Cyma G36 - worth upgrading?

[Gunboat Diplomat]

The boy is generally happy with his G36 (very much so on the ergo and looks front), but inevitably has had his head turned by the snappy trigger response, high rate of fire and less agricultural sound signature of more modern AEGs. 

 

I'm loosely thinking a motor upgrade and shimming the gears (if it needs it, presume it will) will get him towards his goal, but I'm loathe to chuck triple digits at it as the upgrade path is likely to dictate new gun at some point or another. It's a budget AEG after all (albeit a pretty admirable performer if you set aside the fact it sounds like an old VHS player ejecting a tape when it fires).

 

Accuracy and range are not a problem with it and he's no desire to sling particularly heavy weight BBs so no need for upgrades on that front at least.

 

Note this is not the G36 High Speed variant that Cyma also do, so lacks the 13:1 gearset and full metal toothed piston that one comes with, in hindsight I should have gone for that but was ignorant of the option at the time.

[mp5a4]

A shim and a MOSFET with precocking will probably give a nice boost. Quite a few options for a V3 gearbox and easy to open it up

[Adolf Hamster]

Tbh if he's happy with the external build quality then there's nothing wrong with spending a bit to jazz up the internals and frankly the g36 is an under represented platform, guess folk feel their use as a common rental gun must somehow mean they're bad or not worth a bit of spicing up.

 

In terms of the actual spicing up there's 3 main avenues to consider:

1. Mosfet, something like a perun ab++/gate warfet or equivalent mosfet with precocking could do a lot of work with the percieved snappyness. On the v3 you can access the trigger contacts from the outside of the box to do the wiring but you'll need to be familiar with a soldering iron.

2. Motor, budget seems to preclude the brushless options, but a decent neo brushed motor paired with the above will also add to snap and/or auto rof

 

If you dont go too crazy with the end rof figure then a plastic toothed piston isn't the end of the world, indeed there are those that would argue it's a good thing to have an intentional weak spot that lets a cheap part die to save more expensive parts.

 

The stock shimming will likely be ok, improvable yes, likely to explode or cause serious issues no, so it could be skipped depending on your confidence level working on the box.

[Leo Greer]

Are you already using an 11.1v? I don’t know what the spring strength on those G36s is like, but if you can get away with it an 11.1v LiPo is by far the easiest and most effective trigger response upgrade.

 

If you suffer from double shots, you can short stroke and increase spring power, or even shorten the inner barrel and increase spring power.

[Gunboat Diplomat]

1 hour ago, Adolf Hamster said:

In terms of the actual spicing up there's 3 main avenues to consider:

1. Mosfet, something like a perun ab++/gate warfet or equivalent mosfet with precocking could do a lot of work with the percieved snappyness. On the v3 you can access the trigger contacts from the outside of the box to do the wiring but you'll need to be familiar with a soldering iron.

2. Motor, budget seems to preclude the brushless options, but a decent neo brushed motor paired with the above will also add to snap and/or auto rof

 

If you dont go too crazy with the end rof figure then a plastic toothed piston isn't the end of the world, indeed there are those that would argue it's a good thing to have an intentional weak spot that lets a cheap part die to save more expensive parts.

 

The stock shimming will likely be ok, improvable yes, likely to explode or cause serious issues no, so it could be skipped depending on your confidence level working on the box.

 

Thanks that's really helpful.  Good point on the piston teeth, if they strip under load then it's a cheap sacrificial part.  Soldering is no issue.  Perun AB and an XT High Torque for about £75 from AK2M4 fit the budget (though the motors are OOS at the moment).  I can always make a judgement call on the shimming when the gearbox is out.

 

14 minutes ago, Leo Greer said:

Are you already using an 11.1v? I don’t know what the spring strength on those G36s is like, but if you can get away with it an 11.1v LiPo is by far the easiest and most effective trigger response upgrade.

 

If you suffer from double shots, you can short stroke and increase spring power, or even shorten the inner barrel and increase spring power.

 

Running 2S/7.4 currently.  Not tried a 3S/11.v in it yet, honestly because I just assumed it would be too much on a stock setup and lead to overspin or fire, but that's not founded on anything concrete.  I might just order up a 3S while I wait for AK2M4 to restock their motors and do some test shots indoors and see how it goes.

[MrTea]

2 hours ago, Gunboat Diplomat said:

 I might just order up a 3S while I wait for AK2M4 to restock their motors and do some test shots indoors and see how it goes.

Whenever he restocks his motors, I buy up a few ready for future projects because they sell incredibly quick. Last time he restocked I picked up 3x of those SHS High Torque motor with the fans.

[Sewdhull]

My src g36c has a high torque motor and that runs with a home made MOSFET. On 11v lipo I don't have feeding issues, but I do prefer a 9.9v life.

 

[Rogerborg]

I'll echo the above.  My JG G36 is running:

 

Big Dragon M140 motor from Ali Express, these are decent value for money.

11.1V lipo

I can't recall the spring, it may be stock. Either way, it's running at 1.1J with 0.28g

Perun AB++ with pre-cock, active brake to deal with over-spin, 3-round burst, and a touch of ROF reduction as it was running very slighty faster than the mags wanted to feed.

 

A zoomier motor and a 9.9V LiFe might be the sweet spot for snappy-brrrting without overspin, on a budget.

[Sewdhull]

13 hours ago, Leo Greer said:

Are you already using an 11.1v? I don’t know what the spring strength on those G36s is like, but if you can get away with it an 11.1v LiPo is by far the easiest and most effective trigger response upgrade.

 

If you suffer from double shots, you can short stroke and increase spring power, or even shorten the inner barrel and increase spring power.

This is the first move, things are very different on 11.1 from 7.4. You'd want a mosfet with it really. A simple one would do.

[Leo Greer]

16 hours ago, Sewdhull said:

This is the first move, things are very different on 11.1 from 7.4. You'd want a mosfet with it really. A simple one would do.

 

A MOSFET, or the very simple old-school dielectric grease on the contacts, which I should've mentioned. Most people have no idea that you don't actually need a MOSFET to avoid arcing on the trigger contacts.

[Sewdhull]

Dielectric grease cant stop contact arcing, just corrosion over time leading to high contact resistance, the heat then generated at the contacts and carbon build up, which can extend their life. A contact lube is a good thing for airsoft type contacts which slide against each other in any case. It wont stop damage because of the arcing either. Airsoft contacts are electrically awful.

 

It wont help much with our inductive (motor) loads tho. Diodes, capacitors and resistors can effectively eliminate the arcing if used correctly.

 

Mosfets, or a relay,  just put less energy through the trigger contacts so they last lots longer and we still have to protect the mosfet from the inductive load.

 

 

[Gunboat Diplomat]

Looks like AK2M4 are getting the XT motors back in at the start of Oct so will be ordering one of those alongside the Perun AB++.  Should be a fun little project.  I might do it in secret and not tell the boy anything has changed until he tries it at our next skirmish (foreshadowing the moment it shits itself on the field here I realise).

 

Anyone know off hand if I need the long or short shaft motor for the G36?  Lazy I know, but since there's been decent advice so far I thought I'd take advantage!

[Lozart]

1 hour ago, Gunboat Diplomat said:

Looks like AK2M4 are getting the XT motors back in at the start of Oct so will be ordering one of those alongside the Perun AB++.  Should be a fun little project.  I might do it in secret and not tell the boy anything has changed until he tries it at our next skirmish (foreshadowing the moment it shits itself on the field here I realise).

 

Anyone know off hand if I need the long or short shaft motor for the G36?  Lazy I know, but since there's been decent advice so far I thought I'd take advantage!

 

Short.

[The_Lord_Poncho]

4 hours ago, Gunboat Diplomat said:

Looks like AK2M4 are getting the XT motors back in at the start of Oct so will be ordering one of those alongside the Perun AB++.  Should be a fun little project.  I might do it in secret and not tell the boy anything has changed until he tries it at our next skirmish (foreshadowing the moment it shits itself on the field here I realise).

 

Buy your Double Eagle Noveske before you do (!) so you have a spare to lend him just in case it doesn't go to plan!

[Gunboat Diplomat]

Perun AB++ and XT 22TPA motor ordered for the G36.

 

Also picked up another XT motor, ZCI hop chamber and a Maple Leaf bucking + Omega nub combo to go in my Double Eagle whilst I'm at it.  Doesn't really need anything doing to it, but the parts were cheap.

[gavinkempsell]

I can understand the 'need' or 'want' to upgrade a gun you love, my go to is a two tone Scar-L, I'll use it till it stops working (snipers tape holding the broken stock together), no tech skills so my maintenance is simply clean the barrel & a spray of silicon oil in the gearbox.

[Gunboat Diplomat]

I’m an inveterate tinkerer so can’t leave anything standard for long. 

[Gunboat Diplomat]

Bit of an update, had a couple of hours to myself this afternoon so set about installing the Perun and XT motor in the G36.

 

Quick before video of how it fires stock:

 

 

Stripped it down fairly easily, despite being a budget gun everything comes apart and goes back together again with a decent balance between being too tight or too loose.

 

Remove the gearbox and stripped off the original wiring harness.  Old motor out and new one in.

 

Curiously I found whilst swapping the motors that there is a small metal disc at the bottom of the motor cage, presumably to shim the bottom of the motor.  There is still a bit of a gap with the new motor installed, but it doesn't have any play once the cage is done up so have left it as is.

I decided to leave pigtails from the old wiring harness to solder the trigger leads from the Perun onto.  In theory this allowed me an easier time than trying to get the iron tip to the microswitch contacts, but in practice was a pain trying to mate the fine gauge wire for the trigger leads onto the original thick gauge pigtails I'd left behind.  Worked out in the end, but if I did it again I'd probably just split the gear box, remove the microswitch and solder them directly to it.

 

I spliced the trigger return lead close to the Perun so that I can get to it if I ever need to, don't expect it will ever fall off but easier to fix this way if it does:

I left the harness long but the routing I've chosen in this picture actually makes it a real sod to attach the battery and get the hand-guard back on.  I've since folded the extra length and tucked it into the cavity behind the mag-well so that you can just have the minimum amount of wire spare when refitting the hand-guard with the battery installed.

 

Finally, the post install fire test.  Much snappier and a decent increase in ROF.  Perun is on default settings at the moment.  I had a play with the precocking settings but noticed no difference.  I'm not entirely sure how it achieves it anyway since there is no feedback from the gearbox on gear/piston position, I assume it measures current changes as the motor shifts from load to no load?  I'll have to do some more research, but even as is it's an improvement.

 

Hope the boy likes it.   

[Rogerborg]

Noice. I assume the Perun pre-cocks based on timing. I find that it does help a little if you get the right setting, but that V3 trigger limits the snappiness. If - when - you go to 11.1V then it all pays off, especially the active-brake, ROF reduction, and burst modes.

[Sewdhull]

That metal disc is to spread the load from the motor height adjustment screw, in the bottom of the cage, to the bottom of the motor. Otherwise the screw could press against the motor shaft instead.

 

Have you adjusted the motor height?

 

 

[Adolf Hamster]

5 hours ago, Gunboat Diplomat said:

I'm not entirely sure how it achieves it anyway since there is no feedback from the gearbox on gear/piston position, I assume it measures current changes as the motor shifts from load to no load?

 

As 'borg says its a timed system.

 

Pretty much it's a case of run until theres no trigger signal, then run x milliseconds longer before you stop.

 

You'll need to dial it in, not sure on the exact programming steps for the perun but effectively you're just incrementing a timer until one of 3 things happens:

1. You're satisfied with the snappyness

2. The motor stalls (possible, although unlikely)

3. You get a double fire (ie the additional time is enough for it to fire a whole extra shot)

 

For what its worth burst fire modes are functionally identical to just setting a precock timer long enough for fire multiple shots.

 

This means it will run slightly longer after releasing the trigger in full auto, but its not noticable. What is noticable is that the first round of semi after a burst of auto wont have a consistent timing as the gearbox will be wherever it stopped after you last released the trigger as opposed to the defined point in the cycle from the cutoff lever.

 

Cycle detection mosfets (ie the opticals that know where the sector gear is) can make sure they're always in the desired precock state but that comes at the cost of extra expense and faff.

1 hour ago, Sewdhull said:

That metal disc is to spread the load from the motor height adjustment screw, in the bottom of the cage, to the bottom of the motor. Otherwise the screw could press against the motor shaft instead.

 

This, you dont want to be removing that little disk unless your motor has a solid closed end cap

[Hatchet]

24 minutes ago, Adolf Hamster said:

 

 

 

This, you dont want to be removing that little disk unless your motor has a solid closed end cap

 

Because otherwise the motor shaft spins the grub screw the first time you pull the trigger and it instantly violently adjusts the motor height, jamming it into the gears and seizing everything up.

 

Apparently. Not that I've ever done this...

[Gunboat Diplomat]

Ah of course, don’t know why that didn’t occur to me. Yes I reinstalled the disc, just didn’t realise what it was for. Motor height seems okay but I might try adjusting to take up the slack since the disc wasn’t touching the base. 
 

I read somewhere that the Perun measures drop in current to sense where the motor is in its cycle, so perhaps it uses that alongside trigger + n time for adjustment.