The take down and first time "trouble shooting"

[Jaylordofwaargh]

So, this thread will chronicle all the dumb ass mistakes I make whilst trying to repair my "currently not working" bb slinger. 

Still in take down and take apart phase and would you believe it, I'm stuck! 

I have removed all bolts, nuts and other connections I can find but the gear box is just not moving from its shell! Any hints tips and ideas appreciated, I figure it must be related to the fire selector as it seems to be the only moving part on the system at the moment. 

So, moving on, I found the next screw!

Here of all places

[Leo Greer]

Take that grip off, if ya haven't already.

 

Look through the mag well and see if the bolt catch interacts with the gearbox shell.

 

Turn the selector to safe and tilt the gearbox forward while wiggling gently.

 

Good luck!

[Adolf Hamster]

As above, grip and maybe bolt release need to go.

 

Tip for reassembly (and dissassembly) is it's better to install the pins first then grip then stock bolt, as the latter will pull the gearbox tight against the pins making it difficult or even impossible to push them in (certainly without damaging it). The reverse is true for dissassembly take the bolts out first then the pins should be relatively loose to pull.

 

Like leo i tend to pull gearboxes out set to safe, but tbh whatever setting lets the gearbox come free/slide in is the one you want to use.

[Dan Robinson]

Yep, grip needs to come off. 

 

Also, I found on my boy's m16, you need a fair bit of force to get the rear of the gearbox past the back of the receiver.   On my Specna,  it slid out nicely. 

 

Beware of the spring tension too.

[Jaylordofwaargh]

Thanks for that one gents, grip is now off. The box it's self slid out as if lubed.

 

Cool story time: my gear box is stamped with "KINGS ARMS" My reading time tonight will be dedicated to threads and videos with titles such as - 

"So your aeg is broken, how to check each part"

"Is my gearbox worth the scrap price"

"Where does this spring go" (yes I have been paying attention to where they all come from)

And why does this rattle?

 

And finally kings arms, are they any good?

 

 

[Colin Allen]

King arms are ok; nothing special, just ok.  Others may have different views.

What was the gun not doing that caused you to take it apart?

[Jaylordofwaargh]

Not a lot was happening when trigger was pulled, not convinced the motor is cycling, there is no noise from motor. So either the motor is dead or the contacts have gone on the trigger.

But it is a good chance to get my hands inside and learning this so I can build confidence on the next one. I mean the worst that can happen is I take a box of bits to Wolf Armouries and smile sweetly.

 

For ref re kings arms, this gun was bought as a CAA asg M4 for £75.... So I didn't expect a half decent gearbox to be holding it together. I can also find the budget for replacement parts easily enough.

[Colin Allen]

37 minutes ago, Jaylordofwaargh said:

Not a lot was happening when trigger was pulled, not convinced the motor is cycling, there is no noise from motor. So either the motor is dead or the contacts have gone on the trigger.

But it is a good chance to get my hands inside and learning this so I can build confidence on the next one. I mean the worst that can happen is I take a box of bits to Wolf Armouries and smile sweetly.

 

For ref re kings arms, this gun was bought as a CAA asg M4 for £75.... So I didn't expect a half decent gearbox to be holding it together. I can also find the budget for replacement parts easily enough.

I like your approach!

[Leo Greer]

In my experience King Arms is pretty solid, but not all of their guns have the same high quality gearbox internals. Some come with modernized insides--inline MOSFETs, steel rack pistons, neodymium magnet motors... but it's not all of them.

[Dan Robinson]

It might be worth investing in those anti reversal latch holder doo dads - that fecking thing drove me to distraction.

 

@ak2m4 has them on his shop.

[Jaylordofwaargh]

Right, so the motor is completely blank - no mention anywhere of torque, or power or speed or branding. The joining gear, has wear but not mangled...might be usable.

 

Next up then is the gear box disassembly to have a look at the trigger contacts and the gears them selves. Before I do this, is the reversal latch a likely cause or is it more likely the trigger contacts (for now) as the mother doesn't even spin?

It may be tonight of it may be later in the week this happens 

[Colin Allen]

30 minutes ago, Jaylordofwaargh said:

Right, so the motor is completely blank - no mention anywhere of torque, or power or speed or branding. The joining gear, has wear but not mangled...might be usable.

 

Next up then is the gear box disassembly to have a look at the trigger contacts and the gears them selves. Before I do this, is the reversal latch a likely cause or is it more likely the trigger contacts (for now) as the mother doesn't even spin?

It may be tonight of it may be later in the week this happens 

It shouldn't be the ARL.

Have you tried connecting up the motor out of the gearbox to see if it spins?  If you do this, make sure to hold it down firmly when you pull the trigger!  If it doesn't, try the same thing with a different motor; at least that will tell you whether it is the motor or something else.

Just another point: are the bent over ends of the cables where they connect onto the motor intact?  Sometimes, they can break where they bend, which can be hard to spot because the heat shrink holds them in shape.

Edited May 22, 2023 by Colin Allen

[Adolf Hamster]

38 minutes ago, Jaylordofwaargh said:

Right, so the motor is completely blank - no mention anywhere of torque, or power or speed or branding. The joining gear, has wear but not mangled...might be usable.

 

A very vague and not always accurate "test" for motors is to turn it by hand and feel how notchy it is to turn, which gives an indication on the strength of the magnets.

 

Stronger magnets typically associates with more better (a lot of aftermarket motors like shs, asg, warhead etc will feel stronger) but that doesnt necessarily mean that a motor with weak feel can't be decent in-practice.

 

That won't tell you anything about its notional speed rating, although presumably you already have an idea what sort of speed its putting out with your usual battery.

 

44 minutes ago, Jaylordofwaargh said:

Next up then is the gear box disassembly to have a look at the trigger contacts and the gears them selves. Before I do this, is the reversal latch a likely cause or is it more likely the trigger contacts (for now) as the mother doesn't even spin?

It may be tonight of it may be later in the week this happens 

 

If the motor polarity is reversed and the motor drives backwards the anti reversal latch will stop it, although symptomatically if that's whats happening you can usually hear/feel the motor "clicking" as it tries to start before getting blocked (unless the motor engagement is way too tight)

 

The clicking will also occurr if for example the piston is jammed mid-cycle and locking the gearbox.

 

If theres no reaction from pulling the trigger then it's going to be a break in connection, which could be anywhere in the wiring loom, although motor contacts being loose/broken and trigger contacts carboning up are both very common areas to go.

 

Contacts can carbon up, hitting it with sandpaper will solve that, although make sure that they arent/dont get bent to the point they won't connect when the trolley is forward.

 

You can test the electrics with the motor connected outside the gun, but make sure it's well secured to something because inertia is a thing.

[Leo Greer]

Basically just get inside and see what's broken, burnt, or messed up. 🙂

 

I was speaking with Jakub from Perun and he told me that the connectors commonly used for airsoft motors were never intended to be bent, hence why they break so often. Too bad bullet plug mods are a pain...

[Jaylordofwaargh]

2 hours ago, Adolf Hamster said:

You can test the electrics with the motor connected outside the gun, but make sure it's well secured to something because inertia is a thing.

So, maybe I should have actually checked this...

 

*insert Acme "clang"*

Ok so, first off thank you all for the hints and tips so far!

 

Next, my Google history is going to be "where does this spring go"

"If it came out, does it need to go back in?"

"How different can trigger units be?"

 

So inside the box I have 

38 minutes ago, Leo Greer said:

Basically just get inside and see what's broken, burnt, or messed up. 🙂

Nothing that fits this description....

 

What I do have is a couple of bits I need to find homes for.

1. A good solid air seal

2. Greased gears that turn (each in turn, as I would expect gears to turn)

3. Clear, consistent colour on contacts...

4. A growing certainty that I just needed a new motor

5. An excellent Opportunity to learn how to put a gear box back together!

 

Going to find some trigger diagrams, back soon....

 

[Leo Greer]

Have you checked your motor brushes? It's super simple to do basic disassembly on the motor end bell to determine if it is indeed the issue.

[Jaylordofwaargh]

On 23/05/2023 at 21:48, Leo Greer said:

Have you checked your motor brushes? It's super simple to do basic disassembly on the motor end bell to determine if it is indeed the issue.

Going to give this a go and get some items into a basket with ak2m4's shop (not tagged as website is not taking orders for a few more days)

 

[Jaylordofwaargh]

Ok. So. 

Looking for suitable offerings for the Machine Spirit of my 1st gun.

 

It came apart, each piece looks as it should (minor) wear as expected. I (finally) test the motor separately...and it spins....

I put it all together again, not as much cussing as I thought there would be

 

And it cycles....I can hear each part...work.

Hardest part of reassembly was getting the hop unit to align and get the upper back on, well, and getting the wires into the upper/handguard 

Only thing to check is feeding and once I get a crono power out put.

 

So offerings, what's suitable 

[Adolf Hamster]

I find lamb tends to be recieved more favourably than goat, although ymmv depending on the particular spirit you're trying to appease.

[Rogerborg]

1 hour ago, Jaylordofwaargh said:

So offerings, what's suitable 

 

Custard and Haribo are traditional.

 

The Omnissiah welcomes Tangfastics.

[Jaylordofwaargh]

I'll hold up on the offerings, the fecker doesn't feed properly! 

So, is it a case of fiddling with the hop unit to get it in the right place or is there more to it than that? 

I'm off to find threads about this very subject now.....

[Dan Robinson]

Did you put the Tappet plate spring back properly? 

 

I have a thread about my adventures with a v2 gearbox and that was the cause of my investigations. 

Edited May 28, 2023 by Dan Robinson

[Lozart]

@Jaylordofwaargh Slightly off topic, but maybe clean your lens while you're at it? 

[Jaylordofwaargh]

8 hours ago, Lozart said:

@Jaylordofwaargh Slightly off topic, but maybe clean your lens while you're at it? 

I get enough of that from work! It's a broken camera and it's on the replace once pew is working, maybe....

 

 

"Did you put the Tappet plate spring back properly?" Yes...? ...but I am now also going to track down your V2 adventure thread. 

The trickiest part of getting my box back together was not have the tappet plate slip up on to the gear so it could actually close

 

[Dan Robinson]

1 hour ago, Jaylordofwaargh said:

get enough of that from work! It's a broken camera and it's on the replace once pew is working, maybe....

 

 

The guys that work for me rely on me for tech support, and pictures are essential as we are nearly always miles apart on different projects..... Not one of the feckers, even the one with A FUCKING HONOURS DEGREE IN PHOTOGRAPHY can send me a picture both in focus and with the relevant details in shot.  It's becoming a running joke now. 

 

Rant over 😆

1 hour ago, Jaylordofwaargh said:

 

The trickiest part of getting my box back together was not have the tappet plate slip up on to the gear so it could actually close

 

 

Dude I needed several stiff drinks after the first attempt.... 

 

Here's the thread: https://airsoft-forums.uk/topic/55406-specna-sa-c12-core-not-feeding-now-gearbox-rebuild/#comment-476391