Low rpm

Discussion in 'Gun Building, Modifications & Repairs' started by TheInfidel23, Nov 8, 2012.

  1. TheInfidel23

    TheInfidel23 Resident Derp Supporting Member

    9,924
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    Greenville
    About two years ago I purchased a custom gun from airsoft gi. The gun was based and built off of a G&G combat machine blowback platform. After a year and a half, the blowback cylinder broke and I disassembled the gearbox. After figuring out the unit was beyond repair, I ordered a new cylinder and re assembled the gearbox. To my surprise the rate of fire was about half the original(15rps - 7rps). I have tested both my 9.6 batteries On my new CQB M4 I got and friends guns, and the batteries are fine. I am lead to believe its the motor but I don't understand how a motor not in use can die. Any help is appreciated!
     
  2. Maxuhmize

    Maxuhmize New Member

    5,460
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    OKC
    Well, I'm wondering if you assembled something wrong and it's slowing down the RoF. It doesn't sound like a motor issue because it wasn't in use. Or maybe it is a motor issue for that reason:O
     

  3. TheInfidel23

    TheInfidel23 Resident Derp Supporting Member

    9,924
    13
    Greenville
    I am not an expert, but the gun did shoot, so Im thinking a wiring issue maybe, or something with the bearings? the new G&G brass bearings can be pretty tight, and I re-shimmed the gearbox. i wonder if the gears are pinched?
     
  4. Devgru98

    Devgru98 New Member Supporting Member

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    Polo
    Try adjusting your motor height. And is 15 RPS what your getting now? If so that's pretty standard for a G&G blowback
     
  5. Maxuhmize

    Maxuhmize New Member

    5,460
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    OKC
    The gears wouldn't be pinched, it be the wires. Like Devgru said, try adjusting the motor height and if its not that something might be wrong with the wires.
     
  6. TheInfidel23

    TheInfidel23 Resident Derp Supporting Member

    9,924
    13
    Greenville
    I did re-shim the gearbox, and i may have a wire resistance problem. just guessing at this point. the gears were all greased and all theat, the only thing i can think off is maybe they are getting pinched?
     
  7. TheInfidel23

    TheInfidel23 Resident Derp Supporting Member

    9,924
    13
    Greenville
    I've run the motor height to china and back and the rpm didn't change. My motor also took on a new sound after the re-build, sounds strained.
     
  8. Devgru98

    Devgru98 New Member Supporting Member

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    Polo
    Put in a new spring or stretch the current one?
     
  9. alex

    alex New Member

    4,794
    4
    Atlanta
    did you test the shimming by spinning the gears without the cylinder, piston, tappet plate, ARL and the gearbox screwed down? it is important that it is screwed down.
     
  10. TheInfidel23

    TheInfidel23 Resident Derp Supporting Member

    9,924
    13
    Greenville
    i didn't run the gears together, only individually. when i went to put my new cylinder in, the screws were loose, but they were tight when the problem started.
     
  11. TheInfidel23

    TheInfidel23 Resident Derp Supporting Member

    9,924
    13
    Greenville
    no spring change. shot 375 fps with .2 from factory
     
  12. alex

    alex New Member

    4,794
    4
    Atlanta
    there's your problem...

    you need to test the shimming with all the gears installed and gearbox screwed down. it should spin freely with the selector plate pushing the cutoff lever out of the way.

    screwing down the gearbox reduces the clearance on the gears.
     
    Last edited: Nov 8, 2012
  13. TheInfidel23

    TheInfidel23 Resident Derp Supporting Member

    9,924
    13
    Greenville
    Thanks yall when i find time to work on it, ill run the gears and see how it works. i have a feeling it won't matter but ill try it. my dad and I have tried to ressurect this gun all summer. :)