My son and I decided around Thanksgiving we wanted to build an advanced combustion gun over the Christmas holidays. We had built a couple of the basic hairspray models in the past years so we thought it was time to move up. The outcome was basically a slightly large Latke model L3 with a few personal touches. Nothing really innovative here, but a pretty nice presentation, if I do say so myself.
Features are:
- All "pressure rated" parts (please spare me the noob smackdown)
- 3800 CC chamber
- Standard ball valve propane metering
- Magnetic propane tank holder
- 3" combustion chamber opening with screw on interchangable barrel feature
- Stungun ignition, with multigap circuit board for spark source
- 80mm computer case fan, with 9v battery and switch mounted in project box
- 1" Ball valve rear air intake
Everything else is pretty much self explanatory in the pics. I've built a 3.5 ft, 1.5" general purpose sharpened spud barrel, a 3.5 ft slit 2" sched 40 sleeved in 2" sched 40 golfball barrel (man that was a job), a 5ft 2.5" tennis ball barrel and a 26" 3" tee shirt barrel. The only one of these that is optimum is the 2.5 which is roughly .8/1 ratio.
Shooting this thing is a little awkward in that we almost totally ignored human ergonomics in the design, something that won't happen next time. However, because the meter pipe is so well anchored down, it became a handy right hand holder with the left operating the firing stungun underneath.
While I haven't been able to do any performance testing, both golfballs and potatos exit Out Of Sight very quickly. Given the area we were shooting, I would estimate around 250-300 yds for the potatos and 350-400 yds for the golfballs. Tennis balls about the same as potatos. Haven't tried the tee-shirt barrel yet.
Christmas '07 Combustion Project
- Attachments
-
- Can you guess where my son goes to college?
-
- Fan electrics feed through the project box mounting screws in tapped holes.
-
- Circuit board spark gaps work great!
-
- Here she is in artillery mode.
-
- Yes, this barrel is lined up straight with the top barn vent hole...sent a rope shot straight through it.
-
- With golfball barrel attached...
-
- Updated pic. Added regulator to propane fuel system.
-
- Updated pic. Added cam-lock coupler to barrel.
Last edited by starman on Mon Mar 31, 2008 9:05 pm, edited 4 times in total.
thats pretty good, most people (like my self) don't have the patience to build a cannon like that, it looks great.
"physics, gravity, and law enforcement are the only things that prevent me from operating at my full potential" - not sure, but i like the quote
you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
you know you are not an engineer if you have to remind yourself "left loosy righty tighty"
-
Novacastrian
- Staff Sergeant 2
- Posts: 1603
- Joined: Sat Aug 11, 2007 6:59 pm
- Been thanked: 1 time
Looks like a very well made advanced combustion. Do you know the capacities for the barrels that you use? It would seem to me from the pics that they could be a bit longer to gain maximum performance, my bet is that it is a loud SOB!
Nice work Starman- Welcome to Spudfiles
Edit: Fak, i missed the part in your post where you explained the ratios, apoligies.
Nice work Starman- Welcome to Spudfiles
Edit: Fak, i missed the part in your post where you explained the ratios, apoligies.
America, the greatest gangster of all time. With 200 million odd foot soldiers at it's whim and call.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
Nice job, you definately did your research and you should be happy.
Most of the other new member dont search really and end up asking so many questions.
So you should be happy of yourself and your son.
Hope too see damage pics soon.
Also i dont recommend holding it by the meter because it might loosen or break and can damage our chamber.
Also the fittings dont have to be pressure rated in a combustion, but in a pneumatic, yes.
Welcome to spudfiles
Most of the other new member dont search really and end up asking so many questions.
So you should be happy of yourself and your son.
Hope too see damage pics soon.
Also i dont recommend holding it by the meter because it might loosen or break and can damage our chamber.
Also the fittings dont have to be pressure rated in a combustion, but in a pneumatic, yes.
Welcome to spudfiles
4SPC, My 4" piston 3" porting cannon
Memo:
Fix up copper cannon
Fix up 4SPC
Start Stirrup pump
Start Toolies piston bazooka
Memo:
Fix up copper cannon
Fix up 4SPC
Start Stirrup pump
Start Toolies piston bazooka
Oh yes that little spud barrel is only 2.5/1, so I figure I'm only getting about 1/2 of my ultimate performance out of it. However, a 1.5/1 barrel is 87" and a .8/1 barrel is a manly 164" long...definitely special setup to test. This was purely for wowing the family which it more than did....yes it was nice and loud, about 16 gauge shotgun loud, not quite 12 gauge loud.
The golfball barrel obviously needs to be longer as well...Oh well that's what I get for going with a big chamber....
The golfball barrel obviously needs to be longer as well...Oh well that's what I get for going with a big chamber....
-
jackssmirkingrevenge
- Five Star General
- Posts: 26204
- Joined: Thu Mar 15, 2007 11:28 pm
- Has thanked: 572 times
- Been thanked: 345 times
very well made, I was picturing the scenario:
"You couldn't hit a bard door with that thing!"
"Oh yeah? watch me!"
"You couldn't hit a bard door with that thing!"
"Oh yeah? watch me!"
hectmarr wrote:You have to make many weapons, because this field is long and short life
Yeah yeah I hear ya. Believe it or not I've already had someone want to buy the thing as a "gameroom decoration" ...he thought there could potentially be a market for stuff like this.... Color me a little dubious about that...FordGtMan wrote:That is a really nice cannon! The only part i would change is that Clemson Crap on it. Jk, but really, you should put some GA Tech sticks on there...
MERGED:
Well my brother hit the bigger "barn door" with his hairspray model...so of course I had best him....jackssmirkingrevenge wrote:very well made, I was picturing the scenario:
"You couldn't hit a bard door with that thing!"
"Oh yeah? watch me!"
Last edited by starman on Thu Jan 24, 2008 6:42 pm, edited 1 time in total.
Absolutely beautiful - it's great to see someone who's really done their research when they were building and used all the right parts.
One slight niggle with it is that I can't see any pressure regulator in the metering system, which will mean that the changes in propane pressure from temperature changes will affect performance on different days. On warm days, your mix will be overly rich, and lean on cold days.
But, it will still be a lot better than the old spray can, which is very imprecise.
And I'm sure you and your son will get a lot of fun out of that.
One slight niggle with it is that I can't see any pressure regulator in the metering system, which will mean that the changes in propane pressure from temperature changes will affect performance on different days. On warm days, your mix will be overly rich, and lean on cold days.
But, it will still be a lot better than the old spray can, which is very imprecise.
And I'm sure you and your son will get a lot of fun out of that.
Does that thing kinda look like a big cat to you?
-
MrCrowley
- Moderator
- Posts: 10078
- Joined: Fri Jun 23, 2006 10:42 pm
- Location: Auckland, New Zealand
- Been thanked: 3 times
There already is, SGTC was the biggest, but got shutdown early last year, now there are several smaller online stores, such as Spudfiles' favourite store, http://www.bcarms.comstarman wrote:he thought there could potentially be a market for stuff like this
Side note: Sorry but we don't allow double posting at SpudFiles, just edit your posts, or reply to multiple people in the same post.
Cheers.
The stand was actually a trebuchet this time last year...one of those engineering week "see who can chuck something the furthest" kind of things. We just adapted it for artillery this year..MrCrowley wrote: Love the stand too
MERGED:
Yes very true. We were running out of time...I couldn't get my propane adapter threaded...Lord knows I tried hard enough. I have the regulator on the shelf awaiting next project.Ragnarok wrote: One slight niggle with it is that I can't see any pressure regulator in the metering system, which will mean that the changes in propane pressure from temperature changes will affect performance on different days. On warm days, your mix will be overly rich, and lean on cold days.
I finally gave up on the absolute precision and clamped the hose directly on. My ideal gas load is 73 psi for this meter/chamber, which I can easily get if the temp is 55 F or above. Just have to quickly diddle the ball valve on loading... Its been far too cold of late...
Merged:
Re. SGTC and BCarms etc.
I'm aware of this stuff...was thinking more along the line of completed, painted, ready-to-go CUSTOMIZED guns for the rich folks with nothing else to do at their lake house.
Nice nice!
Very clean constructed!
One suggestion:
You should get spark gaps in different places in the chamber.
(like one in the front, one in the back and one in the middle.
Very clean constructed!
One suggestion:
You should get spark gaps in different places in the chamber.
(like one in the front, one in the back and one in the middle.
Thanks! Yeah I was running out of time on that as well. Rather than quickly rig something up I would be unhappy with, I kept it solid and simple. It's actually very reliable.psycix wrote:Nice nice!
Very clean constructed!
One suggestion:
You should get spark gaps in different places in the chamber.
(like one in the front, one in the back and one in the middle.
Hahaha, that must be my grandpa buying that! His living room is like a clemson gift shop. He now uses my other spudgun to "scare" off cyotes.Yeah yeah I hear ya. Believe it or not I've already had someone what to buy the thing as a "gameroom decoration" ...he thought there could potentially be a market for stuff like this.... Color me a little dubious about that...
