qb78 converted to hpa

[mad187]

hi im using a qb78 whit a Guerrilla Air 0.2 liter air tank and tank block.that air tank have a 850 psi Output Pressure.and i was wondering if it safe to fill the air tank when its installed in the the tank block?the reason I ask is that the barrel is to close to the tank for the tank to be removed whit the barrel on the air gun

[Tweeter]

Yes you can fill the tank while it is on the gun, that's what I do with mine.  just do not fill past the tanks recommended fill pressure.  Your gun will be pressurized only to 850 psi if that's what your regulator is set at.  You should have burst disks on your tank also.  I have a ninja tank but I believe they all should have burst disks?

[mad187]

okey yes it has burst disks

[rsterne]

Check to see if the output side burst disc (the regulator should have two) is a 1.8K.... If so, you are good to go....

Bob

[SpiralGroove]

Hey mad87, make sure the burst disk is 1.8K.

Also, make sure your tank block is conservatively secured to the stock and air cylinder.  Once this is done, you really don't want to be removing the tank from the gun unless necessary.  I have used the Ninja 13 CI tank on my QB's.

I followed very good advice given here on the GTA and never had a hinting of a problem using HPA, however, we have seen some major accidents of late, by members and witnessed the POWER of HPA when handled carelessly.



Have fun with the QB78, this gun and the QB79 really bring back the KID in all of us and there very accurate to boot.

My two cents ....................... Kirk   

[mad187]

one burst disk is 1,8k and the other one is 5k.very nice qb79 you got it gave me a good tip how to secure the tank block

[SpiralGroove]

Hey mad187,
That's a QB78D inletted for a QB79 tank block.

Kirk

[Job]

What do you think about this (Polska)
150 J 5.5 mm, price 120 euro
http://allegro.pl/qb-78-kartusz-pcp-bomber-fac150j-5-5mm-i5710269831.html

[SpiralGroove]

Hey job,
About the same cost as a the QB78D or QB79 with HPA (13 CI Ninja Tank).  Probably less dangerous than adding a HPA tank, but not regulated and likely about 1/2 the shot count.  I think it looks a little better w/o the bottle hanging there too.
I have used my Son's Co2 version of the QB78D and didn't like it half as much as the regulated - HPA.
I like the idea of adjusting your set-point to the 1,300 psi to 1,500 psi range.

Good Look
 

[Job]

This set http://allegro.pl/qb-78-rura-kartusz-pcp-630mm-kit-tuning-i5718827019.html , shorten this air tube and add drop block with reg& bottle http://allegro.pl/qb-78-redukcja-pcp-pod-butle-hp-3000psi-200bar-i5718827894.html

[SpiralGroove]

Job,
I think the HPA version gives the user more options.  I don't like the block outside the stock for stability reasons and general appearance, but I'm sure it will get the job done.  The alternative is to buy a separate QB79 block and inlet the QB78 stock as I did (Ribbonstone method).  Keep in mind the additional plenum space provided by having the tank block forward of the stock is unnecessary for power & shot count.
These are JMO's and not for everyone   Just make sure you have fun and are safe.









Have fun ....... Kirk     

[rsterne]

The two screws that attach the stock to the tank block in the QB79 undoubtedly add a small safety margin to the gun.... If you shorten a QB78 tube and inlet the stock, I would use the two screws.... If the tank block to tube attachment was better engineered, I would not bother, but the holes are too close to the end of the tube, and the screws are of questionable quality.... It's easy to replace the screws with better ones, but more difficult to move the holes in the tank block.... For safety, with any QB79 arrangement, I would not remove the stock while the tank is under pressure.... It is possible for the regulator to fail and dump full tank pressure into the gun.... I know of one that failed at 2600 psi, with the stock removed, sending the tank, regulator, and tank block assembly flying.... That is the importance of making sure there is a 1.8K burst disc in the regulator....

Bob