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Junior's bbmg

Posted: Sun Feb 12, 2012 4:29 pm
by Brian the brain
Hi guys...

I'm building my son a bbmg,
Heavily influenced by the Ultimate Inline, one of my all time favourites..

With a twist though..I'm using a 1/4" QEV and my modified 3/8" large diameter pop-off wich I have turned down and rethreaded to fit the QEv directly.
This not only adds a cool daka-daka, it also allows me to tune it's powerlevel ( way down!)

The inside "out"port of the QEV has been cut down so an aluminium piston fits in.
Air can now exit the QEV in a single turn.

Anyway..it runs off unregged CO2 for the moment.
The shoulderstock detaches and will serve as the plug wich holds the plunger.This I still gotta make.

I plan to modify a brightly coloured waterpistol body and fit the thing inside.
Everything will be bondoed up so it'll look original.
The bits I need to fill in will also be painted in some bright colour so it it obviously a toy.
The heatshield will be shortened to fit..

Together with my 12 gram adapter this thing could be taken into the woods for some fun plinking.
Since this is for my 9 year old son power will not be of significance.
But it will be one hell of a toy for him!

When he gets older I can easily up the power.I got springs to pop it at over 300 psi...
The blowgun is rated to 200 bar ( not psi!!) and the vortexblock is a single piece with the front plug and is made out of roundbar I poured myself.
It will be able to withstand 300 psi shots if I were to go up that far..maybe if dad wants to borrow it sometime... :D

Oh..ans the QEV-pop-off-vortexblock thing works...I've already fired it..

Posted: Sun Feb 12, 2012 4:35 pm
by jakethebeast
HAHA, your son must be happy :wink:

Posted: Sun Feb 12, 2012 4:49 pm
by evanmcorleytv
Your son will be thrilled!! Great job!!

Posted: Sun Feb 12, 2012 4:49 pm
by Brian the brain
When he sees it he will be!
I need to do a lot of cosmetic work on this thing, but when all the bodyparts are cut to fit, the magazine hollowed out and everything is firmly set in epoxyputty, it will blow his mind.

And thanks to the powersetting I don't have to worry about that being litterally so...

The magazine ( bright pink FTW!!) will also muffle the pop-off sound a bit.
I imagine this will be quite a cool toy.

And I don't have to worry about wasting ammo as 6-mills are abundant.
One little fun machinegun. :cheers:

Re: Junior's bbmg

Posted: Sun Feb 12, 2012 5:36 pm
by jackssmirkingrevenge
Lucky kid :)
Brian the brain wrote:the QEV-pop-off-vortexblock thing works...I've already fired it..
I has thinking about this recently, but with the QEV sealing the barrel and the BBs already in the pressure chamber...

Posted: Sun Feb 12, 2012 6:49 pm
by jrrdw
Winning! 8)

Posted: Mon Feb 13, 2012 3:53 pm
by Brian the brain
Both sides of the body now chopped up and made to fit.
Some parts will be filed down to get rid of the rough edges on the cuts I made.
I cut out a section of the front grip/heatshield.
As this is slightly conical I had to choose my cuts carefully and use one of the ridges, where the diameter is bigger to get it to still fit together.
This is temporarily held together by black tape over the cut.

I had to do some cutouts wich could have gone better. :roll:

The body stays on firmly when both sides are screwed together.

I got the stuff to make the plunger and seal.

The rest is up to bondo...unless someone knows a reliable method to melt the original scrap plasic down to use that as a filler.

The magazine has been cut up to fit around the internals.
I still need to finish the cutouts as they are very rough.

The mag is still removable fo acces to the internals but it stays on well.
I had to remove the red cover I had made for the pop-off.
It made it to big to fit.
I'll fill the space inside of the mag with foam.

Posted: Mon Feb 13, 2012 4:03 pm
by jrrdw
Bondo is going to shrink a little as will epoxy. Epoxy might even melt the plastic, idk. What about hot melt glue as a filler? Real easy to work with and way less mess/odder/cure time etc...

Posted: Tue Feb 14, 2012 5:03 pm
by Brian the brain
For your amusement I'll update this buildlog with some new pics from time to time untill it is done...

So...found the perfect stuff to fill in the cut-outs..
Foam cut from the grips of a broken pogo-stick... :D

Some non-cosmetic work has also been done..
I used the same compact foam to make a squishy seal on the shoulderstock/backplug..

A cam in the back squeezes it together and as a result it forms an airtight seal on the bb-reservoir walls.
This method will help prevent unnessecary wear on the seal during refills and makes it easier to slide the stock off.
Fast click-clack refills yay!!

The threaded rod sticking out will be cut down and only a little bit of it will remain to hold the plunger-spring..

Replaced the black tape by clear tape just to see what the endproduct could look like.
So far it all still looks prettymuch like a toy.

The bondowork is now pretty straight forward.
Trigger has been cut down on my son's request.
Needless to say he can't wait for me to finish this.. :lol:

Okay, this may not be a big build like my lever action was but it's still a fun little project.. :D

Posted: Wed Feb 15, 2012 2:36 pm
by wyz2285
How does the cam lock works? (if it´s DIYble I may make one from my sentry gun system)

Posted: Sun Feb 19, 2012 2:58 pm
by Brian the brain
The camlock came with a collapsable pogostick.

It collapses when you push a button on the side.
I used that as a lock on the shoulderstock.

The camlock now pulls on a threaded rod, wich runs freely through a plastic fat washer and is then threaded into another one of those fat plastic washers.
Pull the camlock and the seal gets squashed between the plastic blocks and expands onto the reservoir walls.
The seal is formed ahead of the hole into wich the pushbutton locks.
So both mechanisms came from that pogostick..
I just adapted what I had...

The gun is now basically finished.
The front grip has to be filled up to make it a solid piece and I need to paint it over again.
Found out by accident that spraypainting yellow over pink gave me a nice orange.
My son prefers it over pink..

I ran into a problem.
A stupid problem to have, but a problem nevertheless...

The stupid pressurewasher handle had a steel bb-on-brass valve..wich might have worked with water, but with gas it leaks slightly.
Nothing to seal it but metal on metal..

So I made a rubber seal to fit inbetween the valveopening and the steel ballbearing used to close it.
Now it seals perfectly..
Unfortunately I spent all the gas during testing and to locate the source of the problem.

I'll order some 12 grams and a crapload of bb's sometime next week..

Posted: Mon Feb 20, 2012 1:34 am
by jackssmirkingrevenge
LOLOL @ the comedy ghillie suit :D

Looks great, we really need some videos of it in action though :)

Posted: Mon Feb 20, 2012 8:40 am
by wyz2285
Video!!!! :o
Just bought a battery powered water gun, gonna torn it to a full auto bb :twisted: .

Posted: Mon Feb 20, 2012 3:01 pm
by Brian the brain
Bulbs 'n' ammo first...vid later..

Not much more to do on this build but a spring and plunger...well, plunger I got.
So I need to sort out the spring.
I got plenty of those but I'll lay low for a couple of days untill the fybromialgia gets a bit better.
Old people need their rest. :D

Anyway wyz...keeping it looking like a toy and suppressing it means it will be easier to take it outside... :wink:

If you were to leave out the QEV-pop-off and go for the regular bbmg/vortex set up, only the muzzle report needs to be silenced.
pretty easy I'd say.

Posted: Mon Feb 20, 2012 5:40 pm
by wyz2285
My water gun works like a AEG :lol: so I'm gonna use it as a automatic hammer, getting some dak dak dak :D