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South Bend Heavy 10L Spindle Adapter Problem

Pellethuntr

Plastic
Joined
Aug 15, 2013
Location
Livonia NY
Hi all, long time lurker/reader but finally found a question I couldn't answer myself.

I bought an MT4.5 - MT3 adapter sleeve from Grizzly. Part number P97302912.


I had read on a few different posts from here and other forums that this was a direct copy of the original South Bend made adapter and that it would work in the older machines.


It came today and I took it out to the shop to have a look. It's a nice snug fit but it seems a little short? Maybe I am wrong and that is how they are suppose to be?


I was really hoping that this one would work, the originals are a bit expensive for my taste.

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I can't tell you exactly what "should" fit your spindle, others here will chime in with that info I'm sure, but you are correct in thinking that what you have does not look right. Usually the adapter sticks out just a bit from the end of the spindle nose. I'd say nearly flush to an 1/8" or so proud is fairly typical.
I think you either have the wrong size adapter, or someone has remachined the taper in your spindle.
 
I'm still learning the nuances of my own SB lathe tooling and accessories. However, I've noticed that while the particular spindle nose taper angle (Morse or otherwise) may be standard, the diameters at either end of the adapters were often not "standard" in the sense of sharing a particular OD at the big end, for instance, with other machines using the same taper angle.

Looking at your photo, even if it's a good fit in the taper, I think you'd be asking for trouble as much of the inherent lateral support of a taper would be lost.
 
there is SO much BS about SB spindle tapers being spread about it's hard to know what's what.

It's not 4.5...if this is a 10L(and I mean 10L, and not just the generic term "heavy 10" which could be a 10R OR a 10L) then it is a SB proprietary taper that is made to the taper of MT3 but a physical size of approximately MT5

See SB spec sheet here-
http://www.wswells.com/data/spec_sheet/5224.pdf
 
I wish I had the experience and equipment to make up a bunch of SB nose adapters and thread protectors. They go for crazy money on eBay.
 
kinda surprises me that thread protectors go for real money. You can make one on the lathe you need it for provided there is a chuck.

The other parts are only difficult because of the need to make an accurate taper on the ID and OD. The OD is actually not that hard if you set up the compound properly.
 
I wish I had the experience and equipment to make up a bunch of SB nose adapters and thread protectors. They go for crazy money on eBay.

likely to run close they would need a special between center arbor. the taper would need to match the spindle nose for square and fit. The OD close for balance ...and likely need to be at least a little hardened.

Protectors would be an easy job.
 
JFK makes the collet adapters.
Miller Machine makes the spindle reducing sleeves.

I have two nearly-complete JFK lever closer assemblies that I picked up for a steal last year. I have new bearings for both, just need to shorten the tubes about 2", fab (or cast) the swing arms that attach them to the headstock, and make the extended spindle gears to get out past the banjo cover.

I got one 5C adapter with my lathe, but need to find another for the second closer set that I intend to sell to another 16" owner when it's complete.
 
Someone recently posted they got a new SB 5C adapter for 170bucks from JFK IIRC.

That's a bargain.

JFK quoted $206 for the nose adapter today (I believe it to be the same part for all large bore "heavy" SBLs 10L, 13, 14.5, and 16 -- does not fit small bore 10R, 13, or 14.5 which use smaller collets). They will make up to a 2.5" OD flange diameter for the thread protector to push against.

Now that we've managed to hijack the OP's thread about MT spindle adapters completely...JFK may also be willing to make that type of adapter as well, but if it's not a stock item I would guess it will be more than the $206 quoted for the 5C adapter. If the OP needs a MT spindle adapter only to use a test bar, Miller Machine offers ground and hardened test bars to fit the SB nose without an adapter. My recollection from talking to Brian two years ago is they run around $400 each. Miller's quality, by all accounts, is top notch. If you can live with a little less runout certainty, buying the MT adapter wherever you can find it along with a pair of standard 3MT test bars in the headstock adapter and in the tailstock is financially easier to justify. Also more versatile in the future for other machines.
 
Your adapter will not work. It is almost completely out of the taper section (it only runs approximately 2.5" from the mouth of the spindle). I'm not really sure that it is engaged at all. On my 10L, there is a step to 1 3/8" about 3" in from the mouth. If your adapter is approx 3" long, then it is running into the 1 3/8" region of the spindle.

I am in the process of fabricating these sleeves for my 10 (I'll have extras). I had to match the taper of the spindle using a DI with my taper attachment.
 
there is SO much BS about SB spindle tapers being spread about it's hard to know what's what.

It's not 4.5...if this is a 10L(and I mean 10L, and not just the generic term "heavy 10" which could be a 10R OR a 10L) then it is a SB proprietary taper that is made to the taper of MT3 but a physical size of approximately MT5

See SB spec sheet here-
http://www.wswells.com/data/spec_sheet/5224.pdf

Thank you for that link, not sure how I have never come across it before. It has lots of useful info. I am/was positive that my SB is a 10L but I double checked with the measurements shown in the link and confirmed. The spindle bore is exactly 1.629" at the "mouth".

I was hoping that this adapter from Grizzly would work but I will have to send it back for a refund and go with plan B. Which is making my own.

Not sure exactly what the best way to do it is yet.:scratchchin:
 
When I made my adapter i made it pretty close to the measurements above. I did make the female a Morse 3 Taper but it could as easily been anything .



Don
 








 
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