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Thread: Machinists, get ready to shoot me

  1. #11
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    In the case of the BMW temp fit, it is suppose to be able to be removed.

    There are also used to match parts that are tough enough to be machined together and not removed, using closer tolerance.

    In those cases it is often for high tolerance parts, like high RPM bits and the like. Or small turbines. Threaded parts wouldn't be able to keep the fit, and the turbine would need to be partway down a hard center shaft.

  2. #12
    I have just a few years of machining experience and for me, I can make threaded parts in about a tenth of the time it takes me to turn down a press-fit part on a lathe. I don't have any experience with CNC though.

    I'd say for weird sizes, threads are easier, but if you can design something to use a standard size part (say 1/4" round stock) it should be easy to size the hole to a few tenths under and ream it (if that's an available reamer size).

  3. #13
    Quote Originally Posted by ironyusa View Post
    Threads are dirt cheap as long as they're a standard profile and pitch so they can be cut with common tools. Personally, I'd trust threads with a permanent thread locker over a slip fit. Depending on how your threads are done, you can stake it and they won't come loose under a reasonable use case. Assuming this is for the paragon plunger, I think you'll be fine with threads and some locker (though uninformed users will inevitably try to take it apart).

    The m2 bolt is multiple pieces, BTW. We haven't has a single report of one separating. It's threads and locker.
    Wow you know that clears so much up. I never really looked for how the m2 bolt was made but it makes total sense now why it doesnt slide nicely and why so many people have problems with those sail orings leaking, I personally have problems with the bolt not cycling when its first aired up in any weather and with the lpr set crazy high but once it breaks and starts moving free it is fine all day.

    I tossed my m2 bolt in my little china mill and stuck a dial indicator on the side of it, measured at the top to see the machines runnout, then where the threaded section was then all the way down at the tail. Its not concentric by 1/32" and mine isnt one of the markers that has tail sealing problems. For relative measurements I grabbed an old first gen image 1 matrix bolt and at the tail the runnout was about 1/3rd of the m2 tails runnout.

    I am posting up this video, it is set to only show for people who have the link



    I'm curious do you guys have a concentricity tolerance at dye? Any paintball company? I dont know if its so out because of how the threads are made or if the machine is pushing to fast without enough stock support but something is making it off pretty drastically. I am going to try and straighten the tail of my bolt and see the difference in drag because of it, maybe solve my gas up issue. It is surprising none the less as I have run a dial indicator on a few ul backs and they have always been dead money in my experience so its a little shocking that a turned piece would be that far out

    It has me curious, when I get some time, I am going to try and measure up some more bolts to see how straight companies are keeping things.

    I'm sure there is an acceptable threshold for concentricity but 1/32" seems pretty excessive if we are looking at high end markers to have better performance than the lower end models.


    I bet the DSR bolt engine has less drag because that bolt would be easier to keep concentric.

  4. #14
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    Honestly, the M2 was all done before my time. The sail oring is goofy because it's WAY stretched and the colored orings have a wider tolerance than standard seals. I was going to release a "phoenix bolt" and one of the features was a reworked sail oring. I have no clue what's going on with yours, but I can do a little digging. I have to wonder if it's an assembly issue where the torque value is inconsistent. There isn't any columnating element on the M2 bolt threads either (unlike the DSR valve and our 2-piece barrels).

    The symptom you're explaining seems more related to compression set in the orings.

  5. #15
    Quote Originally Posted by ironyusa View Post
    Honestly, the M2 was all done before my time. The sail oring is goofy because it's WAY stretched and the colored orings have a wider tolerance than standard seals. I was going to release a "phoenix bolt" and one of the features was a reworked sail oring. I have no clue what's going on with yours, but I can do a little digging. I have to wonder if it's an assembly issue where the torque value is inconsistent. There isn't any columnating element on the M2 bolt threads either (unlike the DSR valve and our 2-piece barrels).

    The symptom you're explaining seems more related to compression set in the orings.
    I fear I might be going off topic but I would love to know what you dig up. That's interesting about the sail orings as well. I've switched all the dynamic orings in the marker to quad rings and a u-cup at the firing can, it really helped drop my bolt stick issues I first had with it. I replaced the lpr and hpr rings with x rings as well as replaced the seats with some from my dm3 parts kit and it drastically improved my consistency and creep I was having in the winter. I don't know if you are allowed to share your bolt anymore but I'd love to turn one up for myself and see how much better I can get it shooting. I tweeked my bolt sail back in with my lathe and a little torque and got it into 2 thousandths. I stacked some weights on my bolt in the drivetrain before and after and it needed slightly less weight to move the bolt after I tweeked it. Definitely feels that the front can oring is a little tight fitting on the bolt as well. Might take a few thousandths off the bolt up there and see if it gets smoother.

    Another question why did they switch to 2 orings on the hpr piston? Always been tempted to remove one and see what it does to the recharge rate of the reg.
    Last edited by Florypb505; 09-25-2017 at 12:02 AM.

  6. #16
    your best bet is probably, re sizing your parts to take a typical +/- .0005 a nominal size reamer.

    but yeah, threads or a pinch flexure is probably more reliable/easier
    social conservatism: the mortal fear that someone, somewhere, might be having fun.

  7. #17
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    I was asked to keep the phoenix bolt files for a while otherwise I'd be more than happy to share. You can see the old thread here: http://www.pbnation.com/showthread.php?t=5443641 And if you search the title of the thread in google you can see the cached images before photobucket sucked.

    The way the m2 is, the softer orings that some people sell really does help. Xrings really help the running friction, but to very little in improving breakaway friction which is the real problem. I hand fit standard profile orings and run a ucup on the valve and I can run my m2 at stupid low settings.

    The dual orings on the regulator piston is NOT something I had anything to do with... It doesn't really have any functional benefit though it doesn't seem to hurt much either. I tested it several ways with a transducer. The reg setup in my personal m2 is much different. I also have a different LPR configuration that reduces the pressure required to cycle the bolt (has more reserve volume so the solenoid doesn't starve).

    Sorry Steve.
    Last edited by ironyusa; 09-25-2017 at 08:27 AM.

  8. #18
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    Did I miss something?

    I suspect the dual o-rings are to prevent damage to the bore more than performance. It does seem less necessary on a moving base reg with a long piston, but you'll see a few floating poppet regs do it to maintain concentricity, I think including the Axe reg and max-flo, and the CP v1 reg (at least) uses a -1xx ring on the piston (which will push more on the walls under pressure).

  9. #19
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    Didn't mean to hijack.

    There was also some effort to add volume above the piston. Again, I had nothing to do with that reg setup.

  10. #20
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    I have another one for all of you, most could probably answer this. I'm just not familiar with standard practice for this stuff.

    Say I want a 10 thou tolerance. As an example I call a dimension out to two decimal places, covered under "two place decimal" general tolerances in the title block, so it's this: 0.85", 0.01".

    How do machinists interpret that? Say I take my mighty mitutoyos to the part and the dimension measures 0.863". If we interpret that under the above callout, the part is interpreted as in spec, correct?

    Correct me if I'm wrong, but If I want a 10 thou tolerance, I should call it out as the following: 0.850" 0.010"? Above is a 0.01" tolerance, which could be as far off as <15 thou, correct?
    I work for the company building the Paragon...once we figure out a name

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