Hercus 260 (south Bend Gs26-075)

Boris,
I am sure your headstock spindle is 5MT,I wouldn't think that Hercus/Southbend would deviate from the Heavy 10L spindle that much as to bore one as a Jarno taper
UNLESS that spindle was going to a different country(not USA).Those taper dimensions listed above are for male tapers.
Good Luck and I'll measure my spindle for you this evening.
Mickey
 
Jarno tapers were pretty much obsolete by the time that lathe was made. The additional stickout of the male taper will bring it to the chart MT5 sizing. The spindle does not have a full length taper. I am pretty sure you will find it to be a MT5. The MT5 tapers are in use pretty much everywhere, see if you can borrow a tool with that taper to test the spindle. Don't buy the Jarno if you cannot return it or you want a wall ornament (in my opinion.) A quick Google search does not show the words "Hercus" and "Jarno" together anywhere except in your post here.
 
Bob,

thanks for that post, it makes much sense.
If the adaptor doesn't go all the way to the surface of the spindle it would probably be very close.

Mickey, as far as I'm aware they were made for the US market only and many of them were used in the military.

It makes sense that these things were standardised across Hercus and Southbend but you're the first person I've found that has one besides seeing this machine rarely come for sale through an agency.

Ok, thanks again.
 
Boris
Ok my lathe spindle at the large end of the taper is 1.620 so I am sure it is the same as yours I actually measured with an inside mic right at the crest.So you have to find at least 1.72 piece of bar for your headstock center.Bit of advice just turn a center and do NOT harden it,you can always use the machine to fix your 60' cone and not a grinder.
Mickey Mullins
 
I should mention your taper should stick out enough for your drive plate with a D1-4 it's pretty substantial.
Mickey Mullins
 
Boris, did you change your bearings when you pulled your spindle out, if so, do you remember the bearing part numbers?
 
No I didn't change the bearings. They were fine. But the bearing #'s should be in the spare parts manual.
 
I borrowed a test bar from a workshop as I want to make sure the tailstock centre is true and adjust if necessary.

I bought an MT5 to MT2 adapter for the spindle so I can put a dead centre in the spindle to put the test bar between the centres.

Problem I have is the MT5 doesn't fit the spindle. The smaller end of the adapter is too large to fit into the spindle. I
borrowed an MT4 adapter just to see the difference it's much too small for the taper I have in my spindle.

I'm not sure what to do next....
Any ideas or suggestions?
 
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