RostokMcSpoons

Try this on for size... (apologies for the rubbish shop it's at, stock is tricky to find at the moment) https://bbguns4less.co.uk/products/double-eagle-m908a-ar15-rifle-with-falcon-system-in-black.html It's out of stock at Patrolbase but the page is easier to read... https://www.patrolbase.co.uk/double-eagle-m908a-fire-control-system-edition Other variations in stock / receiver / length / rail system are available. Once you drop down to the 904's I think they're all polymer receiver but some might still have metal handguards Quite a few happy DE owners on this forum!

Yeah, still the stock barrel. Perhaps some day I'll get a longer, maybe tighter-bore one, running it through the suppressor Is +-1.5fps (3fps in total) not pretty damned good?

This cheeky chappy? https://www.patrolbase.co.uk/gate-nanoasr-3rd-gen-advanced-solid-state-relay-mosfet (AK2M4 are sold out of the pre-wired Peruns which was the obvious option)

That's a "careful now" for "unsettling" me with that GIF

Oh shizzle. I don't want to get this all put together only to find that it doesn't work, because I've spent enough hours trying to re-assemble it already! Shimming it (my first attempt, of course), fitting the cylinder / head / piston and motor with the soldering and the fitting Deans etc will have kept me quite busy enough. At some point I'll have to MOSFET it, perhaps as per this ... and that'll be a good time to do the nozzle (if I can find a good replacement) and also buy a new hop unit / bucking / nub / inner barrel.

Yeah, that second bunch of chrono results are the Specna 0.28's, so around a 3fps variance!

Just for completeness, here's the accuracy test with ~30-35 shots with the Specna 0.28g BBs. It's a breezy day compared to my previous attempts, so that may be why the grouping includes a few flyers, but there's also a pleasing hole in the paper. I also had my 4x32 scope on the gun. Scientific 'method' gone a bit out of the window tbh, but it ensured I had a good aim. None of the shots were poorly taken, they occasionally just curved left or right (maybe the wind, maybe the hop still slightly askew) So... Accuracy test with Specna Arms Core 0.28g Bio BB's, 15m measured, fired from room @ 19-20C, 13C ambient temp outside, gusty wind, bench rest, 4x32 scope, approx 30 shots (probably a few extra) Chrono results for 10 shots with 0.20g Gold Fire BBs (with hop applied). 348.6 (high) 341.7 345.6 338.5 (low) 346.7 345.8 346.4 342.5 342.7 346.3 And with the 0.28's 280.1 278.4 276.8 279.0 278.7 280.1 280.8 278.6 280.7 279.0 (I've got more but they're all 278/279!) I've got to be happy with the consistency with the 0.28's I suppose the good news to take away from my experience thus far is that changing bucking + nub and spring seem to have settled the consistency of the power output, in warmer conditions at least, but the accuracy isn't massively improved. So presumably the DE bucking and nub are actually fairly decent (excepting the possibility the bucking didn't like the cold and was affecting the muzzle velocity)

There's this one in stock... which I've stuck in my basket https://www.ak2m4.co.uk/rocket-aug-aluminium-nozzle I've already WhatsApp'd @ak2m4 to see if he can add it to the order, but he's not read my message yet... so I can back out of that if you don't think it'll work. I measured the existing one at 25.10mm. Is that near enough (or is "a miss is as good as a mile")?

@Asomodai Right about now I'm finding it very disappointing we don't have an animated GIFs feature, in which I could search for things like "I love you and I want to have your babies" That goes for you too @Adolf Hamster Cheers guys, much appreciated! Order done!

There's a full length un-ported cylinder, and I guess I need the new cylinder head too? The Element motor description doesn't have the TPA, but I'm thinking lower cost = lower TPA I'd like to keep the costs down (obviously) but there's only so many times my sanity and inexperienced tech skills will allow me to try to re-assemble this gearbox ... So is it stupid to carry on with the existing piston and piston head?

Me, over-thinking things? Shurely shome mishtake Thank you so much for that. I'll amend my shopping list accordingly... back with that shortly.

@Asomodai thanks for that useful info! I'm looking at 15-20rps as my target. Current motor has 10 teeth Bevel gear has 30 teeth Spur gear has 39 teeth Sector gear has 30 teeth If I've counted correctly and used this: http://airsofttech.dk/Calculator.cshtml correctly, that is 17.55:1 (If the spur has 40 that would make it a round 18:1 ratio, so it seems likely I miscounted there!) So looking at your recommendations I'd need quite a high speed motor to turn those rapidly, with commensurate high battery drain, and perhaps a a higher wear rate... those don't worry me toooooo much... I just watched the Airsoft Tech explain about volume ratios... https://www.youtube.com/watch?v=LT0ptGQMc5g&t=628&ab_channel=TheAirsoftTech The preferred cylinder to barrel ratio for my preferred 0.28g BB's should be 1.5-1.8, according to him. I measured the internal length of the cylinder from port to back of the cylinder head as 22.3mm, with a cylinder radius of 11.7mm giving a total cylinder volume of 9,590mm3 With the barrel length as 420mm with an internal radius of 3mm giving a total barrel volume of 11,875mm3 That gives a cylinder / barrel ratio of 0.8075 Oh dear...? I'm off to look for a possible set of parts.

Good review @TheFull9 £25 and then £8 for lunch? Ouch. I'll appreciate the free nosh at Special Ops all the more hearing that. Losing a gbb mag would be painful, glad you found it. Please buy me a lottery ticket ? But spare a thought... at my last game some poor bugger lost a TM gold match hi capa pistol. That's an advert for pistol lanyards right there ?

Cheers, I definitely need a big bag of shims. My jig is actually doing a pretty good job for me so the helping hands clips aren't necessary. While the thing is in bits though, it seems sensible to upgrade any more parts at the same time. The cylinder and piston seen to be prime candidates, anything special I need to look for? I saw this https://www.patrolbase.co.uk/master-mods-full-steel-teeth-reinforced-upgrade-piston-set It's out of stock but is that a sensible upgrade?

Blimey. Still not got it back together. Made one change to the jig - drilled a hole under the anti-rev latch's position, stuffed a couple of neo magnets in there, stacked a couple more on top - latch held in place My main spring finds new and exciting ways to escape before everything lines up. I know it's just a matter of strong fingers in the right places, plus perhaps a little bit of luck, but it's not happening. Even if I keep the spring inside the shell, if it 'jumps' then it dislodges the bracket the trigger contact slider sits in, and I have to remove the tappet plate to reposition it. Arrggggh. But anyway... I've rehearsed lining up the shell without the main spring. I can get all the pins to locate and the shell to snap shut nicely. The problem is the gears are wobbling around. I don't think it's the fact I've probably lost 2 or 3 shims with the the spring flying about, the sector is moving perhaps a full 1mm sideways. Perhaps that thing that flew by my ear was important after all I certainly can't put it back together without a bunch of shims at least, and I don't have any. Can I get them from Screwfix? edit: looks like screwfix is a 'no'. Looks like I'll be making an order before I can continue. Might as well get some proper parts too!

I went off, had a bite and a beer and came back to it. Decided to build a jig to hold things (especially the trigger) in place as I'm closing the shell... "Ta-da" Yup, just a block of wood with some appropriately placed nails... Worked a treat, put the shell back on and wiggled things into place on my second attempt! Connected up to the motor, bound up on the first shot. I didn't check the gear positions before I closed it (bound to miss something). Problem is, when I opened it up again, with the spring half-cocked, the spring released and *something* went flying over my shoulder, probably lost for a month or two. I think it's just one of the shims. All the springs are present and correct.

I'm 4.5 hours in and still can't get it back together. Is that par for the course or am I irredeemably ill-suited to this bedroom-teching lark?

I'm sure everyone else has had this problem when putting gearboxes back together, it's possible to get everything in place but not all at the same time. Compressing the main spring and holding that in place whilst trying to get everything else to line up ... arrrrggghh And I've only managed to get the trigger spring in place a couple of times but the pins are so out-of-alignment the shell will never get close to getting together How do you guys do this???

Edit: I got the gearbox out by removing all the bolts towards the rear of the stock and prising the stock open a little, and eventually it dropped out (with me pushing on it). I think the bolt directly above the word 'f2000' stops it moving, that's the key one. Well I've split open the gearbox, and I think I've managed to keep track of all the shims and I can refit the reversal latch and all that other crap. But the trigger spring is giving me the absolute arsehole. the arrowed bit of plastic gets in the way, so I can't hook the spring around the back of the trigger block AND drop it into place, without the gearbox hook coming out. If that plastic block wasn't there it'd be easy but the tappet mechanism needs it. How do I reinstall this trigger? Any handy hints??? It's piss-easy on a normal v3 gearbox, judging by this excellent video: Pertinent bit is at 19:47 Edit: I ended up super-gluing the geabox end of the spring into the gearbox. That meant I could wedge the trigger from an angle in without it popping out altogether. To ensure the pin locates into the hole properly the spring needs pushing 'up' the pin. The damned thing is stepped so it tends to stick where it's not wanted ? OK, I had to give in and take apart the tappet plate etc. The trigger is now in place, I just have to hope everything else will fit together on top Now I've got the cylinder out, I've tried compressing it with my thumb over the nozzle. There's very little resistance, so my air seal appears to be awful. Maybe by design? The cylinder head appears to be ported... my technical knowledge has run out at this point, I thought more pressure = more pew pew power.

Carlos at Special Ops told us at the end of the last game that he's looking for a site to use for CQB. Reading this thread gives me the fear that it'll be in that environment is be bumping into a lot more of the toxic characters with unpleasant rates of fire that you all seem to contend with each time you play. I was starting this reply with the intention of asking 'what rules would you put in place, would you make it semi auto' etc but it would be bloody presumptuous of me, just back in the sport, to start lobbying the business owner of many years experience to tell him how to run his new venture ?? So I guess once it starts up I'll just have to suck it and see, maybe give it a swerve entirely. And hope that any asshole players drawn in don't decide to play the outdoor stuff too!

Cheers again. I was searching for hints about f2000 disassembly and over of the posts was "what's the worst gun you have worked on" and one of the replies was "Cyma F2000, when I split the body to take out the gearbox and the trigger assembly was a nightmare to get back together" So I'll try to avoid that ?

Thanks @Adolf Hamster I think the takeaway message from that comprehensive answer is "no, not if you have no feckin' idea what you're doing (I can see you googling which one is the bevel right now), you clown" But... I've got to learn this stuff sometime. I've got some little neodymium magnets I can use for the latch - that's a good hint How do I shift the gearbox though? Is it just requiring a bit of brute force to get it out of there? The fps went as low as 200fps with (presumably masses of) hop on but I will try adding hop in smaller increments, just to see what I'm working with. I presume you're talking about 'joule creep' where a a slower initial velocity leads to more time for the air pressure to build, and a higher final velocity?

My Tactical Tuna is a big ol' hunk of loveliness, but mechanically I can already see and feel first-hand the failings compared to the much more refined build of my Double Eagle M906C. The highest muzzle velocity I've seen from it with no hop at all is 270fps so it definitely needs more oomph. I've got a few quid I can spare to make it better, so I'm likely to use @Asomodai's shopping list of parts in his recently sold gun as the basis for my long-term build. G&G metal Hop up unit AOLS 380mm Barrel Maple Leaf 50 Degree bucking, Ohm nub Mosfet SHS High Torque 22TPA Motor Short stroked (Asomodai, would you pick the same components again if you were re-building the gun? Any parts you'd substitute with the benefit of experience? Which Mosfet did you go with?) So I'm immediately pulling it apart to see everything is as best as can be, with a view to swapping the hop bucking and nub and the main spring as the first steps in the journey. I'm a little bit stymied by the fact almost all the F2000 videos out there relate to the G&G version, not the Cyma one. I'm trying to be gentle with things because I'm still inexperienced and don't want to break stuff, but I've already found when trying to fiddle the backplate out that some effort, twisting and bending can be needed to make things happen. I can now see the gearbox in all its glory, but it doesn't want to shift at all. I can see the motor height adjustment screw at the bottom but that seems to be just sitting in place, not holding in. I've taken out the two cross bolts from the stock as well, though I don't if they're involved. Pressing backwards on the gearbox above the nozzle from the 'flip top bin' sees a couple of mm of rearward movement, but that's it. Is there a trick to removing the gearbox from the body? Once the gearbox is out, I just want to put a stronger spring in. I've got a spare M100 spring, and also a couple of springs that were inside the box (but they're linear and shiny and look a bit cheap so probably won't try them after all) If I crack open a v3 gearbox, managing to hold the main spring in place, will anything else shift out of whack? Will I have trigger springs pinging around etc? Basically I'm asking: Can an idiot (me) replace the mainspring in the gearbox and put it back together easily?

Just to complete this thread for anyone who comes across it in the future, I bought a stock sling adapter off eBay. It's a d-ring on a length of webbing with a standard buckle on one end. Cost a fiver. It was too short to fit around the end of the stock through the sling slots. At 41cm that should have been blindingly obvious to me before I bought it ? It was also a little wide, the slots are just under 30mm wide, but the 1.25"/32mm webbing will fit through with gentle persuasion. However, rather than buying a second one and linking them together, I decided to just run it through the thumbhole and over the top of the receiver, just in front of the rear sight. This works fine. The d-ring is available to the left for my single point sling to attach to, and it holds the weight of the gun at the center of gravity so I don't feel it is stressing the bodywork in any way. That does leave the gun dangling a little lower than I'd like but it'll do. The sling is definitely important because this gun is a chunky beast, feels noticeably heavier than my m4, at least until it's shouldered. https://www.ebay.co.uk/itm/Tactical-Universal-D-Ring-Sling-point-Adapter-Rifle-Buttstock-Loop-Strap-Airsoft-/194351061265

Blinged up a little with my Kobra, my cheap suppressor and a stock sling adapter that's too short to fit where it ought to go, but does fit nicely through the thumbhole and over the RIS which looks like it'll be fine. It's a cool beast Chrono'd at 270Fps on 0.20g. My spare M100 will go in sharpish, but there's actually two extra springs inside the box, I'll maybe try them too, out of curiosity! The hop unit is cheap feeling compared to the nice one in my DE M906C so I think I'll be finding a replacement sooner rather than later. The hop when applied looks off center, so not expecting much accuracy as it is. Happy Xmas everyone ?