Centres don't line up

[Tiger]

Dear all,

Thought I'd try a little pen turning and found that my lathe the Hare and Forbes 900 b/w centres has its centres well apart:mad: . I reckon at least 2 mm laterally and about 1 mm vertically. I then proceeded to file away the base of the tailstock and that did get it a bit closer but there is some slop in the tailstock now and so getting it accurate depends on where you tighten the camlock. I gather that I would now need to build up one part of the base on the tailstock so there isn't too much slop, but how do you do that? I tried a search on centres not lining up but didn't find much :( . I know that for spindle turning it doesn't matter much about the centres but when drilling it does. Also, what is the best way of permanently packing the tailstock vertically so that I don't have to keep shimming it yet the tailstock will still ride smoothly on the bed?

[Bodgy]

Tiger, how's the parallel universe this morning? Same problems as I have, amongst others.

If your tailstock assembly is steel, you can run a few weld beads on the offending base, then file off. Thats, of course if the headstock is at fault. If its the ways, then it will be out a different amount at different distances from the chuck.

My problems seem insolvable, without buying another lathe. What I plan to do is buy a mini metal lathe, sometime down the track and bodgy it to do the pen turning stuff.

Frustrating, is'nt it.

[macca2]

I have a similar problem with my lathe and have solved it with a piece of brass shim permantly fitted under the back side of the tail stock.
I turn pens and drill pepper mills etc with no apparent problems.
Macca

[Tiger]

Thanks, boys.

The parallel universe is fine, I bet your garage even looks the same as mine with all the mess. My tailstock is cast iron so the welds are out.

Macca, do the brass shims attach themselves or do you need some sort of adhesive?

[bsrlee]

You can buy special rods for cast iron welding & hard facing - I have about 1/2 a pack in the shed, but it would take a day to find them :rolleyes: It is a fair bit of effort to prepare the casting for welding too - you have to heat the whole thing up first, then cool it slowly after. There is probably something on-line, so try Googling weld + cast iron.

You could also think about brazing, but I suspect that you could also make a new lower spacer out of a couple of bits of bar stock, make it a very neat fit in the ways & it might pull the top carriage into place horizontally - you'll still have to shim for the vertical adjustment. I'm looking at having to do this for my lathe - its OK vertically but you can twist the upper carriage so the point is off by 3-4 mm horizontally.

[macca2]

Tiger...I cut the shim about 30mm longer than the tail stock base. Place the shim between tail stock base and lathe bed, then turn up the two 15mm pieces each end. Make sure you round off the ends before fitting or you may end up with a sharp corner of shim just waiting to snag your arm when you reach thru to get tools etc. I know because I did.

Macca

[rocabig]

You could try Belzona or devcon (they are a metal putty) once it has set you could file/machine it to your requirements

Richard

[Tiger]

Rocabig,

Sounds like a good idea, do you know where these products can be bought from?

[hughie]

Tiger, If the lathe is new I would be having a chat to Hare and Forbes. Even if its a cheap lathe, they still should line up as it is key function of the lathe to be able to turn between centres.
hughie

[Bodgy]

Tiger - Appropo of nothing very much, I had a turn on a decent lathe last night. The difference was astounding, and the lathe was probably older than I!

It certainly made me think.

[Waldo]

G'day Tiger,

It may be that the lathe is not horizontal and level to the floor. Had a similar problem myself and found by putting a few shims under some of the legs to get it level that the centres were properly aligned.

[Tiger]

Tiger, If the lathe is new I would be having a chat to Hare and Forbes. Even if its a cheap lathe, they still should line up as it is key function of the lathe to be able to turn between centres.
hughie

It's more than 12 months old and having spoken to Hare and Forbes, they tell me that none of their lathes have centres that line up. "If I want that level of precision I need to get a more expensive lathe".

[hughie]

It's more than 12 months old and having spoken to Hare and Forbes, they tell me that none of their lathes have centres that line up. "If I want that level of precision I need to get a more expensive lathe".

:mad: Now that would p.... me off no end as it is a basic function and operation. I might be inclined to take it further...consumer affairs etc
Its a bit like buying a TV and is volume control is not functioning.
We/you buy in good faith that it actually works and can do what a common lathe can do.
But seeing its 12 months old they would not doubt suggest that it was fine when you bought it -that is if they were ever brought before any sort of tribunal.
I guess you will have to go with the packing idea and damn I suppose my MC1100 is the same.
hughie

[rocabig]

you should be able to get either one of them from repco, not sure if supacheap has them, dont think so.

Richard


Rocabig,

Sounds like a good idea, do you know where these products can be bought from?