boehme]

I believe the Delta 1440 is the "ironbed" and in the same 46-700 family as Timothy mentioned. The one I started with did the same thing, and Dennis has the issue nailed.

My Delta 1440 Ironbed lathe has large rectangular clamp plates.

 

[Jason Matisheck]

It is the "Ironbed" and it does have a square clamp plate. This is really the lessor of my problems, as the Reeves drive has started to grumble and vibrate a lot, to the point that it's affecting my cuts.

 

[Bill Boehme]

It is the "Ironbed" and it does have a square clamp plate. This is really the lessor of my problems, as the Reeves drive has started to grumble and vibrate a lot, to the point that it's affecting my cuts.

That is the sign that the pulleys are wearing out which is a very common problem on this lathe. Replacement pulleys aren't available any longer so you can do what I started to do which is to convert the lathe to electronic variable speed drive. This involves using fixed step pulleys and a three phase motor and VFD. I did everything except getting the pulleys when I saw the cost. Or you could do what I wound up doing which was getting the lathe that I really wanted ... in my case that was the Robust American Beauty.

 

[John Torchick]

Any excuse to buy a new lathe is a good excuse. Had a HF lathe that had the Reeves drive freeze. Took it to a scrap yard, tossed it and now it is the engine block in a 2020 car.

 

[Dean Center]

It's also possible that the sheaves (?sp) that make up the two sides of the pulley have slipped on the spindle. If you're handy, you can open up the head stock and bring them closer together and tighten them down. I vaguely remember that there's a key in there, too. While you're in the headstock, regrease the set up. Unfortunately, Bill has hit on the more likely problem, with which he is quite familiar.

 

[Bill Boehme]

It's also possible that the sheaves (?sp) that make up the two sides of the pulley have slipped on the spindle. If you're handy, you can open up the head stock and bring them closer together and tighten them down. I vaguely remember that there's a key in there, too. While you're in the headstock, regrease the set up. Unfortunately, Bill has hit on the more likely problem, with which he is quite familiar.

You don't really have any options for moving the sheaves

 

[Dean Center]

You don't really have any options for moving the sheaves

My recollection is that the fixed sheave could be moved, but it's been over 5 years since I worked on the senior center lathe. (thankfully, they replaced it with a new Jet)

 

[Doug Freeman]

The vibration could simply be the belt. They develop a bump where joined as they wear. If you have never had the Reeves drive apart to lube it, could be the pulleys are getting sticky.