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Thread: Good Floating Reamer Holder

  1. #91
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    Mar 2016
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    Why not use the flat side of the tool holder as a pusher? You could use an end mill to square it but prob not necessary. Run it up to the flat face of the chuck or cathead, square it up and tighten. Then push with the carriage and whatever ball or reamer holder desired. Even the back of the reamer.

  2. #92
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    Mar 2016
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    Guess I killed the thread...

  3. #93
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    Feb 2003
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    Quote Originally Posted by Shooter71 View Post
    Guess I killed the thread...

    Kind of a good idea and I have tried it. It is just clumsy to do on my lathe.

  4. #94
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    Mar 2016
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    Does it matter?

    I've been thinking about the whole reamer pushing thing a bit. Assuming the chamber remains concentric with the bore and the throat is lined up, does it matter if the back end of the chamber ends up oversized? Might it be preferred? I've read AlinWa's methods and it makes a bunch of sense to me. If he's designing that into his reamers why not just use a dead center like Jackie does and welcome any extra fatness that might happen? I understand wanting the machine work to match the reamer and be consistent but it seems to me the consistency will come from running it through the sizing die anyway. I've used the prebore method as well as just running the reamer in using a JGS floating holder with good results, but some of the chambers are tight enough at the back end that my sizing dies don't size them enough to eliminate the click. My lathe is a colchester 15x56 and I've dialed the tailstock in as close as I can get it but it varies with how much shaft is out and pressure on the lock obviously. Any thoughts from Jackie, Al, or others?

  5. #95
    Join Date
    Dec 2003
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    washington.........STATE that is.
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    Quote Originally Posted by Shooter71 View Post
    I've been thinking about the whole reamer pushing thing a bit. Assuming the chamber remains concentric with the bore and the throat is lined up, does it matter if the back end of the chamber ends up oversized? Might it be preferred? I've read AlinWa's methods and it makes a bunch of sense to me. If he's designing that into his reamers why not just use a dead center like Jackie does and welcome any extra fatness that might happen? I understand wanting the machine work to match the reamer and be consistent but it seems to me the consistency will come from running it through the sizing die anyway. I've used the prebore method as well as just running the reamer in using a JGS floating holder with good results, but some of the chambers are tight enough at the back end that my sizing dies don't size them enough to eliminate the click. My lathe is a colchester 15x56 and I've dialed the tailstock in as close as I can get it but it varies with how much shaft is out and pressure on the lock obviously. Any thoughts from Jackie, Al, or others?

    To Shooter71


    but it seems to me the consistency will come from running it through the sizing die anyway.

    No


    A HUGE no........


    ('YUGE"....???)

    I'm speaking up because you state that "my methods make sense" but they do NOT make sense unless the entire concept of maintaining straight cases is understood. There is only one way to make and maintain straight cases. NO die can make straight cases. And no die ever made can "straighten" a case......nor "fix" a case nor "bring it back to spec" nor any such nonsense. All a sizing die can possibly do is mangle a case and MAKE IT LESS STRAIGHT..........and no press is "stiff enough" nor "straight enough" to help this in any way.


    Everything you've ever heard about sizing dies straightening cases is flawed.





    There is precisely ONE over-riding and all-important factor to consider when viewing a sizing die.

    And that 1 THING is the scrupulous fitment of YOUR die to YOUR chamber.

    only that

    And this fit CANNOT occur when chambers vary one to another. Unless you have a die fitted to each chamber individually.


    And this single item, making identical chambers over and over is the single reason for pushers.......

    And any talk about irregular or egg-shaped or fluted or eccentric or lobular/globular/nodular chambers is completely irrelevant to this. Butchered chambers is an entirely different kettle of worms from FITMENT......and not really even worthy of discussion amongst machinists. No pusher/holder/floater/method should produce mushroom-shaped or duck-shaped chambers...... "Runout" and all it brings to the table shouldn't even BE on the table in polite conversation.




    opinionby





    al

  6. #96
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    Mar 2016
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    Thanks for the reply Al. Always good info. I may have used the wrong words, by consistency I only meant the amount the base of the case is reduced in size by the die, not anything to do with producing straight or consistent brass. I was more thinking about the dead center producing a larger, but straight and concentric chamber, not being a totally bad thing. But I also can see that using a pusher on a reamer with a fatter base matched to a properly sized die is a more repeatable method.

  7. #97
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    Dec 2003
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    washington.........STATE that is.
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    Why THANK YOU Shooter71 for taking my post in exactly the spirit in which it was intended.

    I hesitated to post at all......I perty much only post on old threads in which I'm already a part these days........ but I did.


    Oddly enough I posted because of Boyd Allen......


    Boyd is a much nicer fellow than me in that he feels he can "say things in a less confrontational way" than is my wont.....and I was just having a liddle rollick over Boyd on another forum (on which I DO NOT post ) Seems Boyd nicely asked a fellow "with all due respect, why don't you do a little experiment....?" upon which one of the perennial haters jumped with both footies, howling "cuz then he couldn't have this conversation with know-alls like you....etc, etc"

    Sad, really....


    Ohhh welll......."haters gonna' hate" and all that. I'm learning to just crawl back under my rock cuz mos' folks have no use for facts as they tend to kill the typical conversation. And someone always "feels bad" when facts and tests and long-term evidence chains take the mystery out of stuff....

    Maybe now that the political climate is changing someone will start a shooting board where people are still allowed to be passionate about truth

    Ohhh, and BTW, I haven't found the toolpost to be adequate for driving a reamer even if it's been swept, flycut or machined square for a number of reasons all having to do with flexure and movement due to necessary clearances. In short the driving forces tend to tip, lift and upset the carriage precluding alignment under pressure.....whereas when pushing with a locked-down tailstock assembly with it's wide footprinnt clamped to and using a fairly short section of the ways it's relatively easy to maintain alignment under the pressures involved. Just look at the two assemblies while pushing with your finger and imagining in your mind the load transfer path and you will easily see the difference. Driving with the tailstock is like spreading your stance and blocking your feet to PUSH a large object with a pole....whereas pushing with the toolholder is like doing the same thing...... in a boat.


    anotherspateofopinionby





    al

  8. #98
    Join Date
    Mar 2016
    Posts
    7
    Makes sense.. although the size of my lathe makes me think the flex could be pretty minimal.
    I read a lot and rarely post anything. What do you think about the method of using a center for half the chamber and a flat pusher to finish? I haven't tried it. But I might try pushing with the flat front of the tail stock ram and a wide pusher similar to a design you posted. The whole bulldozer blade analogy. But the way the tailstock droops, changes with the amount of shaft out, lock pressure etc. makes me wonder how it affects the reamer. I prebore the chambers and it seems to me you want the first half or so dead nuts and supported by a center or some method until the reamer has more hole to follow. How do you keep the back of the reamer centered at the start, when it's supported on a wider flat surface? Or does it straighten itself right out as soon as it gets some depth? I haven't done enough barrels to test each method to satisfaction.

  9. #99
    Join Date
    Feb 2006
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    California...unfortunately
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    Quote Originally Posted by alinwa View Post


    Ohhh, and BTW, I haven't found the toolpost to be adequate for driving a reamer even if it's been swept, flycut or machined square for a number of reasons all having to do with flexure and movement due to necessary clearances. In short the driving forces tend to tip, lift and upset the carriage precluding alignment under pressure.....whereas when pushing with a locked-down tailstock assembly with it's wide footprinnt clamped to and using a fairly short section of the ways it's relatively easy to maintain alignment under the pressures involved. Just look at the two assemblies while pushing with your finger and imagining in your mind the load transfer path and you will easily see the difference. Driving with the tailstock is like spreading your stance and blocking your feet to PUSH a large object with a pole....whereas pushing with the toolholder is like doing the same thing...... in a boat.


    anotherspateofopinionby





    al
    Al,

    Interesting observation on pushing with the carriage assembly. I have read that these necessary clearances come into play when turning or threading with the tool upside down...the cutting pressure is applied upwards, which in turn lifts the carriage up until the clearances bottom-out. The manual lathe carriage assembly is designed to take the cutting forces downward. Never thought about this as it relates to chambering...

    As I picture this, specifically chambering using the carriage assembly, I see the movement on the vertical plane, as well as potential movement on a horizontal plane due to the v-ways disengaging. Further, if you are getting vertical movement on the carriage when chambering, the positive effects of the pusher, in which the pressure applied to the back of the reamer holder is working to correct any mis-alignment, are reversed. Am I seeing this as you are?

    And have you ever measured the movement in the carriage you detailed above? If so, what were you seeing, numbers wise? And have you ever checked deflection on your tailstock ram?

    Lots of variables here...lathe quality, carriage weight, clearances, etc. A guy could drive himself nuts thinking about all this. I think I'll go mow the lawns...

    Justin

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