Legacy's Guide to Building a High Speed AEG

Discussion in 'Gun Building, Modifications & Repairs' started by LegacyAirsoft, Nov 21, 2013.

  1. kazuchan

    kazuchan Member

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    hmm, my rps is only around 33rps and 400 fps 1.86J, 0.25g. battery 1000 mah with 35C "advert" ( Main goal to hit 40 or 40+ rps ).

    HS motor 50k rpm
    shs 13:1
    light swiss cheese.
    16 awg
    basic mosfet.

    maybe try to use lower spring strength a bit and other battery.
     
  2. Guges Mk3

    Guges Mk3 Well-Known Member Supporting Member Lifetime Supporter

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    You need more voltage. If that is a 3S and you are not hitting a higher speed. That is a bad battery and motor.

    Also why are you using a 1000mah? Is there a size issue. Most 1000mah LIPO are 14 years old in design and not very good for the price...unless you got them for 10.00 a pack. But you can get newer 1400mah for 15.00 a pack.
     
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  3. kazuchan

    kazuchan Member

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    yes, 3s battery, but there is size issue here, I must have to use "stick" lipo battery. ( E&L AK ). I tried to wire back at rear stock but the space too limit for 16AWG ( super tight fit ) and pretty sure it will get shattered after some fold stock.....

    I'm lazy a bit at I only charged storage mode. I'm still waiting my 1300mah and 1400 mah 3s 30c for maximized my energy source.

    edited: fix grammar.
     
    Last edited: Jul 9, 2020
  4. Guges Mk3

    Guges Mk3 Well-Known Member Supporting Member Lifetime Supporter

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    It's Stick, not "Sticker"

    This is a Sticker

    [​IMG]

    You can get a 3S 1500mah HO LION in that compartment. Or a 1400mah long thin AK LIPO.

    I have an E&L...a 2015 Prototype that is not sold in it's "Configuration" and I use it as a battery fitment tester.
     
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  5. Lefse

    Lefse Well-Known Member Supporting Member

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    How about copying the battery solution in the TM NGRS AK where it's stored in the gas tube and use a small racing grade brick li-po?
     
  6. kazuchan

    kazuchan Member

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    gastube on E&L pretty small too, so i'm not sure about that.

    I replaced lonex tapplet ( which look bent backwards some ) with another one not bent, use a little weaker spring . after test with 1300 mah 30c full charged, the rps only bring up a bit, 36rps with 390 fps w .25g.
    I hit some new problem: the fps when auto is mass drop , from 390 -------> 260, sometimes is 320. Is it normal ?
     
  7. Guges Mk3

    Guges Mk3 Well-Known Member Supporting Member Lifetime Supporter

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    It is is you have a "soft" piston head o-ring.
     
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  8. kazuchan

    kazuchan Member

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    tried with dsg tapplet , no luck.
    trim 2 coils tapplet spring, use alu ph head with other O-ring. no luck.
    I'm out of ideas now.


    [​IMG]
     
  9. aotsukisho

    aotsukisho Well-Known Member

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    Is your hop unit shimmed up to your gearbox with O-rings? Sounds like the vibration is making you lose your compression seal, if changing tappet and strengthening its return spring didn't fix it the leak might be external to the gearbox.

    Use 5/16x7/16x1/16" O-rings. Danco #6, Oringsandmore #11
     
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  10. kazuchan

    kazuchan Member

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    after tinking, check all things, I noticed the tapplet little stuck when it pulled at farest position.
    the fin on lonex tapplet is thinner than china tapplet/ dsg shs tapllet ( 0.4mm ), which make the nozzle pull all the way back>>>>>> fps bring back same like semi mode.
    with china tapplet/shs dsg, it will not pull at fartest position, on semi, it can bypass, but at auto mode it cause mass drop fps , more than 100+ fps.
    problem sloved.

    thank all guys
     
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  11. blaine_green

    blaine_green New Member

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    Hey I'm building a 13:1 with a m120 spring, i have a few motors a TM EG1000, a JG Blue and a G&P m170. But the G&P is short type so i would have to take the shaft out of the TM to put in it to make it long. Was wondering if the JG blue would be fine? The m170 seems overkill i mean its actually hard to turn by hand compared to the JG. Any tips are appreciated
     
  12. Guges Mk3

    Guges Mk3 Well-Known Member Supporting Member Lifetime Supporter

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    JG is fine for a M120
     
  13. Lefse

    Lefse Well-Known Member Supporting Member

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    JG Blue will work well, but the EG1000 armature is a beast when put in a strong neo magnet can.
     
  14. 1tonne

    1tonne Well-Known Member

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    So I had an idea (Not sure if others have tried it but I have not seen anyone so far).
    I know the tappet plate already comes back far enough to feed but in a very high end rate of fire, could we improve the feeding?
    My idea is pretty simple. On the cylinder head, where the 2 holes on either side are, could they be filled up with epoxy resin and then redrilled out a little further forward (maybe 1-2mm) so that the cylinder head sits back further in the cylinder. Then would also need to be shorted 1-2mm as well (Maybe only were the tappet plate is). This means that the tappet plate has more room to move back. Next step would be to plastic wield or use epoxy resin to make the fin on the tappet plate slight wider (Closer to the sector delay clip). This would then mean that the tappet plate would be pulled back further and so you should in theory have a slightly longer period that the air nozzle is pulled back. Giving the bb just that little bit longer to move down into position.
     
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  15. aotsukisho

    aotsukisho Well-Known Member

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    The holes on the side of the cylinder head are just there for alignment, and are not meant to be load bearing. Retro Arms posted an article regarding issues with front-padded cylinder heads in their gearboxes: https://www.retroarms.com/news/destroying-gearbox-by-cylinder-head

    If the bb needs a longer loading window duration, holding open the nozzle for a longer time is all that's needed since the nozzle retracting over 6mm should not matter. If you pull the nozzle back too far, there is a possibility for allowing double-feeds into the chamber. Wider sector delay chip will be effectively the same end result for a fraction of the headache.

    This can be paired with replacing the magazine follower spring with a stiffer one, and possibly the follower itself if it is causing improper doublestacking or binding. This is what I've had to do with my completely nonfunctionl G&P Colt 9mm mags with limited success.
     
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  16. 1tonne

    1tonne Well-Known Member

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    The cylinder head will not be under anymore stress as you would not put rubber pads at the front of the cylinder head.
    The idea for this is more for very high end rps (So where the gun is cycling that fast that it will not double feed). With the sector gear cycling so fast, the smaller the width of the sector chip the better as the tappet plate should seat back in position faster. So making a tappet plate fin longer will mean the sector gear may not need a chip on it.
     
  17. aotsukisho

    aotsukisho Well-Known Member

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    It will put extreme stress on those alignment pins as you are suspending the cylinder head on them, which Retro Arms says they have seen them shear off if they are subjected to impact. The front of the gearbox shell is what should be taking 100% of the impact, for your proposal you need to fill in the gap to transfer shock to the proper place.

    Opening up the possibility for feed failure even though it "shouldn't happen" does not seem like a good idea to me when there are alternatives

    I'd suggest altering the profile of the tappet plate fin rather than altering the distance it travels. You could have a half height fin profile like on DSGs to allow the spring more time to pull the tappet plate forward, but have the fin start further forward near the top to begin pullback sooner at the beginning of the cycle

    Magazine follower spring - stronger spring to increase bb feed speed
    Tappet plate - half height fin, altered profile to start pullback sooner
    Tappet plate spring - stronger to increase tappet return speed and push nozzle forward to load bbs against stronger mag spring
     
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  18. OPairoft

    OPairoft Active Member

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    Also magazine follower shape is extremely important for feeding.

    Ideally you want one that stacks bbs like gas mags if not better.

    I 3d printed about 100+ and got four dead epm mags working again just by changing the followers.



    About RA’s post on cylinder heads, does that mean the newer lonex cylinder heads with the front pads should be avoided?
     
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  19. aotsukisho

    aotsukisho Well-Known Member

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    If it puts pressure on the alignment pins at rest or under spring tension then it should be avoided. The back and forth motion effectively chisels off the pins.
     
  20. -Spitfire-

    -Spitfire- Well-Known Member Supporting Member

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    The alignment pins, as previously stated, are not intended to be load bearing in any way. The front of the cylinder head needs to be firmly up against the front of the gearbox shell, or those pins will fail. This is a known issue with some ASG/Lonex cylinder heads, and the MTHaynes install guide specifically goes over fitment irt ensuring that the cylinder head is flat up against the gearbox wall, without putting stress on the pins (which incidentally, seems to be the only thing on those gearboxes people have broken, as a result of improper installs).