Where can I find a 1 7/32" x 8TPI lathe backplate?
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  1. #1
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    Default Where can I find a 1 7/32" x 8TPI lathe backplate?

    I have a lathe with a threaded spindle that appears to be 1 7/32" x 8TPI. I can't find any back plate with that thread. Where can I buy one?
    Thanks

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    some more info would be nice like who made the lathe that you have

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    I suspect you will have to start with a backplate casting and machine it yourself.

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    Make one. .

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    Quote Originally Posted by 1yesca View Post
    some more info would be nice like who made the lathe that you have
    Don't tell me you never got a blueprint with half of the dimensions missing. You don't do aerospace, do you? You know how all those planes keep falling from the sky?

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    Quote Originally Posted by thechickencow View Post
    I have a lathe with a threaded spindle that appears to be 1 7/32" x 8TPI. I can't find any back plate with that thread. Where can I buy one?
    Thanks
    There are more details you could supply in order to get a more complete answer. The best answer to the question as asked is that you cannot buy one. I will take a wild guess that you cannot make one yourself.

    But you could have one custom made, which is a time-consuming job that should be quite expensive if done right so that it fits your machine. The maker would want your lathe spindle to measure and use as a gage. You would have to have a chuck in hand or at least in mind to allow the diameter of the plate to be known, along with the thickness and where the holes will be drilled.

    And there is always the possibility that the spindle has a metric thread.

    Larry

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    Quote Originally Posted by CORONA VIRUS View Post
    Don't tell me you never got a blueprint with half of the dimensions missing. You don't do aerospace, do you? You know how all those planes keep falling from the sky?
    i hear you but we at this point don't know for a fact that his info is correct and by knowing who made the machine and maybe a model it may clear some things up . yes we all reinvent the wheel at times . time . and that's just it . time . what is yours worth to you . any time you can buy something off the shelf most of the time your ahead of the game but sometimes you must reinvent the wheel

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    Quote Originally Posted by thechickencow View Post
    I have a lathe with a threaded spindle that appears to be 1 7/32" x 8TPI. I can't find any back plate with that thread. Where can I buy one?
    Thanks
    I'll step out on a limb here, and speculate that the thread is quite possibly 1-1/4 x 8, rather than 1-7/32 x 8. I would check the spindle thread with thread wires to confirm its actual pitch diameter, then decide what you are looking for. As others have noted, some additional info regarding make and model of the lathe might help clear up some questions.

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    I came here to say the same thing specfab said. 1-1/4"-8 is a common lathe spindle thread and the actual OD of a threaded part should be less than the nominal dimension. the difference between 1-1/4" and 1-7/32" OD is .016" off the crest of the thread.

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    Let me guess... The OP got a lathe without a chuck, or back plate.
    That is a problem to make a new back plate without a way to hold it.

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    How to measure it. The wires for 8 pitch will be some specific size - look it up

    over-wires.jpg

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    Quote Originally Posted by fciron View Post
    I came here to say the same thing specfab said. 1-1/4"-8 is a common lathe spindle thread and the actual OD of a threaded part should be less than the nominal dimension. the difference between 1-1/4" and 1-7/32" OD is .016" off the crest of the thread.

    A South Bend 11" uses a 1-5/8"-8 spindle thread and I think there is another, more common lathe that shares that size (can't think of brand atm). While not as common as the 1-1/4"-8 it is still a possibility. It sure would help if the OP would give a few more hints as to the machine and size, etc.

    FWIW

    -Ron


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