Hmmm, what's wrong with this mechbox?

[CDN_Stalker]

So, I had an SR-16 fully upgraded mechbox fall into my hands. Previous owner had sent it to a mechbox mechanic recommended by a friend of his. Seller barely used it after upgrading, said he dry fired a few shots then it stopped firing, figured the battery was dead so he packed it away for a few months then sold it. Anyways, check out the things I found and see if you can figure it out for yourself. There is one really obvious one, one barely noticable one (but serious), and one that I won't even bother asking you to find.......... there are ONLY two shims in the entire mechbox!!!

[HaZarD SFD]

:cry: My baby... look at the horror :cry:

[bean]

Oh oh i know but its cheating if i reply

[CDN_Stalker]

Yes, neither of you are allowed to play this game.

[bruce]

What's that Allen key sticking out of the spring guide and your cylinder is backwards.

[Ghillie973]

I know next to nothing about internals but I'll just take a guess.

Isn't the cylinder supposed to have the hole at the back? (away from the nozzel) If it's that far forward you'd get next to no compression right?

[CDN_Stalker]

Bruce, the allen key was used to hold the spring while I separated teh mechbox halves, keeps the spring from shooting out.

And yes, the cylinder is backwards. BUT, all the M4/SR-16/733 I've worked on, I don't recall any of them having a ported cylinder. My MP5 does. Ported cylinders are for short barrel lengths.

Keep looking for the small yet hysterical other.

[Ghillie973]

My ICS M4 has a ported cylinder, but it's tear drop shaped.

[CDN_Stalker]

Hmm, ok. I might not have noticed on some of the cylinders I've dealt with, but everytime I saw one I used to wonder "Why on some and not others?" Need to get MadMax or Illusion to break out their comments.

Just used the "Vondnik Shim Technique" and found the sector gear is set up nice, but there is a 0.5mm movement with the spur and bevel gear. Not comfortable with it, prefer a little less, but I guess we can't fault the guy for a reasonable job doing it.

[HaZarD SFD]

OMG ppl I noticed the Small insignificant but hilarious other issue and I have
never seen the inside of a mechbox...

[[Sigma]*SATAN*]

looks like the spring on the reverse pevention latch is turned the wrong way.....also... the box generally has way to much lube in it... and only 2 shim in the entire box isent good either.....
is there no theeth on the middle gear? kinda looks like the nozzle guide is snaped in half also.....

[bruce]

Anti-reversal latch spring is out of place?

[CDN_Stalker]

Bingo, we have winners! Anti-reversal latch spring was installed backwards. You can see the part that is supposed to be on the latch itself is actually sitting overtop the wires.



Nozzle guide is fine, tappet plate is fine, grease is about normal from my experience (and as I tend to do it as well, without overdoing it.)

[skaterjoe]

so does that meen im suposed to put THAT much lube in my gun?
cause if so, i have been horibly under lubing my mechbox.

[CDN_Stalker]

Need enough to keep things running smooth and lubed, without huge piles of liquid grease getting everywhere. Worst place to get grease going (aside from into the cylinder if it has the chance and blowing out onto the hop up and barrel) is on the contacts, reduces and eventually can cause lack of current flow, making your gun stop shooting. Might be a tad too much in this gun, but once I get it all back together again, there will be less in the box and more on the rag.

Edit: Ok, there IS too much in this, just found a BB sized glob under the sector gear. Having it on the gears like that is ok, but having large globs elsewhere isn't. Add in too much on the piston too!!!

EDIT Again: Found the little block right behind the trigger contact block (keeps the block from moving too far back) has broken off as well. Noticed this in Apoc's G&P SPR, thought it to not be much of a problem, until his gun jammed up. In this case it doesn't seem like it'll cause too many problems, but in the SPR, it's a lot stronger spring, ended up angling the block upwards and it jammed on the bottom of the tappet plate.