Mk IV QEV Popoff. Updated 22 Feb

[inonickname]

This looks great! The thickest perspex i have is only around 1 cm.. Does anyone know if you can sandwich it together with epoxy or something?

Very nice, cool work. Bet it's a blast on full..

[SPG]

The best glue for acrylics like perspex is called Tensol.



It's not cheap but it's one of those solvent cements which effectively welds your bits together.

Second thought, you might be able to actually screw or bolt sheets together, possibly need a gasket between the sheets though so you'd lose the transparency, but that would be a good way to get complex internal shapes.

[inonickname]

Cool, I'll look into it.

Thanks; keep up the good work!

[SubsonicSpud]

This looks great! The thickest perspex i have is only around 1 cm.. Does anyone know if you can sandwich it together with epoxy or something?

Very nice, cool work. Bet it's a blast on full..

I had a similar problem as I could not get polycarbonate greater than 12mm. I didn't want to laminate sheets of it together to get a 30mm block, so I just ended up using acrylic again and taking care whilst drilling it.

SubsonicSpud

[Gippeto]

Bleedin 'ell!! I missed a good thread here.

Until now.

VERY nice work! :thumbright: :thumbright:

[covey12]

i dont get how this works, lol im going to have to read up on these and then post some more stuff on this, it looks sweet though

[VH_man]

Wow. At first i didnt beleive this gun. Now I want one.

I assume this is running on simply Air compressor pressures? Or am I completely wrong.

Makes some sweet sounds. I like it. ALOT. Kudos. I might be making one of these in the future.

[SubsonicSpud]

Thanks for the compliments guys

Anyway I have pretty much finished the main block for the MkII version. I have managed to incorporate the chamber into the block as well as having a bolt on cover plate for the back, to enable servicing and cleaning.

Some pics of the progress:







Now I have to start working on a trigger unit so I can test the QEV


VH_man,
The system could work on a normal air compressor, but the Popoff valve would have to be tuned down a bit to trigger at a lower pressure. I have been running at higher pressures supplied from a converted air conditioning compressor.


SubsonicSpud

[Sparkie]

what sort of ammo are you planning to fire with this puppy? plastic or steel bb's

[jackssmirkingrevenge]

When did this project become a three cylinder engine

looking good!

[Crna Legija]

you can get a spring off a throttle cable or cluch cable on a dirt bike they around the rubber to protect them from heat .

[SubsonicSpud]

what sort of ammo are you planning to fire with this puppy? plastic or steel bb's

1/4 Steel BBs, Lead Shot or Plastic BB's all depends on how destructive I want to be


JSR, LOL I only just realised the resemblance I should call it the Kubota gun.

SubsonicSpud

[Technician1002]

Thanks for the compliments guys

Anyway I have pretty much finished the main block for the MkII version. I have managed to incorporate the chamber into the block as well as having a bolt on cover plate for the back, to enable servicing and cleaning.


SubsonicSpud

Very nice. Plexiglass like PVC is limited in it's tolerance for stress and strain. The plexi end plate concerns me. Will it be able to hold a gasket without bowing, crazing and leaking? I'm wondering if a steel or aluminum bar on top would be a good idea so the endplate doesn't give under pressure.

The other thing I'm playing with is a anti blowback for the feed tube. If it has angled hopper feed into the present feed tube, and the present tube was blocked off, but with a space of 1/3 of a BB detent up the blocked tube, when fired the blowing back BB would get caught in the detent and not alow the next one to get past to the new feed tube. The stuck BB's would prevent the fire blast from exiting out the BB feed tube. I'll need to draw it up and post it later. I have no tools to draw it here. I hope the description makes some sense.

[SubsonicSpud]

Very nice. Plexiglass like PVC is limited in it's tolerance for stress and strain. The plexi end plate concerns me. Will it be able to hold a gasket without bowing, crazing and leaking? I'm wondering if a steel or aluminum bar on top would be a good idea so the endplate doesn't give under pressure.

The other thing I'm playing with is a anti blowback for the feed tube. If it has angled hopper feed into the present feed tube, and the present tube was blocked off, but with a space of 1/3 of a BB detent up the blocked tube, when fired the blowing back BB would get caught in the detent and not alow the next one to get past to the new feed tube. The stuck BB's would prevent the fire blast from exiting out the BB feed tube. I'll need to draw it up and post it later. I have no tools to draw it here. I hope the description makes some sense.

The main body is Acrylic, but the end piece is 7mm Polycarbonate and much stronger, the mounting studs are only about 20mm apart so I am hoping flexing wont be a problem at those sort of dimensions.


Look forward to seeing a diagram of the anti blowback system.

SubsonicSpud

[Carlman]

wow mate just wow, what do you do for a living?