New headstock on old lathe

[Holt]

I am about to buy a lathe, unfortunately the budget only allows an old lathe with bronze (or whatever material it is) main bearings. i am used to use a lathe with a top spreed of 3000 rpm, but i doubt the old headstock can handle this. has anyone made a new headstock with angular contact ball bearings for one of these old lathes? i was thinking of using the front wheel bearing from a front wheel drive car, they are build to run at least 2500 rpm, can take heavy load, and are cheap.
Any thoughts are much appreciated.
Holt

 

[steamer]

What kind of lathe?

Some manufacturers offered both....but it depends


Dave

 

[Niels Abildgaard]

Hello Holt
3000 RPM parts are not very big or long.Do the big things in the old headstock and small parts on a purpose built high speed spindle put up temporary in front of the old one.Saddle will of course be using a less worn area of bed and longitudinal and transverse feeds can work normally.

Kind regards and what lathe is on Your mind?

 

[Holt]

The lathe i am looking at at the moment, is from Danish Machine Company, i have only seen pics of it. i have used a couple of these old lathes at the beginning of of my career as a machinist, with a top speed of app 1500 rpm, and that was rather scary compared with a lathe with ball bearings (the favorite lathe at work is a schaublin 125, so i guess i am a bit spoiled)

 

[n4zou]

The only time I've ever used a lathe at speeds above 1,000 rpm was for polishing the finish. I've done that at slower speeds, it just takes a little longer to do it. Personally; I would just use it the way it is. I would rather have Babbitt or bronze bearings. Pulling the spindle out of a headstock with Babbitt or bronze bearings is no big deal. Doing that with a spindle mounted with tapered roller bearings is a real pain in the A** and it's time consuming.

 

[steamer]

Generally, I would agree....leave it be.

What hasn't been discussed.....is the fact that most lathes are "fitted" and the center heights between the HS and the TS are matched.......Now what they did with this lathe I don't know.....could be OK or could be way off...

Dave

 

[Holt]

The only time I've ever used a lathe at speeds above 1,000 rpm was for polishing the finish

We run the schaublin at work at top speed 3000 rpm most of the time, we use 5c collets when ever we can, we use inserts, and that require higher speeds

Pulling the spindle out of a headstock with Babbitt or bronze bearings is no big deal. Doing that with a spindle mounted with tapered roller bearings is a real pain in the A** and it's time consuming.

How often do you pull your spindle out of the headstock?

Generally, I would agree....leave it be.
What hasn't been discussed.....is the fact that most lathes are "fitted" and the center heights between the HS and the TS are matched.....

I do realise its not a straight forward job, but i don't intend to mount the original headstock again, once the new headstock is straight with the bed, the tailstock can be bored and a bush mounted to gain precise height, another reason is to make a spindle that accepts 5c collets directly

 

[steamer]

Hi Holt,

If your comfortable in your abilities to do that, great! go for it!

That decision is yours though....It can be very difficult to advise someone on a forum as it's hard to tell what capabilities the OP
has.

Best of luck and WE LIKE PICTURES! th_wwp

;D

Dave

 

[Blogwitch]

Just to give you a little insight into what you already have, and what you are considering doing.

I had an Atlas 10F for many years. The first couple of years I ran it with the plain Babbit bearing head, then changed it over to a Timken taper roller head.

By swapping over to the bearing head allowed me to run the lathe a lot faster, but the surface finishes were never as good as when running on plain bearings.
That was the one thing I really missed, and even on my new lathe, which has tapered bearings, I couldn't and can't ever reproduce those superb smooth finishes using a straight cut that the Babbit bearings gave me, I always have to finish off with a final hand polish.

So before you go doing anything tragic, try your machine out fully first, you never know, you could soon start to appreciate what you already have.


John

 

[Florian]

Hi Holt

I can tell something about Schaublin Headstocks:
The old ones had a double row cylindrical roller bearing with tapered bore.
To adjust the bearing play, you drive the inner race onto a taper which has to be on the spindle.

These bearings are high precision bearings and quite expensive, a single one costs about 650$ (had to replace the one on my schaublin lathe... )

When you have such a bearing, you will get very good surface finish. But the bearing alone is not everything.

To reach a good surface, you will need to be able to adjust all the guides to almost no play and therefore they should not be worn out.

Also the headstock should be machined very exactly including precision ground/precionsion machined bearing seats to provide a good fit on the outer race.

To get stability, the headstock needs to be scraped in onto the bed / headstock mounting surface to get a "full contact" surface.

If you are able to do all this and willing to spend a lot of time and quite some money, then go for it.
Otherwise I recommend to search a little longer and get yourself a used lathe in good condition with the desired specifications like collets in the spindel and everything else you want.

Cheers Florian
ps: I bought me a used 102VM and have been restoring it for quite a long time.
pps: www.lathes.co.uk may help you with the lathe identification....

 

[steamer]

Hi Holt

I can tell something about Schaublin Headstocks:
The old ones had a double row cylindrical roller bearing with tapered bore.
To adjust the bearing play, you drive the inner race onto a taper which has to be on the spindle.

These bearings are high precision bearings and quite expensive, a single one costs about 650$ (had to replace the one on my schaublin lathe... )

When you have such a bearing, you will get very good surface finish. But the bearing alone is not everything.

To reach a good surface, you will need to be able to adjust all the guides to almost no play and therefore they should not be worn out.

Also the headstock should be machined very exactly including precision ground/precionsion machined bearing seats to provide a good fit on the outer race.

To get stability, the headstock needs to be scraped in onto the bed / headstock mounting surface to get a "full contact" surface.

If you are able to do all this and willing to spend a lot of time and quite some money, then go for it.
Otherwise I recommend to search a little longer and get yourself a used lathe in good condition with the desired specifications like collets in the spindel and everything else you want.

Cheers Florian
ps: I bought me a used 102VM and have been restoring it for quite a long time.
pps: www.lathes.co.uk may help you with the lathe identification....

Ditto!

Dave

 

[n4zou]

When I was in the US Navy obtaining the technical training to become a Gas Turbine Systems Technician one of the courses involved with that was Vibration analysis. In that class we learned that all roller bearings produce vibration. This vibration was used to determine the health of the bearing in a Gas Turbine Engine. What makes this important to understand is a Babbitt or Bronze bearing has no moving balls or rollers to produce vibration and will actually absorb vibration. This is an advantage when a good surface finish is desired or required.

 

[Holt]

I am in contact with the seller, and i will try to get an appointment on sunday to see the lathe, if i buy it, i will carefully test it and run it for a while before i decide what to do. maybe the attachable high speed spindle that Niels was suggesting isn't such a bad idea after all. The lathe is quite a bit newer as the ones on www.lathes.co.uk
Thank you all for your comments, i will be back when the deal is done

Holt

Fixed link. Don

 

[Niels Abildgaard]

Hello Holt

Your Lathes.uk link is wrongly typed and we want a picture of the lathe.
Making a high speed spindle can maybe be easy.
Use a two bit boring bar between present spindle and tailstock to machine two bearing seats in suitable piece of iron,steel or alu and this is it.

 

[Holt]

The link works in my end you wont be getting pics before sunday, i want to close the deal before i post pictures

 

[dsquire]

The link works in my end you wont be getting pics before sunday, i want to close the deal before i post pictures

Holt

You had misspelled "Lathes" originally, therefore the link didn't work. I edited it and fixed the spelling and that is why it works now. :bow:

Cheers

Don

 

[firebird]

Hi Holt

I had a similar problem with my Myford lathe with a top speed of around 700rpm so I built a new head stock. Follow this link.

http://www.homemodelenginemachinist.com/index.php?topic=15628.0

Cheers

Rich

 

[Holt]

Don, thanks for correcting my link.
Rick,i have seen your tread before, nice work, but i think i would have mounted a second motor directly to the new head, would have been a bit quieter

Holt

 

[Holt]

As promised, a few pics of the lathe i am thinking about buying:
Certainly the right size for my taste, a bit over 1 meter between centers

Most of the brown stuff are grease, and not rust, it would be possible to clean it up quite nicely i think.
There are a few things that worries me

No change wheels at all, how on earth should i figure out which wheels i need
Next thing:

The table on the gearbox only shows tread per inch, and i would mostly be using metric treads
I wonder if any clever heads here could tell me if it could be made metric with the right change wheels

 

[n4zou]

Here you go.
The "NthreadsP" and "BoxfthreadP" Programs
for Screwcutting Lathes
http://www.lathes.co.uk/latheparts/page14.html