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Thread: Shortened Morse Tapers

  1. #1
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    Default Shortened Morse Tapers

    Ive had an idea kicking around in my head for quite some time for some tool holders for my mini mill (Seig X2 clone). As a lot of people are aware, the X2s are about as rigid as wet spaghetti, so all the normal milling issues are magnified including tool stickout. Holding something like and endmill in an er32 collet chuck generates enough stickout that trying to run an end mill larger than 1/4" without chatter is an exercise in frustration, however if i use an MT3 collet, the same end mill works perfect thanks to the 2 fewer inches of stickout.

    Leading me to my theory, what i really need is an end mill holder built like a collet. Normal end mill holders are a no-go here, because the usual stickout isnt much better than that of my ER collet chuck, but the problem is, a holder like i want doesnt seem to exist and ill need to make them. Secondary problem here is my lathes compound slide doesnt have enough travel to cut the full length of an MT3 taper. I could buy some machinable blanks, but $20 a pop is a bit much when id like to have a half-dozen or so of these things in various sizes.

    So, my question is, if i were to cut an MT3 taper out of something like 4140ht that was the full diameter at the large end, with the proper taper, but only half 1/2 to 2/3 the length of a full MT3 taper, would that create issues? I know that less contact in the taper = less holding power, but given the low power of the machine spinning the tapers i cant see that being too big an issue. Is there anything im overlooking that would cause this to not work?

    Im aware the sane option here is "just buy more collets if they work", but thats not really much of a fix for my situation. Id like end mill holders since i would be able to keep the same tool in its own individual holder, to speed up tool switching as well as have a consistent offset i can plug into my DRO. So far as i know, i wouldnt be able to do that with a MT3 collet

  2. #2
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    I dont see any real problems with plan.

    How about stubby er collet holder?
    ER 16 collet would fit inside the mt3 shank and holds up to 10mm.

    Something allong this idea:
    https://www.techniksusa.com/metal/TE...oolholders.htm

  3. #3
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    Is this TTS holder look any shorter? it draws up to the face of spindle,



    https://littlemachineshop.com/produc...gory=209730719

  4. #4
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    Edited, I some how missed the fact your talking about a mill...
    Last edited by RB211; 06-29-2019 at 06:44 PM.

  5. #5
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    The shorter taper absolutely WILL WORK FINE.

    I have made a number of them in MT3, somewhat shorter than standard as to the taper. I made the overall length the standard length so that the regular drawbars would still work. The excess length I just turned down to a clearance diameter of slightly under the small end diameter.

    I have to go to a meeting this morning, but later I will measure the actual taper length if you want it. I do not think it is critical.

    Short end mill holders were supplied with some mills, I have one. It is for MT2, and has only about 3/8" outside the taper, just enough for a setscrew. It has the usual drawbar threads at the small end.
    1601

    Keep eye on ball.
    Hashim Khan

  6. #6
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    The taper will work. I think they only reason there is a standard length is so that the end shows up where a drift needs it to be....but your mill (I assume) has a drawbar and they're removed by hitting the draw bar. It would be a good solution to make some MT end mill holders.....just don't in a moment of mental frailty put one in say the drill press or you'd never get it out
    .

  7. #7
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    this chart refers to a stub shank

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

  8. #8
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    Quote Originally Posted by Ringo View Post
    Is this TTS holder look any shorter? it draws up to the face of spindle,



    https://littlemachineshop.com/produc...gory=209730719
    Thought about those, but the tts holders are a bit more than I can justify spending. The holders themselves I could probably make, but the actual adaptor/collet thing to go from the MT3 to the tts system is an upfront cost I'd rather avoid. Plus, the setscrew holders for the tts system have the same issue traditional end mill holders do with stickout, I'd really like something that draws the cutter up into the spindle

    Quote Originally Posted by RB211 View Post
    What you need is a more rigid machine. My offer still exists for you if you want my old South Bend 9c that's upstate NY.
    Much as I'd still love to take you up on that, the trip from Missouri to New York is pretty out of reach for me

    Quote Originally Posted by J Tiers View Post
    The shorter taper absolutely WILL WORK FINE.

    I have made a number of them in MT3, somewhat shorter than standard as to the taper. I made the overall length the standard length so that the regular drawbars would still work. The excess length I just turned down to a clearance diameter of slightly under the small end diameter.

    I have to go to a meeting this morning, but later I will measure the actual taper length if you want it. I do not think it is critical.

    Short end mill holders were supplied with some mills, I have one. It is for MT2, and has only about 3/8" outside the taper, just enough for a setscrew. It has the usual drawbar threads at the small end.
    Quote Originally Posted by Mcgyver View Post
    The taper will work. I think they only reason there is a standard length is so that the end shows up where a drift needs it to be....but your mill (I assume) has a drawbar and they're removed by hitting the draw bar. It would be a good solution to make some MT end mill holders.....just don't in a moment of mental frailty put one in say the drill press or you'd never get it out
    That's about what I was thinking, thanks for confirming my suspicion gents. No MT3 on a drill press or anything, these would only get used on the mill so no worries with getting stuck. Still need to do some measurements on my lathe to know exactly how long I can make the taper, but I'm figuring as long as I have more than 1/2 the standard length I should be fine for a 3/16" end mill

  9. #9
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    I don't know anything about ER collets, but why can't you pass through the collet and choke-up on the cutter?

  10. #10
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    Quote Originally Posted by chipmaker4130 View Post
    I don't know anything about ER collets, but why can't you pass through the collet and choke-up on the cutter?
    The issue isnt the stickout of the tool, the issue is stickout of the collet fixture itself. I have an MT3-ER32 collet chuck, like this:
    https://www.amazon.com/MT3-ER32-Mill.../dp/B00RN38KPO

    Not that exact one, but close enough. The collet portion of it sticks out by about 2 inches from the spindle, even choking up on the tool as much as possible and using the shortest tools possible, that 2 inches is still more than my mill likes to deal with. To get the best results i need to get whatever tool im using as close to the spindle as possible, ideally inside the spindle taper itself. To illustrate, a 1/2" end mill held in the collet chuck will chatter like crazy on a .010" cut, but take the same cutter and put it in a 1/2" MT3 collet, which situates the tool shank inside the mill spindle, and i can nearly bury the cutter without issue. Think my record is a .125" pass with a roughing mill through a block of cast iron, with full engagement.

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