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9" Southbend Rebuild

turbotadd

Aluminum
Joined
Jul 22, 2010
Location
Stillwater, MN
I know some of you might prefer to not have this thread here because it's a "hobby" machine, but I think there will be some good info.
I was documenting my efforts on another forum, but I noticed Richard was no longer posting over there, and I really value his input as he taught me how to scrape.
Anyways...

I started the project with the compound rest and finished that a year or two ago and finally decided to get after it again.
I had measured about .005" wear on the v-ways so I had all of the surfaces on the bed machined by a machine tool rebuilder. One nice thing about the size of the 9" is that the bed fits nicely on my 36" surface plate. Measuring the flat tailstock way showed no needle movement along the entire length. I hesitated for quite a while before scraping the ways for fear of screwing up the nice flat and true surface, but I decided that I do want a scraped finish on the ways. I started practicing on the bottom of a cast iron lapping plate with my old blue Biax and a 60R blade. My goal was to do one pass in each direction and get a nice checkerboard pattern. I finally got comfortable and was happy with how things were looking, so I did the flat tailstock way. Just for the heck of it, I blued it up with a 36" straightedge and did a couple cycles to knock down any really high points. I was pretty happy with how it looked, so I moved onto the tailstock v-way. I used the biax on the inner surface of the V-way, and hand scraped the other surface.

I plan on putting .016" Turcite on the saddle to bring it back up to height, so i scraped off the ridges to get down to the plane of the worn surface, then I put the bed up on my plate, put the saddle on shims, and checked the fit with the apron bolted on. I established that a few thou off of the surfaces of the saddle should work well with the .018" thickness of the Turcite and epoxy combined.

I hauled the saddle into the shop at work and indicated it in using both the machined shoulder where the block that captures the rear way bolts on, and a 5/8" ground shaft in the V's. Both readings agreed within a thou.
Next steps will be to wrap up scraping on the bed, then apply the turcite to the saddle.

I'll post more as I go.









 
Hobby machine? Looking forward to seeing the progress. :)

Btw, how did the machined bedways initially print up with your straight edge?
 
I should have taken a picture of that... The ways only hit on the ends initially. Even after one pass in each direction, the ends had more contact. Doesn't take long at all to come in.
 
Tadd,
Did you take over to my friend Rick at A & D over in WI? He has a couple of nice converted planer mills. Chris German (Ironsmith) send a grinder bed to him and he did a nice and reasonable $ job. It looks good. I only have one thing I would do differently. Put in a minimum of .032" Rulon/Turcite on the Saddle. If you have to touch up the .018 plus cut some oil grooves in it will be pretty dang thin. I am glad you scraped it as if you leave soft iron smooth the oil won't have anywhere to adhere to and it will wear faster. i would not flake it as the flakes are .002 deep and will allow dirt in under the wipers. Thanks for posting here. Rich
 
I've been making some progress on my little lathe. I took your advice Richard, ordered up some .032" turcite, and re-machined the saddle for the additional thickness.
I scraped the flat ways on the saddle, then the V-ways on the saddle using the dovetail straightedge and the previously scraped cross slide alternately. It is surprisingly difficult to get the parts fixtured in appropriate positions (right height, angle, etc.) I had to end up securing the saddle to a piece of wood, then hang on to that. A little crude, but it got the job done. I also struggled to get a good relief in the corners of the V's. I used a hacksaw, but material was reluctant to leave the middle because the saw would rock. I worked around that by removing all teeth at the ends of the blade, leaving only the middle.
Here are a couple pictures I took along the way.








Prepping for turcite:


The master of chicken-scratching:
 
Better watch your son, he'll want to over haul that Tonka Truck next!

Nice Job you've done on your 9" SBL. I reconditioned my dad's about ten years ago. The bed on his only had about .0015" wear in the worst place. I actually did not do much to the bed. Just a little "touch up" and rescraped the slides. Its just like new.

Ken
 
Tadd,
That looks really good. One thing you should do is shorten the stroke a little on Biax and hand scraper. 1/4" long max. I am glad to see your passing on the scraping....so cute, I bet he loves helping Daddy :-). My Son Alex never liked scraping when I taught him. He is a type A person and had no patience. He now works for the Cell Phone Tower company making a lot of $$ at 28. Do you mind sharing what Rich charged you to machine the bed? I just wrote a member today about relieving the center 40% of the saddle for clearance as the saddle rocks when he changes directions. Your picture with the factory relief is a great learning tool. Thanks again for sharing on here. I am very proud of your progress! Rich
 
Thanks for the support guys! It has taken lots of struggling and practice, but that has provided a great learning experience. Hinging parts and indicator set-ups once so foreign are like second nature now. It was $500 to machine all of the surfaces on the bed. Little man loves "scraping the brue" (can't quite say blue). I need to start thinking about what I am going to put this thing on when I get it done. I've got a bunch of T-slotted aluminum extrusion I think could be fashioned into a nice stand.
 
Hinging parts and indicator set-ups once so foreign are like second nature now.
Thats the joy of getting some expert tuition. You can watch you tube to you are red in the face. But a few days of, thats right, thats wrong, and this is why, just opens up your scope to further learn on your own. Get over the hurdle of the basics, the rest is practice.

I also really enjoyed the picture of your young bloke at the bench.

Best regards.

Phil.
 








 
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