# Parts interchangeability between SB 9A and 10L



## MontanaLon (Aug 4, 2019)

So my lathe is doing well but as always, it could be better. It is an 1939/40 10L. Things I would like to change on it are as follows.

It has the single belt position pulleys on the motor to countershaft. It would be nice to have the wider RPM range the 2 position pulleys offer.

It doesn't have a taper attachment. That would also be nice to have. 

The compound is a little chewed up from PO crashing it. 

So the question is, would those parts work on both the 9A and 10L?

Reason being is I spotted a 9A at a decent price which includes a taper attachment and also has the 2 position pulleys. I could buy it for less than I would pay for the taper attachment alone.

Of course it all depends on if it would actually fit on my 10L. I know some of the parts are completely non-interchangeable, like the saddle and apron, tailstock and the headstock. And the bed is 6" shorter than mine so the lead screw wouldn't be useful to me. 

So will those parts fit?


----------



## SLK001 (Aug 4, 2019)

Almost zero parts are interchangeable between the two models.


----------



## lafester (Aug 23, 2019)

Buy it and part it out so you can get what you want? The pulley might actually swap over. Tool holders and accessories swap between the two.

Sent from my Pixel XL using Tapatalk


----------



## silverhawk (Sep 15, 2019)

The tool posts may swap, but nothing else will.  I struggled with my first 9", a "junior", and nothing from the 9A/B/C/10K lathes would fit it.  It was made in 1929, and sold in January of 1930.  I picked it up thinking all 9" lathes were the same.  In 1938, South Bend started producing 9" lathes called "workroom" lathes, using a much lighter bed than the previous 9" lathes.  This triggered phrases such as a "heavy 9" and such for the previous model.  The newer ones had narrower beds.  These newer ones also utilized 18DP gear trains.  The older ones used 16DP gear trains.

With the introduction of the "light 9", South Bend also introduced a 10K (called a "light 10").  These 10K's are built on the same platform as the 9A/B/C (or "light 9"), so parts are going to be fairly interchangeable for them.  The end of the serial number on South Bend lathes indicates the model starting some time around 1938.  Serial numbers for 10k's end with a "K".

My heavy 10, a 10L, has a serial number ending in "RKL".  10L and 10R lathes (both classified as "heavy 10" lathes) end in the respective designation letter for the serial number.  These heavy 10's have everything interchangeable with the exception to anything that touches the spindle (e.g. the headstock).  The regular (10R) has a larger spindle than the 10K, but is smaller than the 10L.  The 10R has about a 1" through-spindle hole, while the 10L has a 1 3/8 through-hole spindle.  The heavy 10 models used the 16DP gears.  Incidentally, the 10L headstock set onto my junior/heavy 9 bed without problems (other than an under-drive-vs-over-drive).

If you have a 9A "workroom" lathe, nothing really transfers over to a heavy 10.  If you are after swing, go for a 10k - most stuff will translate.  If you need the spindle through hole size provided by a 10L or a 10R, just assume you are starting over with everything (you can keep the tool posts and associated tool holders, but that's about it).  You can migrate a chuck by changing it's backplate, but I'd probably just send the chuck with the old lathe to it's new home.


----------

