# Morse Taper with tang



## SAM in LA (Jul 23, 2010)

I need some advice on how to prevent my tool holders and drill chucks with a MT#3 taper with tang from falling out of the quill on my mill during use.

Also, I have a set of collets which are held in the quill with the draw bar. The collets will not hold my endmills or drill bits securely. What I mean is that the end mill will creep up into the collet.

I have one MT#3 x 3/8" mill holder that has a female thread for the draw bar. This one works OK. The endmill is held in place with a set screw. If I could afford it I would buy these holders for each size of tool.

So, after saying all of that, I need help with these two issues.

1-How do I keep tooling with the MT-3 and tang from falling out of the quill?

2-How can I hold various sizes of tooling with my Collete's securely?

Thanks for your help.

SAM


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## arnoldb (Jul 23, 2010)

Hi Sam

I presume this is all on your mill?

For the tapers:
First off, always make very sure both the spindle taper and tool taper are very clean when inserting - wipe off most oil as well. Check for any damage on either of the tapers - a damaged or dirty MT won't hold.
When inserting solid MT tooling, the best way I have found is to slide it about half-way into the spindle, and then quickly pushing it home; it goes home and stops solidly with a bit of a "dunk" sound and feel.
If the above does not help, I'd advise you to get some marking dye (its not the same as layout dye - andis sometimes called "engineer's blue" or "prussian blue") to mark the tapers to see where things are not fitting properly. Use a known-good-quality male taper for this test though - if you need to, borrow one from somebody; the Asian import tapers are not of too great accuracy.

As to the collets, I've not used MT collets before, so have very limited information to add there, except that they want anything you want to hold in them pretty close to size to work properly. Things like grabbing 6mm shanks in a 1/4" collet is a no-no.

Regards, Arnold


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## lordedmond (Jul 23, 2010)

MT3 with tang is only for drill chuck used for drilling the end load keeps them engaged, any side thrust will loosen the taper

So tangs only for drilling and drawbar held taper for everything else


I only use a posilock chuck for milling cutters that have a thread on


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## Stan (Jul 23, 2010)

So tangs only for drilling and drawbar held taper for everything else

Exactly correct. No if, ands or maybes.

I have used MT3 collets in my mill for many years without problem. I don't understand your problem of endmills pushing up. If the collet is not tight enough. the endmill will pull out.

Don't try to hold any size but the one marked on the collet. An MT collet only grips at the end with the remainder of the collet just a sliding fit on the endmill. If the endmill shank is undersize to the collet, it will rock in the collet and pull out. 

It might be cheaper than endmill holders to change to ER type collets it you still have problems with the MT3.


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## Maryak (Jul 23, 2010)

Sam,

Reads to me like there is some damage to the internal taper on the mill head, probably a burr or a score from trapping swarf between the taper socket and the mill taper.

To check with prussian blue or if all else fails 4 chalk lines drawn vertically around the socket, you need a good taper without the tang so that when it is home you can rotate it. Don't push up too hard as it may lock and on a drill or mill head without the tang they can be an absolute illegitimate child to remove. (Ask me how I know :).

Hope this helps

Best Regards
Bob


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## SAM in LA (Jul 23, 2010)

Thanks guys.

I will try to check the taper tomorrow.

I need to see if I can find some Prussian blue or chalk.

I appreciate the assistance.

SAM


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## deverett (Jul 24, 2010)

SAM in LA  said:
			
		

> ... I need to see if I can find some Prussian blue or chalk.



Sam

If you cant get chalk or Prussian Blue, a wax crayon or a simple lead pencil will also give you a good indication.

Rub the crayon lightly in one line down the length of the taper. A 2B or other soft lead will show up better than a hard lead. Same idea, rub a line down the length of the taper.

Put male taper lightly into female taper so that you can turn the male by hand. Make one complete rotation and withdraw the male taper. You should see that the crayon/pencil line has disappeared, or possibly spread completely round the male taper for the full length.

If there are any parts of your initial coating untouched, that will tell you where the damage to the taper is. 

Dave
The Emerald Isle


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## tel (Jul 24, 2010)

Yep, wot Stan said. The only collets I have are Morse Taper (2's and 3's) and I never have a problem with them holding. You don't even need to reef down the drawbar nut too tightly, just a bit beyond snug.


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## SAM in LA (Jul 24, 2010)

I checked the MT3 surfaces today and it appears that there is some damage to the female surface.

I looked on ENCO site and they offer the following 

Morse Taper - Reamers Taper Size: 3MT Style: Roughing $40

Morse Taper - Reamers Taper Size: 3MT Style: Finishing $34

Should I buy both or just the finishing one.

Thanks for your help.

SAM


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## Maryak (Jul 24, 2010)

Sam,

I would only buy the finishing reamer. You want to remove the minimum material, too much and the socket etc. will travel too far into the mill head and those with a tang will not lock before the tang hits the top of the socket.

Hope this helps.

Best Regards
Bob


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## SAM in LA (Jul 24, 2010)

Bob,

Thanks.

I'll put a MT3 Finish reamer on my shopping list.

I appreciate everyones input.

Regards,

SAM


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## Stan (Jul 25, 2010)

I have used MT reamers in lathes to clean up headstock and tailstock tapers where it it is easy to support the drive end of the reamer aligned with the center of the opposite taper. I have done my mill spindle by putting the spindle in the lathe to do it.

To do you mill spindle with the spindle in the mill, you have to find some way to support the reamer drive end exactly in line with the spindle center. If the reamer can wiggle around, you will ruin the spindle taper. The reamers have a 60° center hole in the drive end for this purpose.


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## SAM in LA (Jul 25, 2010)

Stan  said:
			
		

> I have used MT reamers in lathes to clean up headstock and tailstock tapers where it it is easy to support the drive end of the reamer aligned with the center of the opposite taper. I have done my mill spindle by putting the spindle in the lathe to do it.
> 
> To do you mill spindle with the spindle in the mill, you have to find some way to support the reamer drive end exactly in line with the spindle center. If the reamer can wiggle around, you will ruin the spindle taper. The reamers have a 60° center hole in the drive end for this purpose.



Stan,

What if I fastened the reamer into a chuck mounted on the mill table.

My machine is a combination Lathe/Mill.

Perhaps I can remove the mill spindle and chuck it in the lathe.

This would be a good time to replace the bearings for the mill spindle.

I need to study this some more.

I'm glad you brought this to my attention.

Time to change for Church.

Thanks,

SAM


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## steamer (Jul 25, 2010)

Permanent Magic marker will work too! Get a "Sharpie"







			
				steamdave  said:
			
		

> Sam
> 
> If you cant get chalk or Prussian Blue, a wax crayon or a simple lead pencil will also give you a good indication.
> 
> ...


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## Stan (Jul 25, 2010)

Sam: The reamer has to be free to turn. They have a square end on the shank for a wrench. You don't use them under power like a chucking reamer. A piece of stock with a 60° point turned in the lathe and put in a chuck on the table would work if you can accurately center the point under the center of the spindle.


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## SAM in LA (Jul 25, 2010)

Stan,

I have a rotating table and can make a 60 degree center to fit.

I need to make a shopping list and place an order this week.

Thanks for the help.

SAM


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## SAM in LA (Aug 5, 2010)

Guys,

Just an update.

I received my MT-3 reamer today.

I used it in the mill quill and in the tailstock quill.

Both cleaned up real nice.

Very few metal shavings were produced.

I only tried to remove any burrs or high spots.

Many thanks to all of you that responded.

 :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow: :bow:

SAM


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