Skara

Finger, this is piston. Piston, this is finger *now kiss* Pretty much what happened, the crime scene was the rear cutout section of the box.

This. Can't stress enough the importance of testing kit on the field. I honestly like it, pretty minimalist (almost speedsoft-y which is always good) I'd just swap the black pouches with something either green or multicam (but that's me hating on black kit). give it a run as soon as you're allowed to play and make changes accordingly

I give up. Shimmed for the SHS motor and A2 grip, put the gun back together and installed the zci motor by mistake. Fucking bang on (the adjustment screw is just a smidge from rotating freely). What the fuck. Aight, imma keep it this way, in the meantime I managed to get my ring finger caught by the piston while testing (don't ask how, because I legit have no clue) so now the gearbox is lubricated with blood This gun is cursed, it's probably going to kill me in my sleep someday..

A nice reminder that I should actually program mine as of now I only use it for AB/battery protection

Nevermind, there was some crap stuck in a bearing I've officially reverted back to the stock KA gearbox, whenever my PTS grips arrive I'll test the ZCI motor in my specnas and use the SHS HT in this one with the stock grip. I might even get a game day with the thing before retiring

I think it's the bevel... Can I swap it with a different one or will it fuck the ratio?

So, smol update. Since I have bought them PTS (genuine ones, not clones since they were just as expensive lol) grips I transferred one of the stock specna A2s on this gearbox.. ZCI motor still sits too high, SHS motor sits fine, can be adjusted, but the box is grindy as fuck (most likely because the bevel is super high, or because the gears are fucked or something is wrong with this new box). At this point I will proceed in this order: 1) reshim (spur first) to accept a SHS HT and use the zci in one of the specnas, probably the 933; 2) revert back to the stock KA gearbox and keep this 8mm one as a spare. Shame, as I thought it would work

shit I need one

Fixed power all day!! Switched from a VisionKing short dot to a cheapy 4x40 on my VSR and it's a world of difference

no that is deliberately cheating the chrono on those sites that only chrono on fps (or m/s) on 0.2s.. Joule Creep is about the (whoever has some education in science please don't read) process of energy transfer that happens inside our guns. What happens is that there is only a very limited space (the barrel) in which the system can transfer its energy to the BB. A lighter BB will receive a higher "initial" amount of energy but it leaves the barrel so quickly the system doesn't transfer much energy, whereas a heavier BB that will stay in the barrel for longer will receive way more energy. (you now have autism and won an extra chromosome, but don't blame me, I warned you) At least that's my understanding of JC

In my testing I have found that a lighter piston actually increases Joule Creep, at least it does on my build. A heavier piston only killed the energy output with 0.2s but the Joules on 0.4s stayed the same Either way, 15 fps is roughly 3 m/s deviation, which per se isn't too bad but as a sniper you want all the consistency you can get to have repeatable shots. Check each individual "step" in air seal: Piston head to cylinder; Cylinder to Cylinder head; Nozzle (on top of the cylinder head) to hop rubber lips; Hop rubber to barrel. The first two are easy to check, with just the cylinder in the receiver (so everything else, stock, barrel removed) cock it, press your finger on the nozzle and pull the trigger, the piston head (where the o-ring sits) should travel just past the port and stop, being held back by the compressed air inside the "closed" portion of the cylinder. If it doesn't, there is a possible air leak around the piston head o-ring or the cylinder head. Use proper lubricant and not PTFE, please. Nozzle to hop rubber lips: gun upside down, place a piece of tissue paper where the bb feed hole is and fire a shot, if it flies away it means that there's air escaping from the rubber's feed lips. Either replace the hop rubber or wrap (and then superglue) a small portion of heat shrink around the nozzle end. Hop rubber to barrel: hardest to test, it's always good to wrap PTFE where the rubber overlaps the barrel. Some people wrap until the bottom channel of the barrel is covered (so say 3-4 centimetres from the end of the rubber). The hop chamber will compress the PTFE enhancing the seal, don't overdo it or you won't be able to close the chamber anymore. Some hop rubbers, like the Maple Leaf MR-Hop, are known for not giving good air seal (GBB/VSR version only, the AEG version is super air tight), but in my experience with them the leak is so consistent that it becomes irrelevant. Once you sort these things out the fps deviation will drop considerably and test the seal with the gun fully assembled (by doing test n.1 but with your finger over the inner barrel this time). I've read of people getting less than 5 fps in deviation in some cases and it's pretty impressive tbf, given the shit tolerances of our toys..

It is, the cylinder volume is similar to the VSR, which is known for being a creepy fuck (my VSR gains 0.5J going from 0.2s to 0.4s) @AP77I suggest chronoing in Joules with 0.43g or whatever bb weight you want to use and the hop set for that weight, just to make sure you don't run a hot gun Having the hop on vs off does not exactly give the same results in every gun. Some will see a decrease of fps/J, others will have a boost.

Aaaaaaand I just bought two PTS EPG-C grips for my M4s, one in black, one in FDE. Now.... Are EPS stocks decent?

Well I think you have the same issue I'm having on my KA PDW. On mine the new motor is longer than the stock one and despite having completely removed the motor adjustment screw, it is still way too high and causes mad screeching. Check if your new motor is longer than the stock one, if so, I'm afraid you'll need a different pistol grip.

I like the concept, but from what I've seen the material is suuuuuuuper flimsy 😮 you madman

I swapped motors with my 933. ZCI motor in the 933 sounds perfectly fine although it wants to sit 1/1.5mm lower than the SHS. SHS in the PDW (just the gearbox with ICS pistol grip) sounds shit, no matter how high/low I set it. Spinning gears by hand you can definitely hear them grinding, I also had doubts about the spur/idler not being flat because when I had the box shimmed spur first, at one point it was getting stuck with the bevel. Now it spins fine though (read scratching but not binding). So the motor is ruled out, the gears might be part of the issue and I can still replace them with ZCI advanced (my tech has some in stock, a lot more expensive than buying online though). The major suspect remains the grip then. Unfortunately, other than the ICS mentioned (which is also wonky as heck) I don't have any spare. I was thinking of getting a couple of PTS EPGs for my M4s sometime soon (tm) so I could give a specna A2 a go. Can't be arsed right now but I might try tomorrow.

New bushings in, tried spur first and it's dumping a moulinex into a bucket of nails and a spanner levels of scratchy. Tried bevel to pinion, still scratchy but without the spanner. Also tried with the stock motor, still the same. Good thing about these Modify bushings is that they have a little ridge protruding into the gearbox so I didn't use too many shims. At this point it's pretty clear, I got a lemon somewhere. I ran the thing for a couple of minutes to try and scratch the gears, the shell or anything else and locate the source. Gears are spotless, the shell has just a tiny bit of scratching under the spur (fixed by swapping a 0.15 shim with a 0.2). Bevel teeth seems fine, pinion seems fine (I might try and swap it for a SHS one but they look identical). With the motor inserted and the height somewhat adjusted there is just a tiny bit of play on the bevel, with the shell closed and tightened each gear has about 0.1mm of play which looks bang on to me. There is no grease that may conceal scratches. I'm giving a SHS HT a go, just to eliminate the motor as a cause. I'm legit clueless, anyone got an idea? @Sitting Duck

Being in Germany with your retarded F mark, I suggest the SSX-23. Reason being it seems to have a thinner grip than the TM/STTI ones, so if you have "normal" sized female hands it'll be just a tiny bit less uncomfortable to grip. Unfortunately it does NOT come with a suppressor and it might require some work right out of the box (most likely check the alignment of parts because mine was atrocious). Regarding suppressors, either the Novritsch one or @Samurai as it is just as effective but comes in a much shorter (and stylish) size. Even at sub 1J it still has stupid range provided you use *at least* 0.3g bbs and it's a perfectly skirmishable gun on its own (I have had a couple of games where my primaries died and I had to use the mk23, still had tons of fun literally sniping people) whenever you find a field or club to play with

Three of these https://emperionstore.com/competition-rapide-carbine-pouch-multicam-helikon-tex.html Two of these https://emperionstore.com/competition-rapid-pistol-pouch-multicam-helikon-tex.html To add to my new rig and to replace the Condor cheapo pistol mag pouches on me FRV belt. And a Maple Leaf I-Key because you can't have too many.

Bushings profile isn't the issue. It's how they went in and the fact that they don't spin (well one does but still, 1/6 is not good enough lol). I'll pick up some decent ones this Saturday. In the meantime I started dicking around with various parts and decided to try a different pistol grip. Swapped the stock one for an old ICS grip I had and it made a world of difference! The stock grip, as mentioned above, makes the motor sit way too high despite having removed the adjustment screw. The "new" grip, on the contrary, almost completely removed the pinion to bevel scratching, although now it doesn't sit flush but is slightly canted to the side and the motor gets warm quickly. There is still some gear scratching noise but that will eventually go away as soon as I replace the bearings.

Texture on the receiver sides, can't remember which one has them though

Just ignore the whole thing, as everyone should.

Forgot to update this thread. In the end I went for a ZCI 22tpa motor, quite slow but the semi cycle time on a 11.1 is good. The gearbox shell, though is utter shit, or the motor is, or the grip, I can't figure it out -.- I can't properly shim it, I did the good ol' spur first but the bevel wants to sit really high. Tried bevel to pinion, the bevel now has zero shims on top yet it appears to be too tight, moreover the ZCI motor is really pushing against the bevel even with the grip adjustment screw completely removed. I thought it was the gearbox shell being a bit shit, so I bought an 8mm one but the bearings I got (SHS) must've been a friday night job and they don't spin -.- stayed up until 2 AM last night to try and figure out what was going on and I'm really pissed. I'll see if I can pick up a set of decent bushings later today and try again -.-