MT3 Standards

[Steve WithnellParticipant @stevewithnell34426]

Last year I treated myself to a Glanze 32mm endmill, the type with the carbide inserts.

 

Got a job for it this afternoon, to my disdain, it won’t fit in my Warco Mill spindle!

 

I’ve never had this problem before, and I have a fair amount of MT3 tooling accumulated over the past few years.

 

On examination, the taper on the endmill is quite a bit longer, c10mm than my other MT3 tools. Pretty sure I can turn off the offending length, but the question I have is – Is there no defined standard for MT3 tooling (I not just the taper but the complete fitting)?

 

 

 

 

[Steve WithnellParticipant @stevewithnell34426]

[John McNamaraParticipant @johnmcnamara74883]

Hi Steve

 

I did a search for:

“Machine tool tapers”

 

There are many references.

This Wikii details the Morse taper rather well…….

It was second on the list

 

The actual standards documents are available (for a cost hmmmm)

 

Any machine builder that does not adhere to the standard Morse is clearly being deceptive. Was this machine bored out from a smaller taper? I suspect it was. There was no room for the complete socket. NBG

 

Or is the tool shank at fault? I would have thought not?

 

Cheers

John

Edited By John McNamara on 29/08/2011 03:31:02

[JasonBModerator @jasonb]

Just make sure there is enough thread left for the drawbar, may be better to turn the end to a smaller dia than turn it off completely.

 

I’ve got the 40mm version and it fits my X3 fine, let me know if you want to compare the length.

 

J

Edited By JasonB on 29/08/2011 07:43:07

[Steve WithnellParticipant @stevewithnell34426]

Thanks guys. I’ll take a photo and overlay the dimensions. There is plenty of meat in the Warco Mill, at time of manufacture it would not of been an issue to produce a longer socket).

 

The drawbar thread appears to go pretty deep into the taper so, shouldn’t an issue to “adjust” it.

 

Steve

[JasonBModerator @jasonb]

I can see why my one fits.

 

The line to the right is the 0.938 gauge, the line to the left is how far the taper fits into the spindle, about 1/16″ difference. The end of the shank is the correct 3 3/16″ from the gauge line but just to ensure a good fit the end has a reduced parallel section.

 

Steve you probably only need to turn down a short section like mine, this will also be easier to hold as you can support the end with the tailstock ctr. It also means you won’t ding the end of the taper.

 

J

[Anonymous]

In my newest Machinery’s Handbook the depth of Morse taper in a socket is defined, as is the length of Morse taper tooling with a tang. Hence by implication the length of a Morse taper without tang should also be known. It shouldn’t be longer than the depth of taper in the socket.

 

Regards,

 

Andrew

[JasonBModerator @jasonb]

This table gives the length without tang and is the 3 3/16 I mentioned above

 

http://www.tools-n-gizmos.com/specs/Tapers.html#MT

[Chris TriceParticipant @christrice43267]

I had an interesting surprise this week. My Compact 5 which gives all the signs of having a 2MT spindle is slightly too big to grip my Jacob’s 2MT drill arbor before the chuck hits the end of the spindle. One of them is wrong.

[Anonymous]

Or they could both be wrong. And we all know two wrongs don’t make a right.

 

Andrew

Edited By Andrew Johnston on 29/08/2011 11:15:15

[Steve WithnellParticipant @stevewithnell34426]

The two chucks at the top have a taper 77mm long. The top one is an autolock type from Warco, the other chuck an ER32 type from Arceurotrade. The Glanze mill has a taper 89mm long which exceeds the 3-1/16 quoted above by some way. The parallel section is not threaded, so that can go without a problem. Depending on how hard the taper is, I could turn the first 10mm of the taper parallel and then it will fit no problem.

 

 

 

Steve

 

 

 

[John Stevenson 1Participant @johnstevenson1]

Steve,

It should turn with tipped tooling, I have modified holders before.

 

John S.

[JasonBModerator @jasonb]

Steve have you checked the gauge dia and measured the taper from there as the overall length is not a good indication of the taper length. If you look at mine the taper is well over 90mm long but it fits a sthe gauge is about 12mm back.

 

J

[DustyParticipant @dusty]

Steve before you start cutting lumps from the morse taper can I sugest that as Jason said you measure the relevant dimensions. If these are not standard, return the tool to the supplier. I take it from your posting that it has not been used. The supplier has a duty to supply goods that are’ fit for purpose’ and of a type and quality demanded, this clearly is not. It may just be a rogue cutter or it may be that all are defective. In any event the supplier needs to be told, if only to protect any other potential customers. The fact that your other milling chucks fit seems to indicate that the machine is not at fault. If the supplier tries to fob you of with the ” nothing we can do, you purchased it over a year ago” speak with your local Trading Standards Office. They will give you advice on the law. We should not accept sub standard items, it is in none of our interests.

[Steve WithnellParticipant @stevewithnell34426]

Good point Jason. Just measured the tapers again based on a datum which is the diameter of the bottom of the taper socket on the machine. This makes the Glanze taper an actual 9mm longer than the others.

 

I’ll take John’s advice and have at it with a decent carbide tip tool.

 

Steve

 

 

[Steve WithnellParticipant @stevewithnell34426]

Wouldn’t fit in the lathe chuck, a nats wotsit too big, so I circumised it on the grinder and now it fits like a glove.

 

 

 

 

 

[JasonBModerator @jasonb]

What no reverseable jaws? or just a very small chuck.

 

J

[Steve WithnellParticipant @stevewithnell34426]

5 Inch Chuck. The primary issue was that the business end of the cutter has two large profiles machined out to take the tips, not too obvious in the photo, which meant I needed to get down the throat of the chuck to get a good grip and the throat was just not big enough. Grinder was faster than setting up on the lathe anyway.

 

 

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