Skara

Worst case it's a reshim and slight modification to the pistol grip (or a new pistol grip altogether) to achieve a proper engagement angle.

Very odd.. Do you happen to have an amp meter you could plug to check the power consumption? My experience with 22tpa motors is limited to the good ol' ZCI one (bought from Pete when Brexit wasn't a thing) and it didn't pull more than 13 amps in full auto on a 7 tooth DSG. on 13:1s it pulled 12 amps and no sign of overheating even after full mags spammed in semi.

Nah, piston has no part in this. The nozzle resting position is set by the position of the sector gear after a shot, the position of the tappet cam, the dimensions and shape of the delayer if present and the shape of the tappet plate. All my guns have the nozzle fully forward when in their resting positions, others have it fully retracted, most guns have it somewhere in between.

Phone mics for some reason like to enhance high pitch noises, but overall it looks like it's a little too tight.

When shimming the sector gear you will need to take into account what components it interacts with: On one side you have the spur gear, on the other side you have the tappet plate and on top you have the piston rack. Spur gear interaction is easy, shim the sector low enough to have a tiny gap between the upper flat side of the spur and lower flat side of the sector. Rack is also easy, as most piston racks allow for plenty of movement anyway. Tappet plate is where it gets tricky. At first, have the gearbox with just the tappet plate installed, close it and check if the plate moves freely, if not the plate needs slight trimming. Then open the gearbox, install the shimmed sector gear and close again with the tappet plate. Tappet plate should be able to still move freely while the sector gear is in there, also try to rotate the sector gear as if it was actually cycling the piston and check for binding. Should there be rubbing, you will need to lower the sector gear. I recommend using 0.15mm shims along with 0.1/0.2s because you get an extra level of adjustment.

As a non native english speaker (more like I can read and write okay, but when I open my mouth I sound like a demented australopithecus), it has always puzzled me how easily y'all can fuck those up....

Just make sure you get the pinion/bevel meshing right, as most of the gear noise comes from those two.. Having good meshing also ensures that the energy transfer from the motor to the rest of the gearset is as smooth and less violent as possible. At the same time do not shim the sector gear too high in an attempt to get the most contact surface between teeth, it's a common mistake that leads to the tappet plate rubbing and binding against the sector and that is bad for air seal and in general tappet plate longevity.

13:1 for me. Any 22tpa motor can pull pretty silly springs without any issues, pulling 13:1s at UK powers won't strain them in any way possible unless you get a lemon motor, but if you're buying from @ak2m4I'm sure he'll provide excellent service should anything happen. For reference, at 0.99J a 22tpa + 13:1 setup powered by a 11.1v will produce around 30 rps and a VERY snappy semi, on 7.4v performance will be similar to a stock gun on 11.1 (so 20ish rps). 22tpa + 18:1 ratio is going to be painfully slow and it'll feel like you just wasted money. Also your X-ASR will be fine.. It's not the greatest electronic unit out there, but it is "free" (read already included with the gun) so use it and replace with a better ETU once it breaks.

Keep in mind that past a certain bb threshold those mags really take a toll on AEG nozzles. ALL of them, some brands more than others but it's still an issue.

I would avoid T238 motors, they have a rather high failure rate.. Go Solink or Warhead, these are the two with the less shit quality control of the bunch. A much more cost effective way of upgrading your AEG is to set a very definite goal first, then look at different ways to achieve said goal and choose accordingly. Swapping random parts without a precise plan often leads to waste of money and time.

Nope, it's only those three grub screws. Luckily it has anti rotation tabs which effectively lock it in place and prevent loosening.

I had the Core version (now it's completely different). Barrel not being aligned is pretty common, maybe one of the three handguard retaining grub screws is tighter/looser so it pushes the thing out of alignment. Regarding shimming, the one place where most of the noise comes from is the bevel and pinion area, they are also the weakest link in the chain so it's very important to get them right. There are multiple guides over the internet to shim those two components, I'll post the two that I found to give the most comprehensive information:

The only brushless motors that come with unidirectional bearings (effectively eliminating the need for a mechanical ARL) are the Solink Advanced and V5 motors (the latter is also known as G5 under Gate's branding). Unless using the aforementioned motors it's utter bollocks to remove the ARL, so is a mechanical decocking feature like the one found on ICS guns because all these do is damage the tappet plate. It's much better (and safer for the gun's internals) to have an electronic decocking feature where the gun fires one shot with maximum AB to stop the piston fully forward.

Doable, but I found that past a certain threshold (say 30 rps) it's much more convenient to build a DSG instead. I managed, by mistake, 36/37 RPS on a single sector gear running off 12:1s and 36k warhead but I had to shortstroke the sector by 4 teeth to achieve proper timing.. You will need a very good tappet plate and spring because the poor thing will be the most stressed component as it has to reciprocate at ludicrous speeds almost 40 times a second.

I kinda like the short fixed stock, I wish I had a tan/fde one to match but heh, 'tis just a test.

It's not much about the hop rubber but rather the hop unit. If I'm not mistaken G&G rotary hop units have a clicking retainer that helps with.....well....retaining the hop up adjustment. One option is to try a hop unit that doesn't have said clicking retainer so you can fine tune the adjustment, ZCI plastics are cheap enough to give them a try. Another option is to shave a tiny bit of material off the tensioner, so that when you click it in "too much" setting, it'll hop slightly less and give you the adjustment you want... it's a bit trial and error with this one.

I suggest to stick to the AR platform.. I know they're boring and it'd be just another M4 variant in an ocean of M4 variants, but the fact it's so widespread means that there are many, many parts to pick from and the gun itself can be customized both in performance and looks/ergonomics, something that unfortunately is not always possible with other less common platforms (MP5/P90). Specna C-10 is also a good alternative to the Evolution mentioned above, just make sure you don't buy the PDW stock version, those stocks are unnecessarily heavy and offer very little battery space (you can buy extended tubes but it defies the whole concept of the pdw stock while adding even more weight). You can worry about the internals later, when you have acquired enough experience to understand what you want from your AEG. Please keep in mind that while they provide a decent base to build your dream gun on, out of the box performance will not be great. This is true for pretty much every AEG.

W-⚓-🔫

You can change the barrel and handguard on any M4 to the desired length, but you're just starting out so you're better off with an off the shelf short gun. Go for polymer receivers too, they save a lot of weight and cost. Evolution is decent, on par with Specna and Dboys (their polymer body series all come from the same factory, so pick whatever you like). I would personally stay away from the 9mm platform unless you REALLY like the looks, magazines tend to be kind of bad and they're not always cross compatible between brands, whereas regular M4 mags are essentially universal, plus you have plenty of options depending on budget. On the technical side, barrel length doesn't do much in terms of range/accuracy so I wouldn't think too much about it (all my V2 based guns have barrels 155/185mm long).

The declared values are nominal, without any load applied. The actual RPM under load depends on a lot of factors, spring rating, gear ratio, shimming, ETU, wire gauge, battery voltage, battery current and so on. Generally it's impossible to achieve 100% efficiency to the declared value unless said value is not true. For example my 36k warheads are 25k nominal on 7.4v but the actual RPM under load is closer to 20k rpm. Most ETUs control the rate of fire by sending semi auto impulses at different frequencies which, as Lozart mentioned, doesn't affect the actual cycle time of the motor/gearbox. For example, if your gun cycles in 25 milliseconds (netting a FA rof of 40 RPS), full auto at 50% won't make the gun cycle in 50 milliseconds, but rather cut the cycles in half (so 25 millisecond cycle, 25 millisecond delay, 25 millisecond cycle and so on to achieve a "finished" rate of fire of 20 RPS).

Well it's not that easy to build a performing AEG out of the blue without any teching experience. First of all you need to set a goal (rps, energy and such), then you need to understand how things work inside the gearbox before even looking at a website to buy things. Plenty of guides around the internet, watch them and learn the theory behind teching. Only after you've done all of this, you can look at your gun and check if you can actually achieve your goal with that or if you are better off buying a second gun.

39k brushless motor + 13:1 gears, in that long of a barrel... Have fun destroying all your internals

Skirmshop sells halo/nano screen, I'd use Theyma only if bulk buying one specific tone/material.

That indicates that either the nozzle is too long or the hop rubber lips are. Is the hop rubber stock? Borderline impossible, there is a guide on the right side of the gearbox the plate runs onto, it keeps the plate from bending and doing what you described. In any case the plate would have to bend so much it would snap in half regardless.

That nozzle bouncing back and forth doesn't look normal, but it could be me. If you turn the gun upside down and place a bb on the feed tube (without pushing it down) and fire a shot, does it drop in the right position?