Krytac mk2 shimming is hell

[Katana]

All of the bearings inside the gearbox are raised up so this thing is tighter than....use your imagination.

I mean seriously tight to the point of only having say, 0.1mm on the bevel gear per side which leaves no room me to shim it from bevel to pinion which means I apparently need smaller shims or perhaps some new gears as my brother wants to upgrade it and I was looking at SHS 16:1's so I don't have to possibly deal with overspin. He wants better trigger response and less whine so i suggested shimming it and having shimmed my own gearbox really well where it sounds like fabric slapping together (I know not all guns sound softer when shimmed) and it's incredibly quiet, I thought I'd give it a go. I had no idea that Krytac would use an auto-shim on the spur gear so I've had to put on a million shims to fill that out.

Just overall this gearbox is a freaking nightmare with shimming and IMO it's just that bevel. I'm closer than I was when I started but I've been at this for a couple days and am actually looking at buying a new gearset to increase performance so could anyone recommend a setup that could both decrease whine which is one of the reasons I'm also looking at a new motor.

Holy hell this thing has virtually no breathing room for la shims. I'm thinking that if the pinion prods the bevel, I may be able to leave it a lot looser than I am which is the next thing I'm about to try but it's still a nightmare to then stop the bevel grinding on the gearbox but have it seated high enough so that the pinion and bevel engage correctly.

Man I probably repeated myself about 10 times here..........Help......I boobed

(Just for reference....it's a completely stock Krytac Mk2 SPR)

 

[PT247]

Get no whine from any of my Krytac AEGs, once the motor is at the correct height they all run sweet as a nut.

 

[ImTriggerHappy]

Get no whine from any of my Krytac AEGs, once the motor is at the correct height they all run sweet as a nut.

Yep if there is any whine its probably not the gearbox its the motor height. I have had lots of experience with Krytacs and never came across one that needed shimming.
To the op just put it back together as it was and leave alone because unless you are going down the Siegetek route you wont get any better than what you have got. SHS is a downgrade and 16.1 wont improve anything much over stock.

If you want to improve trigger response use 11.1v and if you do get overspin swap the mosfet for one with active break.

Everything else just leave alone.

 

[PT247]

You can piggyback the kong burst wizard mosfet, so can possibly do the same with one that has ab

 

[Katana]

Yeah I'm just gonna throw it back together as it was and leave it alone. I may put an SHS High Torque in it and an AB mosfet. I can't be bothered with it anymore.

 

[ImTriggerHappy]

Yeah I'm just gonna throw it back together as it was and leave it alone. I may put an SHS High Torque in it and an AB mosfet. I can't be bothered with it anymore.

If you are going to upgrade the motor go for the Ultimate CNC 30k.

 

[PT247]

I have a Krytac 30k motor I could sell you if you are interested?

 

[Katana]

I have a Krytac 30k motor I could sell you if you are interested?

naa man I'll probably go with a non krytac motor, probably the asg trigger recommended or maybe a Lonex HT? Cheers for the help guys, it's all back together and I'm pretty sure it's shimmed....well enough. Not perfect but I can't tell when it is shimmed right because I usually as well as most go by sound and it sounds pretty much the same. Maybe a little snappier. It was definitely shimmed a bit tight for bearings.

 

[ImTriggerHappy]

naa man I'll probably go with a non krytac motor, probably the asg trigger recommended or maybe a Lonex HT? Cheers for the help guys, it's all back together and I'm pretty sure it's shimmed....well enough. Not perfect but I can't tell when it is shimmed right because I usually as well as most go by sound and it sounds pretty much the same. Maybe a little snappier. It was definitely shimmed a bit tight for bearings.

The asg is better. Lonex used to be my go to motor and are good but the ultimate has taken over.

 

[Sitting Duck]

Krytac shimming is pretty good

some pinions/motors mesh better (quieter) than others with certain bevels

also - can't be ar$ed to take pic but some bevels have more material than others and so the teeth can sit higher or lower

on some bevels this difference can be a bloody lot to see straight away so this can really throw shimming right out

You think that is bad, on some builds using bushings protrude more than bearings

I have had to sand the bevel ones on emery paper for a while to reduce them a bit and use virtually no shims on bevel & spur

(laid flat and circular motion etc & even then just one hex 0.1mm shs shim on top of bevel)

Pistol grip - especially if grip slides on very loose fitting will throw up slight variations too

have changed grips not always for looks/feel but some have been so damn loose it has allowed the final fit to vary when checking each time

not to mention the grip & motor plates can cause a variation in motor angles which will sound great or $hit no matter how good the shimming is

(in bad cases the pinion is trying to recut the bevel or vice versa)

Normally in most cases the std grip should be fine - but when you consider changing stuff it can throw up more grief for different builds/boxes

Think VFC also use a sprung spur gear - not a fan of that myself

have found that "spring" slows the gears a little when doing gear spin test and if shimmed/spaced as close to perfect as possible it rolls better imho

One guy on here had a funny slight faint clink on his krytac - they use 4 latches on their std gears

this should of provided 25 latch clicks which would be same as using a 12:1 with 6 latches - still 25 latches

I had a hunch the AR latch might be binding or spring weak on his gun - so as a precaution...

lightly - stretch AR spring if it feels a bit light and check the latch itself is flying back to latch asap

(had one G&G that really thick wire was rubbing against - bad positioning of AR latch on G&G's so had to do a little careful mod)

Think the std mosfet will be fine tbh up to about low 20's before you get chance of overspin

if you go faster then over-spin will increase & double firing can happen which if you are only going to keep her below 30rps may not be worth agro

unless you wanna go nutz for Active Braking and/or short stroking with stronger springs n crap

I advise most people to go in stages and do further upgrades as n when it starts to play up if you can resist the go faster urges

trust me - it is a ball ache coz learning from mistakes is fun but it can be so f*cking time consuming just for a few more rps

 

[Katana]

The bevel has absolutely no play when the pinion is inserted and I'm trying to add shims to push it up so it has at least the tiniest amount but then I make the bevel gear too tight....it's a friggin nightmare haha

I don't want this to turn into a repeat of my gun although I have learnt a lot from upgrading that thing. On top of that, this thing has an ambi selector which isn't too much hassle to install but it's still bloody annoying and honestly one more thing I don't need. Unless you are left handed, it's a bloody nuisance and something that I will never use even when shooting offhand and especially since the krytac ambi selector is so spongy and stiff and just....gross to switch.

It is tempting to just go....AHH f*ck IT...Another Gate Titan, Siegetek 10.44:1 SS by 3 teeth, M115 spring, SHS 14 tooth SC piston with AOE corrected blablabla but this thing is known for it's reliability and I don't want to honk out a load of money for reliability if I already have it at the expense of some SLIGHTLY sub par trigger response compared to what I'm used to and a slightly screechier sound.

It doesn't have perfect compression which is something I noticed between the piston and cylinder which I have helped but it still isn't perfect. It is more than good enough and takes ages for it to slowly decompress which might be as a result of me tilting the piston head around inside the cylinder and air slipping through.

I have an SHS HT on hand so I'll give it a go to see how it runs on a higher torqued motor, I think I already know the answer and that is that it's gonna start overspinning as krytac purposely didn't ship it with the 30k motor for that reason due to the weaker spring but I guess there isn't any harm in trying. If it's all good then I'll look into the ASG series which I have to say look clean as hell compared to the SHS ones which always seemed a bit hit and miss to me.

If I wish, like really really hard and click my heels together 3 times, do you think by some off chance that I will wake up tomorrow morning and all of a sudden there it is on my desk, completely finished with the whole Shabang? Something tells me it won't happen

Also, isn't this a much better pick than the 30k ASG motor? It's got a much higher TPA: http://www.redwolfairsoft.com/redwolf/airsoft/Accessories_AEG_Motors_ASG_Infinity_Motor_CNC_U_18000_Long_Type.htm

 

[Sitting Duck]

Motors - your SHS torque is a good motor

or Rocket RA from ak2m4

or a zci balanced - not torque imho

the zci balanced is same as shs/ra torque

though some say the zci pinion is a little weak compared to shs but not noticed myself

the zci torque is sssssslllllllooooooooowwwwwwwwwwww

torquey is in general slower but pulls a train

the shs torque isn't really a torque motor but a balanced motor that spins at about 25k but draws less amps than a crazy speedy shs one

TBH - go through ya shims and find the best thinnest smoothest 0.10mm perhaps

don't worry about having to shim the bevel underneath where it meshes with spur

it isn't going anywhere coz the pinion is in the way if you understand - this is the only place where you can undershim a bit and not worry

Try to not do the box up too tight - not clenched fist but tighten lightly and just nip the screws with thumb & forefinger is plenty

if you go nutz you risk stripping m3 threads & you will clamp the box up tighter and throw the shimming out making it tight

the 20k motor might be ok on 11.1v = might give you say 24rps

the shs on 11.1v will be quicker I'd say and maybe a smidge too quick on 11.1v & put you say 27rps & overspin

these are rough figures and probably max rps quoted depending on spring inside but you get the idea

might be about right coz you are on bearings than bushings etc.... and you shouldn't shim a bevel too tight then try to force pinion to mesh

them bearings can go under extra stress

so you may have to try both motors anyway - decide on what sounds or runs best and then see what juice or burst rating will keep her happy

might be a 20c 11.1v or a 9.6v or a zest 30c 7.4v

all depends what works best

get yourself an amp meter - either a plug in one or the more expensive loop if you wanna blow some dosh

the amps or current draw along with sound is a proof of pudding in the eating test

but amps will or should show/confirm when you have hit the sweet spot on motor height/shimming

faster motors do draw more amps so the wires get hot quicker and battery drains quick too

very fast motors are not wise I have found

think you could build a 13:1 gear set with a balanced motor and draw a lot less amps but not lose that much rps

I mean you can hit 30rps on speed gears and speed motor but f*ck even thicker wires get very very warm very very quick on 7.4v

or you can go balanced drop say 4rps and see the amps drop from say 24/25amps to say 17amps without it all heating up too quickly

Speed motors of 35k+ I would only use on std gears - they do draw more amps/heat

is why most go for balanced or not too crazy motors and 13:1 or so gears for response

Juice level - well like I say you gotta see how she rolls and decide what works best - you got a mosfet so you can up the juice ok

afraid this toy gun crap is a matter of sometimes you end up using slightly different stuff than you had planned

just so you are happy with what works best to achieve the best final result without too much trade off

don't matter to me much how good it shoots - I still get my ar$e handed to me by 13 year olds with JBBG guns

 

[ImTriggerHappy]

Also, isn't this a much better pick than the 30k ASG motor? It's got a much higher TPA: http://www.redwolfairsoft.com/redwolf/airsoft/Accessories_AEG_Motors_ASG_Infinity_Motor_CNC_U_18000_Long_Type.htm

The u-1800 is an extremely high torque motor but low rpm and totally unnecessary for your gun, its for high fps DMR builds.
The u-30000 is still high torque but with a decent rpm so you get a snappy trigger response but also a decent rate of fire on full auto.

As with any build getting the balance right is key.

 

[jcheeseright]

Honestly I'd just chuck an active braking mosfet and a big 11.1v LIPO in there.

 

[ImTriggerHappy]

Honestly I'd just chuck an active braking mosfet and a big 11.1v LIPO in there.

Same as I said half a dozen posts back. Simplest option is usually the best.

 

[Katana]

Well i tried out the SHS HT motor and it doesn't overspin at all on semi but it stops shooting after like 10 rounds? No sound of it trying to turn over at all and it sounds good, like it's seated correctly. It's so strange. It cuts off on a 7.4 or 11.1v. Battery doesn't matter.

Anyone know?

It's the motor I had in my one and I thought I'd give it a try but the only thing is, the pinion's look very different so maybe the gear meshing might not be to great over time and the size of the motors are different with the Krytac being larger and a better fit for the pistol grip. My guess is that the smaller SHS is shaking its wires loose with the extra room it has to bounce and shake? It never happens after an exact amount of shots but it just stops. It cycles much faster on semi but on full auto it is slower which isn't a bad thing at all, actually preferable.

 

[Katana]

Okay guys, I have no idea what is going on but when it shoots, it has pretty much no compression. I mean it just about makes it 20m and shoots incredibly slowly with hop up off. I have checked compression in the gearbox and it's fine so I can't figure out why it's doing this. I thought I may have boobed and put the tappet plate spring on the wrong way round but I just switched it back around the other way and same result. I did notice how the cylinder fit strangely inside. There is a groove where it looks like it should seat but doesn't quite make it and sits just out of that which makes me think that maybe the piston strikes it at a strange angle and air escapes out?

I'm just leaving the rest of the gearbox alone for now as I think everyone is right in saying that simple is better and that I should just throw an AB mosfet, new motor and a chunky 11.1 in when it starts to fail. Anyone know why it might be shooting like it has no compression?

 

[ImTriggerHappy]

Okay guys, I have no idea what is going on but when it shoots, it has pretty much no compression. I mean it just about makes it 20m and shoots incredibly slowly with hop up off. I have checked compression in the gearbox and it's fine so I can't figure out why it's doing this. I thought I may have boobed and put the tappet plate spring on the wrong way round but I just switched it back around the other way and same result. I did notice how the cylinder fit strangely inside. There is a groove where it looks like it should seat but doesn't quite make it and sits just out of that which makes me think that maybe the piston strikes it at a strange angle and air escapes out?

I'm just leaving the rest of the gearbox alone for now as I think everyone is right in saying that simple is better and that I should just throw an AB mosfet, new motor and a chunky 11.1 in when it starts to fail. Anyone know why it might be shooting like it has no compression?

There are so many things that can cause low fps.If the gearbox is back together correctly then its probably the air nozzle not mating correctly with hop. Try testing it with the hop set though because with no hop you will get really random shots so its difficult to judge how its really firing.

Do you have a chrono? Because if you dont then you need one if you are taking guns apart.

 

[Katana]

I don't have a chrono but completely agree. A chrono would of saved me money when I have turned up to fields with some very annoying fps readings.

I thought it was exactly that as well. I already tested it with hop up set to multiple settings as well as off with the same results. It's definitely firing with about 150ish fps (VERY ROUGH) just for some kind of guide. I haven't touched the hop up or the springs around the hop up and it seats back well against the gearbox and nozzle.

I believe here is the part where I regret ever touching the bloody thing in the first place.

 

[jcheeseright]

I believe here is the part where I regret ever touching the bloody thing in the first place.

If it ain't broke....