Other uses for Jig Grinding Mandrels?
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  1. #1
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    Default Other uses for Jig Grinding Mandrels?

    Hi All,
    I stumbled into a small hoard of what I think are jig grinding mandrels, probably from a Moore #2. Example picture should be included showing a few of the diamond bits, but there are regular abrasive stones as well. I don't have much experience with grinding operations, so a couple of questions...

    Are these correctly ID'd as jig grinding mandrels?

    I don't have a jig grinder, so what else can I do with them?

    I have a Dumore flex shaft die grinder, would it be uncouth to use these in the die grinder? My ignorant brain thinks they look the same as die grinder bits except for the larger diameter shaft. Actually, I don't mind if it is uncouth - is there any reason to not use them this way?

    Would the diamond tools in a tool post grinder get around the common complaint/fear that tool post grinders on the lathe are a dodgy proposition die to the excess grinding dust? I would think that since the abrasive is designed to stay in the bit that one could accomplish a relatively clean grinding operation.

    Any other clever ideas?

    Thanks,
    Mike

    img_20201022_092258074.jpg

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    "Are these correctly ID'd as jig grinding mandrels?"

    I know them as grinding pins.

    And I use them in anything that they fit.

    Chuck
    Burbank, CA
    Last edited by Chuck Evans; 10-22-2020 at 09:47 PM.

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    Thanks Chuck. "Grinding pins" is helpful terminology.

    -mike


    Quote Originally Posted by Chuck Evans View Post
    "Are these correctly ID'd as jig grinding mandrels?"

    I know them as grinding pins.

    And I use them in anything that they fit.

    Chuck
    Burbank, CA

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    Highly likely that those grinding pins are not actually diamond, but rather CBN

    Unless they came from a shop that jig ground carbide....

    Have a good close look on the pin shank for type, grit size, and concentration numbers.

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    I did a lot of jig grinding as an apprentice. I knew them as "mounted points". As macds said they are not likely diamond. If used in a Moore jig grinder they were intended to be used at 45000 rpm +. Do you really have anything that can use them properly? They are likely CBN or WC. No, the abrasive is not designed to "stay in the bit" and the horse does not care.

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    Thanks guys. Some of the pins don't have markings, but some do so some forensics is in order.
    As tdmidget suggests, I don't have anything suitable for proper use of these at 45krpm which is the root of my original question: are there other worthwhile off-label uses for these?

    Follow up question for tdmidget or others:
    You said that the abrasive is not designed to stay in place. My impression of things that look similar on the surface, like electroplated diamond lapping wheels, is that the abrasive basically stays in place. Are these made differently? Not arguing, just trying to learn.

    Thanks,
    Mike


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