Troubleshooting new build: Opinion requested!
 

Hello ACS Community!,

I have a question for you guys! I have been getting better and better with AEG upgrades and mods, and I am always wanting to know more about them to enhance the performance of aeg's. I have my setup that i've built and I finished putting it together and she runs amazing except for one problem (currently, TONS of trouble shooting has taken place up to this point to make the gearbox run). I have near-perfectly shimmed the gearbox, short stroked 3 teeth, corrected AOE (both shaving teeth from piston & adding 70D sorbo pad), swiss cheesed the piston and so on.

Currently, the issue that I am having is that the nozzle stops in different places which is leading to the rifle not feeding at all. I am hypothesizing that this is either from pre-engagement (although unlikely as the short stroke and AOE corrections should eliminate it) or over-spin. Would you guys have experience with this? How would I adjust/fix this issue so that this does not happen any more?

Bellow is my complete gearbox setup for my VFC 416 CQB:

Lonex Gearbox (bearings, not bushings)
SHS M4 nozzle
Lonex aluminum double o-ring cylinder head (equipped with 70D sorbo pad)
Modify enhanced cylinder type-1
Siegetek Revolution 14.09:1 Gearset (short stroked 3 teeth off pick up side)
Lonex Titan A1 Motor
SHS 15 tooth piston - full metal rack (filed 2 teeth after pickup tooth for AOE correction, short stroked 3 teeth off release side and fully swiss cheesed)
Lonex POM Ventilated Piston head (Ball bearings installed)
Stock VFC bearings spring guide
Lonex cutoff lever
Lonex tappet & selector plates
Lonex M130SP non-linear spring
PiccoSSR 2 Mosfet (installed using setup #2 on installation guide with 16 gauge silver wiring)

I think thats about it for the gearbox, so please let me know if you need any other specs. My goal is ~395 fps. If you could please let me know your opinion on this matter, it would be greatly appreciated. Thanks for your time.

Flarebrass

Reserved. **Also please note: the PiccoSSR 2 mosfet is a NON-Active Breaking mosfet**

it is my understanding that you shortstroke off the release side of the sector gear, not the pickup. SSing off release side messes with tappet timing which affects load timing.

First reaction: Dude, you short-stroked a Riot gearset :(

Second reaction: From the pick-up side D: (Edit: Pick-up side is the correct way.)
(Edit : Short-stroking from the RELEASE will mess the tappet timing, which can lead to a bad air leak.)

With 14.09, short-stroking is barely needed. Three teeth is excessive (I know, I did the same for my first build because I was fearing pre-engagement)

Third, nozzle stopping randomly does mean slight overspin, but should not affect anything. Your BBs should still feed, so I'd look elsewhere, especially when you say "not feeding AT ALL".

Which magazine/BBs are you using?

Hey Lurk,

That is what I did! (your first sentence differs from your second, so I am going off what i read). When I did my short stroking research, the guides I used said to take teeth off the pickup side of the sector gear and teeth off the release side of the piston. This was to omit your exact reason of messing up the tappet plate timing. The guides that I used were as follows:

http://airsofttutorials.com/tutorial...-stroking.html

http://www.airsoftsociety.com/forums...uestion-87086/

http://www.airsoftforum.com/board/lo...p/t278152.html

Are these guides incorrect in doing so? Should it be teeth removed from both the release side of the piston and the release side of the sector gear?

Thanks,

Flarebrass

Hey K3vX,

I was quite fearing pre engagement as well. That is why I went with 3 teeth and upped the spring!

In regards to mags & bb's, It was an Emag PTS + .25 Bioval bb's.

What do you think it would be then for the feeding issue? Where are the guides that say to take it off the release end? Why would all the guides (accordingly incorrect) still be up on the main google list?
I listed the guides I used above; are they all wrong!?!

Thanks for your time,

Flarebrass

sorry.. .3 hours of sleep. I meant short stroking off pickup side of the sector might mess with tappet timing.

To be honest, I can't remember at this point what the method is. I haven't done it myself and don't remember what the process was. 14:1s might require a sector clip though.

Hey Lurking,

No problem. Maybe if I clarified a little better it would help. When I shoot in semi, wherever the nozzle was, is where it ends up. It only changes position (middle, forward, back, etc) after I shoot in full auto then swap back to semi again. The nozzle DOES stick out a bit in its fully recoiled stage, which is probably why the bb's aren't going up into the hop up. Is there a way to stabilize it so it doesnt keep changing stages after full auto (were excluding the AB mosfet at this point as I do not want to have to rewire it and purchase a new AB mosfet if its not required)? That is what I meant by a timing type issue.

Do you have any guides in regards to taking teeth off the release side of the sector gear (as I stated above all the guides I reviewed and learnt from are saying pickup side; if that's wrong, where are the guides for the correct way haha)?

Thanks again,

Flarebrass

wait, wait, wait. what? you shortstroked a set of riots?


...how long did that take?

Edit: TL;DR : If short-stroking, do it from the pick-up side.

I'm retarded too, haha, let me explain in details.

Removing teeth both side can screw the tappet timing. Removing from the release side of the sector gear will release the piston before the tappet is fully extended. That sucks. Removing from the pick-up side could lead to the tappet being picked up and pulled back before the piston finished it's stroke (which would normally cause premature engagement if the teeth were still present). But that's less likely, so that's why we recommend removing from there.

So, the guides are right, but only to a point.

On both cases, you will lose power but will still shoot a BB.

Myself, I got confused by lurkingknight's post, and I'm really sorry for this. Nothing I hate more than giving false information.

About the nozzle not at the same place after full auto, that's perfectly normal.

In semi auto, the cutoff lever is activated by the sector gear revolution, so it stops at the same place every time. Since in full auto the cutoff is not engaged, the cycle will stop where you release the trigger. And since us human cannot release the trigger at the same place every time, the nozzle will stop at random. Like I said, not a problem ;)

Does the gun feed with a weaker battery?

If yes, the nozzle, when at full speed, is too quick for the BB to get up and chambered in the hop-up chamber. A sector clip will help, as well as better mags ( don't know the EMAG, but if they're genuine PTS they should feel ) or better BB (* bioval should be okay, but try something else just to eliminate that variable ).

If not, I'd look at the nozzle itself. Maybe it's too long, so even when fully retracted it doesn't allow a BB to get in. Flip the rifle around, point a flashlight at the BB feed path, and shoot with a low powered battery so you can see the cycle. If you put a BB in there, it won't feed if the nozzle is too long.

some quick ASM google-fu says pickup side is correct.

I had the same reaction. People usually shortstroke a sector gear from another gearset (XYT/JG is really popular on ASM).

Yes, read above, I brainfarted and corrected myself. At least now we're sure.

where the nozzle ends up after semi or full auto cycle is irrelevant. The backstroke of the tappet is what allows the BB to enter the HU. Provided you have enough torque in the motor or amps in the battery to move it wherever it stops. (semi auto lock up)

The cycle will just start where it left off, it doesn't care where the nozzle ends up, the BB will still load if it can load.

AB fet will help more with overspin imo and you aren't describing overspin as an issue.

How is it chronoing? is it all over the place or is it a pretty good seal?

Using a lower power battery to slow it down will hide the possibility that the tappet stroke is happening too fast with the battery he wants to use. It may reveal that the nozzle is too long and won't allow it to enter the HU. Generally speaking some builds start needing a sector clip at 16:1s with neo motors and big 11v lipos. 30~rpsh in that area is where feeding without a sectorclip is dicey.

So you pulled the factory VFC nozzle out of the gun for an SHS aluminum nozzle? Did you happen to compare lengths of the new nozzle to old?

a KA nozzle vs an SHS nozzle is clearly shorter by about 2/10s of a mm. Unfortunately I don't have a stock vfc nozzle on my bench to give you the exact measurement, but I did measure KA vs SHS because I had a massive FPS swing with an SHS nozzle on a KA gun with KA HU. Went back to the factory nozzle and it's 395fps all the time. The SHS being too long here.

How quickly do the BBs spray out of the mag when you hit the release? Do they spring out with a lot of velocity or is it closer to pooing out?

When the mag is in the gun and you're pulling the trigger, does pushing the mag forward or up make a difference? how about back? Does rocking it around make a difference?

Have you tried other mags? Other BBs?

The air nozzle stopping in a different position each time is a result of varying degrees of overspin. That is not why you are having feeding issues. You also should not be worried about pre-engagement unless your gun is jamming, I'm using a 13:1 gearset with 2 teeth SS from the release side to prevent tappet plate pre-engagement with a delay clip, PicoSSR2, Tienly GT45000 motor and M90 spring. No signs of pre-engagement after 4000 rounds.

Try turning the gun upside down, and seeing if it feeds on semi auto upside down. If it doesn't feed, cycle the gun until it stops with the nozzle in the full rear position and see if it requires force to push the BB down into the chamber.

@wind_comm: I used a cutting edge on a dremel. for all 3 it took me about 10-15 minutes.

@K3vX: Unfortunately I do not have a lower battery as I only have 11.1's and rifles. I do not believe it is moving to fast, as after more observations, firing semi 30 times in a row, the nozzle still moved irregularly (from being all the way back to sticking 3-4 mm into the hopup chamber, more so the latter than the former). Unfortunately with these gears, a sector clip is of no use, as the Siegetek sector gear has a build in over sized round "nub" which goes almost all the way to the gear shaft. The mags are PTS and feed very will in both my other rifles (as well as the bb's), so I think we can rule those out as well (keeping in mind PTS Emags are the mag of choice for 416's due to the modified magwell). Noticing, after those 30 shots, that for at least 5 of them the nozzle was all the way in the recoiled position towards the gearbox; which in theory means it isn't too long. There is something (whether it be overspin or what have you) that is catching it just a tiny bit forward each time and it finished anywhere from 0mm - 4mm in the HU. Frankly I am still stumped on how to adjust this w/o an AB mosfet.

@Lurking: Sometimes the nozzle goes all the way back (which shows it can), but more often than not, its a couple mm into the HU. I will pull it out some time this week and check the length of the VFC one compared to this one, but after seeing that it could go all the way back towards the gearbox has me thinking otherwise. The motor is a high torque and speed neo motor so it should have enough kick to do anything. Maybe it has too much kick for a lower ratio gear set (even after short stroking?). I haven't had a chance to chroni it as it hasnt even been able to fire a bb yet. For the Emag, they spray out super fast, so the spring seems ok. When the mag is in the well, there is no vertical or horizontal wiggle. I will try another mag tonight, but the nozzle seems to be (probably connected to a larger problem somewhere) blocking the feed itself. No idea how to truly fix this issue. The main question is, how to I make the nozzle stay recoiled ALL the time. That is, the magic question haha.

@pestobanana: Would overspin not create an issue with the nub on the sector gear to finish in different places, therefore leaving the nozzle in different places and creating a feeding issue? I will try turning it upside down and see if I can, by hand, put a single bb down in the hop up. I mentioned to another helpful hand above that more often than not the nozzle is a few mm into the magwell, preventing it from feeding, BUT I have seen it a few times go all the way back, which means its not too long, therefore must be another problem. I will cycle it as you said and get it in the rear position and see if a bb slides down inside. If it does, what does that mean? Do we go back to the overspin stopping at random different intervals, therefore putting the nozzle in different places and unable to feed?

Other than an AB mosfet, would using bushings rather than bearings make a difference? (I know it will slow the gears down slightly, but will it be enough? Is it that dramatic of a difference?).

Thanks again for all your brain power guys. It really helps to have more than one head on things and together, I am sure we can figure this out! Thanks a ton!

Cheers,

Flarebrass

SHS nozzle is just a tad longer than other M4 nozzles, but I've never had feeding issues from the SHS nozzle being longer. I've used SHS nozzles in both of my VFCs.

Also, if 395 fps is your goal you can do it with a M110 if your air seal is perfect (even with 3 teeth SS)

No, where the nozzle stops is irrelevant. If it stops halfway back, that means the sector gear has only pulled the tappet plate halfway back and will pull it all the way back to load a BB before shooting.

Seeing the nozzle go all the way back doesn't mean the nozzle is not too long. Dropping a BB into the magwell with the nozzle all the way back will tell you if it's too long. If it isn't too long then gravity alone will be able to pull the BB into the chamber. If its too long then you will have to push it in with a screwdriver, and that is why your mag is having trouble.

Also, when you say it isn't feeding, do you mean it never shoots at all or does it sometimes work fine in semi?

If it is not feeding in semi automatic then your rate of fire is not your issue.

@pestobanana: I agree, I have 2 other rifles, and the SHS nozzles work fine in them as well. One is a G&P and the other a VFC. I will do the manual bb by hand when I have some time and see if it goes in when its all the way back. Assuming that it does go in at that point, what would we be looking at in regards to the issue? It does not feed any bb's at all (full auto or semi) whether it be right side up, upside down or what have you. What does that tell me?

It tells us that most likely the BB is not entering the chamber or your barrel is jammed. I'd rule out the latter because your piston would have stripped from jam induced pre-engagement.

If it does actually go into the chamber freely, I will be extremely baffled. Next steps would be to try shooting the BB after its in the chamber.

@pestobanana: So I had a few minutes last night and tried feeding one bb into the chamber to see if it took. It did not, and every time i shot it moved a little, but never actually went into the chamber. I am starting to think that this has to do with either the tappet plate spring or the nozzle is not in the tappet plate probably. I will check both of those when I get some time, but what other ideas may you have if both the mentioned are ok? Thanks again for your help.

Flarebrass

If the nozzle wasn't in the tappet plate the nozzle wouldn't retract. It has nothing to do with the spring because the spring pulls it forward, not backward. Try opening the gearbox and making sure the tappet plate isn't broken and using the original nozzle, it is probably too long.

are you using the lonex tappet plate?

@pestobanana: Yes for sure. Ill double check the nozzle and maybe even throw in the original VFC tappet plate and nozzle and see what kind of difference it makes. Thanks again for the help!

@Lurking: Yes it is the lonex tappet plate that came with the gearbox when I purchased it. I might throw in the VFC one to see if that works any better as well as the original nozzle as suggested by pestobanana above. What are you thinking?

Flarebrass

So I removed the stock VFC hop up from the rifle and added a ProWin hop up and the nozzle is still protruding a bit. I shaved it down a bit, but its still in the hop up unit by about 3mm or so. I will take it apart again and see if I was possibly shipped the wrong nozzle or what have you, even try the stock one again. But I have at least eliminated the hop up unit being the issue. Will post again when I have more info. Thanks.

So just an update for anyone who may come across these forums looking for an answer. I have messed around with the gearbox a bit more and also finally found some information hidden on the 7th page of some D-list forum somewhere and the consensus was this: The Lonex tappet plate DOES NOT work with the Siegetek SSG's. It is roughly 2-3mm LONGER than your average tappet plate and is meant to work with lonex gears with a sector clip. From my research, most other tappet plates will work (in my case, it was suggested to get a SHS nylon tappet plate and modify it a bit to fit into the reinforced lonex gearbox). I hope this helps anyone who may have the same issue in the future and knows how to use the search function!

Cheers,

Flarebrass

That depends on what generation of Lonex gearbox that you got - the newest Lonex tappet plates that ship with their complete boxes are back to standard spec.

Hey Stealth!, Very true it seems. I guess it was the longer version (I bought the shell from you as well haha). Do you have any lonex tappet plates of the new sort kicking around that you could send me to try out and see if it works? I bought the SHS from your site, but if I can get one that fits like a glove in there already without modding, I would prefer that. Thanks.

Good question - we'll look into stocking the Lonex tappet plates in the future.
For now, you will just have to modify the SHS ones that are coming to you. Takes about a minute on the dremel.

Hey guys,

It seems I have solved the tappet plate issue and modified a SHS nylon tappet plate that is shorter than the stop lonex one and fits pretty good. I am now however, experiencing another problem.

I was working on finishing my gearbox again last night (broken record much?), and I seem to have some across a new problem... YAY!! I think I will name this gearbox; Christine... Anyways, When I put it all together, and get the motor in to test it, as soon as I pull the trigger, it pulls the piston all the way back, but won't release it OR just whines a bit and wont move the piston at all. I checked the gears to see if they were shimmed properly, and they are and spinn 2-3 times before stopping on their own in the gearbox when shimming (however, could it be the bevel gear is slightly too tight, stopping the motor from turning the gears as a whole as it takes a lot of torque to pull 10.44:1 gears??? Being too tight might stop it?). I did not mess with the motor height as the gears I put into it were exactly the same, just a different ratio (Siegetek 14.09:1 to siegetek 10.44:1, SSG both short-stroked the 3 teeth). The motor "hums" when I pull the trigger, making it seem like all the electrical is working and that the motor wants to go, but it wont release the piston or even pull it at times (numerous dis-assemblies and re-assemblies). I modified the SHS tappet plate to match the lonex one and it moves backwards and forwards properly. What do you think this could be. Frankly, I am getting extremely frustrated with this thing as it has been months of work to get it even to this point, and every time I fix an issue, a brand new one, out of nowhere, arises. Do you guys have any ideas as to where to trouble shoot this issue (as most of my research hasn't lead to much as the seemingly common answer was "check your battery", which is no help to me as my batteries are fine). Please let me know what you think.

Cheers,

Flarebrass

What battery?

was about to ask the same thing and went back to check the thread to see if you listed it.

Sure, I have 3 Turnigy Nano-tech 11.1v 1100mah (1 15c 2 25c) batteries and one no name battery that is 11.1v 1100mah 15c.

Take your spring out of the gearbox, tighten everything back up again, turn your mechbox with the nozzle pointing up. If the piston will not easily slide all the way down (flip the box the other way) and back again, your piston rails are too fat or misaligned. Had this happen recently which is why I responded.

I'm thinking not enough amps. Was just discussing a build with stealth the steve half, my lonex a1 build with shs 13:1s in my g36 110spring pulls 22.5A and an m4 build with sci 13:1s, lonex a1 and 120 spring is pulling 26A.

Your best battery is pushing 27.5A at full charge in the best case scenario. A 10:1 setup will probably draw more than 30A.

create a parallel battery adapter and tie your 2 25C packs together so you have 2200mah at 25C then you'll be pushing 55A but that's still not very high.

Your batteries probably won't be able to handle the power spikes needed to drive that gun, even in parallel.

Hello again guys,

Thanks for all the help. I love these forums for this kind of stuff!

@Varjeal & Stealth: I did try this and it is actually from steath, the 2nd piston mentioned in that video (2nd gen 15 tooth piston SHS) and moves correctly in the gearbox.

@lurking: Man, I didn't even think about the amperage as a cause. I knew I wanted to run buffertube batteries but totally didn't even think about that portion of things. Would swapping back to the 14:09's be the best route to take then (I don't plan on changing the batteries to a PEQ type). That does make sense as I had the 14:09's in there and it did cycle (before I swapped the tappet plate and the such). What you are saying is I need a honking battery to run the 10:44's.

I will swap the other set of gears back in tonight and see if that makes the difference.

Would this issue be the only cause or would there be another underlining issue?

Thanks for your responses guys!

Flarebrass

@OP: IMHO you need to ask yourself what you are putting all these "high speed' components in your mechbox for in the first place. Are you familiar with the concept of "stacking tolerances"?

Basically (for anyone not in the know), if you have a whole bunch of parts that are each off by a small amount, but they are designed to fit and work together, small variances in size and spec can add up to large enough ones to cause problems.

This especially rears it's ugly head when you start throwing random parts from many different manufacturers together. These days, when you buy a quality AEG from a good manufacturer, there is absolutely no need to rip out the mechbox and start from scratch. The shell, gears, cylinder assembly, wiring harness, motor etc should all be of high quality and will last you for years (99% of the time).

Case in point; I have a Classic Army SLR-105 (steel) which I purchased back in 2006. You want to know what upgrades it's had?

1. Replace classic army piston w/ stock TM piston (CA pistons were horrible back then... note I didn't spend $40 on a souped up piston, just a stock TM one. Stock TM pistons are some of the most reliable in the industry, hard to find though sometimes.

2. Changed the spring, gun was shooting 350fps out of the box, upgraded to a higher spring to get it shooting 390fps.

3. Reshimmed.

That's it. Period. In eight years of gaming, I've only cracked the gear box four times, to conduct a (holy cow it's been two seasons, better relube the ole mechbox!) cleaning.

This AEG has never had a stoppage.

So I think the question you need to ask is not IF you can throw all these parts in your gun, but SHOULD you?

@Kokanee: I understand your method! Stock guns don't break as easily and for the most part run for quite a while before you have to open them up. This I understand. However, my goal and purpose of this build was to create a monster that has great distance potential as well as efficiency within the gearbox for great trigger response on semi (I could care less about full auto as most of the games I attend are semi only for riflemen). Keeping those 2 things in mind, that is what this build is based on, and regardless of how well a stock gearbox can run, a well tuned upgraded one (after troubleshooting all the kinks albeit), will run better in the end for my requirements above. I hope this sheds some light on my insanity ;).

Cheers,

Flarebrass

if you have the materials or a bigger battery I would try that first. Better if you have a watt meter to measure what it's actually drawing. Semi auto spikes a lot more.

The 14:1s might even be close to the max your battery can produce.. remember that the battery's performance drops off as it gets used.. at 1100 mah you're not going to get much game out of it.... this is why most ASM guys stack wicked amounts of C/mah onto these types of builds. It's safer for the packs, otherwise you risk overdrawing packs and potentially damaging/causing a fire.

@Lurking: Assuming that the 14:09's are right on the limit and are the causing factor to this issue, your idea of stacking batteries does make sense, but having limited space on an M4 platform (preferring buffertube batteries), from your experience, how would you propose stacking batteries. What suggestions do you have, or am I just going to have to run around with all 4 on me at once (not the end of the world)? Thanks again.

Cheers,

Flarebrass

external wire, single brick pack.. 25C+ as much mah as you want to stuff into wherever you put it, (stock pouch) IF you want to do a battery peq then your options are a bit more limited as the packs get taller with more mah, at which point whatever you can double up in it that will still fit.

Most builds with that kind ratio and motor configuration I've read about all use external batteries.. it's just the easiest way to wire it and not worry about cramming the pack somewhere.

The gun I'm building will be running an external 7.4 with a 4600mah hardcase pack.. it'll pretty much be the size of a m4 mag.

Your build is not a stock replacement build or a slight upgrade... this is a super high performance gun. Properly powered with 11.1v lipo and 10:1s you're looking at RoFs over 45 rps, possibly into the mid 50s.

I personally would not field such a gun without a computerized fet to bring down auto rate of fire, even if you only use semi. DSGs in that RoF range only shoot 300-350fps unless you like a lot of maintenance or replacing gearbox shells.. you're shooting closer to 400 with a full stroke in the high 40rps.

Ok so I put the 14:09's back in, close everything up, fit is great and everything is in place. Pull the trigger and nothing. Wont connect the circuit or anything, motor wont turn, battery isn't even getting warm. I changed absolutely nothing except the gears. ***STRESS***. Any ideas as I am now completely fresh out of ideas.

Flarebrass

How are you testing shimming?
Are you testing with all the gearbox screws in?
Have you tried adjusting motor height?
Did you check your contacts and connectors?

Upload a video.

Batteries should not be the issue. I'm pulliing a M100 level spring on 13:1 gears using a buffer tube lipo no problem.

@Pestobanana:

I test each gear to get about a mm play using multiple shim guides online and then test them all together. They turn beautifully multiple times before stopping when they are together (finger flick).

The shim test was done with the bottom 4 screws in each time.

Motor height was adjusted multiple times then reverse gearbox shell adjusted to be the optimal height.

I will double check all my contact and connectors to be sure, but all seems well. Will confirm.

All I have is my phone on me at this time, so when I have a chance Ill try and make a video.

Thanks!

Flarebrass

1mm of play is way too much, that's as bad as stock G&P shimming, but that shouldn't cause it to be seizing up.

When you started getting gearbox lockups what parts did you change

check the motor connectors.. they get loose over the course of repeated connect/disconnect cycles when you take things apart. You may need to pinch them tighter with pliers.

@pestobanana: meant .1mm heh sorry for the mis-info. I just checked the connections as you mentioned and it did it again. When I close the box with everything in place, and attach the motor to the connectors without the pistol grip on, the motor spins as it should. However, once I connect the motor to the gearbox, it fired about 5 shots (give or take when the trigger was pulled on full auto) then stopped when i let go of the trigger. I pulled the trigger again and nothing. Not getting the lockup any more which is a bonus i guess heh. I pushed the two contacts at the trigger assembly together further, but it doesnt seem to have made a difference. It seems that it may be a trigger assembly/sled and/or cutoff lever issue. Any dealings with this?

@lurking: double checked those motor connects and all is well. pinched them a bit just to be sure and they connect with no issue (or sign of being loose for that matter). Can you read my bit above and let me know what you think.

Thanks for the help gents. I will be heading to bed and pick this mess up again tomorrow haha.

Cheers,

Flarebrass

Test the gun without the cylinder assembly.
See if the gears run smoothly, and then see how semi auto cycles without a piston. If the cutoff lever or trigger assembly is having issues, you will be able to clearly see it like this. You can also feel the trigger sled reset when you release the trigger in semi. If you don't feel that then maybe that is the issue.

Did you recently change the spring or anything? This can happen if the spring has too many coils. This happened to me once last year in my M14, it was because the back of the piston was too big and was hitting the receiver, but that shouldn't happen in a V2 box. Check your piston for signs of jamming anyway.

@Pestobanana: I will give that a shot either later tonight or tomorrow without the piston/cylinder installed to see what happens with the sled. It HAS to be a connection issue somewhere which is why I guessed the trigger sled or cutoff lever. Something is not resetting properly and I just need to find out what it is. Never had this many issues with a gearbox before and its just frustrating to have problems after problems when doing this stuff (i took my other gearbox apart probably 3 times before it all worked right; this one I am probably over 100...).

The spring has been the same one that I put in originally (Lonex M130 w/ short stroke to achieve ~400 fps). It ran before on the current setup, but the tappet plate was too long so I ordered a new one and did some minor changes but now reverted them back other than modding and installing the new SHS tappet plate to match the lonex one (it moves correctly in the box).

I am just a little baffled as I said I had it running but then discovered (see first half of posts on this thread) that the tappet plate was the issue, then when I modded the new one and put it back together, its now having this problem with connectivity somewhere.

Thanks again and let me know if you think of anything else.

Flarebrass

On a side note; think it would have something to do with the trigger sled post? Ill check that as well when I am back inside.

It shouldn't, if the post was broken the gun would never work properly.
So let me get this straight.

Gun worked with 14:1 gears
Gun would NEVER fully cycle and piston would ALWAYS get stuck in the back of the gearbox with 10:1 gears
Problem persists with 14:1 gears

Was it that it would NEVER fully cycle or would it cycle a few times before locking up? Does it ALWAYS lock up with the piston in the full rear position?

Only jams I have ever had where the gun just became unresponsive like that is the trigger parts interacting in a weird way, the shuttle getting caught mid return cycle or not sitting back down onto the trigger so it floats between everything. That usually only happened after a few normal cycles and then it would jam and never reset so I'd have to take it all apart.

@Pesto: Had it working 100% with the 14:09's but the nozzle wouldn't go far enough back due to the longer tappet plate. I ordered the new tappet plate and while I was at it said "hey, lets try the 10:44's too". Those were the only 2 parts that I replaced at the time. The first time the piston got stuck in the full rear position, the second attempt the gears wouldn't even pull the piston, you just heard the "hum" of the motor trying to turn. I then replaced the 14:09's back in and its now having the sled (or whatever the connectivity issue is) problem (note: the last re-assembly i did last night was the one where it fired once on full auto before i let the trigger go, then would not fire again on either setting; this enforces my statement above that the 14:09's DO work in it and still work). Hope this helps making it a bit clearer.

@Lurking: It could very well be that, but at which point is the question haha. We shall see I guess.

Flarebrass

Does the the trigger only stop working when you fire in semi auto? Does it keep working in full auto?

Show us a video of what is happening with just the mechbox and grip, no lower receiver.

@Pestobanana: Negative. It stops working on both. I will try to take a video when I am working on it next.

Thanks,

Flarebrass

So when it jams now do you hear the motor moving at all?
Test the trigger with the motor outside of the gearbox.

^ test this when it jams... I bet you it's not the gears causing the jam in this case.

@Pestobanana: Just to clearify, when I put the 14:09's back in, the jamming ceases to exist and the issue is that when the trigger is pulled, it does not fire. It does seem though, that it is a lighter pull which would indicate that the sled might be out of the way some how or stuck somewhere?

I tested the motor outside of the grip last night, and it worked, spun like crazy. But as soon as I connected it into the grip as if installed (no receiver obviously), It pulled once on full auto then stopped and wouldn't fire again.

Flarebrass

With the motor outside of the gun, battery connected,
-Pull the trigger, hold it down and let the motor spin
-Spin the sector gear to engage the cutoff lever
-Release the trigger, see if the trigger carriage slides back down
-Repeat, if this works your trigger mechanism is fine

Have you tested this without your cylinder assembly yet?

@Pestobanana: That is a great idea. I will try that when I work on it next! I am unfortunately still at work and haven't had time to get back at it yet, and I have a team meeting tonight so I probably wont get much time on it, but I will be back at it tomorrow night for sure. Thanks again for all your help and will let you know my results.

Cheers,

Flarebrass

Update: Ok so I made a video of what was happening (and I was working on it last night without the cylinder or piston in), but it is very blurry and frankly, I am having a hell of a time trying to get it off of my phone.

However with that said, from what I saw, I will try to explain; The trigger is pushing the sled as per normal, but there is a very loud and distinct click noise from it every time is passes roughly the 60-70% mark on the pull. Note that I also tried 3 different sleds out (1 modify, 1 VFC and 1 SHS) to see if they made a difference, which they did not. The gears are spinning freely with no issues, but there are 3 issues that seem to arise.

1) the trigger locks up (common problem from what I have read for V2 gearboxes, so I am not sure this is a main problem). I am assuming the gears are just stopping in a bad position on the cutoff lever (which is when you swap to full auto, clear it then swap back).

2) The trigger sled sometimes locks forward (but it still wont fire or connect the circuit). For example, the semi works (albeit the clicking is a very rough pull on the trigger), but after quickening the pace between shots, the sled will sit forward and the cutoff lever will not engage it and the sled spring is not pulling it back. It must be getting caught on something which seems very odd. I double checked the cutoff lever to ensure that it wasn't damaged at all, but it seems perfectly fine.

3) even on semi (I used a small screw driver to hold the selector plate in place so it did not move to safe or full auto), it sometimes fires full auto and the cutoff lever wont engage. The sled either is returned on the trigger release (and the connection is broken), or it gets stuck and I had to use a screw driver to release the sled.

Any ideas? It really sounds like a sled/cutoff lever issue, but as I have never come across an issue like this before as it does not seem like a normal one, my ideas to fix are slowly running out.

Thanks

Flarebrass

Take a photo of how it is getting stuck.

If it is a friction issue get it stuck a few more times, you will see marks where it is getting caught and you can sand there. I've had this issue with a shs trigger assembly in one of my vfcs before.

**UPDATE**

So, after feeling like a newb, I realized that sometimes going back to the basics and looking for the simple solution is the way to go, instead of looking for some big bad answer to a problem that doesn't even exist. The issue has been fixed and is now shooting and sounding like a dream (left the 14:09's in there as I didn't wanna take the chance of messing with the 10:44's and having to troubleshoot it again!)! For anyone looking up a troubleshooting thread; There were two issues bumping into one to make it seem like there was something worse going on with the GB. First; the selector plate -> cutoff lever spring was not strong enough to push the cutoff lever back down far enough, which in turn, was not engaging the trigger sled, creating full auto. Solution: elongate the spring! Second; the negative contact wire for the motor was loose, and after multiple shots would slowly fall off the motor post and break connectivity and making it unable to fire. Solution: Use pliers to to make the negative connector wire clip smaller!

Thanks everyone for all your help, it was GREATLY appreciated! I hope I can return the favour to someone else in need like myself in the future! If I need anything else, Ill post up here!

Cheers,

Flarebass