Thread: Lathe Bed Theory

Could 2. alternatively be caused by wear in the tailstock quill?

Brendon good topic

Lathe bed wear is a fact of life, unless they and the tailstock are hardened like metal lathes..but even over time they also wear. Brendon not just the beds but the slide sides also wear.

Having them re ground is the best way finding someone to do it at reasonable cost

I'll be interested to see where this heads.

I'd have thought that the bearing surface on the bottom of the tail stock

would cop more wear then the bed ? Phil

Hi Brendon

Have you thought that the banjo may be wearing the bed in that 200 mill closest the headstock.

Cheers Tony

Originally Posted by rsser

Could 2. alternatively be caused by wear in the tailstock quill?

I don't think so, no slop in quill.

Originally Posted by Tony Morton

Hi Brendon

Have you thought that the banjo may be wearing the bed in that 200 mill closest the headstock.

Cheers Tony

Yes, I did think of this but the question of why the tail stock sticks at that point still remains. I really am doing the electronic version of thinking out loud and was hoping someone might be able to shed some light on the whole issue. The fact it has happened to two of my lathes has me wondering.

I have experienced this on my lathes also. I honed the ways with some fine (600#) wet and dry paper on a block of wood, and the problem disappeared. Clean also the inside edged and and the underneath surfaces of the ways. I put it down to an accumulation of grain fillers, and residue from some timbers. Both these lathes are Woodfast lathes, one is 30 years old and the other is about20 years old. Does the "cleaning" cause excessive wear? Not that i can detect. After "honing" I rub Ubeaut Traditional wax onto the ways.
Jim

I have a rotating head lathe, but even after locking it down hard, the headstock does move over time. Not sure why, perhaps vibration or the hard work it does . I simply unlock it, rotate it back, then re-tighten and it is as good as new. It always rotates in the same direction, away from the cutting edge, so I assume it is from the work it does. I've never had any trouble with the tailstock not running true, except when I bent my live centre

Interesting question. My first blush is that if there is wear it would be so negligible as to be of no consequence. However, you use yours a lot and have experienced the problems described.
Other thoughts are: what kind of surface is the lathe setting on? A wood floor might yield affecting the level.
I'll opin that this would never happen with my lathe. I regularly clean and wax the bed so my tailstock would be sliding on wax not the cast iron. (actually, with my lathe cast steel)
I'll follow this thread. Interesting.

Well, in the mode of thinking out loud ...

The question is what is causing the relative binding in prob no. 1. I'd assumed you'd done the cleaning up that Jim suggested, and also that the clamp plate hadn't cinched up slightly over the years. Not a prob where it's been used mostly if that's where there's wear.

Another possibility is that the bed castings may have moved and narrowed slightly at the headstock end. So is there still good clearance between the clamp plate shoulder and the bed slot?

The banjo, bed and tailstock are all cast iron (which comes with some graphite in it acc to GJ which will help perhaps with sliding) but the clamp plate is steel, prob medium tensile, and maybe this causes greater wear against the iron where it's mostly been used. This, or a stretched clamp plate bolt may have led you to take up the slack on the clamp plate at some stage to accommodate the wear but which now makes for binding where there's little wear.

Anyway, that's my brain dribble for the day.

I wonder whether the too and fro (back and forth?) movement of the tailstock along the bed slowly polishes the bed
If that's the case it would seem to bind at the point where it doesn't travel as much

My 2c worth

Hmmm... Surely if the bed is wearing it'd be becoming thinner and I'd expect the tailstock to slide more freely rather than stick? Unless it's so worn that it's twisting between the ways as it moves... and I suspect that much wear would be eyeballable.

Have you closely examined the underside of your ways, Brendan? The condition of the top of the bed is fairly obvious at a glance, but how many of us peer underneath our lathes on a regular basis?

A drop or two of finish may've set under there? Or perhaps there's a burr that's catching the lower mech of the tailstock? After all, most of us set the tailstock mech so that it's only barely releasing when we move the tailstock... so it wouldn't take much of a burr or "debris buildup" to snag things.

(Also just thinking aloud. )

Interesting puzzle. Wear or polishing on the top of the bed should be immediately apparent.

Have you examined the underside of the tailstock after removal? A possible culprit for vertical mis-alignment could be the manner in which you move the tailstock. Pressure near the top would tend to wear the opposing underside, so that it's no longer flat. The same can occur when sanding a block of wood by moving it against sandpaper on a flat surface - if the pressure isn't uniform, the piece can wind up tapered, which of course might be the objective in such a case. BTDT. Corrective action would be to move the hardware by longitudinal pressure nearer to the bed.

It might be too late to institute that new habit, but shim stock at one or more corners of the tailstock could restore alignment. BTDT too.

Cheers,
Joe

Hi to Brendan & Others,
I also do a lot of Turning, & had the same Problem with my 1990 " Tough " a while back.
Like Powderpost, Jim, I completely cleaned my Bed with I think 800G.& the Banjo, as well as the Tail Stock.
I don't think 800 would take any steel off anyway.
I then used my "Silbien Gliet " Silver Glide, on all surfaces,& Bingo, it did the job.
So I thought I also may have had some Rubbish where it shouldn't have been.
So that was my solution. Hope that might help Brendan.
Regards,
issatree.

The sticking ain't the problem. I was more concerned with the possible connection between the sticking and the tail stock/ head stock misalignment. Is it possible that the lathe bed and the underneath surface of the tail stock wear over time to the point that the tail stock no longer aligns with the head stock.

As Wheelinround said, bed wear is a fact of life and I perhaps need to have the whole lot reground. However, I would only trust Vicmarc to do this and it is such a hassle to get the lathe up to them (or down depending on your cosmic view the world).

Thanks to all who have contributed thus far and your suggestions.