# MT5 Collets? MT5 Lathe Spindle Taper



## wildo (Apr 19, 2018)

I'm doing it! Finally after a year of waiting and collecting nickels & dimes, I'm a mere $500 away from a new lathe!! 

I was reading the specs a bit closer and noticed that the spindle taper is an MT5 taper, rather than the 5C I has assumed. I'm glad I caught this before adding a set of 5C collets to the bill. With a spindle bore of 1 9/16" I was starting to wonder how a 5C collet would work.

Ok- but I don't seem to get any google hits for MT5 Collet sets. Can anyone fill me in on what the intention is for using collets on a lathe with a MT5 spindle taper? Would I need to instead purchase a 5C collet chuck or something?

The lathe: http://www.precisionmatthews.com/shop/pm-1236-t/

Spindle Bore: 1-9/16”
Spindle Taper, Internal: MT #5
Spindle Mounting System: Cam Lock, D1-4


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## wildo (Apr 19, 2018)

Perhaps I've made a bad assumption here (which is why I posted this in the Beginner Forum) that ALL lathes would have a "C" style spindle taper. I assumed that ALL lathes would have something like a 1, 3, 4, 5, or 7C spindle taper to use C style collets. Clearly that wasn't a good assumption, but it leaves me wondering how collets are used in non-C style lathes. This might have been a more broad question than I realized.


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## ttabbal (Apr 19, 2018)

MT seems to be more common on newer hobby size lathes. My PM1127 has MT5 in the spindle as well. 

If you want to run collets, you have a couple choices. 5C are available from PM along with the matching chuck. Your spindle takes D1-4 chucks like mine. The direction I went was to use ER40 collets on an adjustable chuck from Shars.


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## wildo (Apr 19, 2018)

ttabbal said:


> The direction I went was to use ER40 collets on an adjustable chuck from Shars.



With the ER Collet Chuck- do you still get full pass through? With an MT5 to ER collet holder you would lose the ability to pass long stock through the spindle, right? I will likely go down the 5C D1-4 collet chuck because the nature of the stuff I make means removing from the lathe, working in a spindex on the mill, and then back to the lathe. It would be nice to not remove the stock from the collet to help maintain tolerances. Since the material I'm working with can be well over $1K per foot, it's very important to me that I can utilize the pass through capability of the collet so I don't waste material.


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## Dave Paine (Apr 19, 2018)

Collets options come up in a number of threads.   A recent example.

Collets and collet blocks

5C allows up to 1 1/8in dia.   ER40 allows up to 1in dia.

You should get full pass through.   The spindle opening is often the constraint.  Your intended lathe should have greater opening than the collet max diameter.


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## ttabbal (Apr 19, 2018)

It sounds like you already have some collets for the spindexer. I would get whatever chuck matches your existing equipment. I have read that the 5C PM sells is a quality device, and you could get it shipped with the lathe. I have not personally used it though. 

The chucks generally have full passthrough, MT adapters usually don't. I would verify with the vendor to be sure as it's very important for your work.


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## derf (Apr 19, 2018)

You need a 5C spindle adapter. It's a sleeve that goes into the MT5 socket and accepts 5C collets.


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## Bob Korves (Apr 19, 2018)

The way this usually goes is you buy a 5MT to 5C adapter, and then buy or make a drawbar to draw the collet tight on the work.  The spindle adapter is $98 from Grizzly (import).  Grizzly's part number is 4026001.
https://www.grizzly.com/parts/COLLET-ADAPTER/P4026001
Here is my collet closer build.  The only things I bought for the build were the thrust bearing and the collet to spindle adapter.  Edit: And the DOM draw tubing.
https://www.hobby-machinist.com/threads/hand-wheel-collet-closer-build.62278/


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## Glenn Brooks (Apr 19, 2018)

Looks like Derf and Bob have it covered.  I have MT 5 in a tailstock for my old standard Modern lathe.  Live centers look like huge tank killing sabot rounds.  Never heard or seen an MT5 (or MT4) collet. So eventually bought a 7” lathe for the smaller stuff. So good to know about the 5c adapter.  

Thanks for bringing up the thread. 

Glenn


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## pacifica (Apr 19, 2018)

you might want to consider a bison or tmx d1-4, 5c collet closer that  fits on the front spindle nose, $500 to $800,should give you .0002 with hardinge collets.
 Lever type would need to be removed if you change belts for the low speed and hi speed ,interrupts the work flow costs $599.


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## wildo (Apr 21, 2018)

Thanks everyone- great info!


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## e189552 (Apr 21, 2018)

I had a Summit 19 x 60 some years ago, had a 4” spindle bore with an MT#6 spindle taper.
At the time I had Royal Products build me a 5C closer. The only really strange, custom part was the huge aft spindle adapter.
The front was a combination MT6 to MT3 or 4 and that adapted to 5C.
Worked great for anything under 3/4” diameter or so.
Currently trying to locate a similar arrangement for my MS1250 have everything except the 5C adapter for the spindle.


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