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Kings arm box shs gears


Gazzalesta
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Sometimes - it can be because another factor....

I say SOMETIMES because it all depends on the switch installed.

 

Some old style switches have 2 prongs at the rear which MUST have a copper plate

on selector plate AND MUST make good consistent contact when firing.....

 

It is a crap old design than can cause issues when firing - often in semi than auto

 

I'm not saying this is the exact case in your instance but another thing to check

see the copper plate may not be making good contact in semi and some resistance ?

In auto the plate slides further back and makes better contact with these 2 prongs...

 

So you "can" get intermittent firing issues if these prongs are not bridged by the selector plate

 

NB - I'm not saying for certain this is the case but it is a fairly common issue at times

 

Most modern switches do not have these rear prongs - eg: shs switches G&P & G&G plus others

But others like Cyma SRC - these two I know have the prongs at the rear - ooh APS as well I think

 

If the prongs are not bridged soundly you will have issues...

 

NOW there is a way you can bridge these contacts with say a staple/wire and solder them

BUT you should ONLY do this if you run a mosfet

mosfet's run very low juice at the switch so it is fine

DO NOT JUST BODGE IT IF YOU ARE NOT USING A MOSFET !!!

 

pic says a 1,000 words...

 

UKfir.jpg

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Ahh right then if it has the SHS switch assembly, not just a SHS trolley then you won't have those prongs.

Now another thing is risk of piston/spring bottoming out or get close to it.

 

If you shortstroked then this won't be the case

But it is hard to pinpoint as to why a lockup might be happening without seeing, hearing it or checking the amp current draw etc...

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Weird it is locking up on semi but ok on auto ???

especially on stronger motor - stock motor & poor battery yes if precocked it might not shift easily

 

The semi issue led me to think the copper plate/prongs not touching but that is not the case

 

if it is shortstroked then piston can be bottoming out at back of box then - nope

 

piston binding - some pistons are very tight fitting in some boxes that they bind

normally this slows the rof down and with a strong motor it should still fire coz it has the grunt

if you have shortstroked 2 teeth then the piston will just pass the window at rear of box

if you shortstroke 3 teeth the piston just reaches the far rear end of window

 

it could be catching at the window - file these rear guides of pistons at angle to reduce any chance of catching

BUT tbh I doubt if if this is the real issue if she is firing ok on auto....

 

I'm leaning towards a tight binding piston either too tight piston or rails

the piston inserted in box should fall freely if tilt box up/down

google some vids coz the copy/paste feature is not working - but you will need to check for binding

slightly file the rear of the runners on piston right at back to assist or reduce the risk of catching on window

 

Really tbh - you need to maybe check the amps if possible - I'd say you are well over 20amps

if the motor is straining a bit to cycle on auto & locking on semi

 

it is either a bad bad connection on motor or wiring (not the prongs but along those lines)

or you got some mechanical lockup to extra stess which kinda overcomes on auto but not on semi from start

 

possible chipped tooth on gears or a bit of plastic can lock up stuff - but I don't know

your shimming MUST have some tiny play side to side when box is finally assembled

bevel must be shimmed as close to possible the perfect height...

too low and pinion will try to jam or push the bevel right through the box as tries to mesh - straining and ramping the amps

too high and the tip of pinion will nearly hit the bevel's AR lugs the AR latch uses

(not a common thing but some boxes have a bit more shimming space in say bearings than bushings and you can shim too high)

 

It is something daft, that is for sure but I'm seeing nothing and the new host isn't too clever for posting links/pics/vids either atm

so I suggest to strip it ( AGAIN ) and really really check just how silky smooth them gears turn

how smooth that piston glides back & forth in the runners - how the piston falls or slops about

 

Deffo worth checking piston out - loads of agro I know but welcome to the world of toy guns

How hard can it be ???

 

I reckon it isn't until you reach the thried build you start to get a better idea

around about 6th build you are sort of getting there by overcoming previous issues

and I reckon about 9th or 10th build you finally build a box that you are really proud of that lasts

and we are ALL STILL LEARNING - think we never stopping saying WHAT THE F*CK on these poxy toy guns

 

hope some of crap helps

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Check your amps & new battery higher burst....

what spring you using - should only need a m110-115 if Shortstroked a couple of teeth

 

weak motor connections, bad joins etc.....

 

try another motor just in case

 

did you correct AoE properly ?

if not it could be getting bolloxed on the next cycle or pick up but then wouldn't it screw up on auto

 

wiring - mosfet - contacts at switch

 

if it all operates smoothly mechanically then it must be some sort of electrical issue

 

worse case scenario it is a number or mixture of issues

I would try a higher brust lipo 25c 7.4v - NOT 11.1V if using 12:1 gears ffs

it will smash up using a high burst 11.1v on speed gears

 

ensure all connectors are sound tamiya/deans deans is best but reckon some electrical problem perhaps

really need to check amps well over 20amp you may have undue stress in the box maybe ?

 

check motor spins outside the box/grip - had one with an iffy armature - rare but can happen if a winding blows

try another motor

 

chrono the sod on auto - you may have a m150 spring in there but you would notice it tbh when closing up box

 

it is something bloody weird or a few things or a bad part of some description

but I can't tell coz I haven't got it front of me & not even got a pic of your box/work to look at

 

try a few things above if not open the thing up & take some pics - upload to imgur of stuff

don't worry if it isn't a perfectly neat job - I've done worse bodge or bad teching in the past

(not that great now tbh but have f*cked up loads in my quest to get it better)

 

somebody - one of us can look at it and likely shed some more light/suggestions on the bastid box

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I have no way to check amps and only standard motor I tryed my 7.4 wouldn't work with it only with 11.1. 120 spring or that's what I was told

 

Ahhhh that might be part of the problem.....

With higher speed gears you are placing more strain from start position

12:1 or 13:1 is like you trying to pulling much higher spring than a m100

then add in a higher spring on top & the poor stock motor is trying to start pulling say a m150

but due ratio's it doesn't have an easy start

 

like trying to do a steeper hill start in fully loaded clapped out fiat panda or something

even if you rev the thing the lame engine is going to struggle no matter

 

I suggest you look towards a shs torque & try her on 7.4v 25c lipo

the motor upgrade is going to be required imho

some stock motors are ok but most are not for an upgraded mechbox

 

try looking out for a shs torque - not speed motor - long type most likely

check ak2m4 and others for shs or RA torque or at a push zci balanced

reckon that should sort it out

 

sorry thought you had an upgraded neodym magnet already

but obviously I got confused with similar post

do not get a speed motor - you want a good balanced motor like a shs torque

 

run on 7.4v - not 11.1v as that may be too much and could wreck the box if you go too quick

depending on what you get rps then 11.1v will be 50% again...

problem is at 25rps you start getting a bit close to PE or PME

you should be ok to say 27 - 30 rps but finally rps can vary

if you push it too much the sector engages the piston and makes a nice mess inside

trust me - if there is one thing I have done often it is taking the pi$$ and smashing f*ck out of a half decent box

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