# What can you tell me about fitting a collet chuck? (mini lathe)



## Mr. Science (Mar 24, 2019)

So - i've done LOTS of searching on this forum and others as well as watching pertinent youtube et.al. on the subject but I'm STILL a  bit confused on this topic. I'd like the ability to run collets since I'm needing to do most of my work with small diameter parts ...

My chinese mini has a Morse 5 taper - from what i understand I can find a collet chuck that will fit the taper directly or I can go to an adapter PLUS an ER type chuck - but if i want to maintain my pass through hole capacity (from my understanding) i'm better off with the MT5 direct fitting chuck ( or no?) - if you know of any great FAQs on the subject I would be grateful though I guess my situation is unique enough that it may not help ... I'm just trying to connect the dots here ... thanks!


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## Latinrascalrg1 (Mar 24, 2019)

Well if you use the headstock taper attachment method I would think you would loose a good portion of your "pass thru" capacity.

If your lathe is similar to the HF mini lathes on which the chuck attaches to the backplate with 3 or 4 mounting studs and nuts that mount from the backside and you wish to keep the pass thru capacity I would think your best bet would be to go with one of the "Shorter" length collet chuck/collets that mount the way the stock chuck mounts usings the studs and lock nuts.  The shorter style are suggested so the amount of work area available is diminished the least amount.
Hope that helps.


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## mikey (Mar 24, 2019)

Let's see if we can make this clear for you. A collet chuck can directly mount either as a direct mount (meaning it has the same mounting configuration as you OEM chuck does) or it can be bolted on to a back plate (this is the correct term for a plate that has the same mounting configuration as your spindle) or you can use a MT version of that collet chuck. 

It is unlikely that you will find a direct mount collet chuck because your spindle is unusual. There are many direct mount collet chucks but none that I know of that mount to the large three-stud mount that you have. _For those of you who have not looked at this lathe, it has a large spindle bore and an MT-5 taper but with the familiar 3-stud configuration common to the cheaper Chinese lathes. _

You best bet is to contact the manufacturer of your lathe and see if they have a back plate to fit your spindle. If they do, buy several because you'll need them if you keep this lathe. Then learn how to mount a collet chuck or any other chuck to those back plates.

The least useful option is the MT-ER chuck option. A MT chuck mounts via the morse taper. Yours would have an MT5 taper to mount in the spindle and an ER chuck that is an integral part of this assembly up front - its all one piece. The MT part of this unit requires a drawbar to pull it into the taper and hold it there. Since this drawbar is typically solid and occupies the space inside your spindle, no pass through of stock is possible. This negates one of the most useful aspects of having an ER chuck on a lathe.

Well, there is one final option. You can make your own back plate and I suspect you may just have to do this because of the atypical spindle nose you have. 

Hope this clears it up for you.


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## TakeDeadAim (Mar 24, 2019)

Mr. Science said:


> So - i've done LOTS of searching on this forum and others as well as watching pertinent youtube et.al. on the subject but I'm STILL a  bit confused on this topic. I'd like the ability to run collets since I'm needing to do most of my work with small diameter parts ...
> 
> My chinese mini has a Morse 5 taper - from what i understand I can find a collet chuck that will fit the taper directly or I can go to an adapter PLUS an ER type chuck - but if i want to maintain my pass through hole capacity (from my understanding) i'm better off with the MT5 direct fitting chuck ( or no?) - if you know of any great FAQs on the subject I would be grateful though I guess my situation is unique enough that it may not help ... I'm just trying to connect the dots here ... thanks!


  You might try Little Machine Shop, they sell a 5C collet chuck and a number of backing plates for it.  Worst case is you would need to make or adapt a backing plate to mount this on your machine.  Its worth a shot anyway


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## Mr. Science (Mar 24, 2019)

yes thanks for that - Mikey - the many different possibilities are precisely what have been stifling me a bit ... but point taken on the taper mount chuck option - i was under the impression (somehow) that this system DID allow for the better pass through - but that makes sense i guess with the drawbar and all. I just thought maybe it would be also the most compatible if i were to get a mill later too. But I was attracted to the taper mount option since it would be the more elegant (fewer parts, better control and rigidity etc) ... I THINK i might be able to find a spindle mount for mine though - i managed to get a 5 inch 4-jaw from ebay that fit perfectly ... but anyway - thanks I'll take your advice under consideration. so - the spindle mount would give me the best pass-through opportunity you think?


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## Mr. Science (Mar 24, 2019)

mikey said:


> Let's see if we can make this clear for you. A collet chuck can directly mount either as a direct mount (meaning it has the same mounting configuration as you OEM chuck does) or it can be bolted on to a back plate (this is the correct term for a plate that has the same mounting configuration as your spindle) or you can use a MT version of that collet chuck.
> 
> It is unlikely that you will find a direct mount collet chuck because your spindle is unusual. There are many direct mount collet chucks but none that I know of that mount to the large three-stud mount that you have. _For those of you who have not looked at this lathe, it has a large spindle bore and an MT-5 taper but with the familiar 3-stud configuration common to the cheaper Chinese lathes. _
> 
> ...




THIS ONE looks like it might be a DIRECT fit - the rear flange on my 5" chucks look identical to the back of his chuck - same diameter too i think for spindle mount

i thought a '5C' meant the mount was a direct morse 5 taper mount


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## mikey (Mar 24, 2019)

No, 5C is the collet type. You can look up the differences between the various collet types. All have pros and cons.

Spindle mounts are very specific, especially with regard to the taper of the spindle register. Before buying a chuck, verify the configuration of the spindle register and hole locations to be sure it will mate with your spindle. Because something "looks" like it will fit does not mean that it will. On the other hand, you might get lucky and the makers of your lathe may have duplicated the specs on more popular lathes, like Stephan's Asian lathe, but I suspect not. His lathe has a MT3 or MT4 spindle bore, I think.


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## mikey (Mar 24, 2019)

Mr. Science said:


> so - the spindle mount would give me the best pass-through opportunity you think?



Most definitely. Something that mounts to the spindle with three bolts would allow you to clamp stock in the collet and pass excess stock through the spindle, up to the limits of the spindle bore inside diameter.


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## Aaron_W (Mar 24, 2019)

I second the suggestion of looking at Little Machineshop, they specifically support the small Sieg lathes, as well as their own Sieg based machines so they are likely to have a bolt on solution for you.

This ER40 chuck shows compatibility with the Sieg 8.5x14 lathes.









						ER-40 Collet Chuck for Lathe | Small Collet Chuck
					

This versatile ER-40 collet chuck easily mounts on the lathe spindle and ranges in size from 1/8" to 1." Order the small collet chuck for your lathe machine.




					littlemachineshop.com
				





An outside the box option that hasn't been mentioned would be to get an ER collet block that would fit into your 4 jaw chuck. I don't think that is a great idea but if other solutions fail that might work for you. The 4 jaw would be better than the 3 jaw so you could more accurately center it.

Something like this ER40 square collet block would work.








						Collet Block, ER-40 Square 5914
					

ER Collets & Collet Chucks 5914 Uses standard ER-40 collets; Through hole permits long parts to be machined; Hardened Tool Steel, Ground to .0005" on ...




					littlemachineshop.com


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## ThinWoodsman (Mar 24, 2019)

The collet block is a nice idea, especially for an ER. With all of the ER collet chucks I've seen (though I am by no means an expert) , you lose the pass-through capability.

So 5C would be the way to go. Poking around ebay I some some odd stuff ("MT5 5C collet sleeve"), and on the forum which nobody dare name there was a discussion of Sieg 5C collet chuck design which mentioned the Metal Lathe Accessories project.


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## Mr. Science (Mar 25, 2019)

ThinWoodsman said:


> The collet block is a nice idea, especially for an ER. With all of the ER collet chucks I've seen (though I am by no means an expert) , you lose the pass-through capability.
> 
> So 5C would be the way to go. Poking around ebay I some some odd stuff ("MT5 5C collet sleeve"), and on the forum which nobody dare name there was a discussion of Sieg 5C collet chuck design which mentioned the Metal Lathe Accessories project.




YES THIS is JUST the kind of thing i was imagining ... and from the looks of it - it might give me the best option for pass through ...  though I suppose it may also take a bit longer to switch over 






						Trade my MT5 collet adapter for your MT 4 1/2 collet adapter
					

This is a very nice hardened and ground no.5 Morse taper 5C collet adapter, but my lathe spindle takes a 4 1/2 Morse taper.  Anyone out there have a 4 1/2 Morse taper 5C collet adapter they'd like to trade (or perhaps just sell)? Mike



					www.practicalmachinist.com


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## Mr. Science (Mar 25, 2019)

like ...what about something like this? uses a draw TUBE instead of a draw bar ... any idea how large a pass through bore i can get out of it?









						5C Collet Nut For MT5 to 5C Draw Tube Sleeve  | eBay
					

5C collet nut for welding to a draw tube for the MT5 to 5C collet sleeve.



					www.ebay.com
				




thanks


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## Latinrascalrg1 (Mar 25, 2019)

What size bore hole does this mini lathe actually have?  I was assuming (which is always the problem)  that your lathe was similar to the HF 7x12 style! 

Well the largest bore you will be able to maintain using that style collet holder setup would be the Inside Diameter of the "DrawTube" aka drawbar that you choose.  So the thicker the tube wall is the less pass thru clearance you will have.


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## MozamPete (Mar 25, 2019)

Another possible option - can you get an MT5 collet set?

I have a set of MT2 collets that fit straight into my spindle bore.  Something like this


You still need a draw bar so pass through is lost, but M5 is much larger so you may be able to use a draw tube you still have enough diameter depending on the size stock you need to used.

The big advantage of ER style collets as I see it is that the nut pushes the collet in from the front so there is no need for anything behind the collet that would limit the pass through capability of your spindle.


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## Mr. Science (Mar 25, 2019)

Latinrascalrg1 said:


> What size bore hole does this mini lathe actually have?  I was assuming (which is always the problem)  that your lathe was similar to the HF 7x12 style!
> 
> Well the largest bore you will be able to maintain using that style collet holder setup would be the Inside Diameter of the "DrawTube" aka drawbar that you choose.  So the thicker the tube wall is the less pass thru clearance you will have.




Sorry NO idea what the pass through size would be using the draw tube setup as I only JUST heard about it and am mostly a greenhorn with this stuff (though I'd like to think i learn fast) - the max. spindle bore pass through is 1.5" IF THAT ... might be a HAIR below but it's advertised as a 1.5" pass through - i've just heard talk of it being 1-2mm less


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## Mr. Science (Mar 25, 2019)

MozamPete said:


> Another possible option - can you get an MT5 collet set?
> 
> I have a set of MT2 collets that fit straight into my spindle bore.  Something like this
> View attachment 291173
> ...



well THOSE look expensive LOL - wonder how much for a 40 piece metric set (then having to buy an imperial set on top)


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