Dboys Kac Pdw Gearbox Compatibility

[dagga333]

Just picked up a Dboys KAC pdw and want to do a nice custom gearbox, anyone know what if any quick spring change gearboxes will fit the receiver? Was thinking either VFC Avalon or the VFC retro arms but both are a touch in the pricey side. 

[mightyjebus]

The VFC and Dboys KAC PDW has a proprietary gearboxes due to the way the ambi selector works. You won't squeeze a different gearbox inside without lots of work (not sure its actually possible). That leaves you the option to just tinker with the currently installed gearbox.

[dagga333]

Thanks for the info. 

[Sitting Duck]

18 hours ago, mightyjebus said:

The VFC and Dboys KAC PDW has a proprietary gearboxes due to the way the ambi selector works. You won't squeeze a different gearbox inside without lots of work (not sure its actually possible). That leaves you the option to just tinker with the currently installed gearbox.

 

Is it ???

 

I thought it was a std v2 just with ambi stuff passing through and it has an odd metal selector plate

with a raised bit to allow the cam/ambi gearing to slip under it

ahh fuck it pic says 1,000 words...

 

 

now this is slightly different to other D-Boys M4 v2 boxes

on the PDW it has an ARL release hole & it is the no lug on top

(to stop you ripping the M4 charging handle off - no lug box often found on say MP5's)

 

where as the other type has a white plastic selector plate

(yeah you might not get the ambi cams/gears under a normal selector plate)

and no ARL release but has the lug on top for some M4 models

(anybody who has ripped a charging handle off will know what i mean)

 

The other issue if you can actually get to the spring guide to change the spring in situ

which I "think" you might be able to do, if you can remove the folding stock

which I "think" can be removed by two screws fixing to the receiver

then the top half of the receiver has no back and you should see the exposed back of box/spring guide area

 

That check is critical imho as it would be pointless to fit a QC box and not be able to change spring in situ

I think it should be exposed from what I have see, once stock is removed

BUT I don't have one

 

Otherwise - if you can't access the QC spring guide, then you gotta remove the grip, qwirky bespoke medium motor

(or change grip to a regular M4 grip to use a more common long type motor - yeah you got an odd medium motor)

anyway - you gotta gut the fucking thing to remove the box, to then gain access to the QC spring

(so not quite the QC spring like first Specna Arms & Krytac's = not such a great "quick change" gearbox spring)

 

It probably "could" be do-able I think - if the stock removal reveals easy access to a QC spring guide

then a QC v2, without lug on top, could be used but need to re-use the ambi stuff

AND the D-Boys qwirky metal selector plate, but fairly sure another v2 will have the indents for ambi bits to fit

 

REALISTICALLY THOUGH....

 

IT IS A BIT OF FUCKING ABOUT & unless you was dead set on this project

AND VERY COMPETENT - I would lean towards forgetting about it

and maybe buy another cheapy cqb gun like the M904B

which is prebuilt gun ready to go with fancy mosfet & QC out of the box

 

which some super duper nice guy has reviewed and gaining popularity...

 

 

Dunno who that guy is, but he seems very pleased with it

and tbh - I would likely lean towards grabbing one than fuck about on a pdw

 

if they both crap out, then the m904g box could be used in the pdw

(but would need to resolder it for front wired as it is rear wired)

but is an option should they both crap out, break/crack or something

(though again, you would need a good level of skill to do this)

 

also with ANY tech work, there is a risk of compatibility and stuff like that

like nozzles, minor filing to get other stuff to fit (and work, work properly)

so unless you have a bit to a mil/moderate amount of experience, I'd avoid too much work

 

TL-DR, yeah it COULD be done PERHAPS, but like @mightyjebus said - maybe avoid it

(even if the stock removed allowed access to a QC spring & if not then forget it completely) 

[dagga333]

Thanks for the info, I only asked about the QC gearbox so that it makes it easier to work on. 

 

The research I have done seems to indicate that I could use a v2 gearbox as long as it has the hole to stick the ambi selector bits through to the other side of the gearbox but I would need the dboys selector plate. The plan is to rear wire it into a buffer tube and stock as I don't just want another normal M4.   Hopefully I will be able to keep the folding usability of the stock while having the ability to carry a large batter in the stock.