Overhaul of a 9" SB model "A"

[steamer]

After the above is done:

Overhaul the lever action collet closer
Paint and make functional the lever action cross slide.
Repaint the turret tailstock and the milling attachment.
Put door handles on the base cabinet.
Make a high speed spindle.
Lever action cross slide gib replacement...I may do this sooner as I'll be set up.
Auxillary spindle drive and idler pulley stand for the high speed spindle.
Other storage options...Maybe a backsplash with shelves?

Dave

 

[Maryak]

This is going to be the mother of all South Bends on the planet :bow: :bow: :bow:

Best Regards
Bob

 

[steamer]

Well, I've suffered with old worn out lathes long enough to want something better ....now that I've gotten some hard won experience, I know what it is I want .....so now I'm trying to get just that.

Am I indulging? Probably.....but I earned it and I know plenty of men my age who spend WAY more money on far more trivial objects of affection....or affliction...as the case may be.

In the end , I'll be using the lathe for projects that I want to do, and teaching my son at the same time, an education you can't buy today anywhere.....that's money and time well spent in my book.

Dave

 

[bronson]

I can't wait to see your southbend lathe finished with all those rare factory options it will be a dream to use.

Bronson.

 

[steamer]

Got the NOS half nuts today!....SWEET!

I'll put them on this weekend!

I found a new problem, the nose of the compound swivel, on the side of the clamp screws is worn .002" This is because the previous owner turned the compound without ever cleaning under it. OK so that's the bad news

The good news is the new T slotted cross slide is nice and flat and should make a nice reference to scrape it back in.
That won't take too long.

Maybe I'll bring it to the show tomorrow.....we'll see

Dave

 

[steamer]

OK got some scraping to do.

The compound base is worn at the nose. Kinda like a snow ski.

It's flat at the back and swoops up at the front ahead of the pivot.
This comes from the operator not cleaning the cross slide before he rotated the compound. There are two design features of the Southbend that exacerbate this problem

The compound pivot is clamped via two wedges that bear on a tapered pivot that is part of the compound base.
These two wedges act on the front half of the pivot diameter only. Nothing on the back half

Additionally, the bearing area of the compound base is at it's smallest over this area. This area is the dirtiest part of the lathe right under the cut zone of the tool. When the compound is loosened and then swiveled with out cleaning this area, dirt and chips get under it and act like abrasive...and of course, this is the area where the clamping force is the highest!

The wear here , because of the way it's clamped can be detrimental to the performance of the lathe. Instead of laying down flat against the bearing surface of the cross slide, when the clamps are tightened, the nose of the compound tips down and the rear tips up. The compound isn't sitting on its bearing surface anymore, but is now like a "See saw"...depending on how the cutting forces are transmitted to the compound, it can start to move and vibrate under a cut.

Unclamped, I push down onthe back of the compound and nothing happens, push on the front and it bounces .002"
So I need to correct this.

Dave

 

[steamer]

Additionally, I'll need to create a master to scrape the top of the Tailstock Base. This master will need a groove in it to clear the tongue on the TS base.

So, if you go back a ways, I mentioned that the first TS base I started was scrapped when the endmill pulled out.
I'll use this piece of stock as the basis of a scraping master. But it will be recycled into a useful tool once that purpose has been completed.

Dave

 

[Mosey]

How did you determine whether the TS was at the proper height relative to the HS? (dumb question)

 

[steamer]

Hi Mosey,

Not a dumb question at all!
I swept the tailstock spindle with a indicator mounted to the headstock spindle. It was about .018" low at the TS side

that was the data I used to make the decision to make a new TS base.

Dave

 

[steamer]

Hi Mosey,

I'll try to stage the indicator set up to sweep the tailstock this weekend.

I had a rather unpleasant revelation this past Thursday. The Saddle was not flat!

It was touching on the front "V" but was rocking on the back "V". I was convinced that it had worn that way....but checking the movement...all .003" of it, it was the same anywhere on the bed......OK What's up?

So I marked up the tailstock end of the bed....like the Headstock end, this part of the bend is pretty much pristine and original...of this there is no question. I rubbed the carriage there and low and behold, the front V had pretty good bearing , but the rear was touching at 1 point!

The saddle was twisted! OK...the front V showed signs it was rotated ....so lets do this I started scraping the rear V at the high tailstock side and slowly brought the surface down...as I did the front V bearing got better and better, so I didn't scrape it at all...just the rear V. Pretty soon it was touching on both the front and rear V way in the back and I slowed down and gently finessed it in. And there it was ....rock solid on the ways again and showing a good bearing.

I put my T slotted cross slide on the saddle and swept the table along the long axis of the lathe and it's parallel to the ways within .0003" over 4 1/2 inches.... I'll leave that be.

Next I need to install the countershaft and bolt down the bed for real to level it. I have a more optimistic outlook about her now.



Dave

 

[bronson]

Sounds like we should see this lathe running in the near future. :big: Doing a great job. :bow:

Bronson

 

[steamer]

What I think happened is 60 plus years of stress relaxation happened. I think it was flat when new, but relaxed as time went by. Man my right arm hurts right now......but the beer tastes good! ;D

Dave

 

[steamer]

Bronson

Thanks for your interest and support!

I can't quantify "near future" at the moment....but I've just about convinced myself I don't need to regrind the bed....as the wear appears minimal

We'll find out soon enough

Dave

 

[steamer]

I scraped in the compound last night and this morning. The guides had been scored from dirt and lack of oil, but it came in pretty quick....its WAY better than it was when I started!

To do this you scrap the bottom of the compound flat ways to the surface plate, then use this as a master to scrape in the swivel base flat ways.

Then I scraped in the top of the compound parallel to the flat ways. Here's a early on markup

This surface was worn very hollow ...about .0025" and leaning toward the front. I started with a file to bring it in to about .001" and then scraped it in from there. At the end I used a flat blade and draw scraped it so that it would match the cross slide appearance. It's parallel to about .0004....

I then scraped in the bottom of the swivel compound. I used the cross-slide as a template It didn't take very long. You can see the mark up and also the reference...the marking is pretty well removed.....It sucks right down tight with a dab of oil now.

I may still need to tweek the cross slide flat ways on the saddle, but I think for the most part the scraping is done on the saddle components.

Dave

 

[steamer]

Went to my home town "Tractor Supply" that just opened up. NICE PLACE!

I bought 3 casters for the base to make it mobile. I started to make the frame work that will hole up the base from 3 x 4 x .25" angle and 1x1 angle

I'll post more as I get there.

Dave

 

[steamer]

OK yesterday and today I spent stripping and degreasing the lathe bed. I had to set up a temporary tank to set it in while it soaked in simple green

The tank lined and ready to go.

And with the SG in.

I eventually took the bed feet off.

I'll post some of the aftermath once they're loaded

Dave

 

[steamer]

Here's the lathe the next morning.....

And ready to paint.

I found that during the night it got cold....about 40 F while it was nearly 70 during the day.

The old rule of a chemical process rate doubles or halves for every 10 degrees certainly held true!

During the night, the SG cooled down and very little happened....I needed to warm it up in the moring with more hot water to get it to kick

I recycled the SG into my "soup bucket" and cleaned out what was in that.

That way I get to use this stuff for a while.


Dave

 

[steamer]

After the bed came out and was set to drain, I washed it down with isopropyl alchohol ( standard dry gas)

That drys the part without leaving a residue.


Dave

 

[steamer]

Well, I am setting up the base to mount the casters, and then mount the lathe to it. In preperation to do that I needed to strip the top of the base of it's two coats of paint. SG started to work if I sprayed it on, but on a part this size laying flat, it's not real effective. I resorted to Citristrip for this application, its a big flat surface, and it all came off in a couple of coats with a putty knife. I'll need to mount the lathe and the countershaft so that I can size and order the belt.

Dave

 

[steamer]

Score!

Got a pair of factory leveling feet off the bay. That will help in fine tuning the leveling of a lathe that will probably be moved alot.

Dave