Author Topic: Banban's 13" South Bend Lathe Saddle Reconditioning  (Read 1372 times)

4GSR

Banban's 13" South Bend Lathe Saddle Reconditioning
« on: August 18, 2018, 09:54:10 PM »
I've taken on the job of reconditioning of Bambam's saddle for his lathe.  I believe I had a thread started on the old forum which is now lost.  I'm going to try to restore some of it here.

Started out re-scraping the cross slide which is about 85% complete.

The hacksaw blade shown is for cutting undercuts at the bottom of the dovetails for clearance of your scraping tools and mating dovetail.

Here some pictures of the progress on it.

« Last Edit: August 18, 2018, 10:29:33 PM by 4GSR »
Ken

4GSR

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #1 on: August 18, 2018, 10:27:13 PM »
Started blanking out the cross feed screw last week and almost finished today until my 9" South Bend lathe crapped out on me. A babbit bearing seized up on the counter shaft next to the large flat pulley.  Get to this later.
For the cross feed screw, started out with a piece of 1045 T.P.G. material 1" diameter.  I thought it was Stressproof, but it did not cut as good.  But that's okay, it'll make a nice replacement screw that will last several life times to replace the original that is probably made from 12L14 steel. 
Since this cross feed screw has to be turned down from 1" down to .625" on each end and a short section in the middle turned to .906", it has to be roughen out first.  Before doing anything, Center up and center drill each end.  I start out by roughing the longer end first.  Leave it about .070-.080" big on the OD. Let cool with the live center still holding the end.  Flip the part to the opposite end and rough it down to .070-.080" oversize. Again, let cool. Flip to the other end.  Check runout, should be close within say .005-.007" TIR.  Any more than this, I'll discuss later on handling this.  Getting late, I'll add more tomorrow.
Here's a few pictures.  Darn, I didn't take any pictures of it being rough out.  Sorry.

 
Ken

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Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #2 on: August 18, 2018, 11:20:47 PM »
What are you using for a straight edge, ken?
I never did start scraping. Never got the tools. However, I have a decent hunk of cast I can practice on...
the town repaved my in-laws street a couple months ago. The surface grinder/ripper didnít pull the wheel up fast enough and hit the sewer in the road. Took a huge chunk of the sewer out. He tossed it on the side of the road along with the 5 fist sized broken carbide button teeth. I should have kept one, pretty impressive looking.
My plan with the sewer cast is to mill it flat/ square and start playing with it if I ever manage to get a scraper. I COULD cut it into a short straight edge. Itís about 8Ē long. About as long as my lathe compound - which will either get rebuilt one day or removed for a solid tool post.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

4GSR

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #3 on: August 19, 2018, 03:17:45 PM »
What are you using for a straight edge, ken?
..........................................

I have a couple for doing this stuff.  Here's a picture of two of them used on this project.
Ken

4GSR

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #4 on: August 19, 2018, 03:39:09 PM »
When the diameter gets to .650" diameter (.625" is finish OD), the runout should be near zero, or less than .002" TIR for the entire length. Just eyeball it, if you see any movement, you got TIR.  This cross feed screw has a hub or boss almost midways on the length of the cross feed screw.  Chuck on one end with center in the other end.  Take a sharp pointed high positive rake tool and very lightly take a cut.  May have to take several until the runout is zero on the hub.  Next run the steady rest or chuck on this hub and take a light cut on the one end. Next swap ends and take another light cut.  This should eliminate all TIR. Now to take the finish cuts.  Nez sent me a DCMT holder that uses DCCT insert.  This is a high positive insert for cutting aluminum.  It also works good for finish cuts on most stainless steels and steels.  This is what I used to make the finish cuts on the screw. The last and final cut, halfway thru it, my 9" South Bend lathe crashed on me.  Watch on my thread on getting it back up and running.

Here's some more pictures of the cross feed screw in the last few finishing passes.
Ken

4GSR

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #5 on: August 19, 2018, 03:41:54 PM »
Oh, one more picture of my device used to alleviate chatter while taking finishing cuts.

Ken

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Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #6 on: August 19, 2018, 04:46:21 PM »
Just a brass rod? I was going to ask how you managed that long thin piece without a steady rest.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

4GSR

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #7 on: August 19, 2018, 05:15:31 PM »
Just a brass rod? I was going to ask how you managed that long thin piece without a steady rest.

A block of hard wood works too. 

Oh, this is not OSHA approved, use at your own risk!
Ken

Bamban

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #8 on: August 20, 2018, 08:18:25 PM »
Looking good, Ken.

Thank you for taking on the project. I have a couple barrel blanks for my personal use for next year that would the first ones to be finished on the reconditioned carriage.

Thank you.

Nez
USAF 1972-1978
Distinguished Rifleman Badge 1234
P100
High Master XC, LR

4GSR

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #9 on: August 20, 2018, 08:21:24 PM »
Got the South Bend back up and running.  Cross feed screw is ready to get threads cut on it.  Get the follower rest set up tomorrow evening and start thread cutting.  I'll try not to forget to take pictures.

Ken
Ken

4GSR

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #10 on: August 22, 2018, 10:02:33 PM »
Here's a pic of start of the threading of the cross feed screw.
Ken

Bamban

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #11 on: August 22, 2018, 10:23:40 PM »
Here's a pic of start of the threading of the cross feed screw.

Looks good, glad Miller Engineering responded with no sale for the screw when I sent an email to Brian, yours would be much better as it is fitted to the almost new nut.

Thanks for the update, Ken.
USAF 1972-1978
Distinguished Rifleman Badge 1234
P100
High Master XC, LR

4GSR

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #12 on: August 23, 2018, 09:28:35 PM »
Bambam,

Have bad news, I cut the screw undersized.  The nut has about .010" visual slop in it. :'( :'( :'(

Other than that, it looks good.  But it's not right.  I can either make a new nut to fit the new screw or go ahead and make a new screw.  Either way, it's about the same time involved.  If I make a new screw, I have a better piece of material that will be a lot easier to cut than this 1045 was.  I have plenty of 660 bronze I can use to make a nut from if needed.

Ken
Ken

Bamban

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #13 on: August 23, 2018, 09:32:37 PM »
Ken,

Whichever makes sense to do, easier and takes less time would be my input. Obviously, you make the call. Again, at your convenience.

Thank you for the update.


Nez
USAF 1972-1978
Distinguished Rifleman Badge 1234
P100
High Master XC, LR

4GSR

Re: Banban's 13" South Bend Lathe Saddle Reconditioning
« Reply #14 on: August 23, 2018, 10:04:55 PM »
I'll sleep on it tonight.
Ken