Page 1 of 6

TBMA-230 V2.0

Posted: Wed Nov 23, 2011 7:03 pm
by SpudBlaster15
Thermobaric Mass Accelerator Version 2.0
AKA Gun Freak's favourite launcher.

Recently, I decided to rebuild the TBMA-230, which had been sitting in storage for nearly a year. The primary objectives were to compact the launcher for transport purposes, improve the fueling system, and solve the piston and chamber vent valve failure issues. All of these areas have been addressed in V2.0.

Specifications

Launcher Configuration:
Over/Under
Chamber:
Galvanized steel/malleable iron construction, 2.067" inside diameter, ~22" length, ~75in<sup>3</sup> volume
Barrel:
Galvanized steel EMT conduit, 1.61" inside diameter, 48" length, ~100in<sup>3</sup> volume
Valve:
1.61" porting piston valve with o-ring sealed steel piston and spool valve venting system
Loading:
2" Aluminum cam-lock fittings
Fueling/Filling Setup:
5/3 lever action directional control valve, volumetric meter, 3000PSI rated steel meter isolation ball valve, optional 3/2 DCV operated modular oxygen/air filling setup.
Fuel:
Onboard propylene cylinder
Ignition:
12kV HV power supply with ignition safety switch and LED indicator, 1/8" NPT spark plug
Venting:
Pressurized air exhausting system
Estimated Performance:
3200ft-lbs energy, 1100FPS for a 100g round @ 7X air/propylene

Pictures

Launcher overview:

Image

Launcher w/accessories:

Image

Chamber overview:

Image

Image

Fueling and filling operations are managed by a lever action 5 way 3 position directional control valve (5/3 DCV):

Image

Pilot setup:

Image

The piston now uses 1/2" UNC 304 stainless steel threaded rod, which improves corrosion and bending resistance. Travel distance is ~1.5", with a calculated opening time of ~6ms at 5X.

Image

Modular oxygen supply:

Image

Operation of the 5/3 DCV:

Image

Image

Image

Videos

I don't actually have any footage of the new version firing, but I threw together a quick video compilation anyway.

Seems to be no generic video embed support here so click this link

Additional videos will have to wait until the outside temperature increases to reasonable levels.

Edit: Added thumbnail image.

Edit 2: Updated with new pictures.

Edit 3: 8 years later, finally restored the pictures

Posted: Wed Nov 23, 2011 7:11 pm
by mobile chernobyl
Easily one of the most aesthetically pleasing, powerful and well thought out guns made of standard plumbing parts! :D

Posted: Wed Nov 23, 2011 8:08 pm
by POLAND_SPUD
Operation of the DCV
Ohh god I almost got an errection when I saw the diagrams!!

Posted: Wed Nov 23, 2011 8:14 pm
by Gun Freak
Ohh god I <s>almost</s> instantly got an errection when I saw the diagrams!!
Very nice SB. Very nice indeed. Honored to be mentioned in the second line <3

Posted: Wed Nov 23, 2011 8:55 pm
by Lockednloaded
Its alright I guess, have you thought of converting it to a pneumatic? You'd get a much better gun and you would no longer be such a noob.

:lol:

Posted: Wed Nov 23, 2011 9:16 pm
by Gun Freak
I didn't think that was very funny. This cannon is pretty kick ass and I never at all hinted at the superiority of a pneumatic version.

Posted: Wed Nov 23, 2011 10:24 pm
by jackssmirkingrevenge
POLAND_SPUD wrote:Ohh god I almost got an errection when I saw the diagrams!!
I bet you dropped your pants and reached for the tissues almost immediately ;)

Very nice work as always SB, looking forward to some new foorage :)

Posted: Wed Nov 23, 2011 11:04 pm
by evanmcorleytv
Awesome job!

I might just pirate your design for mine when I build mine after Christmas! (cash pending of course, I already have 2 pneumatic going on right now lol)
That is, if you don't mind.. haha

Posted: Wed Nov 23, 2011 11:53 pm
by SpudBlaster15
POLAND_SPUD wrote:Ohh god I almost got an errection when I saw the diagrams!!
jackssmirkingrevenge wrote:I bet you dropped your pants and reached for the tissues almost immediately ;)
I'm sure once PS saw the push to connect fittings, JSR's prediction became valid. :wink:
Lockednloaded wrote:Its alright I guess, have you thought of converting it to a pneumatic? You'd get a much better gun and you would no longer be such a noob.
I thought about it extensively, and I was even going to order the DWV PVC fittings to build a 400PSI pneubmatic version, but then I realized that a pneubmatic can't do this:

Image
evanmcorleytv wrote:I might just pirate your design for mine when I build mine after Christmas! ...That is, if you don't mind..
I have no problem at all with people using any of my designs. Feel free to build whatever you want.

Posted: Thu Nov 24, 2011 12:09 am
by evanmcorleytv
POLAND_SPUD wrote:Ohh god I almost got an errection when I saw the diagrams!!
jackssmirkingrevenge wrote:I bet you dropped your pants and reached for the tissues almost immediately ;)
SpudBlaster15 wrote:I'm sure once PS saw the push to connect fittings, JSR's prediction became valid. :wink:

lol, Poland "faps" to cannons............... OMG. He should make that his sig.

"I fap to cannons, ifap2cannons, ifaptocannons, 1f4p2(4nn0n5" there are multiple ways of displaying it, but they all deliver the same message. haha

evanmcorleytv wrote:I might just pirate your design for mine when I build mine after Christmas! ...That is, if you don't mind..
SpudBlaster15 wrote:I have no problem at all with people using any of my designs. Feel free to build whatever you want.
Thanks! I'll be sure to start as soon as I can!

Re: TBMA-230 V2.0

Posted: Thu Nov 24, 2011 12:34 am
by MrCrowley
SpudBlaster15 wrote:and solve the piston and chamber vent valve failure issues
Piston bounce or sealing issues?

You actually hip fire this thing or do you rest the elbow against your shoulder? Unless you fire lefty, looks like there's a lot of stuff in the way that would hit up against you with recoil :shock:

I've always loved the sleek pilot setup, now even more nice looking.

Re: TBMA-230 V2.0

Posted: Thu Nov 24, 2011 1:44 am
by SpudBlaster15
MrCrowley wrote:Piston bounce or sealing issues?
Well, I'm sure you remember the ball valve seal failures I was experiencing with oxygen mixes. With the large chamber vent gone, those issues should be a thing of the past. The other problem was related to the piston shaft; I ended up bending the 1/4" B7 grade threaded rod, which is why it has been replaced with a piece having 4 times the cross sectional area.
You actually hip fire this thing or do you rest the elbow against your shoulder?
It's shoulder fired; I choose to leave hip firing to the Kiwis. :wink:
Unless you fire lefty, looks like there's a lot of stuff in the way that would hit up against you with recoil :shock:
It is designed to be fired lefty. While I shoot normal firearms from my right shoulder, I discovered with V1.0 that for a cannon this long and heavy, it's highly beneficial to have my much stronger right arm (inb4 Poland) supporting the chamber against my left shoulder, while my left hand activates the firing switch.
evanmcorleytv wrote:lol, Poland "faps" to cannons
Mostly just to DCVs, push-to-connect fittings, air cylinders, and pics of a certain member's sister. :lol:

Re: TBMA-230 V2.0

Posted: Thu Nov 24, 2011 1:55 am
by jackssmirkingrevenge
SpudBlaster15 wrote:Mostly just to DCVs, push-to-connect fittings, air cylinders, and pics of a certain member's sister. :lol:
HAHAHAHA is that a reference to this thread :D :D :D

Re: TBMA-230 V2.0

Posted: Thu Nov 24, 2011 11:11 am
by ramses
jackssmirkingrevenge wrote:
SpudBlaster15 wrote:Mostly just to DCVs, push-to-connect fittings, air cylinders, and pics of a certain member's sister. :lol:
HAHAHAHA is that a reference to this thread :D :D :D
That is great!


What is the maximum ROF of this system, without loading projectiles? I can't imagine it would take more than about 5 seconds per shot!

Posted: Thu Nov 24, 2011 11:38 am
by jrrdw
HAHAHAHA is that a reference to this thread


and to a few chat conversations lol.

@Gun Freak, What mention? I thought you where allergic to hybirds?

Nice cannon Spudblaster15.