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Thread: Good Floating Reamer Holder

  1. #46
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    Quote Originally Posted by DSM View Post
    He is not pushing it with a dead center. Just pushing with a flat surface and the reamer simply follows the perfect bored hole. I run a similar set up with similar results and my tailstock sits high. When the needle on the DTI doesn't budge after reaming...something must be straight, lol.
    All that means is the bore at the point the stylus is touching, is that the bore is round.

  2. #47
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    Quote Originally Posted by TRA View Post
    All that means is the bore at the point the stylus is touching, is that the bore is round.
    Yep..exactly

  3. #48
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    Quote Originally Posted by DSM View Post
    Yep..exactly
    I think there's way too much faith in this "perfectly bored hole" as that's highly unlikely that anyone can bore such a hole with a compound. If you used a roughing then a finishing reamer, maybe, but not with a boring bar hanging out that far on a compound. Compounds are like a tailstock. They are only in position at one point. When you move it, it wanders. With a tailstock the further you extend it the more it's skewed. a compound is no different, just not as bad, and it all is affected by every moving surface down to the lathe bed.

  4. #49
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    Quote Originally Posted by TRA View Post
    I think there's way too much faith in this "perfectly bored hole" as that's highly unlikely that anyone can bore such a hole with a compound. If you used a roughing then a finishing reamer, maybe, but not with a boring bar hanging out that far on a compound. Compounds are like a tailstock. They are only in position at one point. When you move it, it wanders. With a tailstock the further you extend it the more it's skewed. a compound is no different, just not as bad, and it all is affected by every moving surface down to the lathe bed.
    The key is whatever falt is in the compound the boring bar is still going to cut a true to the spindle axis hole as long as it doesn't push the part out of alignment.
    That is why you check your work after every operation right.
    Then you know and aren't guessing or assuming it's right. The words first article come to mind

  5. #50
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    Also your setup is going to have to be capable of the goal.
    If the setup won't hold it right it won't mater if you have the best technic or equipment
    Last edited by cloudrepair; 02-17-2017 at 12:33 AM.

  6. #51
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    Quote Originally Posted by cloudrepair View Post
    The key is whatever falt is in the compound the boring bar is still going to cut a true to the spindle axis hole as long as it doesn't push the part out of alignment.
    That is why you check your work after every operation right.
    Then you know and aren't guessing or assuming it's right. The words first article come to mind
    I hate to disagree but a worn compound is not going to cut true to the spindle axis. Never gonna happen. All lathes have a sowbelly,or are twisted, and move around with the weather. Take the distance from the bed to the tool edge and just think how much .001 out of parallel at the bed would affect the tool edge. It's almost certain that the tool edge will rise of fall over the distance you would need to cut that taper. So much for your setup. Anytime something on a lathe moves it smiles at your set up. Cutting tapers with a CNC is not an exact science. Doing it while cranking on a wobbling compound is just not doable, with any so called perfection. If, IF, you bored a perfect hole with your compound, then you should be using that assembly to push the reamer. After all it's perfect to the spindle axis??? I don't think so. The one thing that is guaranteed is the tailstock is no where near true to the spindle axis throughout it's overall travel. Move it and it's going in a different direction.

    With little short cartridges you can slide by, but when you are moving things 2.5-3"+ a lathe cannot perform miracles.

    Those of you with access to CAD software, draw a circle and a flat round pusher. Give them an axis, enlarge them and then move the axis of the pusher around and also extend it at the same time. You will soon see that things are not as they seem.

    Does any of this matter? That's up to you.

  7. #52
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    Quote Originally Posted by TRA View Post
    I hate to disagree but a worn compound is not going to cut true to the spindle axis. Never gonna happen. All lathes have a sowbelly,or are twisted, and move around with the weather. Take the distance from the bed to the tool edge and just think how much .001 out of parallel at the bed would affect the tool edge. It's almost certain that the tool edge will rise of fall over the distance you would need to cut that taper. So much for your setup. Anytime something on a lathe moves it smiles at your set up. Cutting tapers with a CNC is not an exact science. Doing it while cranking on a wobbling compound is just not doable, with any so called perfection. If, IF, you bored a perfect hole with your compound, then you should be using that assembly to push the reamer. After all it's perfect to the spindle axis??? I don't think so. The one thing that is guaranteed is the tailstock is no where near true to the spindle axis throughout it's overall travel. Move it and it's going in a different direction.

    With little short cartridges you can slide by, but when you are moving things 2.5-3"+ a lathe cannot perform miracles.

    Those of you with access to CAD software, draw a circle and a flat round pusher. Give them an axis, enlarge them and then move the axis of the pusher around and also extend it at the same time. You will soon see that things are not as they seem.

    Does any of this matter? That's up to you.
    The boring bar doesn't need to cut a perfect hole it will still be true to the spindle axis even if it is leaving ugly finish that is different diameters through the bore. Even with the ways worn it will still be true to the axis if your part doesn't move on you
    then you can let the reamer do its job shaping the chamber
    now if your chamber measures same as reamer and part doesn't move you have dialed in right you will get the best results. The pusher also has to allow the reamer to follow your true hole.
    Last edited by cloudrepair; 02-17-2017 at 01:24 AM.

  8. #53
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    that certainly looks like a chuck in a tail stock with an indicator added on top.
    and i clearly said if all is straight, it will work, BUT ONLY WHEN PERFECTLY STRAIGHT.


    Quote Originally Posted by DSM View Post
    He is not pushing it with a dead center. Just pushing with a flat surface and the reamer simply follows the perfect bored hole. I run a similar set up with similar results and my tailstock sits high. When the needle on the DTI doesn't budge after reaming...something must be straight, lol.

  9. #54
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    Quote Originally Posted by zfastmalibu View Post
    Heres my holder. The idea behind it is, its round so it cant grab your hand. Also being round makes it easier to hold the reamer without influencing it. Theres a ball bearing pressed in the holder and its pushed by a ground piece of carbide. I measure every chamber, they measure what the reamer does and I have never had a run out or chatter issue. I am pleased with it.
    That looks like my third generation pusher

    Now, lose the ball and carbide arrangement, push it with the chuck or with a ring at least 1" diameter that sweeps perpendicular to the bore and ya' GOT Sumpin!

    LOL


    al

  10. #55
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    Quote Originally Posted by cloudrepair View Post
    The boring bar doesn't need to cut a perfect hole it will still be true to the spindle axis even if it is leaving ugly finish that is different diameters through the bore. Even with the ways worn it will still be true to the axis if your part doesn't move on you
    then you can let the reamer do its job shaping the chamber
    now if your chamber measures same as reamer and part doesn't move you have dialed in right you will get the best results. The pusher also has to allow the reamer to follow your true hole.
    Yep. No one is claiming their bored hole is perfectly on size over it's length, but it will be round and coaxial with the spindle.

  11. #56
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    Quote Originally Posted by Rubicon Prec. View Post
    Yep. No one is claiming their bored hole is perfectly on size over it's length, but it will be round and coaxial with the spindle.
    Isn't that exactly what TRA is saying ? Maybe not perfectly size but if you reread his post you'll see the reason for mine I didn't intentionally imply he was saying the hole would be perfectly sized just tru to the spindle axis was in quistion
    Sorry misinterpreted your response disregard ^^^
    Last edited by cloudrepair; 02-17-2017 at 10:58 AM.

  12. #57
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    Quote Originally Posted by cloudrepair View Post
    Isn't that exactly what TRA is saying ? Maybe not perfectly size but if you reread his post you'll see the reason for mine I didn't intentionally imply he was saying the hole would be perfectly sized just tru to the spindle axis was in quistion
    Sorry misinterpreted your response disregard ^^^
    He was saying it would not cut true to the spindle axis. I say it will even with a worn lathe, within reason, obviously. It may not be on size or shape but it will be concentric. But it doesn't matter because the reamer gives the final shape and size. If it has a concentric hole to follow and is allowed to do so, it will give a concentric and on size chamber.

  13. #58
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    Quote Originally Posted by Rubicon Prec. View Post
    He was saying it would not cut true to the spindle axis. I say it will even with a worn lathe, within reason, obviously. It may not be on size or shape but it will be concentric. But it doesn't matter because the reamer gives the final shape and size. If it has a concentric hole to follow and is allowed to do so, it will give a concentric and on size chamber.
    Yes agreed.

    Machining and my family is what I live for not exactly that order
    I'm not above learning from anyone I just want to do the best I can
    And I don't always see what I should because I'm blind in one eye and can't see out of the other

  14. #59
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    Quote Originally Posted by cloudrepair View Post
    Click image for larger version. 

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    What do you think of the change Alex?
    and I'll use the same pusher

  15. #60
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    Quote Originally Posted by cloudrepair View Post
    Click image for larger version. 

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Views:	79 
Size:	1.57 MB 
ID:	19057

    What do you think of the change Alex?
    and I'll use the same pusher
    Guys and gals, you are making this reamer pushing thing way too complicated.


    .

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