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Model A and Model B parts compatibility

Ben1272

Plastic
Joined
Nov 14, 2011
Location
Massachusetts, USA
I am a newb at all this and sadly could not tell you the proper names for all the different parts of my lathe (for now), so please bear with me!

I have a Model B that I have taken down, cleaned, and rebuilt with various new and replaced components along the way. It was not probably deserving of such a rebuild, but it is the lathe I had and I felt compelled, so I did the work. It has a 36" long bed. I bought a rebuild kit with the felts and seals and bearing, and found replacements for the myriad damaged parts. Other than a worn-more-than-i'd-like bed, it is probably not half bad now. My biggest gripe is how sloppy the main handwheel is on the carriage. Question: Maybe there is a way to tighten it up?

Now, I purchased a rough Model A lathe with a 48" long bed. It has v-belts (instead of my flat belt Model B), it came with a decent cabinet, obviously the gearbox, and the rest of it is as rough or rougher than my model B was when I started.

Another question: I am thinking there is probably a way to best combine these two machines to make one better machine. Specifically, I am thinking I'd like to take the Model A head and mount it to my model B bed and also use my refurbished model B carriage and tailstock. Can someone tell me if the leadscrew on my Model B will mount into the gearbox of the model A? If not, could I find the parts needed to do the swap?

Also, the backgear on the model A is missing all sorts of teeth, but my model B has a nice clean backgear. Can I swap them?

I guess, in general, are most of the parts swappable between these machines without some unforeseen problem that a newb like myself would not consider?

Thanks in advance for your help.

-Ben
 
For the most part,yes.

But it is easiest to cut down the model A lead screw and turn down the the end to fit the bracket.

You will be one bolt short for attaching the gearbox too...that should be addressed also.

Make sure all parts will fit up before making mddifications, it may be best to swap the wanted parts into the your old headstock rather than swap the whole head.
 
Thanks for the suggestions. I thought about turing down the Model A lead screw, but then looked at the model B lead screw and thought it looked like it might be able to use it with the gearbox. I have never turned something so long and am a little hesitant to try this as my first attempt!

I am curious why you say it may be best to swap the wanted parts into my old headstock versus swapping the hole head?
 
I do not have much experience with lathes, and I am wondering how much impact my worn bed ways will have on my ability to make accurate parts. The Model A bed has a small lip worn into the ways. My model B bed is less worn, but still has not insignificant wear. I figure my own inexperience will have the biggest impact on the parts, but if I am doomed to never hold a decent tolerance I should keep looking for a better bed. Any thoughts are much appreciated.
 
Forget what the bed looks like.

How it turns is what matters.

Ps- best to swap parts because the headstock casting is fitted to the bed,
 
I bought the felt/gasket kit for the model a. (I already own the rebuild manual)

Took the carriage apart and found the apron wheel shaft (and another shaft) have worn their holes large enough that I think I'd like to try and bush them. Is this as straight-forward as reaming the existing holes to a larger size and turning a brass bushing to fit it and the handwheel shaft? Does anyone know of a good description of this process in this or other forum? I have a Clausing mini-mill and access to a hardinge lathe, so I think I can make the parts/mods. Would love suggestions/advice.
 
I've rebuilt a few aprons. I think you'll find that not only are the bores worn oversize, but the shafts are worn undersize. Bushings won't fix that, because you cannot install them on an undersized shaft when the shaft ends are still original size. What I have always done is to clean up the bores, and make new oversize shafts. The only place you cannot do that easily is the clutch- but that one can generally be turned undersize for it's entire length. Then a bronze bushing can be used.

allan
 
It is not quite that straight forward.
The holes wear egg shaped. If you run a drill or reamer through the egg shaped hole the new hole will have a different center location. Now your gear and shafts won't line up.

You have to mount the part and indicate it in on unworn part of the bore. Then bore the hole round. At this point you can run a reamer through it to get it to the bushing size.
 








 
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