south bend 9" questions

S

savet06

Mike Suhie
Gents,
I have had the distinct pleasure of refurbishing a 1945 9" model A (48" bed) that I picked up for a song and have been gathering tooling to be able to do my own barrels.
I have done a lot of reading and have come across many different ideas regarding setup of the lathe, leveling/untwisting, and have borrowed a good friend and fellow shooter's machinist level. There is now no twist in the bed and I have been having a great time grinding my own HSS tool bits and fitting a quick change tool post to the compound. I have fitted one of Butch's tuners to some stainless drops from a local metal supply yard and making some mock savage tenons as well. Turns out my great grandfather was a machinist and when my grandfather passed away a few years agao I have been finding tools that his father used in his machining days...I am using his depth micrometer, needle nosed pliers, a bench vise that he made, a milling vise and v-block, and some screwdrivers that he machined as well. I wish he were around to talk to about this stuff... But I digress.

My question is regarding a test bar: 1) are they necessary, 2) if so, my lathe has the typical wear apparently common in these old lathes up near the headstock, but out where I would be doing barrel work the ways are in great shape. would it be wise to make a test bar the length of a typical barrel or would the wear at the headstock take away any benefit of creating one. 3) If I were to make a test bar from a 2' length of cold roll and then two collars made from aluminum with holes bored to fit the bar would this suffice? would putting the collars towards the tailstock end of the rod say 1' apart give me the information I need? - I'd rather not spend $200 on a long test bar and I don't know if the 1' bar such as Brownell's sells would tell me what I need to know.

Thanks in advance,
Mike
 
Difficult with wear on your ways. When you need your tail stock in a certain place and fairly well aligned, a test bar is not needed. A dial indicator instead of your cutting tool on the live [or dead] center OD and a piece cut to that diameter at your chuck will work. Just run the saddle over from left of the piece stopping to indicate then move to the live center and adjust as needed. Easy to check the height or the tail stock this way as well.
Some like to have a headstock to bed check done by turning a large diameter thick walled tube without using the tailstock. A face cut should be performed as well but that doesn't work with tubing unless you plug and weld the end. It doesn't take much distance to cause issues due to deflection. The idea is to have an extremely stiff piece but people underestimate how much deflection occurs on a regular basis and don't used a rigid enough test piece for the length they use. I don't trust the dials since I use a DRO; the dials can be out a thou easily depending on how the cross slide is manipulated. Moving the saddle can also cause the Y axis to shift into place if it was barely moved initially and that won't show unless you have a DRO.
 
Thanks for the information, Rob. I will give the dial indicator tip a try. I realized that I would have a hard time getting my tail/headstock aligned when I started making cuts and was getting a significant taper. I moved my tailstock the appropriate amount to get an accurate cut and noted that when I brought the center in the tailstock up to the center in the headstock they were nowhere near each other.
I will give it a try today and see how things play out. I have a piloted center and bushings coming soon and am looking forward to eventually chambering my first barrel.
Thanks,
Mike
 
I'm sure you would figure it out but when using the indicator, height is important due to the fact the pieces are round. If you just run over to the center it will read smaller in diameter if it is significantly higher. When the tailstock is only a couple of thou higher and your measuring a piece over an inch, the diameter indicated will be very close.
 
Tonight I took your advice though modified slightly and I wanted to see what you thought. I placed my live center in tailstock and another center in headstock. Took measurements of the od of both with a .0001" mic and subtracted the difference and cut that in half. Placed a di in my tool holder and placed the stylus on the top of the tailstock center and zeroed the I indicator. Ran the indicator to the headstock and. Noted the change in height and left to right. I was off by .002 left to right from the furthest point on the bed to the head stock, but nearly .020 difference in height! I checked my numbers three times and repeated the test twice. This is a similar number to what I get if I just bring the tailstock center to the headstock and visually compare the two points (I know this is a crude method but it was easy to see just how far off they really were).
At that level of difference I will need some sheet metal to get the height right....I just happened to have some in the basement but I wanted to see what what the consensus was on that.
thanks again.
Mike
 
Get the Bed ground flat?

Hey Steve :) ,

Years ago I worked for a dear friend who had a Machine Tool Rebuilding shop in the building across the street from the Duck Inn there in Milldale? Anyway, he sent my SB bed out some place and had all the ways ground flat. He also fitted the Saddle and Tailstock back to the bed after it was ground.

Recently, I decided I would check my Tailstock to see if it was parallel to the ways and at the proper centerline to the spindle. Sure enough, it is not. What I found is the rear of the tailstock' base ways are .008" higher than the front. The quill in the tailstock is accurately horizontally when measured set up on parallel blocks on a surface plate. What to do? Did you see my thread on the SB forums on this? I , so far, have decided to shim the front slightly to get near the center of the Spindle but am considering having the base ways ground parallel, top to bottom.

I had loaned the lathe to friends who had a repair shop for a couple of years and I haven't used the lathe that much over the years so I don't know how the Tailstock could be that far off. I would like to be able to drill somewhat accurate holes with the lathe, eh?

Pete
 
Pete,
I did see your post on the SB forum and wondered if mine would have suffered the same malady. I put an indicator on the quill and spun it out to full length and the needle did not move one bit. I then ran the apron back and forth with the stylus of the DI on the quill and noted no difference there, either, so I think I am in pretty good shape though I really am just guessing.
I have been able to make some very nice threads on this machine and have "fitted" a tuner to my father's shot out kostyshyn 30BR. It has very little slop and mates with the muzzle nicely. I am just awaiting my 60degree piloted center, bushings, reamer and then to find a nice, cheap barrel blank with which to practice my 300wsm build for my savage.
It has been a lot of fun learning all this info and I look forward to screwing up and learning more!
Do you think you'll make it down to the CT States this year?


Mike (Steve)
 
most reasonable way to fix your bed

Mike,
Last Saturday, I talked to a couple of guys who were in the tool rebuilding business. They agreed that having your bed scraped or reground would be more $$ than it's worth. They suggested looking around for another bed that you could swap as more cost effective. We could take a ride up to the used machinery place on the Berlin Turnpike to look.
Regards, Ron
 
not a bad idea, Ron. I am curious as to whether the fact that the ways out where I would be doing barrel work are OK will suffice for now and if I feel the need to "upgrade", as it were, I can always do so later.
My lathe budget has become a bit tighter after my trip to the ER so I have to try to avoid temptation...it is difficult because I see things I "need" all the time!!
Where is the used machinery place? temptation lurks nearby....
Mike
 
I am, but we are having the joint birthday party for the kids on that day. I looked up the website for the Berlin company and it seems like they have a good deal of equipment there.
I will have to keep them in my thoughts for the moment, but rest assured that they will see me there at some point! Hoping to get out to the range tomorrow morning if you want to play hookie.
Mike
 
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