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Thread: making Er16 collet chuck

  1. #11
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    Bluing against a known good taper is the best way IMO. When I made my Er 20 collet holder I made a male master along with an er16, and 32 while I was dialed in. It's all well and good to make stuff to the #'s and standards, but fit and finish are what matters in the end, so if you can measure directly, cut out the middle man and go direct.

  2. #12
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    Bluing the final taper is a great way to use for testing. But on something like an ER chuck by the time you know it's wrong it's pretty much too late unless you do the check when you've still got about 1mm of material to remove off the ID to go. So the check needs to be done while the collet is still sticking out proud of the final depth.

    There is certainly "more than one road to Rome" and any number of options to set the compound angle will work. But do do so to within 0.1 by using a is one fine trick. That must be one fancy bevel protractor ! ! ! ! Looking around at google images of bevel protractors only the very best has any better a chance than half a degree.

    I don't have one of those and I don't have a sine plate or gauge blocks. And besides, even with all that we still need a dial gauge. So my choice would be as mentioned earlier and make up a turned true stub and with that still held true I'd slide on one of the collets so it's a firm sprung fit and then with the dial gauge in the tool holder adjust the compound angle until there's zero runout and call it a day. In effect using one of the collets as my sine plate.

  3. #13
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    If you absolutely have to reproduce the internal taper, then 0.1 degrees is not good enough. You need to setup one of the existing er holders running true in a four jaw chuck better than 0.0005" tir. Then with a lever indicator (plunger dti will not do) set up with its pivot vertical and the tip exactly on the centreline to get the compound angle perfect. Then you can finish bore the taper with the tip of the boring tool exactly on the centreline. If the indicator or the boring tool are not exactly on centre, the taper will be wrong.
    I still think the sleeve in my post #10 would be easier. Also, an 8mm spindle on that er collet seems as about as stiff as wet spaghetti.

  4. #14
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    Quote Originally Posted by BCRider View Post
    Bluing the final taper is a great way to use for testing. But on something like an ER chuck by the time you know it's wrong it's pretty much too late unless you do the check when you've still got about 1mm of material to remove off the ID to go. So the check needs to be done while the collet is still sticking out proud of the final depth.

    There is certainly "more than one road to Rome" and any number of options to set the compound angle will work. But do do so to within 0.1 by using a is one fine trick. That must be one fancy bevel protractor ! ! ! ! Looking around at google images of bevel protractors only the very best has any better a chance than half a degree.

    I don't have one of those and I don't have a sine plate or gauge blocks. And besides, even with all that we still need a dial gauge. So my choice would be as mentioned earlier and make up a turned true stub and with that still held true I'd slide on one of the collets so it's a firm sprung fit and then with the dial gauge in the tool holder adjust the compound angle until there's zero runout and call it a day. In effect using one of the collets as my sine plate.
    Lots of bevel protractors come with nonius scale that gives you degree split to 5 minutes. So you can read it to 60/5=20 = 0.05 degree accuracy. But even that is still kind of coarse for any taper.

    Using existing ER collet to indicate is also bit risky business IMO. Lot depends on how well the collet "settles" to rod without external clamping like its normally used.
    Partly same problem if you use blue.

  5. #15
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    I would venture to say that the compound slide on the lathes
    that most of you home shop guys have has more slop than
    the accuracy required to set and cut the angle needed for
    precision collet taper setup work. I would thoroughly scrutinize
    the slideways and the gib for wear and proper adjustment
    before attempting a precision job like this if you want to
    achieve satisfactory results.

    -Doozer

  6. #16
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    Dead right, Doozer, I would not try it on the Smart & Brown model A at the museum, although the compound is pretty well adjusted. I did a test of the taper turning attachment for that lathe to produce an R8 taper. Using a 12" length bar and trigonometry, I got a passable taper within a minute of arc, but not exact.
    Using the collet to set the taper is a fools errand.
    ER16 is capable of holding up to 13mm, 1/2", but with an 8mm spindle on the motor, 3mm, 1/8" cutters would be risky
    Last edited by old mart; 03-15-2019 at 11:01 AM.

  7. #17

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    Quote Originally Posted by old mart View Post
    <snip>
    ER16 is capable of holding up to 13mm, 1/2", but with an 8mm spindle on the motor, 3mm, 1/8" cutters would be risky
    DIN standard says ER16 goes up to 10mm so he might be a little safer there.
    .
    "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

  8. #18
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    Reading through all the replies in this thread one would think that it would be best if the OP just gave up and took up some other sort of hobby.

    Oh sure, proper care is a concern. And there's lots of good suggestions for options in the replies. But overall I find that this thread in particular has a strong current of anticipated failure unless he's got some pretty snazzy stuff to use.

    Let's face it, no group of people can be more OCD at times than machinists. We constantly work in amounts that are well past invisible and require special instruments to even detect. But "we" have been making functional parts on basic machinery that works just fine for a long time. Far longer than any of us have been around.


    Between the bevel protractor, the mis-sized adapter socket and a collet pushed onto a turned arbor and a good DTI you should be able to set and confirm the angle to a degree that is sufficient to produce a good working part.

  9. #19
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    10MM it is, TGT, I must have misread the chart. On an 8mm spindle I would steer clear of steel and take very small cuts in aluminium. A motor spindle of 12mm would be better though at minimum.

  10. #20
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    Quote Originally Posted by BCRider View Post
    Reading through all the replies in this thread one would think that it would be best if the OP just gave up and took up some other sort of hobby.

    Oh sure, proper care is a concern. And there's lots of good suggestions for options in the replies. But overall I find that this thread in particular has a strong current of anticipated failure unless he's got some pretty snazzy
    I've made a number of home shop tools out of 12L14 free cutting steel. Soft as butter. I had some guys tell me you can't make tools out of it. Won't last. All the usual stuff on why it won't work.

    They work great. I'm not a production shop. It's home shop machining. Most of us aren't making stuff for CERN or something.

    Same people who think Rong Fu mill drills are useless boat anchors and you can't do anything at all with them. I just refer them to George Britnell's work.

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