TK4235 Posted October 23, 2011 Report Share Posted October 23, 2011 Ok, when i opened up the gearbox, the tappet plate was almost bent against the sector gear knob thing.This suggests to me that the sector gear timing is wrong. Secondly, the compression with the air nozzle seems suspect. When the nozzle is held against the cylinder head (and I place my finger over the nozzle) if I push the piston into the cylinder, I can't move the piston. This is fine. If I hold the nozzle so that it's say half way up the shaft of the cylinder head and I place my finger over the nozzle, I am able to push the piston into the cylinder. Is this normal? I checked the prommy air nozzle and I can see the o ring. I think the marui nozzle has a better seal though lol... Anyone? Quote Link to post Share on other sites
TK4235 Posted October 24, 2011 Report Share Posted October 24, 2011 Well, i put the gearbox back together and just chronoed it... I'm getting less fps now! Back to around 296-305fps!!! Can't think of why this is happening unless the piston is short stroking....? Quote Link to post Share on other sites
akiraspeedstar Posted October 24, 2011 Report Share Posted October 24, 2011 (edited) Well, i put the gearbox back together and just chronoed it... I'm getting less fps now! Back to around 296-305fps!!! Can't think of why this is happening unless the piston is short stroking....? yeah something is definitely wrong, my gun when the only mod was a tk twist barrel was doing 297-300. Not sure what's causing your issues though, hopefully someone can chime in with some advice. Edited October 24, 2011 by akiraspeedstar Quote Link to post Share on other sites
Richard Y Posted October 24, 2011 Report Share Posted October 24, 2011 can you take a picture tk ? Quote Link to post Share on other sites
TK4235 Posted October 24, 2011 Report Share Posted October 24, 2011 (edited) Hold the press..... 346fps, 333fps, 331fps, 326fps 341fps....... You guys will not believe what I just did.... reverse engineer... I looked at the gearbox and thought what is causing the incompatibility...? So I went back to stock Marui.. yes stock Marui parts....! (well kinda).. Stock piston, stock piston head, stock cylinder head, eagle6 m100.... but I kept the pommy air nozzle and pommy spring guide....and it worked! What gives? My thinking is that the pommy piston, pommy piston head and pommy cylinder head needs a pommy cylinder to work perfectly.... I was using the Marui stock cylinder so that has to be the differentiating factor here.... Good thing is I can take down a whole SOPMOD now in less than 20 mins... Oh well...... happy times.... Only thing I need to do is to go back and loctite all the screws... but hey they can wait till the weekend!!! Edited October 24, 2011 by TK4235 Quote Link to post Share on other sites
Kunlun Posted October 24, 2011 Report Share Posted October 24, 2011 Ow, I'm about to find out tomorrow as I got all the Promy parts except the cylinder and piston ... Quote Link to post Share on other sites
Richard Y Posted October 24, 2011 Report Share Posted October 24, 2011 prob the piston head o ring on the promy was a little too small, take it off and stretch it over the cylinder and leave it over night. 1 Quote Link to post Share on other sites
TK4235 Posted October 25, 2011 Report Share Posted October 25, 2011 Ow, I'm about to find out tomorrow as I got all the Promy parts except the cylinder and piston ... This will be interesting....are you going to stretch the o-ring as Richard said above? I found that when i put my finger over the air nozzle I was unable to push the piston into the cylinder any further due to a good air seal, however I was easily able to pull it back. With the marui pison, I cold neither push it or pull it back with my finger over the nozzle. I will end up buying a pommy piston sometime soon so then at least I know all parts are the same brand. BTW, what is the timing of your sector gear? Have you got the raised bit of the sector gear at 90 degrees (pointing in the direction of the front of the geabox?) Quote Link to post Share on other sites
Richard Y Posted October 25, 2011 Report Share Posted October 25, 2011 Ive never need to stretch it with a promy before usually that stuff just goes in and fits. But its just something to do if your getting low fps regardless of your compression test, the reason the promy goes in easy vs the tm is that the promy is vented and relys on the vents expanding the oring on compression and makes it a faster ROF when reseting the piston beucase its not fighting unneeded compression. The TM piston relys on a constant seal. If you want to add vents theres 4 small marks on the tm piston just drill those out. Out of the parts youve removed it couldnt only really be the o ring that was cuasing it. Theres no timing of an aeg gearbox on installation you simply install the sector gear timing lobe at 2 o clock postion to aid in it not getting trapped under the tappet plate. The timing is govened by the timing lobe which is the same every rotation. The activation of semi is separate and part for the cut off lever system. Quote Link to post Share on other sites
TK4235 Posted October 25, 2011 Report Share Posted October 25, 2011 This is what's really bugging me... I've built plenty gearboxes with no problems so I can't understand what the issue may have been. So far as to say, the TM parts seem to be working so far. One thing I noticed is that I am unable to pull (reset) the TM piston back if I have my finger over the cylinder head. This is due to the compression?. However if I try the same with the pommy piston, I can pull the piston back through the cylinder but not push it forward. I assume this is due to the vented nature of the pommy piston head. I've set the lobe at the 3am position, perhaps I should reset it to the 2am so that the tappet plate does not get stuck over the lobe. Compression test - can someone explain to me what compression tests I should be running? Thanks Quote Link to post Share on other sites
Richard Y Posted October 25, 2011 Report Share Posted October 25, 2011 I explained in the post above about the difference piston heads what vented does. You did the compression test fine, and it should have worked but it didnt. But since it can only be a few things it had to have been the piston o ring regardless of test results. Also sometimes you build it up and its low fps, then you go back in rebuild it and do nothing different and you get a normal fps reading again. Some times theres no reason and you just have to do it again. Quote Link to post Share on other sites
TK4235 Posted October 25, 2011 Report Share Posted October 25, 2011 It's not an exactly science really is it... lol Richard, Can you let me know when your next stock of the prommy type A cylinders will be in? I'll play around again at the weekend but this time i'll stretch the o ring on the pommy and see what happens.... the search for the elusive 340-350fps goes on.. Quote Link to post Share on other sites
Kunlun Posted October 25, 2011 Report Share Posted October 25, 2011 Euh, someone told me that the AWS Sentry http://www.awsairsoft.com/sentry would fit fine in a SOPMOD/SOCOM? Anyone can confirm? If so, I'll install that one first till the Raptor comes out ... Quote Link to post Share on other sites
ADnams Posted October 25, 2011 Report Share Posted October 25, 2011 (edited) Euh, someone told me that the AWS Sentry http://www.awsairsoft.com/sentry would fit fine in a SOPMOD/SOCOM? Anyone can confirm? If so, I'll install that one first till the Raptor comes out ... I can't see why it wouldn't its basically just a fancy mosfet. The wiring diagram indicates you need to connect the red and black wires to the motor and battery whilst the blue wires are connected to either side of the trigger switch. The unit looks like it can then be placed anywhere the wires can lead to in the gun. Space may be an issue on the Sopmod, but it should easily fit in the fore grip of the Socom. Edit: The website also states it fits all gearbox types. Edited October 25, 2011 by ADnams Quote Link to post Share on other sites
akiraspeedstar Posted October 25, 2011 Report Share Posted October 25, 2011 (edited) Anyone ever put that First Factory VLTOR MUR-1 style upper receiver on their gun? If so, how'd it fit? Also the ARS Magpul Style Lower receiver has been pushed back to November 15. Edited October 25, 2011 by akiraspeedstar Quote Link to post Share on other sites
Kunlun Posted October 25, 2011 Report Share Posted October 25, 2011 Put in the the Promy parts and used the Magic Box piston with Systema hop up bucking. Also installed the cqb outer barrel with a Prometheus 6.03 285mm inner barrel. Getting consistent 310 fps, so my fps dropped 20 fps but I think it's due to the barrel/cylinder volume ratio? I'm not someone who achieves to be as close to the fps limit (350 with 10 margin here in Belgium) so 310 is acceptable for me. Quote Link to post Share on other sites
Kunlun Posted October 26, 2011 Report Share Posted October 26, 2011 Done! After some shooting/plinking today FPS increased to about 330 FPS (VERY) consistently with 0.20g. I am VERY happy with my build atm! Looking for a replica MBUS 2 in FDE as I type this ^^ Internals: M90 Eagle6 spring Systema HU bucking Prometheus 6.03 285mm barrel Prometheus spring guide Prometheus selector plate Prometheus cylinder head Prometheus piston head Prometheus nozzle Magic Box piston Long term purchases: AWS Sentry and Prometheus gears 1 Quote Link to post Share on other sites
TK4235 Posted October 26, 2011 Report Share Posted October 26, 2011 Well done and congrats. That's a superb looking beast you have there... Kinda like the 2 tone... One change i'm gonna make is to see how the gurader clear 50% bucking performs... Quote Link to post Share on other sites
akiraspeedstar Posted October 26, 2011 Report Share Posted October 26, 2011 (edited) Wait, Prometheus make 285mm barrels? I ended up buying a 300mm because I couldn't find a 285. Oh well, nothing wrong with an extra 15mm, anyways very nice gun! Anyone want to buy a SOPMOD rail system? $55 shipped or with the Echo1 flip up front sight for $65 shipped for people in the US. Will have to look into shipping charges for international if someones interested. Edited October 26, 2011 by akiraspeedstar Quote Link to post Share on other sites
TK4235 Posted October 26, 2011 Report Share Posted October 26, 2011 Akira, so what have you replaced your RIS with then? Quote Link to post Share on other sites
akiraspeedstar Posted October 26, 2011 Report Share Posted October 26, 2011 Honestly I haven't even gotten it yet haha, I got a Madbull Daniel Defense MK18 RIS 2 coming in (should be here tomorrow). I was originally going to convert my CQB-R into a MK18 impression, though I just don't really like the look of the FDE rail, ended up going with a black one instead. So it'll be MK18ish haha Quote Link to post Share on other sites
akiraspeedstar Posted October 29, 2011 Report Share Posted October 29, 2011 Got my madbull mk18 ris 2 rail installed, still don't know how I want to set it up with accessories. Also got a first factory VLTOR MUR-1 style upper receiver coming in next week. Quote Link to post Share on other sites
TheFull9 Posted October 29, 2011 Report Share Posted October 29, 2011 Also got a first factory VLTOR MUR-1 style upper receiver coming in next week. Let us know how you get along with it, hopefully they've improved their tolerances. 1 Quote Link to post Share on other sites
zaimon Posted October 29, 2011 Report Share Posted October 29, 2011 good luck in your vltor upper receiver i had one before the fitment was so bad i end up using back the TM stock one Quote Link to post Share on other sites
akiraspeedstar Posted October 29, 2011 Report Share Posted October 29, 2011 (edited) Dammit, none of you could've replied when I posted earlier asking how it fit? Haha. Well thankfully they had not yet shipped out my order, I just emailed them and messaged them on their order inquiry system to cancel the order, hopefully they see that before they send it out. I'm not willing to risk $175 hoping that it fits okay when you guys have already said it fits bad. Though if they send it out before seeing my email, at least I see that it is possible to return defective products, hopefully that works out if worst comes to worst. What were the fitment issues with the upper? Gaps? Edited October 29, 2011 by akiraspeedstar Quote Link to post Share on other sites
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