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Help identifying spindle taper

Hathaway98

Plastic
Joined
Oct 30, 2021
Hi, new here. I’m having trouble identifying what spindle taper is in my Nardini ND1760E lathe. I’m pretty much a novice machinist. I went to Trinidad State gunsmithing school, and know the general functions of lathes. I chambered 20 rifles while I was there, and machined various simple tooling. Unfortunately, I never had a class that taught more specifics on lathe parts, tooling, standardized parts, etc. I ended up buying a lathe after graduating, and never got power to it. It’s been setting a couple years, and I’m now looking at getting things running. I’ve got most all the tooling I need, but having trouble ID’ing my internal spindle taper. Thought it was an MT6, but only about an inch of the dead center fit, and it’s obviously the wrong taper as well as size.(light Ring formed on dead center where contact stopped the center). Way too large for mt5. I have some rough measurements on the taper and just wondering if anyone could recognize it. I believe it’s a D6 camlock spindle nose casted to the spindle. Anyway, here are the measurements, forgive my lack of proper terminology.

Large side taper dia.: 2.200”

Small side taper dia.: 2.075

Taper degrees: 2*

Taper length: 2.75 roughly

Spindle standard dia: 2”

Any help would be greatly appreciated. Also, if you know of a good machinist handbook with this sort of info, I would love to hear your recommendations. Also have a sharpe lmv 9x42” vertical mill. Sorry about the lengthy post….
 

deltap

Cast Iron
Joined
Sep 3, 2004
Location
Wisconsin, USA
Get a Machinery's Handbook. It should have all the info you need on standard tapers. If mt5 is way sloppy you could turn an adapter for a 5. For temporary service chuck a piece of round stock and machine a dead center on it. I have one I marked the number one chuck jaw on and it is repeatable for most jobs.
 

johnoder

Diamond
Joined
Jul 16, 2004
Location
Houston, TX USA
Assuming the length is nearly what you wrote, it comes out to .545" taper per foot on dia

(Its also fairly close to 3mm taper on dia. in 70mm of length)

less taper than Morse (and Jarno) and more taper than B&S

Lots less taper than the American Standard which is .750" per foot on dia.

Handy info here

Standard Tapers

have fun
 

thermite

Diamond
Way too large for mt5.

D1-6 is what is published, yes. Also that your TS is "full" MT 4.
"Expect" the spindle taper to be "partial" MT5, same as Nardini used when building Cazeneuve's HBX under license, ELSE a "partial" of MT 6.

Spindle bores are constantly using partials of standard tapers to maximize through-bore vs available space and wall thickness.

Most run about half the normal for the full-length goods. The makers just never seem to agree on where to take the "half"... for over a hundred years, already, yet!

:)

IOW it should seat oddly as to gage line, but match the taper.

Try that with an inexpensive adaptor sleeve if you don't have anything else handy.

"Whatever" it is, you can make an adapter for it to mount less costly stock MT 3 or MT 2 goods. Most lathes left the factory with those. They get lost.

Or do as most folk do and turn a 60-degree cone on stock held in a chuck for the HS-end centre. Drive the dog off a chuck jaw. Use it, aside, it, take a fresh skim cut next time you need to work 'tween centers, else not bother.
 

Hathaway98

Plastic
Joined
Oct 30, 2021
Hey guys, thanks for the info and tables. Ya it’s a funky taper, not very handy. I’m planning on building an adapter when I get the machine running. Hopefully I can keep the TIR to less than .0005”, but we’ll see. Thanks for the other info as well. Would still love to know what Nardini threw in there, are there metric tapers as well? Can’t find much info on them. I’ll get that book ordered, looks like it’s pretty much the industry standard.
 

thermite

Diamond
Hey guys, thanks for the info and tables. Ya it’s a funky taper, not very handy. I’m planning on building an adapter when I get the machine running. Hopefully I can keep the TIR to less than .0005”, but we’ll see. Thanks for the other info as well. Would still love to know what Nardini threw in there, are there metric tapers as well? Can’t find much info on them. I’ll get that book ordered, looks like it’s pretty much the industry standard.

It is only likely to "matter" if you try to find a collet-closer system that uses the spindle bore taper for mounting.

I do NOT use my 12 jarno on the 10EE's for that - my several collet systems mount off the D1-3. Sjogren 2J, Rubberflex 9XX, Hardinge 2J "loop" closer, Burnerd Multi-Size, 5C key-crankers, ER-40..

ELSE.. a "no dogs allowed in the dining room" face-driver centre. Which I have (Bakeur) for the HBX-360-BC (5 MT) ...but not for the 10EE's.

Those, too, can be had in plate-mount for DIY backplate or in native D1 mounts. See the Riten catalog for examples.

With a more expensive D1-6 to satisfy, you might use the taper to hold a DIY handwheel & drawtube closer. Not all that fast as to cycle-time, but handwheel closers are easily made dead-nuts accurate for small money.

Tube stock can be bought pre-threaded for 5C etc, so that is about the SECOND lowest cost and least machining a start to a collet system as can be had.

The "first lowest cost" is ER-40. On a "plate-mount". Held in a 4-J chuck.
Each collet covers 1 mm range... and you have a capability "at once", and cheaply. The 4-J + collet even lets you do eccentric round goods easily.

CAVEAT: ER wasn't meant for stock holding, like a 5C or 2J. It was intended to hold tooling. So it can be a slow-to-operate pain in the arse if you are in any sort of hurry.

ER can give you damned good grip and accuracy for small money, though. Same again as hex, round, or square collet blocks for mill, grinder, or hand working on the bench, same collet set.
 

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
A little searching says the tailstock is MT4. in my limited experience I would guess MT6 in the headstock. Probably a cut down short version of the taper.
The Nardini 1440 lathe is MT5 for the headstock.
Bill D
 

L Vanice

Diamond
Joined
Feb 8, 2006
Location
Fort Wayne, IN
The 5C lever collet closer maker called "JFK" has apparently undergone a change of address and website usefulness. I recall they had a very long list of 5C headstock spindle adapters (including dimensions) that would fit almost any lathe. I think that the list included some that were called 5-1/2MT, a size not included in the original list of Morse tapers for drill bit shanks. But JFK also had a number of different "gage diameters" available for the 5 and 6MT tapers because the various lathe makers never standardized their products. Their current website is useless, though one could try asking them what 5C adapter will fit that particular Nardini.

Larry
 

thermite

Diamond
Hey guys, thanks for the info and tables. Ya it’s a funky taper, not very handy. I’m planning on building an adapter when I get the machine running. Hopefully I can keep the TIR to less than .0005”, but we’ll see. Thanks for the other info as well. Would still love to know what Nardini threw in there, are there metric tapers as well? Can’t find much info on them. I’ll get that book ordered, looks like it’s pretty much the industry standard.

Of necessity, Morse was adopted into Metric-world. ISTR they call MT out as KT?

Metric-specific tapered goods are more commonly seen on motor shaft to flywheel fit-ups, such as 1 in 8. As with jarno those are agnostic, being ratios. IOW are sort of linear or diametral unit "independent", much as degrees are.

S**t still has to fit. Or not. But Wot the hey.. part of why machinashitists even have a trade and get paid, ain't it?

Why bitch about THAT?

:D
 

Hathaway98

Plastic
Joined
Oct 30, 2021
Thanks all for the conversation. It’s not an mt6 cuz it’s to small and the wrong taper angle.(tried bison mt6 dead center) Not an mt5 cuz it slips right past the taper, and on into the spindle, as well as being the wrong taper angle again.(tried a mt5 adapter sleeve there)So I don’t think it’s a short Morse taper. For starters here, the main use would be a dead center, which as others said, I can build an adapter, and use a sacrificial center in the mean time. A 5c or possibly R8 collet system is hopefully in my future down the road. I used 5c with a handwheel constantly during my time at school. It is indeed an mt4 live center in the tail stock. Just don’t understand why they wouldn’t have just cut an mt6 or mt5, and skipped a tolerance stacking adapter bushing…. Not sore about it, but seems foolish.
 

thermite

Diamond
Thanks all for the conversation. It’s not an mt6 cuz it’s to small and the wrong taper angle.(tried bison mt6 dead center) Not an mt5 cuz it slips right past the taper, and on into the spindle, as well as being the wrong taper angle again.(tried a mt5 adapter sleeve there)So I don’t think it’s a short Morse taper. For starters here, the main use would be a dead center, which as others said, I can build an adapter, and use a sacrificial center in the mean time. A 5c or possibly R8 collet system is hopefully in my future down the road. I used 5c with a handwheel constantly during my time at school. It is indeed an mt4 live center in the tail stock. Just don’t understand why they wouldn’t have just cut an mt6 or mt5, and skipped a tolerance stacking adapter bushing…. Not sore about it, but seems foolish.

Nardini is an odd entity. Not so much a "factory" as the typical ever-shifting sands of a multi-way Brazilian cross-breed between investors, marketeers, engineers, craftsmen, project managers,.... and politicians.

So yeah, "weird" does creep in! Or never leaves? You'd have to know Brazil and the Brazilians?

:)

D1-6 works a right treat for low-stress goods - such as a drawtube collet-closer thimble or a HS-end centre ..... using only three of its normal six camlock studs. At which point it still repeats well, but swaps faster.

Tempting to JF ignore the oddball bore taper?

I surely would.

Much as I import-not-fab the painfully proprietary Cazeneuve HBX backplates. Don't need but so many. Last near-as-dammit forever. And I have other s**t to do.

Or even other s**t to NOT do! You'd have to know FRENCH weird?

:D
 

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
I have no idea what was common in Brazil 30 years ago. maybe they were told that the taper used was the coming thing in world wide lathe production and they better get with it or be left behind in the dust.
I remember as a high school kid hearing the USA had to metrify or petrify. That was some 45 years ago, still waiting to see more metric then English nut and bolts in a store.
Bill D.
 

thermite

Diamond
I have no idea what was common in Brazil 30 years ago. maybe they were told that the taper used was the coming thing in world wide lathe production and they better get with it or be left behind in the dust.
Oscar Beale never did get the take-up on jarno B&S goaled for it, BUT... jarno IS one of the easiests tapers to do as any fraction one cares to chop out of it and in any size ever standardized or never.

Simpler math. ALWAYS the same side angle where B&S & MT are NOT! Both have oddities in their ranges.

Soooo jarno HAS been adopted for a lot more HS spindle bores than ANY OTHER use of it.

There is another less-mentioned taper standard not uncommon in large bores. Some other PM'er will recall it?
 

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
My understanding is the MT was supposed to be a nice ratio like 5/8 per foot. I think it varied by size? But Morse could not measure that accurately, before micrometers were invented etc, so it is off a little bit and everyone keeps making it to match. Jurno does make sense and it is modern enough that it really is a whole number taper.
Bill D
 

thermite

Diamond
My understanding is the MT was supposed to be a nice ratio like 5/8 per foot. I think it varied by size? But Morse could not measure that accurately, before micrometers were invented etc, so it is off a little bit and everyone keeps making it to match. Jurno does make sense and it is modern enough that it really is a whole number taper.
Bill D

I had the impression that - either of MT or B&S - they could measure well-enough.. but.. as with US threads ... had optimized some of the sizes for better performance AS the size altered the wishes?

That left the USA with hard-to-explain threaded goods. But each is stronger than its Metric closest equivalent, where a numerical system had to go forth off theory on paper and meet actual metal instead of what had been proven to JF WORK "in the metal" being adopted TO paper tables....because... ta da... it worked.
 








 
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