Downgrading From 420 FPS to 350 FPS Help

Richard89

Richard89

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Hi there guys i'm very new to airsoft played a few games with my little brother who has gotten me into the sport.

I just recently received my first gun its a Krytac LVOA which out of the box using a 11.1v Lipo is shooting at 410-420 FPS, i need to get this down to 350 FPS. I thought all i needed to do is change out the stock M120 spring for a lower one, i went for a M100 but once i installed that it was double shooting in semi and the bb's rarely came out. I looked into this and think its to do with my motor being to strong for the weaker spring.

Any help or suggestions would be much appreciated.

Cheers,

Richard

 
Not likely. Probably you just didn't put it back together correctly.

 
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Bit of both me thinks but wtf do I know....

Samarai could be correct because it should fire ok if everything was replaced correctly I would tend to think.....

But if your Krytac was shooting at 420 out of box then it probably wasn't a UK gun so it could have the faster 30k motor not 20k motor in there

Then add in you are running 11.1v on a m100 spring with neodym you will be hitting 25-30rps and yes at this speed with m100 it will double fire

(well quite likely you are going to be 30 or over I would think on good neodym & 11.1v)

Double fire I mean it will cycle twice on semi

(God knows how many times people say double fire when in fact it isn't double firing but friggin' misfeeding and nothing then 2 then 1 bb's come out)

So by what you said on that much juice it quite likely to fire twice on semi......

Your basic options is to drop to 7.4v or 9.6v and stick in low to mid 20's

or

old spring back in and ShortStroke the bloody thing to reduce fps aprox 15 to 20 fps pre tooth removal

but depending on barrel length you may only be able to remove 2 to 4 teeth

of course you could put in a m110 and just shortstroke 1 or 2 teeth if needed

or fit a less powerful motor to prevent it going nutz and firing twice on m100 spring

should still fire ok on semi though unless you did something wrong or it really going mental in which case PE may occur if you continue

the double firing on semi is an early warning sign of you taking the pi$$ so it needs to brought under control a bit

a little pre-cocking is ok but not firing twice - that is going too quick on present setup imho

 
Last edited by a moderator:
Sitting Duck said:
Bit of both me thinks but wtf do I know....

Samarai could be correct because it should fire ok if everything was replaced correctly I would tend to think.....

But if your Krytac was shooting at 420 out of box then it probably wasn't a UK gun so it could have the faster 30k motor not 20k motor in there

Then add in you are running 11.1v on a m100 spring with neodym you will be hitting 25-30rps and yes at this speed with m100 it will double fire

(well quite likely you are going to be 30 or over I would think on good neodym & 11.1v)

Double fire I mean it will cycle twice on semi

(God knows how many times people say double fire when in fact it isn't double firing but friggin' misfeeding and nothing then 2 then 1 bb's come out)

So by what you said on that much juice it quite likely to fire twice on semi......

Your basic options is to drop to 7.4v or 9.6v and stick in low to mid 20's

or

old spring back in and ShortStroke the bloody thing to reduce fps aprox 15 to 20 fps pre tooth removal

but depending on barrel length you may only be able to remove 2 to 4 teeth

of course you could put in a m110 and just shortstroke 1 or 2 teeth if needed

or fit a less powerful motor to prevent it going nutz and firing twice on m100 spring

should still fire ok on semi though unless you did something wrong or it really going mental in which case PE may occur if you continue

the double firing on semi is an early warning sign of you taking the pi$$ so it needs to brought under control a bit

a little pre-cocking is ok but not firing twice - that is going too quick on present setup imho
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Thanks for that, your information helps alot.

And yes its from the US as the ones her in the UK have been delayed so it does have the 30k motor.

I assure you i have put it back together correctly as i checked over and over again then gave up and put the stock spring back in and works just fine.

I think ill try say a 20k motor and different spring and go from there.

Cheers,

RIchard

 
Oh could you point me in the right direction to a decent 20k long shaft motor ?

 
easiest thing first is to drop the volts

I don't know how fast & strong the 30k one is coz I don't own one

but neodym motors vary a LOT

some torques can pull tanks - well no but very strong springs but speed wise offer not much more than a decent stock ferrite

others go like the clappers and pull most stuff say up to m130 easily

then there are speed motors that go nutz but get very warm spamming on semi if using anything over m100 spring

as a guide or general rule - connect up a 7.4v lipo 20 or 25c and she should be hitting 20rps

then that would mean you was hitting 30rps aprox with another 50% or extra cell and quite likely that 30+ figure is giving you the grief

loads of ways to get it under control - but if you wish to shoot at such a rate shortstroking might be only real way to fire at 27+ on 350fps

reduce the juice - hey I'm a poet and didn't even know it

reduce the charge then, and see if gun behaves better

I would do this first before you start ripping her open again & again

a shs torque pulls say 33% more than a stock ferrite

a shs speed puls 50% more than ferrite

a zci balanced motor I found was about 25- no more than 30% faster than ferrite

and another torque neodym I had was nigh exact same as good ferrite pulling 20rps on 11.1v lipo - kinda crap speed wise

so it is really hard to give you an exact answer on the spot

check it out that all feeds ok on lower juice and you may find 7.4v - maybe a 25c or 30c will be ok for now

plus if 7.4v is ok you should be able to use a higher capacity/burst in there too - plus cheaper

 
Last edited by a moderator:
The 30k motor was utilised to be able to pull an M150 using 11.1v LiPo and the reason we in the UK get the 20k motor is due to our low FPS limits as the symptoms you have discovered are to be expected. You could always lock it to semi and re-fit the OE spring then just use a pistol when up close and personal!

 
thanks for everyone's input its much appreciated.

Ill try the 7.4v 25c lipo option first with the selection of springs i have and go from there. I have a game tomorrow its just a shame i cant use the gun for it. Next time though :D

 
Hi there guys just a quick update i borrowed my brothers 9.6v battery and tested with the M100 spring and it works perfectly :D

Thanks everyone for your help

Richard

 
just to throw a curve ball in there, if you correct the AOE you generally lose a few FPS so might be worth trying that with your stronger spring.

 
I suspect you are correct but it is at least an easy thing to try :)

 
and could always replace the spring guide with a bearing spring guide to bump the fps back up again

 
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