AUG Build Problem

Discussion in 'Gun Building, Modifications & Repairs' started by Splode, Aug 21, 2018.

  1. Splode

    Splode Well-Known Member

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    So today I bit the bullet and took apart my AUGs gearbox to put in a full cylinder and also to put in the Tienly motor Guges sold me. I then reshimmed and also put the original semi auto trigger switch back in because the new one was too short and wasnt contacting. Closed everything up without too much difficulty (i hate that trigger) this time and hooked up a battery to test fire.
    First of all, the RPS is fantastic with the motor upgrade. Thanks Guges.
    Anyway, heres the issue. The semi auto works now, but now Im getting the typical issue of it bursting 2 rounds instead of 1. It doesnt always do this but it does about half the time. Also, it ONLY does this on my 11.1 lipo. The 7.4 is fine.
    The only thing I possibly could have changed as far as I can tell is the trigger slide spring. Does it matter which way the loops are flipped? Like should it be O||||||_ or O||||||¯ ?
    But if thats the problem, then why doesnt it do the same with the 7.4? Possibly overspin?
    Too much POWAH?o_O
     
  2. link0

    link0 Well-Known Member

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    What power spring do you have in there? The combination of the 11.1 and a powerful motor often causes double shots (too much overspin) when paired with a weak spring.

    You can cut a few loops out of the cut off lever spring to increase the tension and make it cut off faster.

    A bit of overspin is good though. It gives you that sweet precocking effect.
     
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  3. Lefse

    Lefse Well-Known Member Supporting Member

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    I think you mean the trigger switch return spring, but yeah, that can help significantly in many cases.
     
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  4. Splode

    Splode Well-Known Member

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    Im using an m120 and may even have to switch to a 110 once i chrono.
    I wouldnt think a 120 would be too weak?
     
    Last edited: Aug 21, 2018
  5. Lefse

    Lefse Well-Known Member Supporting Member

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    It's not the spring, it's partially because of how the motor is designed. Tienly motors have a slanted armature design AFAIK and this can actually increase the overspin because the motor doesn't slow down as quickly.
     
  6. Splode

    Splode Well-Known Member

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    Dang. So how do i counter that because i love the trig response with the 11.1.
    would streching out the cutoff lever spring help anything?
     
    Last edited: Aug 21, 2018
  7. link0

    link0 Well-Known Member

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    My mistake earlier. As Lefse pointed out, it's the trigger trolley return spring that you should shorten/modify.
     
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  8. Splode

    Splode Well-Known Member

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    Will that actually work though if the problem is the motor?
     
  9. link0

    link0 Well-Known Member

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    It will reduce overspin by a certain amount. Whether that amount is enough to eliminate double shots depends on how much total overspin you had in the first place.
     
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  10. Splode

    Splode Well-Known Member

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    It does 2 shots about half the time. 3 shots rarely.
    Ok so I just cut a couple of coils and then bend another loop?
     
  11. Lefse

    Lefse Well-Known Member Supporting Member

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    Try taking off 3 coils and then make a new loop. If that doesn't help you may need an AB mosfet or use a stronger spring and short stroke.
     
  12. BOA_SP3CT3R

    BOA_SP3CT3R Moderator Staff Member Moderator Supporting Member

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    Which Tienly motor is it? Yeah, definitely overspin.
     
  13. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    GT30K High Torque. I don't have overspin on my M120 AEG's. What FPS are you getting with .20g?

    Wait...is that the short motor GT40K HS? Red Label.
     
  14. Splode

    Splode Well-Known Member

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    yes, red label 40k.
    Havent got a chance to chrono yet. Ill try to this evening. Probably well over 400 because i was getting a bit over already with a windowed cylinder.
     
  15. BOA_SP3CT3R

    BOA_SP3CT3R Moderator Staff Member Moderator Supporting Member

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    Oh ok, your RPS should be in the low 30's. Try trimming coils of the trolley return spring and if that doesn't fix it an active braking mosfet would.
     
  16. Splode

    Splode Well-Known Member

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    That seems to be the common approach, although i didnt want to go the direction of AB mosfet due to the extra load. Augs have very limited battery space. Ill see what the spring mod does. or maybe i can short stroke since ill probably be over fps limits anyway.
     
  17. link0

    link0 Well-Known Member

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    Orrrrrrrrrrr, you can just use a 7.4v lipo instead and have zero overspin problems ;). I know it's sacrilege here among techs to not use 11.1v, but if you are anything like me, and just want problem free reliability and longevity over squeezing out every last drop of trigger response, then 7.4v is the way to go. Active braking significantly reduces motor lifespan.

    The trigger response difference btw a well-tuned 7.4v setup and a 11.1v setup is noticeable but only barely for me.
     
    Last edited: Aug 23, 2018
  18. Splode

    Splode Well-Known Member

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    NOES! I will get all da trigga responses!!!
    Lol, but yeah, the 7.4 is nice too but only slightly better than the 11.1 was with the old crappy jg motor.
     
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  19. -Spitfire-

    -Spitfire- Well-Known Member Supporting Member

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    I've actually never owned an 11.1 lol... Never had the need.
     
    Last edited: Aug 23, 2018
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  20. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    Some people just want the .18 second faster response time.