v2 nightmares - I hate old stock parts!

[coach]

I got a v2 that's been kicking my ass today. It should have been a basic swap from a cracked TM box to a reinforced JG box. But I can't get it to work. This is for an M4

Had a multitude of issues with it that I swapped parts with. Spur gear missing teeth/flat teeth. Sector gear had a spur gear embedded in it. Switch assembly had no power going to motor....

Anyway, got all the parts in and it should be working but it's not. When assembled I sometimes get a single full cycle. Other times I cannot turn the selector from safe to semi, or I'll not be able to pull the trigger in semi but can in auto.

It appears that when the trigger is pulled, instead of the switch sliding straight forwards, it's goes forwards and up getting stuck and allows the trigger to freely move back and forth.

Everything else operates fine. With no power connected, I can get continuity with a multimeter in semi and auto. As soon as power is connected, the trigger fails to push the switch.

Any suggestions?

[ujiro]

So just to be sure cuz I can't tell, is the switch block (the piece that moves when you pull the trigger) in the guides properly on the main switch assy? Or are the guides on the main switch assy that the switch block slides through screwed up at all?

[coach]

not the part screwed to the shell. just the little piece that moves when the trigger engages it. trigger essentially engages it once then is able to move under the piece with out touching it. it seems to be in position but there is space which allows too much play. is there a piece missing? the switch assembly is just 2 pieces with 2 covers screwed on right?

[ujiro]

Yeah its just the piece that slides and the piece thats mounted to the box wall. Hmm sounds weird... It does sound like something is missing, off of the trigger or the switch block.

[Styrak]

Is your trigger post broken off? There should be a post holding the moving part of the switch so the trigger can push it.

[coach]

Originally Posted by ujiro

Yeah its just the piece that slides and the piece thats mounted to the box wall. Hmm sounds weird... It does sound like something is missing, off of the trigger or the switch block.

What's weirder is that I have 2 other switch assemblies and they all look the same. the one that was originally in the cracked box was essentially new and worked when the box broke. (G&P handguard assembly)

Originally Posted by Styrak

Is your trigger post broken off? There should be a post holding the moving part of the switch so the trigger can push it.

trigger is fine. identical to the one in my M4 and for a visual, is the same as this:

[Styrak]

Originally Posted by coachster

trigger is fine. identical to the one in my M4 and for a visual, is the same as this:

No, trigger POST. Like I said it holds the moving part of the switch in the right resting position.

[ujiro]

I think he means the trigger post on the inside of the mechbox shell. Its a little metal bar sticking up out of the shell just to the left of where the switch block (moving part of the switch assembly) is. So that when the trigger is not pulled and the switch block is all the way to the left, it is pushed up against this little post

[coach]

yes, that's there. I have to unscrew the switch to change the block.

[ujiro]

And so the block is identical to the ones from other functioning boxes, and so is the trigger..?

[coach]

Originally Posted by ujiro

And so the block is identical to the ones from other functioning boxes, and so is the trigger..?

yes. resting postition is not the issue, it move to the right and up and doesn't return properly. and yes, the spring is installed and when I move the block by hand, it returns properly.

[Styrak]

Might want to take it to a gundoctor who know's what he's doing. Like you said, your gun has a bunch of problems!

[ujiro]

Hmm.. Weird. I have one idea.. It probably wouldn't do anything but hey its worth a shot. You know how the spring is shaped like this...

o--------_

Where there are loops on both ends to go to the post that the spring attaches to on the box, and then the catch on the switch block. Well, maybe its on not.. properly so that it is pulling the switch block up a little bit when it is all the way to the right. If you switch the spring so that maybe it isn't pulling the switch block from too high up, it might resolve the issue?

[Styrak]

No that shouldn't be an issue, any way you put that spring.

[ujiro]

I didn't think so, as I recall putting it on both ways and neither way causing any issues. But hey, its worth a shot. This is really curious though, considering from what he says, the switch assy, switch block, and trigger are all in perfect condition (nothing broken, missing, etc), there seems to be no reason as to why this would happen. It just sounds like the guide on the main switch assy is messed up somehow so that when the switch block is all the way to the right, making contact with the other half of the actual switch on the main assembly, it gets pulled up a bit.