Nothing but problems with my Custom G&P M4

[Katana]

DAMN you got that MOSFET locked down

 

That makes a lot more sense because I was positioning the gears already picked up by the piston which was causing me all kinds of hell.

 

Have you ever thought about putting the motor underneath the ARL area to hold it? I just thought of it but it might pull things into all kinds of strange areas. Worth a go.

 

The way that you've positioned that MOSFET in the stock is probably what I'll try tomorrow if that silver wire turns up. Some shrink wrap and duct tape looks like it helps out a lot with the whole crunching fiasco.

Save on a bag on my stock and loose wires.

 

My buffer tube has those slits in the sides for routing wires so maybe installing the MOSFET a bit better than it is now will be much easier than I thought.

 

Should I shave a couple mm off of the front of the tappet plate to improve air seal to the hop up? I feel that the air leak might be in that area if it isn't in the gearbox. Don't want to do it if unnecessary though so maybe I should see how this goes first before I wack out the sandpaper.

 

Maybe there is no air leak and the cylinder volume is what's causing the fps loss?

Maybe the Nuprol springs are actually rated a lot lower/ are sh*t? (Wouldn't surprise me)

Maybe the air leak is in the hop up? (That would really surprise me with the o-rings and such)

 

Only one way to find out... "FIGGHTTT!!"

Or....you know...testing n stuff...I guess

[Sitting Duck]

 

Should I shave a couple mm off of the front of the tappet plate to improve air seal to the hop up? I feel that the air leak might be in that area if it isn't in the gearbox. Don't want to do it if unnecessary though so maybe I should see how this goes first before I wack out the sandpaper.

 

 

Not all stuff is the same and is true with nigh on all stuff like tappet plates:

 

 

also the shs tappet plate seems to have the ridge in the U slot sitting a little further back from center

so with shs tappet plate you can sand it down at least 0.25mm maybe a little more

just lay a sheet of emery/sand paper flat and standing the tappet plate upright sand it in a circular motion & reverse circular

or what ever way takes your fancy - just try to do it evenly

 

0.25mm sanded off front of tappet plate should push the nozzle that distance further forward to help seal better

you should feel resistance placing the hop to nozzle at its full extension

would suggest doing this on a fully assembled box and ensure nozzle fully forward:

 

 

you should feel resistance of about 1mm to 1.5mm at that point of the nozzle pressing to seal against bucking lips

you want some resistance to seal without blowing out in operation

but not too much that it knackers the bucking lips quickly

 

if gearbox seals piston/cylinder ok, the nozzle seems to seal against bucking

then unless nozzle is damaged or something daft....

Any air loss will likely to be in bucking/hop or badly aligned gearbo/nozzle to hop unit that might rub/catch impede it in operation

 

google up ptfe hop unit mod - you can have air leaking out around hop C clip or end of hop barrel

hop/bucking air loss is another thing but that bridge can be crossed if needed a bit later after box is sorted

[Katana]

Shimming as we speak using the bevel to pinion method. Getting a lot more comfortable with gearboxes and shimming is more time consuming than I thought but with a

bit of practice I can see how one could speed up the process significantly. The shimming before hand was lazy as I thought previously. Very loose but it's quite a ton

better atm.

No play when I shift the bearings either side and gears spin freely.

Did each gear with the gearbox screwed up and found that doing it whilst pressing down on it and actually doing it up can have massive differences in tightness.

I'm actually shimming bevel to pinion right now. When I go to wiggle the bevel gear though with the motor in, there is absolutely no play from what I can tell which

I'm thinking is probably too tight but I'll have a look at the guides. The G&P Gearbox isn't exactly work friendly as there is an absence of holes around the bevel so when I

have the motor in and the gearbox done up, it's hard to tell how much play the bevel actually has.

 

Really surprised with the shim job I was given though. It was rather...well...crap.

 

I have an SHS tappet plate so I'll shave a touch off and do it like you said.

Is there anything bad about shaving too much off of the tappet plate or can I go up to the ridge?

Will I eventually shave so much off that the air nozzle starts slamming against the hop up and break?

Or weaken the tappet plate too much maybe?

[Sitting Duck]

The bevel is in fact the one gear that you can have a bit more play side to side

the pinion is inserted so there is no way it will slop about when you think about it

the pinion is going to keep it there so as long as it is skimmed to correct height it can have a little more give underneath the bevel gear

 

Yes you are correct - you get it all shimmed with just a small smidge of play then when you tighten it up it is shimmed tight coz it all disappeared

 

With practice you get to suss out you have say 0.20mm when clamping the box by hand

this halves to a nice 0.1mm when all tightened up which is what you want

Bevel can have a little bit more play especially if pistol grip is a bit snug - but it ain't going nowhere with pinion gear holding it in place

Just as long as motor height is nice and not too high/low or forcing the bevel out of the gearbox drawing loads of amps and everything running red hot etc....

 

Have a look at Rogers - shut up gears - jeez that is the shimming guru mofo - but c'mon think that is a little too involved

but it explains the fine details of it - you don't have to go that mad but think most people's will shimming will improve after watching that & a some other good guides - bloody good of people to share their wisdom like that

 

TBH - you want bushings or mainly bushings on a high speed build

At the very least you should have 1 bushing underneath the middle spur gear - honest

that is THE point that is bombarded with stress from motor & spring and that one alone will fail first - even ceramic bearings can fail there

So if you splash out £30 on ceramics - still fit a bushing under spur

Yes it is wise to glue them in - especially if loose fitting bearing/bushings superglue or epoxy

But 8mm bearings is going to better than 7mm & 6mm especially won't last - I had a build wreck itself after 15k

the 7mm bearings were stock and thought they would be alright - developed a LOT of wear & were all over the place until it smashed all teeth off bevel

(luckily most bevels are 10 teeth so it could be redone with 7mm bushings and the old bevel from the std gear set was fitted into a 13:1 set)

 

Everyone will do stuff differently - guess you could use bushings underneath the gears and maybe bearings on top

but deffo that one under the spur is where most stress all meets up

Shimming - again you can never guess it especially the bevel height

spur has a thin one underneath it (0.1 to 0.2) & whatever is required to space it just right

sector has roughly half & half what is needed on both sides aprox - checking there is a slight gap where spur/sector lay

bevel - well I won't say can be ANYTHING on top 0.1mm to 0.55mm on one crazy slack v3 box I built - all gears had loads of shimming splace on that box with 6mm bushings and if using bearings/bushings that can make a difference as bearings tend to lay lower than some bushings - in fact not uncommon to reduce the bushings a bit by sanding them on emery - shs 8mm solid bushings are sometimes too thick and care is needed to ensure a low spur gear's teeth isn't rubbing on bevel/sector's lower bushing - blah blah blah...........

 

There is no ultimate guide - everybody does stuff a bit differently - uses different stuff works to certain standards and still we keep learning/changing/trying different stuff as each build is slightly different or unique....

 

The tappet plate you will be fine with, if you are that worried - run a marker over it all at front to show you are filing/sanding it down evenly

though tbh I feel the emery paper sanding it with it vertically - just going in a clockwise & anti clockwise - ok counter clockwise motion as anti clockwise is incorrect term to some

Sanding it down will be fine - 2mm is very fine - was shocked to the SRC one

but 0.25mm down to 2.25mm will help and be fine

If that SHS blue is like most I've seen and your nozzle isn't superglued on (hot water helps to remove)

if you look at groove in the U you will see the ridge is set a little off center - say 40% back so you can shave off 10% off front 2.5mm down to 2.25mm

 

To be honest though I say 1.5mm max resistance when pushing hop to nozzle - you can have a bit more up to say 2mm

BUT this is due to the M4 having a sprung loaded hop pressing against the box

on AK's the hop is fixed and that is why I say 1.5mm limit to stop people smashing the lips to bits if no give on hop unit

The M4 isn't a set in stone rigid hop so you can go a little tiny bit more - not insane but you want the lips not to blow out but not smash them to bits

 

Shave that tappet plate - sand it is best - it won't take too much off too quickly

some guides use dremel sanding discs - that is a bit daft to me

file it yeah maybe then sand to finish but a power tool - no that is for Short Stroking & grinding stuff down like metal teeth on piston etc....

 

Get the nozzle's "groove" in center of " U " if you haven't got a digital caliper gauge - get a cheap metal one off fleabay if you do more work

[Katana]

The bevel is in fact the one gear that you can have a bit more play side to side

 

Literally just tearing my hair out trying to find the right combination for the top because it's either too tight or too loose. I had a setup with the tiniest amount of wobble and amazing "free-spin" but the bevel was wobbly slightly.

 

 

Yes you are correct - you get it all shimmed with just a small smidge of play then when you tighten it up it is shimmed tight coz it all disappeared

 

I figured that out the hard way when I looked at a 4 year old "How to shim" on youtube only to realise that the method he was using just doesn't work.

 

 

TBH - you want bushings or mainly bushings on a high speed build

 

I considered this at the very start of the build but some people on the forums were saying that bearings can last if you take care of them and then

others were saying that it is best to buy bushings because bearings will at some point fail. Knew I should of gone with the latter but I guess that's just another thing

to consider for the future builds

 

Have a look at Rogers - shut up gears - jeez that is the shimming guru mofo - but c'mon think that is a little too involved

 

if you look at groove in the U you will see the ridge is set a little off center - say 40% back so you can shave off 10% off front 2.5mm down to 2.25mm

Get the nozzle's "groove" in center of " U "

 

I used someone called "Stinger" on YouTube. He used the Bevel to Pinion and it seemed fairly alright but I'll definitely check out Rogers' Guide.

 

I'll sand it back after I'm done with the shimming which looks like not long. Holy shit I have a new appreciation for shimming and people that shim very well/ near perfection. This stuff is time consuming.

[Sitting Duck]

Shimming is time consuming - sometimes it can come together quite quickly

often though depending a bit of luck (swear this applies to numerous stuff in airsoft)

quality of gears/box/bushings/bearings - even shims - Element ones seem to be cut or punched quite roughly so you get slight deviations

not a lot but if you place a 0.20 shim in caliper gauge and rotate it a little you can feel the rough punched edges varying the shim

not a great massive amount but say it can show up 0.25mm on an Element shim where as a SHS may show 0.21 or 0.22 at very most

it isn't the deviation so much but it just feels rough as well and not finished so well like SHS ones

 

Also depends on your fussy standards too BUT a LOT depends on how well the shimming is done

Bad shimming, crap motor height puts strain & wear on motor wiring and drain battery quick draw excess amps too

The box/motor will crap out quicker - heck fuses blow on badly assembled builds very easily pistol grips get bloody hot

And above all it just sounds $hit

 

It is not always simple to get it purring so sweetly but hopefully we try to make them as best as possible without sounding like you are kicking a dying cat being stung by wasps whilst jangling a bag of rusty old bolts on the field

 

Bearings - they would be fine for most "normal" builds of say 20rps or just over I'd say

But most insane nutty builds at 40rps+ will use bushings

You are using a high speed set on 11.1v so you are likely to hitting say 35rps - so yeah bushings or at least a mixture is what I would use personally

I use a mixture at least - some boxes the bushings has stuck out a bit and used a bearing instead of bushing but underneath gears a bushing over a bearing

BUT to each their own - and again depends how you use it - if you hose people then yeah it won't last ages

but if sensible semi & some spamming now n then it will last longer maybe - but how long is a piece of string ????

 

All this opening/closing box stuff - when inserting the M3 bolts usually by hand at first,

turn the bolt counter clockwise first and eventually you will see the bolt rise & clonk a tiny bit as it finds the threads

then do up the bolts - this helps to reduce chance of wear or stripping threads

This is more important on plastic components as often video consoles & stuff can have their threads on plastic cases worn or stripped very easily if you just jam the screws in and tighten - unwind-clonk-tighten will prolong the threads

Also unless you are very very weak do not go for a clenched fist when doing up fine screws and threads

Seriously - you should only need a thumb and forefinger to tighten the screw/bolt up with a mild nip if you feel it might really need it

Do not use a clenched fist to tighten you will strip threads very easily and might as well run it down kiwk-fit-euro to tighten with air tools

 

When you have closed the box up for the final time without stripping the threads....

If the box was assembled with gears and no real tension on spring you should still be able to feel a bit of play in them

 

As said - sometimes when you "think" you got it all perfect it is no biggie to re-open it to say change spring or check seals

coz at this point you can check stuff - clean/regrease and also just double check the pinion height again on bevel gear in other half of box

Wouldn't be the first time I have found the pinion a tiny tiny bit lower than I was expecting and so swapped say a 0.20 shim on top to a 0.15mm shim, adjusted motor height a bit but felt a bit more confident the gears were meshing a bit better

Note I'm talking very small amounts of adjustments if it is far out then something is really out of whack

 

This is why often that little toy gun won't just take a few hours but more like a few days on & off if you really want to get it as close to perfect as possible

(and that is if you got all the parts to hand in good working order, not on your knees looking for that little bastid AR spring or something - damn it better order a new one)

 

When it all works and you are pleased as punch or nigh on delighted with all your own work and celebrate with a beer & a large:

 

[Katana]

Order ID: 871
Date Ordered: 21/08/2016

Your order has been updated to the following status:
Shipped

The comments for your order are:
-------------------------------------------------------------------------------------------------------------------------
Have shipped out just the spring and have refunded you £7.50

If you still need wire message me on FB in 2 weeks time I'll get you some at rock bottom price

All the best
Pete

Please reply to this email if you have any questions.

--------------------------------------------------------------------------------------------------------

 

Looks like that wiring won't get delivered tomorrow. Alternatives? I'll have a look around unless you have a backup for your backup haha

 

Finished shimming...bevel has very very slight play without pinion attached. Gears spin freely..all that good jazz.

 

It is not always simple to get it purring so sweetly but hopefully we try to make them as best as possible without sounding like you are kicking a dying cat being stung by wasps whilst jangling a bag of rusty old bolts on the field

That needs to be a velcro patch...A very long velcro patch.

 

I am getting worried about the screws stripping on the gearbox shell. I must have closed it and opened it around 25 times.

I just do as you advised. The screws are of decent quality but they aren't invincible, that's for sure.

 

When this thing is working, I'll be running up walls and scaling rooftops (not literally, for legal purposes)

Hopefully it'll be at a point where I can take it to a MILSIM event because at the moment I wouldn't dream of it...well I mean it is kinda in pieces at the moment so....yeah

[Sitting Duck]

pm an addy ffs

 

I'll send ya some silver and some Alpha

you can use the silver as positive and Alpha as negative

or use either but I only bought 30m of Alpha in black

I'll grab a 30m of red one day soon

 

when boxes remain in bits too long that is when little bits go walkies

so pm me and I'll post ya some wire

[Katana]

I'm really surprised that you would stick your neck out for me like that and help me so much. I really appreciate it so thank you but I wish I saw this 15 minutes ago because in that 15 minutes I've just spent 16 pounds on some ASG Ultimate Silver plated wire (price including Next day delivery even though it won't be delivered until Wednesday)

 

http://www.patrolbase.co.uk/airsoft-switches-selectors-and-mosfets/asg-ultimate-silver-plated-wire.htm#.V7tgepgrIuU

 

I really appreciate you helping me out so much though, you have been beyond helpful and I can't thank you enough.

[Katana]

http://imgur.com/a/pFbGv

 

Just a couple of pics.

First showing the extent of the posi wire damage

Second showing orientation of the gears I was trying to pull off when putting it back together (without the spring on).

[Sitting Duck]

ahh well no worries

 

could of gone to fleabay:

http://www.ebay.co.uk/itm/AIRSOFT-MOTOR-WIRE-BATTERY-CLIPS-CONNECTOR-TAMIYA-DEANS-HEAT-MALE-FEMALE-T-SET-/272009124279?hash=item3f5501d9b7:g:eBoAAOSwx~JWFWSd

 

http://www.ebay.co.uk/itm/Ultimate-Airsoft-Silver-Plated-Wire-2-Meters-16640-/351790069738?hash=item51e85277ea:g:zgUAAOSwPpFXMHmn

 

yup - think many of us have had a cable chew up around motor

some pinions/motors seem to catch more than others

a very fast motor I had was a bit tight to get into a shell's entry point than other stock or shs ones

you see jack squat didley - maybe a slight bit of resistance as you refit motor - bit of wiggle/push and if it shreds you are too late

 

so we all learn by our many many mistakes or mishaps

[Katana]

Okay so I've wired the new motor connectors.

This asg wiring isn't very bendy...kind of spring witha weird stiffness too it.

I want to wire it to an external pack and keep the crane stock.

Im thinking of wiring it with the mosfet through the stock and out through a hole in the side using a deans extension where I would my plug in my battery from.

 

Thoughts?

[Sitting Duck]

you got a split stock tube

 

get gun working once again - the wiring can be tidied up later

 

You could wire it to half of tube, plug in gate

then if needed add a smaller couple of inches of silicone deans wire at back so it flexes when fitting batteries

yes it is more connections/links so adds a bit more resistance

but real nutters hardwire thick wires with only one deans from gun to battery - soldering in just the mosfet on neg with a signal wire

but is a bitch to remove in stock tubes

So there is always a trade off unless to go for stuff like fixed stocks

 

main thing is getting gun running - wires well you can look at various options and tidy/trim up the wiring later once she is all working sweet

[Katana]

https://vid.me/fdTJ

 

SHE IS DONE. FINALLY HOLY MOTHER OF JESUS.

Lonex springs are long as my

But really, they take some force getting in there and I lost some faithful shims along the way. Rest in Peace.

 

The wiring wasn't all that hard but I will say that in now way is it the cleanest job. I didn't have a clamp and had to improvise.

It works...it's secure...I'm happy. Don't know how it feeds. Gonna test fire it now.

 

Thank you for your help in sorting out the bastarding gearbox

 

Edit: Another video including semi. https://vid.me/S8U4

[Katana]

And just like that....problem number one rises.

 

Okay so when firing, it:

A: Jams

B: Makes a weird soft thump noise

C: Fires very slowly

 

My guesses....

Prowin Hopup with the Lonex Air Nozzle aren't a good combo

Prowin Hopup with G&P Body isn't a good combo

The new cylinder is undervolumed. I doubt it because it shouldn't jam because of this...well I would think.

I shaved off too much when sanding the tappet plate....I doubt this very much because I didn't sand off that much. It was equidistant on each side of the air nozzle groove

I'm going to throw the G&P Hop Up Unit in there and see what happens

[Sitting Duck]

 

Okay so when firing, it:

A: Jams

B: Makes a weird soft thump noise

C: Fires very slowly

 

 

 

a - jams - gonna guess that is likely hop area

 

b - soft thump noise - didn't quite hear it but that clicky bit in 2nd vid where it stops firing then works again

sounds like a dead zone

 

c - fires slowly - you gotta be kidding in that first vid link

 

I presume you are running on 11.1v still which is still pushing that mofo especially if the 11.1v is a 25c burst

if you have a 7.4v and turn off active braking on 7.4v

 

Get the gun working first - feeding and chrono on 7.4v which should give you a rof at about 25-27rps on bearings

if you can turn off AB etc....

 

It is a case of NOT trying to run before you can walk

 

eg: 25rps say on 7.4v, mags should feed no problem chamber bb's test on semi & chrono & full auto

 

you need to know what the gun is shooting at roughly too - heck roll a bb down barrel from the other end

yes this bb will sit other side of bucking and therfore nigh on no hop on so it will be higher than usual

but if you are really out on fps and low/high

 

I'm gonna do a VERY VERY rough guess and say with hop off or a bb down the end of barrel rolled back to bucking you should get about 375fps

but this is just a guess

if that bb - and you may have to do this a few times

if that bb comes out at 300fps then you got a problem

 

run the gun at MODERATE speed first to test it

you may have feed problems above 30rps - could be mags/bucking

the faster a gun cycles the closer to perfection everything has to be - and I mean everything

stock guns will feed a lot better at 15rps unless it really is f*cked

30rps things have to pretty good - not all mags feed above this

45rps yeah you will need it absolutely perfect and deffo not all mags will feed well

 

seriously - a sweet mag that feeds great on a 25rps means jack $hit when you start going faster n faster

same goes for bucking/nozzle chambering etc.....

 

The gun should be tested on 7.4v first see how it runs

then get an idea of how fast she shoots and what fps

 

Trust me above 35rps which you might hit you can still smash f*ck out of that gun getting close to PE etc....

Your shs torque should be pulling that thing very well - you shouldn't need too much AB on semi

but AB will not save your gun from smashing PE on full auto @ 40+rps

the brake only kicks in when you release trigger - yes it will stop the semi asap but not be braking until you release trigger on full auto like the clappers

 

However - I think but don't know if there are any special features or delay on each cycle to keep the rof at say a max 35rps

but that is getting ahead of things for now........

 

What you need to do is ease up a sec - test the gun on 7.4v 25c aprox

13:1 should get you about 26rps on bearings @ say 340fps - rough estimation btw..... but with a shs torque

(speed motor - 30rps but that can get hot)

 

so test the gun is mild modest stages

believe me I've done a couple of same gun model's upgrades and the first one was a nightmare or very least a learning curve

a d-boys one & a china gun - jeez the first ones were a major throw it against the wall bastid

but the second time I did it - it was a breeze working as it should or better

 

There is still an element of luck as well as skill/care & attention

just go easy on the juice for now and get her working on 7.4v first before you crank up the juice

 

see if you can get the feeding issue solved first and go from there in small stages

[Katana]

It was the hop up.

The ProWin just doesn't like the body of my gun or the nozzle

Throw the G&P inside and it works like a charm.

Feeding is perfect, even on automatic

Hop up is working fine

Haven't tested to see if I still have that problem where I fill a mag and fire and it fires badly on the first 30ish shots

Ill look tomorrow because it was dark out

BB's are getting hopped fine and all

I teflon taped the hop up lock and where the barrel comes out from the hop up

I threw an O-ring over the teflon to lock that mother down for good measure

 

I am getting into more of a sprint aren't I

The ROF is ridiculous

It's definitely over 30rps when I compare it to Youtube videos (Bad comparison I know)

I think it's about 35 because looking at the 40rps videos it's just a hair under that

 

 

c - fires slowly - you gotta be kidding in that first vid link

 

Sorry I meant that when I fired with the ProWin, the fps of the bb's was insanely low.

I'm quite contempt with the speed hahaha

I never really use auto much anyway besides suppressing

The trigger response is what I was after more than anything because I practically rape semi-auto

 

I do use 11.1v 25C batteriesand about that

Quick question: I switched from a 7.4v 20c to a 25c and noticed an increase in ROF and Trigger response

If I raise my c rating higher, will it raise my ROF or will the amount of current reach a point where it will stop increasing ROF because it has reached its "current potential"?

 

Anyway, I can program the MOSFET to reduce the ROF to whatever I want it set to.

Not exact but it is percentage based varying in increments of 10%.

Is it wise for me to reduce ROF then?

 

The soft thump noise I was hearing was referring to the strawberry JAM

I should of clarified on that rather than randomly saying a soft thump

 

ATM the gun is...working.

Now the question is...what is the FPS when chrono'd?

I can pray below 350fps, I mean I guess it's possible but something tells me that it's gonna be over

You say 375fps...I hope not

[Sitting Duck]

I said 375 if you rolled a bb from the end of barrel as you was having feed problems....

the bb will roll down to nub but sit the other side of it

so when you fire there will be no drag or backspin being created so no reduction in fps

 

eg: normally a hop wound on/off can be a 30-40fps difference depending on hop & bb weight used

so a 375 with no hop will drp to 340fps on a normal bb with hop so to speak.....

again a rough guide but you was getting jams you said so was only suggesting this to get a bb shooting out and maybe to get a rough reading....

 

so once you got your hop set - tilt gun to its side and bb should curve left/right on its side a bit to easily prove hop working

set ya hop to your weight - 0.25 say

then chron on 0.20's or hopefully 310-ish on 0.25's "should" be under 350fps on 0.20's

 

YES the C or burst rating makes a difference

 

normally 15c is well lame for tweaked guns - ok for stock but I wouldn't suggest buying a 15c to anybody unless you have no choice on a tight battery space gun - stock tube lipo's don't give you many options for choice but at LEAST go for a 20c or 25c if you can

30c maybe but as the C rate increases you get more punch and the response/rps creeps up a bit too

 

However - please be careful when upping the juice - trust me SS 3 teeth doesn't mean a 350fps gun will deffo like 40rps

You are sailing close to the wind and even when I have swiss cheesed like hell keeping weight below 20gms on a full complete piston

It doesn't mean a lightened piston will return in plenty of time to avoid PE

Well it has smashed on a 30sec auto burst nudging 40rps

(I'd rather smash it at home than on the field even though I wouldn't go that nutz - if it is likely to bust I'd rather know now that at weekend)

 

Yes you may be ok on semi with AB n stuff but all the same be careful going too nutz is what I'm trying to say

Most of us on here settle for a modest 25rps which can be easily achieved on 7.4v or 9.6v

The difference once you go past 30rps isn't really that noticable and tbh no response/rof past that will make up for a player/teams skill or gun's/players's accuracy

Plus there is a trade off where reliability in feeding with present mid range mags & reliability of the gun or durability

unless you wanna buy better more expensive mags and that one iffy component failing quicker etc......

 

RPS is only ever a guide - this is effected by motor - gears - spring as well as the volts/burst (I just refer to this a juice and be done with it)

 

You would be wise in getting gun to fire at around 24rps on 7.4v 25c and then around 36rps on a 11.1v 25c

you can set the delay a little lower to ensure you don't go past 35rps

I'd advise keeping to 30-35 no more - ffs would you really notice that 5rps off of 40rps ???

metal racks don't give you any weak point in drivechain like a half+half piston rack does

if PE takes place then everything is metal and so anything or numerous things can crunch

at pinion-bevel/spur can go as well as piston - so really consider this before going too nutz

 

11.1v's can only drop to 9v = 3v per cell

on a 7.4v you really really notice the juice dropping to 6v

on 11.1v not quite so much so change batteries at lunchtime

do not use 30c - I've used a titchy 33c block 11.1v lipo to test and jeez she really ramps up - whixh is why I break a fair few guns

normally I run 7.4v 25c on a 25-27rps gun

 

yeah weird the hop units - some work great and some are just crap for some people......

 

if you are over the fps then I guess you can remove spring guide or piston bearings

or try the old spring as your fps was quite low so could have been an old spring or mis-labelled one ?

also a shorter spring say 150mm in length is very easy to install

compared to a newer spring say 180mm in length

but I have noticed them shorter springs that install easy can overspin more even at mild 22rps on a m100/105 rated spring

(probably something to do with little initial resistance on milder springs like m100)

so yup - it is a good thing I feel to have a spring of a decent length than an easy to fit one if you are going to want a responsive/snappy gun

 

you still ain't out the woods yet, get her firing, chrono'd, feeding great, tidy wiring etc....

then you still got to get her shooting straight with some accuracy - this area I'm not so experienced

breaking guns - yup I've done plenty....

improving accuracy - ah yeah I still use cheapo guns so I can blame the gun still than my lack of hop/bucking skills

[Katana]

I use a mixture of mid caps but will be switching to mag brand mid caps because...they're awesome.

They completely empty rather than a few left behind like the G&P ones

No follower that sticks out of the magazine meaning you can break it really easily

Their design is so basic

They are made of really light yet rock hard plastic. I can drop these things all day on concrete honestly.

 

I'll stick to 11.1v 25c batteries because I love the snap to em.

However, I will reduce my rps to around 28? Somewhere around there

There is no point in my eyes in having an rps where I have it, especially if it's gonna start snapping all kinds of shit up

I'll pop in to my local shop soon and get chrono'd

See if I'm rocking close to the limit

 

It's weird how my opinions of fps have changed drastically

 

Started airsoft thinking fps = range like everyone

Learnt that the hop up assembly is most important for range and accuracy

But then you eventually go back to fps = range once that's fully upgraded

 

I used to run my gun at around 280fps with a 0.2 and fuck me I'm never doing that again

A squad was in column about 25metres away from me and I was using 0.25g bbs.

They literally heard the shot, saw me and moved before my bb's even reached them

I couldn't hit any of them

It was ridiculous

 

Now I aim for about 335-340 just incase of variations like weather and such that do some weird fps things to me

I've tried absolutely loads of barrels and absolutely loads of buckings. I mean like 10+ of each for the bucking

and at least 8 different brands of barrels

 

Settled on what I have now: Prommy TB, G&G green (flathopped) and flat prommy nub

 

I even tried the RHOP but holy crap that thing is delicate

No luck after 3 attempts...because it was the sand papers fault and the clamps fault and the....

 

The gun itself is actually half of the noise it was before

I'm still having counselling over that shimming job

It was like they didn't even try

They literally went faaak it and threw on some random shims. It sounds so smooth and soft now.

i sanded down the pistol grip so it fit the receiver a bit better because there was a massive gap, like quite substantial

As I said before, I definitely got a lemon but there is still some of the gearbox showing in the upper corner of the pistol grip

Need to shave some more.

[Katana]

So finally after some time I get around to playing a game day. Gun shoots insane. Amazing range and accuracy and I was overjoyed until I touched the chrono.

 

Shots read:

370

369

371

369

370

370

371

 

So very very consistent and no problems where about 30 rounds would lose compression which is good.

 

Site limit is 350.....oh shit me.

 

It's okay though because I now know what I'm doing somewhat with a gearbox so I open her up on site and trim the spring about 3 coils ish or maybe 2 and a half and bent the spring back flat as someone told me that not doing so may turn the piston on its side when firing (Sort of makes sense I guess)

 

In the process I lose the anti-reversal latch spring (MOTHER******) but I have active breaking so I can get through the day without an anti-reversal latch but the motor might not like it too much.

 

Go to fire and realise the trigger trolley spring slipped off. (MOTHER******)

 

Open her up again and put it back on and all that and she shoots.

 

Chrono.....

349

350

351

350

349

348

 

And eventually settled just under the 350fps mark. NOICE Played from after lunch til the end of the day no problems.....besides the battery setup.

Literally ran ghetto wires and mosfet on the outside of my stock

Duct taped it all to avoid the rain because the extension cord someone made so I could run an external battery pack was shockingly badly made and worn to hell but didn't think it looked that bad because the shrink was all nicely done. Nice on the outside, in bits on the inside.

 

I then remembered something. Clipping the spring now has put it at a lower power of course but that leaves me open to pre-engagement of the piston if I run it at 35rps and I did because I wanted to see the accuracy and range of the bb's when running such a high rps (Not that bad if I'm honest). I didn't use it during the games that much at all because I never really touch semi but I'll be sure to set it back to the 20ish rps mark when I next use it.

 

I am without a doubt getting the new spectre mosfet when it hits consumers by the end of this year. I'll run the gate mosfet setup in a separate gearbox in a separate lower body so that if my main goes down...I have a backup lower rather than a whole other gun.

 

Thanks for everyone's input and help...much appreciated.

 

Something I did change because I noticed my wiring chewing on the motor insert again was route both wires down the same side....works absolutely fine and no hungry motor wanting to eat red things.