Cybergun F2000 (Cyma) - Internal upgrades / tinkering

[RostokMcSpoons]

Quick question, because the next step is trying to cut a slot in the hand guard, to fix a RIS rail into it....

 

How do you take the front hand guard off?  

It looks like I just need to take the main locking pin out and then slide the barrel assembly off.  And then push down on the handguard from the inside.  

But I don't want to push too hard in case I'm going to snap some clips (and I need as much stability there as possible)

 

A quick pointer in the right direction would be much appreciated 😊

[Adolf Hamster]

Unless cyma have decided to be weird about it, and i dont see why they would then that is how its supposed to come off (copies the original)

[RostokMcSpoons]

27 minutes ago, Adolf Hamster said:

Unless cyma have decided to be weird about it, and i dont see why they would then that is how its supposed to come off (copies the original)

 

Thanks, with that you gave me the confidence to use a screwdriver to lever it gently away from the rest of the body.  The front lugs were sticky, but there aren't any latches or anything, just a slight excess of friction.

 

Here's what I'm trying to achieve...

 

... but I'm really not attempting to get a copy of that, so no need for the tri-rail look, it's just getting a stubby grip fitted solidly to the front.
In fact that's quite a low fitting, I'd rather have it nearer to the barrel axis, so it could go further forward to help with that.  (Not sure if the drawing of the grip, which I borrowed from an MP5K plan, is properly to scale)

 

 

There's a cheap stubby on Amazon that I'm willing to hack to bits, if necessary

https://www.amazon.co.uk/Element-Style-Stubby-Airsoft-Paintball/dp/B01N9LSV12/ref=sr_1_28

 

Here's what I'm working with inside the foregrip...

 

I can grab a cheap 12cm length of RIS rail from my local retailer (Action Hobbies), and then it becomes a matter of dremelling a slot to hold the RIS with the grip in place, stabilising it the inside (maybe just need some woodwork screwed in place to the guard + body?)

 

Is this all a silly thing to attempt, or have I "got a shot at the title"?

Edited January 6, 2022 by RostokMcSpoons

[RostokMcSpoons]

Well I said I didn't need the Tri rail look, but I just found this at Ant-Supplies...

 

https://www.ant-supplies.uk/rifle-bipod-fittings/tri-rail-spigot-adapter.html

 

 

I'm not sure if the spigot makes it easier or harder to mount into the handguard, but it sure looks the same as the game...

 

Edit: found another of my pics from the game... yeah it's a little different, and I can see the game's version would be a simpler fit (just in terms of square sections where they intersect through the handguard versus the more complex outlines of the spigot version).   

 

It's not going to be super-easy, might go back to a simple piece of rail and some relief cuts for the grip itself.   Grip on order, won't turn up for another week though.

 

 

Edit:  For completeness, here's the finished work:  a simple piece of rail fixed into the handguard, with the stubby grip attached.

Edited January 31, 2022 by RostokMcSpoons
Pic of finished work

[RostokMcSpoons]

Quick question:   Is there any easy way to make the cross-bolt a bit stickier within the body?  Depending on how hard the upper receiver is pushed back (and I'm guessing the difference is less than a millimetre), that bolt can either be nicely held in place and requiring a decent push to remove it, or so loose it could almost fall out.
Is there anything I can do to the bolt or its slot, or do I need to shim the whole upper receiver a little forward?

[Adolf Hamster]

Try some o rings to space the hop unit against the gearbox, not too many though as you dont want to put too much load on the hop

[RostokMcSpoons]

On 21/01/2022 at 20:23, Adolf Hamster said:

Try some o rings to space the hop unit against the gearbox, not too many though as you dont want to put too much load on the hop

 

I actually need to shim the upper receiver away from the gearbox though - it's having it ~0.5mm forward that puts the resistance on the cross bolt. Is putting o-rings on the gearbox side of the hop unit going to stay in place?  And do that shimming job?

Also... the hop unit feels quite... crap.  I spin the wheel, it goes from no hop to 'a bit'.  And then back to zero again (with a little click).  It doesn't have any positivity or resistance to it.
Now obviously I'm only shooting at 15m, I have no idea if it's actually doing a decent job in spite of that cheap feel... but should I just go ahead with a new hop unit?
@Asomodai would you recommend the G&G metal unit?

 

Edited January 23, 2022 by RostokMcSpoons

[Adolf Hamster]

1 hour ago, RostokMcSpoons said:

 

I actually need to shim the upper receiver away from the gearbox though - it's having it ~0.5mm forward that puts the resistance on the cross bolt. Is putting o-rings on the gearbox side of the hop unit going to stay in place?  And do that shimming job?

Also... the hop unit feels quite... crap.  I spin the wheel, it goes from no hop to 'a bit'.  And then back to zero again (with a little click).  It doesn't have any positivity or resistance to it.
Now obviously I'm only shooting at 15m, I have no idea if it's actually doing a decent job in spite of that cheap feel... but should I just go ahead with a new hop unit?
@Asomodai would you recommend the G&G metal unit?

 

 

i mean o rings between the front of the hop (around the inner barrel) to push the hop unit back from the upper (and by the inverse push the upper forward from the hop unit)

 

it's the same tactic you'd use in most guns to ensure the hop is tight to the box so you get a more consistent seal.

[Asomodai]

2 hours ago, RostokMcSpoons said:

 

I actually need to shim the upper receiver away from the gearbox though - it's having it ~0.5mm forward that puts the resistance on the cross bolt. Is putting o-rings on the gearbox side of the hop unit going to stay in place?  And do that shimming job?

Also... the hop unit feels quite... crap.  I spin the wheel, it goes from no hop to 'a bit'.  And then back to zero again (with a little click).  It doesn't have any positivity or resistance to it.
Now obviously I'm only shooting at 15m, I have no idea if it's actually doing a decent job in spite of that cheap feel... but should I just go ahead with a new hop unit?
@Asomodai would you recommend the G&G metal unit?

 

Yeah the G&G M14 unit is perfectly fine. It might change your air seal characteristics but didn't seem to affect mine. 

Edited January 23, 2022 by Asomodai

[RostokMcSpoons]

I mentioned this in the 'how did your day go' thread, but I found the hop unit was doing approximately 'bugger all'.   So although my gun seems fine at 15m, it's not hopping and consequently can't reach out past 30m.  So time to get a new hop unit in there.

So I have a couple of options...

Either this lot:

 

I could swap the bucking and nub for the usual Omega / Macaron combo of course
 

or one of these

 

 

which is a bit pricey but looks like it's got everything and should therefore be well matched ...?

 

Which option is the better way to go?

 

[Asomodai]

Lonex hop unit. But get a Prometheus purple or Guarder clear bucking. 

 

There is no need to get a separate nub as most buckings come with a nub. The only bucking I know that doesn't come with a nub are the G&G ones. 

Edited January 31, 2022 by Asomodai

[RostokMcSpoons]

Hop unit and bucking arrived and fitted!

I actually just got the Lonex bucking as Airsoft World were cheap for the hop unit and p&p, and I could get the Guarder off eBay later (£6 inc p&p) if needed.  It's 50deg, and seems nice and flexible - especially compared to the stock item that feels like it designed to survive being nuked from orbit

A quick fire test fire in the garden was successful!  I could see a difference between hop off and half-on, and it was back to feeding well, whereas it wasn't after my field tech experiment at the weekend (I tried to reinforce the nub, and then tried to pack the bucking window with a bit of thin plastic film.  Both caused feeding problems)

 

Obviously there's a difference between my room temperature gun shooting at 15m, compared to out on site at 30+m, but I have a better feeling about it.

 

------

 

An issue arose though.  I plugged in my Titan 7.4v Li-Ion battery, and it wouldn't shoot.   It (the battery) seems to be dead in fact.  I can't get it to charge.  I suspect my second warranty claim won't be entertained as successfully as the first

Is the High Torque motor the cause?  Will I need to drive it with an 11.1v now?

 

Edited February 1, 2022 by RostokMcSpoons
Edited for clarity re: dead battery

[Adolf Hamster]

do you have a voltage checker see what the cell voltages are?

 

not sure which charger you're using, but i've seen it happen before where a charger has failed to charge one of the cells and killed the battery.

 

i use an etronix battery doctor (other brands are available) and it's a helpful reassurance even for just checking "did i remember to charge this?" before game day.

[RostokMcSpoons]

Yeah I have one of those little Amazon jobbies...

 

Not a peep (or indeed a beep) out of it... 

 

Tried charging with my new SkyRC T100 (which is how I charged it initially) and in desperation the old ASG Balance Charger too.  Nothing doing

The T100 reports "Connection Break"

Edited February 1, 2022 by RostokMcSpoons

[Adolf Hamster]

Hmm, may be lost connection to/between one of the cells.

 

Tbh, i'm not one for some of the "fixes" folk do for batteries, i just get new ones if there's an issue. Although admittedly i've also been mostly lucky with them.

[RostokMcSpoons]

52 minutes ago, Adolf Hamster said:

Hmm, may be lost connection to/between one of the cells.

 

Tbh, i'm not one for some of the "fixes" folk do for batteries, i just get new ones if there's an issue. Although admittedly i've also been mostly lucky with them.

 

I've fired off an email to Titan, to see if the customer service people have any suggestions. It'll be bloody annoying if I can't get it fixed / replaced, the 7.4v Li-Ion is ideal for my non-Mosfet F2000 if it's enough to drive that motor.

But if I do have to go the Mosfet route... I'm thinking the Perun AB++ and a bunch of Turnigy Nano-Cell 11.1v sticks should see me all right