5C spindle adapter Sheldon UM-56-P 13" swing

[earthbound]

Hi folks, I have a question about my lathe that I seem to get a lot of conflicting information on when I scour the internet. It's about the spindle taper dimensions. It's really unclear what exactly I need to suit my needs with regards to a 5C spindle adapter. I have read countless times that the L00 noses take a morse taper 4.5, but now that I just purchased a MT4.5 to MT3 adapter from grizzly, I'm seeing that that's not the case. I own a dead center MT5 that also doesn't seem to seat quite nicely. I've read about the issues with it sticking out ~4 inches but I just don't feel it seat correctly like a MT3 does in my tailstock. Can someone either confirm or deny the "modified MT5" that I've seen tossed around these forums? I have my lathe setup to cut a MT4.5 with a larger gauge line right now (using that MT4.5 adapter as a reference), but I don't want to waste my time if it's actually supposed to be a MT5 with a smaller gauge line. Thank you in advance for your help.

Drew

 

[dlane]

I've been told they are a short mt 5
I have a te1256 p, but haven't messed with it yet.

 

[earthbound]

Thanks for the input dlane. Maybe the MT5 dead center I have is a little wonky? It just doesn't seem to lock so well. I'll try polishing it and reinserting it. If it locks, I can just use that as a reference and machine the adapter with an appropriate gauge line.

 

[4GSR]

It's really a 4-3/4 Morse taper, which is non-existence. The gage line at the face is 1.625", with a taper equivalent to a no. 5 Morse taper. There is a drawing of the collet adapter available in the Sheldon Lathe group on Yahoo. If I can find the drawing, I'll post it here.

Ken

 

[earthbound]

Ken, thanks for the drawing! That will be helpful. Upon looking at the dimensions however, the indicated taper on the drawing doesn't match that of a MT5. The taper per inch comes out to .0498" taper/ inch. Whereas, a MT5 should be .0526" taper/ inch. Is it definitely supposed to be a MT5 taper with a 1.625" gauge line? Or is it a "Sheldon" taper?

 

[4GSR]

Ken, thanks for the drawing! That will be helpful. Upon looking at the dimensions however, the indicated taper on the drawing doesn't match that of a MT5. The taper per inch comes out to .0498" taper/ inch. Whereas, a MT5 should be .0526" taper/ inch. Is it definitely supposed to be a MT5 taper with a 1.625" gauge line? Or is it a "Sheldon" taper?

It's been a while since I checked the taper against my adapter. I swear up and down the taper is exact to a 5 morse taper. I get a chance tomorrow I'll recheck it. Ken

Sent from my SAMSUNG-SM-G920A using Tapatalk

 

[4GSR]

I checked the collet adapter and I come up with .0507" taper per inch. The adapter I have has been checked against two different Sheldon spindles and blue in exact!!!
I want to check this one more time when I get a chance and make sure of my measurements. Ken

Sent from my SAMSUNG-SM-G920A using Tapatalk

 

[wa5cab]

Ken,

I put the drawing in DOWNLOADS. If we need to edit it, let me know.

That's the problem with these "specials". Sheldon isn't the only one to pull this. It's my understanding that there are at least two different companies that call their taper "MT4.5". And they apparently aren't the same. At the other end of the cost spectrum, AA did the same thing with 0MT.

 

[4GSR]

Robert,

Was checking over the drawing, It's not 100% correct according to the adapter I have on hand. When I get a chance, I'll redraw to what I believe is correct.

I recall reading somewhere, and I'm not going to mention any names right now, that Sheldon did not make any of these adapters. They were supposedly made by Royal and maybe one of the other tooling manufactures out there, too. I don't know how true this is, but is probably a valid statement to say.

 

[wa5cab]

OK. I'll add a note to the entry in DOWNLOADS for now. Adding a note to the actual drawing would be more trouble so I'll wait on doing that until you are sure of your numbers.

If the Sheldon spindle taper is supposed to be 5MT, I would see whether actual measurements confirm that.

As for who actually made the adapters, Royal would be a good guess. It isn't generally known who actually made them in the 1930's or 40's (Atlas or some sub-contractor) but by the 60's, Royal was making the lever-type collet closers for the Atlas 12" machines that Atlas made and Atlas and Sears sold..