How would I Convert SB9"B" to model "A" with quick change gear box?

Hey Thanks Bill. I didn't realize I had to change the apron too. And then there's the issue of the "0" dial which my lathe does not have and neither does the one in the second photo I posted..I think? If I could find a good parts donor machine it would be worth doing but I'm not sure I want to invest a lot of money in this small lathe. I paid $100 for it and probably put another $400 in it for a chuck, AXA tool post and a better motor. I've been looking for a good 12" or 13" x 4-5' lathe with a quick change for a while, but nothing has turned up yet.

Bill, We're practically neighbors. I'm up your way all the time.

Marcel
 
I just noticed that, we are neighbors (almost).

"Billy G" :thumbsup:
 
The link Bill posted was for a C to A. Yours would be similar, but the apron should be the same between B and A. The gearbox info is what you need.

There appears to be a typo in the 'required parts' list for converting a C. It says you need an A or a C apron, but I'm sure you need an A or a B apron, so you're good.
 
xalky said:
Hey Thanks Bill. I didn't realize I had to change the apron too. And then there's the issue of the "0" dial which my lathe does not have and neither does the one in the second photo I posted..I think? If I could find a good parts donor machine it would be worth doing but I'm not sure I want to invest a lot of money in this small lathe. I paid $100 for it and probably put another $400 in it for a chuck, AXA tool post and a better motor. I've been looking for a good 12" or 13" x 4-5' lathe with a quick change for a while, but nothing has turned up yet.

I didn't have to change the apron on my B to ecome an "A".... get the box and a leadscrew from another "A" with the same bed length your bed is.
you will also need the 20 and 56 tooth syud gears that an "A" model requires and the gear for the leadscrew that will reside in the gearbox on the end of your leadscrew.
If you want , pplease feel free to contact me via e-mail joe@oldetimemachines.com
joe
Click to expand...
 
I did the conversion of my SB9 last year. Only trouble I had was putting the counterbore in the hardened V way. I got it mostly in and then had to use a Dremel to grind it larger. I was lucky enough to buy the QC gearbox, keywayed lead screw and the small I think 20t gear. I did not want the cross feed to work ,but I needed an easier way to thread than the changing of gears provided. It works great. I have a homemade thread dial and it is great also. I did 2 jobs on it and I have to make a new shank for my boring head. I tried turning the shank down that's in it and I didn't quite get it running "0" . I must now unscrew it and turn and thread a new one between centers. I only paid $125 for my gear box and it's in perfect shape. I used the instructions given in a pdf file that you have access to. Good luck to you, Boot
 
The apron on the pic does not have a power feed selector lever or a clutch knob, just a half nut lever. It looks like a change gear type or "C" type if you perfer. So for power feed you would need a apron. See my 9A pic.
Paul

SB LATHE.jpg
 
I missed that too, Paul. That is a C.
 
xalky said:
I would like to convert my 1938 southbend 9 model B to a model A with the quick change gearbox. Does anyone know of a write up to do this conversion?

Marcel,

I did the conversion and it was simple...just follow the advice you have been given in this thread.
get the gear box, the proper leadscrew, the required gears and put it together.

On my conversion i was perplexed with the binding of the lead screw until I realized that if the machine was to be a Model "A" the factory properly aligned the lead screw with the lathe bed rack
I had to slightly shim the QCGB to get the screw in alignment and then All was well....simple matter once you know the problem.

you may not need to do this but if you have a problem once you tighten the screws on the QCGB to attach it to the bed....you know what it might be. Don't turn on the machine untill it works smoothly after it is all set up. Good luck and you will love it !
joe
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