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Sitting Duck

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Sitting Duck last won the day on September 10 2018

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  1. Remember LiFe's use totally different settings to LiPo's If you slap a LiFe on a LiPo setting you will f*ck it up (in general - though there a couple of special LiPo's a tiny tiny bit over the 3.7/4.2v limit) LiPo's get charged up to a max of 4.2v (0.5v max over cell std rating - no more or damage occurs) LiFe's get charged up to a max of 3.8v (0.5v max over cell std rating - no more or damage occurs) So if you slap a LiFe onto a LiPo charger - even a B4 or balance lead charger & charge @ up to 4.2v you will bone it (and it's f*cking dangerous to overcharge) some B4 balance chargers have a LIFE/LIPO setting - most do not a B6 charger you have to adjust the LiPo settings - RTFM, or I had to to change/charge the few LiFe's I had not very clear but you tweak the LiPo/settings to charge 3.3v cells not 3.7v... you could have got a duff LiFe or you could have overcharged it if not careful & charged it with LiPo settings
  2. Gun & battery used ??? In "general" overspin starts to occur at say 20rps but all guns overspin/cycle a smidge to what some say is pre-cocking double firing is when a gun is firing so quickly it pre-cocks or overspins so much that at times it double fires often on most shots - this tends to happen at around 25 rps in a std 350fps gun This speed or rps of pushing the gun's speed is basically the gun "talking to you" in a way continue to push this at say 25rps long term or foolishly push it further at 30rps then you can get PME where the piston & sector meet earlier than expect and munch up as piston gets caught by sector before fully returning..... That is the general rule of thumb - roughly speaking..... HOWEVER...... IF gun is quite old or well used then the Cut Off Lever (usually weak alloy than steel) if you have a well worn COL it fails to pop the trigger trolley properly or fails to raise/pop the trolley switch and thus double fires or triple fires or just goes full auto regardless of fire selector So you could get overspin or double/triple firing or in bad cases full auto on semi with a badly worn COL So depending on how fast gun cycles you either need to: tone down the juice a bit if running fast with 11.1v or high speed motor or replace a worn Cut Off Lever - a nice steel hard wearing one like SHS COL An AB mosfet "might" help reduce the overspin a bit but not if your COL is shagged (it will only brake the motor if COL operates correctly) most of the COL stuff applies to guns that actually have one of course
  3. a 25k to 30k motor on 7.4v "as is" would be a good starting point (probably say 14~17rps, bit of snap but nothing too crazy & no real overspin) I'd be tempted to run with that for a while that go much further with limited experience wait until gun plays up or needs a service or something
  4. 40k is a speed motor, not as fast as 45k but pretty quick (think 30k is a bit sensible snap) keep it on 7.4v - it might run a bit warm but don't ffs try anything higher than 7.4v or it will wreck 20k-25k you can run on 11.1v most likely but the faster motors - yeah keep them on 7.4v it will get a bit warmer than stock motor as it's running faster of course will drain your battery quicker to as it draws more amps etc.... it's ok but keep the voltage sensible @ 7.4v max
  5. That is a lot of money when really you only need this..... PS I love the 18yr warning about this not a f**king toy
  6. I tend to use Zippy Compact's 7.4v's 25c's (got a few 11.1v's but mostly stuff ran with 7.4v's) 104 x 14 x 35 dimensions goes in most guns that like a small "brick" type https://hobbyking.com/en_us/zippy-compact-2200mah-2s-25c-lipo-pack.html (obviously add a bit of space for wires etc.... ) This is what I was saying about listing up options for say batteries up to say: 114 length, 35 width 20mm thick @ 7.4v or 2 cells at 25c to 36c rangeypoohs.... https://hobbyking.com/en_us/batteries-chargers/batteries/lipo.html?config=52&capacity=1195-2709&discharge=25-36&length_a=0-114&height_b=0-35&width_c=0-20&wrh=1%2C7&dir=asc&order=price yeah you might have to change the XT60 to deans with solder/adaptor but you get a battery that fits
  7. Only if you like rebuilding gearboxes Basic gun fires about 12~13rps on 7.4v with a 18~20k stock motor you dropped in a SHS/RA motor that runs at 28~30k - sort of 50% increase well not quite 50% in reality as motor speeds are unloaded at 8.4v (so they say or lead to believe) So you won't quite hit 20rps perhaps BUT with a rewire 16awg, deans blah blah will give you 10% maybe 15% max (depends on dire stock wiring pansy small tamiya blah blah blah but yeah add on say 12% for rewire) So yeah you are now on 20rps, deffo just broke 20rps imho on 7.4v all dean'd up etc.... Now add on a similar 11.1v with extra cell - well it is a bit more than 50% say 55% imho over the same 7.4v (the gun is already cycling & in motion, so the extra cell is 101% extra boost hence 55% than 50%) So now expect 20rps x 1.55 = 31 rps on a UK gun, yeah I wouldn't push it that fast on just 1 SS setup I mean it might be OK and just get by but long term I think it is a sailing too close to the wind and will overcycle/double fire (unless you got AB, but still on full auto it will be a bit risky) 20~25rps is a sensible snappy build that should last (at 25rps most guns are starting to double fire on semi without work) Your gun should pull only about 13 amps I reckon if done really well on std 18:1 & SHS HT (not HS motor) measure it through a RC power tester on full auto for 5 secs say from still the current really ramps to like double, to get the drivechain to cycle from stationary (hence they fit a fuse double the normal operating draw) well your gun should only draw 13amps unless shimming is crap I'd try to find a nice 1500mah+ 25c 7.4v work out what room you got to play with, may need stock extended a bit measure with mars bar or anything what room you got take off say 5mm each way - maybe a bit more on length for wires check out hobbyking or whoever for dimensions and weigh up your options (just don't buy a battery that is too tight that if it puffs very very slightly it won't fit) ((oh and double check your measurements)) By all means use 11.1v - but on a sluggish stock motor to get 20rps but 11.1v on 30k motor - yeah I wouldn't, plus the 11.1v is bigger/fatter and more expensive If you do a nice tweaked build and do it well most people will get by on a compact 7.4v 25c~30c
  8. Very nice sir, yeah 16awg is a thick bitch at about 3mm diameter Alpha eco wire is quite a bit thinner but stiff as f*ck If a Gate nano mosfet was used, one with deans at both ends then you could run Alpha 14awg stiff as f*ck mofo wire in the box & silicone for the battery, as silicone is nice and bendy/flexible to tuck in stock etc... (but that is me being a tart but pointing out pro's n con's of the popular wire types) A tiny bit shrilly on the start of the cycle - but I have heard & done a LOT worse at times half a turn either way on motor height screw should help a smidge and/or as it is a v3 with motor cage, loosen the cage very slightly you should have a minor bit of play, see if you can alter the angle a smidge retest and see how it sounds reckon with a whisper of adjustment the shrill should quieten down throwing the motor cage angle a smidge should work & hold to improve the angle of pinion to bevel on some boxes though there was a little bit of a wobble where the cage doesn't bite/clamp you don't want to go ultra nutz tightening the motor cage to box or risk stripping M3 threads so if still a smidge loose/wobbly, work out if cage tilts forward/back a smidge then place a bit of paper/card on one side below box where it meets the motor cage That should just swing the motor angle a smidge & hold it there a bit of a pull to one side should get the motor inline better and reduce that slight shrill TBH, I've never been a fan of LiFe's, they do seem to have a bit more juice but I think real raw grunt they are not quite on par with LiPo's I know they add some zest to stock guns over a 7.4v BUT when I've tested them in tweaked guns there was not such a difference leading to suspect they might lack as much raw brute power as the punch from mofo LiPo's So I've tended to get a gun tweaked up a bit and just run with 7.4v 25c (cheap & easy to source in a variety of sizes/specs) But that is just my opinion - but I know others love their LiFe's, just I feel LiPo's still rock
  9. Not really back, think I've hung up my guns - as duck jnr is at uni but my youngest might take it up in a year or two I hope to get me back to being shot to shit by other little sods just if somebody messages me or I got some time spare, I'll stick my head in now n then just to see how you guys are and what "fun" you have been having with these bastid toy guns
  10. Some SRC's sectors are shite the cheap SRC sector is made of alloy - not ferrous/attracted to magnets plus not only it is not as hard wearing as a steel/ferrous/magnetic sector but the teeth at back of sector that meshes with spur gear are much thinner too So much so I will never bother using a SRC sector ever again, the alloy thin tooth type the moment a bit of stress, even just in general use, the thin weak teeth at back of sector just wrecks.... see here... If you got a better SRC sector then no worries, but if it was an alloy looking SRC stamp sector with real narrow teeth on the rear, watch out coz there is little strength/contact in that shite sector (only thing decent-ish in the whole cheap SRC gear set is the bevel as it is 5 arl lug bevel - rest is crap)
  11. For the record I just wish to clarify something in case anybody is confused I did not tell him to go nutz and wind the hop on and empty a mag etc.... I mentioned the gears/motor speed issue but with the ETU he is kinda bound to run 11.1v Just the way the post was worded it could seem I mentioned winding hop & dumping mag etc..... which I most certainly did not - it was his colleague btw not moi I can't stress enough for ETU owners - just use the damn thing "as is" on 11.1v only consider to mess with stuff if/when it fucks up and still keep anything in moderation if your gun fires at 18rps with a std 18k - live with it, a few rps won't matter (it is the player's performance/skill rather than the gun's rof that usually wins the game) if your gun fires 22rps with the Ifrit - great but again leave it alone happy shooting all
  12. The I'll sand that or mod that was in general terms rather than sand the back of piston for example an some reinforced v2's long tappet fins can also bottom out with all that extra metal material they chuck in at back of box you look at the runners of tappet plate in the box and where they end and what takes place at full tappet retraction etc...... SOME tappet fins "can" in "some" boxes hit on parts of box or on the thick axles of "some" spur gears for example... but it was just a general term of checking & deciding to to sand/file/mod or try other combinations/parts etc..... I mean you don't have to nutz ordering more gears though any or almost any std sector in a junk box will do as 18:1's are same sectors as 16:1's etc... what meshes fine with present gears are in there and if another JG sector is about then shimming should be fine most likely You can file the sector's last tooth down to say 75% height, it is likely 3mm in height so take off up to 0.75mm absolute max you check and see that the last tooth clears the piston's rack as it slams back etc..... but feel if you reduce the last tooth any more to half its height it might risk not quite clearing fully as piston is released hence you need to make this judgement yourself but if it still doesn't allow clearance then you could simply go with SS one tooth off the pickup side If you have another JG sector gear, then taking your incorrectly SS 2 sector, file down that a bit, the last available tooth (which was originally the 3rd to last tooth) align that tooth on that the last tooth, now filed down a smidge, align this with last tooth of the piston rack check if the piston still bottoms out & experiement to decide if that will work with a filed down last tooth if it does then apply this minor modification to the other full JG sector, test again - viola max stroke & no bottoming out if you old sector won't work with a shaved tooth then mod the other JG sector to a SS 1 tooth off the pick up side - job done ps - for delay clips I love these..... https://www.ak2m4.co.uk/internal-parts/gears/zci-gear-delayer they have a slither extra material just above tappet lug on sector that retracts tappet/nozzle a whisker more than most other clips and they fit quite snuggly onto sectors too - sometimes a minor mod coz so damn tight however you do need to check it doesn't retract too much and bottom out on cylinder heads this needs to be checked as SHS tappets retract a smidge more than others imho so combined with these brass delayers with extra whisker of material the nozzle retracts a bit more to assist feeding - even with so-so mags long duration delay clips are not always the answer if the nozzle doesn't retract enough if you only got a 5.75mm gap in front of nozzle then a bb may not slip past & feed no matter how long it is retracted for but on an insane dsg which doesn't have a delay clip as such, it will feed if there is enough nozzle clearance to slip past
  13. I wouldn't really advise sanding the back of piston too much if at all possible as you might loose strength or material require to retain a metal rack's pickup tooth etc..... Best thing is to test stuff in the top half of box, from tappet plate retraction bottoming out on cylinder head if using a mofo jumbo delayer to piston bottoming out at the back of box, tested with sector (remember to include the spring guide of course in test) The top half od a gear box is a good way to test anything sector related as it is more stable in rotation than the wibbly wobbly in the lower half upon assembly The top half of box is where you can quickly test for smooth operation of stuff and reduce a number of issues arising So easy to drop that in there add that have a looksey and go ooooh erghh looks a bit iffy, just sand that or try that instead And some spring guides might be a bit more lumpy that others etc...., different pistons blah blah blah yeah always worth giving it all a once over using the top half of box if going for full stroke setup or fuck it if you are removing a tooth for a SS setup then no worries (well still need to check other stuff etc...) I think you would probably want a full stroke setup with maybe the sector's last tooth filed down just a smidge I mean you you probably be ok with a slightly vented cylinder but tiny slits at back.... as a full cylinder is for a 455mm AK or 510mm at a push but if lifting .25's or .28 especially a full cylinder would be wise - especially as you lose say 3mm stroke or effectively one tooth as the teeth are 3mm pitch when you corrected AoE so the stroke has reduced 3mm from stock setup after correcting AoE I mean yes you could SS one tooth - no more off the pickup side but I'd be tempted to go full stroke or nigh on & very very slightly over volume a whisker than be bang on what all the graphs/books/maths say which once the o-ring wears a smidge the efficiency of compression may reduce slightly & under volume I think on a 407 barrel I'd be happy with correcting the AoE, which reduces the stroke by say 3mm then mod the release tooth very slightly to get it to just slip/release without bottoming out - yeah that is what I'd do for an AK ' 455mm not much more than your barrel and use the full cylinder if the piston head operates sweetly and the o-ring falls forward and allows the piston to retract quickly and seals promptly etc.... yeah nigh on full stroke and full cylinder, just slightly reduce the last tooth on sector a tiny bit keep checking the operation on other half of box until satisfied and go with that
  14. I'm 99% certain or think the piston head itself won't affect the piston's final retraction point For example you can place washers between the piston & the piston head to correct AoE effectively pushing the piston head further forward or rather setting the piston's position slightly further back - a bit of bodge or alternative way to correct AoE but some do this (personally I'd only use this to very slightly tune or adjust AoE a smidge but to each their own) However - even if place a 3mm spacer between a piston & piston head to correct AoE it alters the piston & the rack/pickup tooth's initial position BUT it does not alter the final retraction point of the rear of the piston - it doesn't It might alter the point of rest where the rack sits to engage with sector but the final point of travel for the rear of the piston has not been altered at all But different pistons can be very ergh uhm "different" and issues can arise For example - they can bind in one box but glide smoothly in another box There are pics and studies on say Airsoft ociety of various pistons & lengths they can vary in say 1mm - maybe only 0.5mm but that is not just the full picture but the exact position of the pack/teeth on the position specifically how much material is behind the initial pickup tooth = more/longer material at rear to bottom out Doesn't matter if the piston has a large lump of plastic pickup tooth like stock pistons or less material like some metal racks have behind them, but more as to the position of the rack at full retraction This is checked by placing the piston - complete of bare piston in the box and rolling the sector back Best method to check stuff is test in the top/other side of box without the switch/tappet etc.... (just seems to operate better as the sector-piston teeth are on that side anyway) if you suspect at the final point of retraction just as the teeth slip past to release themselves.... if you feel that it might just be a possible risk of bottoming out then review the situation..... try another piston or look to file down the last tooth on sector just 0.5mm max so it slips without hitting the box now under spring tension that piston will be very pressed up against the sector gear's teeth but as I said if you test it in the other half of box and feel it could strike the box or a risk of it bottoming out then if no alternative piston is available then modify the teeth slightly to reduce this In a medium length gun - sod it I'll just SS 1 tooth, but in a AK you need full stroke so in that case just a very mild smidge - just 0.5mm max filed off sector release tooth should suffice It is the variation(s) or different tolerances in different pistons that can cause this bottoming out in some builds not the piston head used or if you pack/space the piston head & piston method of correct AoE I think it was MadBull Alien pistons were known to bottom out in many boxes at full retraction but other pistons operated perfectly at full retraction coz they had the rack/final tooth position slightly differently or the material at back of piston wasn't so thick yeah basically - it is recommended to check the piston & sector's operation to check for bottoming out in the other half of gearbox, observe closely the operation and clearance at point of release and decide if it fully passes this check or if alternatives or slight modifications might be needed But it is the piston or different pistons used not the piston head that can cause these issues I feel
  15. Wow - very nice post - full of info and detail (I got an ARX160 so this post will come in very handy) Good to see you will chuck a mosfet soon as the microswitch do tend to burn out Just a tiny note on piston & Short Stroking...... (pmsl - since when did my posts ever become tiny or concise ffs ???) Some piston's or piston upgrades/replacements can hit the back of boxes it is a question of tolerances and where the rack/teeth sit slightly slightly differently plus some boxes have slightly bespoke/shorter piston etc...... The piston hitting the box was very likely just about 1mm or 1.5mm extra travel Some sectors have an ultra thick last tooth - but most don't What you could have done to the last tooth is just filed/ground it down a smidge (say take off a third of it's height, to release the piston a whisker earlier and not hit back of box) Just a smidge on last tooth would have sufficed most likely Or - just removed one tooth Also - me thinks or it is recommended to remove teeth for short stroking on the PICK UP side rather than the RELEASE side like you did but I did the wrong side too when I first Short Stroked a sector (must be a bad tutorial out there somewhere) should really be on pick up side, if taking off one or two teeth and maybe a third tooth still on pickup side, though some start to remove one on the release side to "balance" the weight (nah - I still take 3 off pickup side, but maybe 4th tooth if I was ever SS that much, though only done 3 teeth myself) Anyway - waffle waffle & all that, reason they recommend you take off pickup side than release is to do with tappet timings, if you take off the release side too much, the piston now releases a little bit earlier than the tappet/nozzle returns - so throws out the tappet plate timing So the general rule is to SS teeth from the pickup side/first tooth on two on sector rather than the last tooth or two on the sector gear like you did..... Now this may not be too much of a problem in a stock/moderate gun but higher rof guns this altered tappet timing can effect stuff - eg: piston/releases before nozzle seals so compression is lost as it builds & leaks before the nozzle seals on bucking at higher speeds etc..... Plus you added a delay clip so the tappet remains retracted a little more than usual on top of piston releasing earlier One of these things may not be too much of an issue on their own but combined the piston & tappet timing is thrown a bit more out of whack - hence my war & peace post So IF you notice weird stuff happening then locate another sector and file down: last tooth slightly if a gun needs max stroke like 455mm AK47 (if you can't find a piston that doesn't hit/lock up at back of box) or grind down just one tooth or only what is needed on the PICKUP side you don't need to remove any teeth on rack unless you got jumbo last tooth sector (fairly rare) if you had a jumbo release tooth like pic and SS say 2 teeth off the pickup side then yes you need to remove the teeth on rack but in general you don't need to remove teeth off the metal rack as most teeth are evenly pitched/size etc..... If tappet timing becomes a real issue then it will need to be addressed another possible thing is to trim the tappet fin so the tappet plate releases earlier and comes back into sync on much higher speed setups the tappet fin is trimmed down with a strong spring to ensure tappet returns asap etc... or this trimming of the fin is performed to compensate for ultra long delay clips Whoa - ultra long post, my bad but maybe next time take off the teeth on the other side, removing the first tooth/teeth that contacts the piston..... other than that - brilliant teardown on the ARX box
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