How do i stop my pneumag from short stroking?

[longi]

Having finished my Pneumag i'm now fine tuning it, however if i try to walk it it short strokes severly. It fires ok at single shots but not if i try to walk it. I've tried both the RT on/off and the ULT on/off and both short stroke easily. Just for the record i'm using a Retro valve that was modified to accept the ULT on/off. The velocity is slightly down on the marker and will be turned up tomorow when i resume fine tuning it. Any ideas?

[Pneumagger]

Stats of the 3 way? Too much Hosing? Are you fully releasing the trigger? Is the trigger depressing the 3 way enough? is your sear stop too far in? Level 10?
PICS 'N' VIDS HELP!

Have you tried paint through the marker. I've had dry fire short stroking occasionally before, but not with paint.

[longi]

I'm using an MSV-2, I think iv'e got the sear just right, i was quite painstaking with this part because i had a few complications with the sear angle. As far as releasing the trigger enough, i know i have alot of work to do on my technique, so it could be that. I will be trying paint through it tomorow. I'm not using a sear stop as i thought this would inhibit the bolt resetting in the same way as if you use trigger stops on a standard RTmag. Does the sear stop make any difference to the perfomance? I have to say i was a bit sceptical of this idea so i didn't try it. Yes i do use a level 10, i'm currently using the softest spring as the reactivity was insane coupled with a short on/off pin pre-pneumag. Againthis will be changed tomorrow. Alas i don't yet have any pics or vids. I'm not to sure about the hose length, the only thing i have done slighly differently is to move the QEV from the MPA-3 into the frame as i couldn't make enough room for it and use the MSV-2.

[Pneumagger]

ok... try to get many shims in the ULT. Make sure the trigger is traveling a little more than needed to actuate the 2way than needed. Don' use excess hose between the valve and piston. QEV?

Once again, pics and vids are great to see what's happening

[longi]

Mmm...I have about 3 1/2 inches of hose as a rough guess between the QEV and the MPA-3 and about 1 1/2 inches of hose between the MSV-2 and the QEV. I'll try to upload some picture tomorow if i haven't sorted it. Thanks for responding so quickly. :)

[Pneumagger]

My initial guess would again be your trigger needs to open the MSV-2 more, You need more pressure for high ROF flow, or the ULT needs more shims....but if the RT on/of is messing up too, you may need more velocity or a higher and faster input.

What kind of LPR do you run?

[longi]

I'm using a Palmer Micro Rock LPR. I have also been having a few problems with the ULT letting air thru. I'll try more velocity and input pressure and open out the MSV a bit more see how i get on. I'm keeping my fingers crossed. I'll let you know how i get on. :)

[longi]

While i think about it, i think i have the input pressure set quite low so as it only just trips the sear. Mmm....

[longi]

OK! i got it working using the standard RT on/off, however i still can't walk it. I've still got a bit of fine tuning to do. At some point i'll try the ULT again but for now i'll work on this. Are there any other tricks i might try to make the trigger walkable?

[Pneumagger]

not walkablee like, too heavy? If it's too heavy with an MSV-2, then your running too much pressure.

[longi]

If i walk the trigger the Pneumatic frame walks ok, but it doesn't seem to trip the sear every time. Single shots in quick succsession ie 5-6 bps works a treat. I'm wondering if i have sear mounted too high in the frame, as mine is mounted slighly higher than the sear shown in the pictures of your latest pneumag, it still maybe the position of the sear, its sooo close it hurts!

[Pneumagger]

the searis fixed isn't it? It shouldn't matter a whole lot about the mpa positioning.

Does your frame cycle nicely without the rail or valve being there? Make sure nothing is impeding the return of sear.

[longi]

Yes, it works really well, on its own it walks great. With pressure set lower and the valve connected, the valve will walk with the frame, but its very very hit and miss. It will fire once then nothing happens then i might get a 3 or 4 round burst in quick sucsession all whilst walking the trigger. The MPA-3 hose doesn't appear to inhibiting the sear in any way (i've run it back over the top and behind the MPA-3). It's close but there is clearence.

[Pneumagger]

hmmm. IDK. A short webcam or betterr clip of what it does would be great.

[longi]

I have a clip but i'm unable to upload it, i'm open to suggestions! lol!

[longi]

Ok here goes...Sorry about the quality....http://media.putfile.com/longis-pneumag-problems

[Pneumagger]

If the frame seems to be doing it's thisng and looks good internally when firing, I'd say it sounds like the sear isn't returning well enough. Are the bolts tightened down and the on off oiled well with little friction? And be sure the sear isn't resing on the piston when not firing. There should be a near-imperceptable gap between the sear and piston.

[longi]

Back again have been working away from home and have not had the internet. I have a feeling you may be right about the sear resting on the MPA. I'll check it out tomorrow. All is well oiled.I may have to shave some of the metal off the piston, or move the piston further down.

[Pneumagger]

unless the sear frony is hitting the top of the MPA body,, You don't have to move it down. the fact that it is high dosn't matter so much. and shave the sear leg... it's easier.

[longi]

Well, the underside of the sear just touches the top of the MPA. The vetical leg of the sear is well clear of the MPA in it's rest position. I'm also going to try to increase the on/off reactivity as it's never been the same since it's been modified. It works ok, it just doesn't have the super reactivity it once had..ie...I can't bounce it so as it goes full auto anymore.

[longi]

I may also try it without the QEV.

[Pneumagger]

you dont want the sear leg too far away either. I really think it may be that that you need to add shims to the ULT and/or rt on off

[longi]

I'm keeping my fingers crossed!

[longi]

Blimey! I think i've done it!! It seems that i needed less input pressure and i moved the MPA-3 towards the front of the gun slightly. I now can walk it dry firing but it still miss fires very slightly. I'll be putting some paint through it in a while. Now i think it's down to improving my walking technique. I think i may well buy a gauge for setting up the input pressure correctly as this should help me out in the future. I'm now going to play some guitar solo's extremely loud untill the Police turn up and arrest me! :headbang: 'AVE EET!!!

[Pneumagger]

I've seen them never short stroke with paint through them, but when I take off the hopper they'll chuff occasionally.

[longi]

Put some paint through it this arvo and omfg! It works put it back to back with my friends DM6 and there isn't too much difference between the 2 (unramped that is). I've just need to work on my technique now and get out and play. Thank ever so much for helping me out, i'm very gratefull (and well pleased!) :dance: IT'S ALIVE!!!