Repairing Atlas 10" lathe

[Ross77]

Hi John
(sorry to hijack your thead Irving)

you mentioned the atlas 10, do you know of a fix to repair the bed? I was given one because the previous owner cut two slots in the bed to machine a disc brake..........Unfortunatly I was mis-informed by a local welding shop who said they could fix it no probs........ and you guessed it I now have a bananna shaped bed. I know its probably a lost cause but its a shame because the rest of the machine is in perfect condition.

[Ross77]

Thanks John.
This was a "one day I'll fix er up" but since a 16mm dia, ball screw wont fit through the chuck on my working Granville lathe (Myford7 Copy) then its just come to the top of the list. Its not as simple as cutting the bed is it? the motor mount and the screw cutting gears will be lost no?

Maybe Id better start my own thread if this has options...........( sorry Irving)
Ross

[bogstandard]

If you look at how the lathe is built up, you should find that most of what you are worried about is mounted onto the detachable head not the main bed girder.

The girder will have to have a few holes recut in the correct places, namely the head hold down bolt holes, the reverse mechanism holding screws and one end for mounting the foot. There might be a couple of others to drill and tap, but nothing of any consequence.
The leadscrew would need shortening at the tailstock end, but that can be left until the very end, but that would need a lathe to recut the threads on the end, as your lathe won't be able to do it because you are working on the required threading leadscrew. Catch 22. I was lucky in that my old leadscrew was in position while I cut the new one down to size, so I used the Atlas to do the job.

For someone who knows what he is doing, maybe 3 to 4 hours taking it steady, and that is for the whole job.

Yet again, you are a little far away for me to assist with my machinery.

If you do raise a new post, I can show you a couple of easy mods to do that make the lathe even more accurate and easier to use, as I still have a few pics of some of the mods I did.

You must also realise that I am quoting from memory here, so I just might have forgotten a few things.

John

[Ross77]

You make it sound so easy. New post started in the lathe section.

Is it posible for you to copy your previous posts across?

Many thanks

Moderater: Copied older posts across, they appear above due to timestamps

[bogstandard]

I didn't realise how bad it was. I thought maybe one cut, somewhere close to under the chuck. But having two, so far apart puts a different light onto it.

A gap bed just isn't feasible, due to the way the lathe is actually made. My new lathe, even though massively built compared to the Atlas, has a gap bed, but as soon as it is removed, all guarantees are down the river, as they can't ensure it will go back in exactly the same position as it came out. The Atlas would just bend like a banana in the middle.

The first option would be the best bet in the beginning, but you would need to ensure that you got a bed to match either the 42" (rather rare) and not have to cut the leadscrew or the 36" version and hope that the person selling has retained the leadscrew to go with it, or you will end up cutting the one you have. If you can find a 48" one with leadscrew, then great, snatch his hand off. The price of a new leadscrew (about 10 years ago) was around £125. I daren't even consider the cost of a new bed. Clausing USA still stock most new spares for these machines. Putting a wanted ad on John Stevensons site would be one option, or trawling ebay for "Atlas 10F" will eventually come up with something that might be OK. I got a lot of bits off there, and even in the last few months, I have noticed a few.

For a repair job, and now having seen it in the flesh, I would cut it off at the weld under the chuck, leaving the cast in bridge next to it intact, then dress the remaining cut off end to the same as the end you have cut off, and put in all the required holes

Doing it that way, you could dress the welded part of the bed under the head down to or below level of the main bed. You can then easily shim up the head to get it back into the right position if you had to go low. Anyone with a mill with a largish table should be able to machine that for you.

With regards to putting in linear rails. I personally don't think you could get a lathe of this size rigid enough with just rails. It would be nowhere as near as rigid as the girder. Once you get over a certain diameter of cutting on a lathe, the cutting forces required can get very large indeed, and do require large masses to keep everything stable.

You said over on the minilathe post that I make it sound so easy. In fact in my eyes, it is a dead easy fix to do, IF you have the machinery to do it, and the experience of fixing large items such as this. I can't help it if I have both. The main problem is I am not there to do it for you, so I, and hopefully other people, will have to try to give you as much info that is required, so that at least you stand a chance of completing it.

John

[Swarfing]

I never said it would be easy.. Ask yourself a question? you would not be here if you were not up for a challenge?.... Seriously though falling short of repairing it or replacing it then you are only left with shortening it or shorten it with gap still but smaller and remake the portion on the back end?

[irving2008]

Theres a 10F on ebay right now... but finishes in 10mins

[Ross77]

Thanks John, you are the lathe master, and I really appreciate your advice (just wish it was a year ago before i had it welded) So the best option is to hold out for a replacment bed and do it properly.

With regard to shorting it the only bit that cant be moved is the mounting foot as this has a wider casting at that point. I would also have to redrill the tray and move the stand legs closer. The other option is to just reposition the headstock and ignore the screw cutting stuff, replace the lead screw with a ballscrew and fit an indexer on the spindle shaft for cnc screw cutting, while I wait for a new bed.

I never said it would be easy.. Ask yourself a question? you would not be here if you were not up for a challenge?....

Ive just converted a pillar drill to a cnc mill so yes I'm up up for a challenge

Its just that Ive learnt from my mistakes and there are no shortcuts, eventualy you end doing as you should have done in the first place but it costs more......:heehee:

[Ross77]

Theres a 10F on ebay right now... but finishes in 10mins

Damm didnt see your post, looked like a 36" anyway and complete so would be a shame to break just for the bed...

Cheers anyway

[Ross77]

John
Ok I've placed a few wanted ads and saved an ebay search so hope fully one will turn up...(Flying pigs etc...)

In the mean time would you care to expand on the other mods you talked about? Thanks