Downgrading From 420 FPS to 350 FPS Help

[Richard89]

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

[Samurai]

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

[Sitting Duck]

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

[Richard89]

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

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

[Richard89]

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

[Sitting Duck]

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

[Guest PT247]

edited: retracted offer

[Guest PT247]

If you want a proper Krytac motor but the 20k version you could try the UK importers of Krytac: http://www.shieldpsd.com/product-category/airsoft

Their website only lists the 30k motor but if you contact them they may be able to sort you a 20k version.

[ImTriggerHappy]

Just use a 7.4v 25c lipo and it will work fine.

[Guest PT247]

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!

[Guest PT247]

Just use a 7.4v 25c lipo and it will work fine.

If this is the case then it is a bonus as you'll be able to fit in a higher capacity 7.4v LiPo than you can an 11.1v LiPo which will save having to do a battery swap at lunch time! :-)

[Richard89]

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

[Guest PT247]

at least it has a quick change spring mate! :-)

[Richard89]

at least it has a quick change spring mate! :-)

 

haha yeah takes about 4 min to take apart and get to it plus ive taken it apart and put together so many time now, so im learning alot which is good

[Richard89]

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

 

Thanks everyone for your help

 

Richard

[simonh]

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.

[Lozart]

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.

 

You wouldn't lose that much though (unless he screws it up completely).

[simonh]

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

[Guest PT247]

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

[Lozart]

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

 

True. It's worth doing regardless to improve the gearbox and extend its life!

[ImTriggerHappy]

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.

Krytacs come AOE corrected.

[GiantKiwi]

Have to question what the point of the MOSFET in them is (outside of the obvious) if it can't do cycle completion but hey ho...

[Guest PT247]

Have to question what the point of the MOSFET in them is (outside of the obvious) if it can't do cycle completion but hey ho...

allows them to run on 11.1v LiPos without wrecking the trigger contacts. Do agree it would be nice if it finished a cycle/precocked with it though.

[Sitting Duck]

Thing is the precocking malarky can be achieved if you start running it with a little more juice.....

so that she nearly double fires - half cocked so to speak

Obviously as battery loses charge a bit the precocking gets reduced

 

And you don't want to store a precocked gun either

so people have been known to use a lower juice battery at end of day to park the gun/spring correctly

 

This is not going to be nowhere as programmable as a Spectre but just one other option to consider

Along with AB Mosfet needed or not - to each their own as they say

 

If guns cycles quick-ish or is quite responsive, then the chances of releasing trigger too early is greatly reduced imho

 

There are numerous methods & options available when tweaking and choosing a mosfet

Think we all have our own preferences which we go with

[Richard89]

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.

 

Sorry still very new with messing around with my gun and airsoft in general but what is the AOE ?

 

So my gun still has the 30k motor using a 9.6v battery with a SP100 spring this is shooting 360 FPS, still to high :/ any suggestions ?

 

I was thinking SP90 spring and tighter barrel to bring it up a little more near 350 FPS what you guys think ?