| Author |
Message
|
| spudman029 |
 Posted: 03/27/2008 12:04 PM Post subject: Hybrid Questions |
 |
|
Private First Class
Joined: 19 Mar 2008
Posts: 35
85.02 Spud Bux
|
It seems that these days, most hybrids are being made out of stainless steel or something similar. In general, metal. Back in the day everyone made theirs out of sch80. Did something change? Is sch80 not reliable or safe anymore?
Yes I know that metal is much safer, and can also be taken to higher mixes of 5x-6x. Although most metal parts that are accessable to me only go up to 2" in diameter and I would like a 3" chamber.
Also, I realize that with a metal chamber, a spark plug is needed for ignition. I've never used one on a combustion before, and the search didn't help any. Would it need to be tapped into the chamber? Could someone give me a breif explanation on how they work? |
|
| Back to top |
|
 |
|
|
|
| SpudFarm |
| Posted: 03/27/2008 12:15 PM Post subject: |
|
|
Hybrid Guy
Joined: 04 Nov 2006
Posts: 2083
1166.72 Spud Bux
|
nice to see that someone else is on the full size trail!
i am going t use my hybrid at 10x so metal is good to 9999999x if you got thick enough walls.
a sparkpug works like this: a wire is slided through an 1/4" or smaller endcap the wire has to be insulated from the rest of the chamber and endcap so the spark will jump to the chamber walls again.
look at advancedspuds.com to get more info..
then look at my signature for the hybrid i am building and to get the reaon i am not explaining so complete  |
|
| Back to top |
|
|
| spudman029 |
| Posted: 03/27/2008 12:28 PM Post subject: |
|
|
Private First Class
Joined: 19 Mar 2008
Posts: 35
85.02 Spud Bux
|
thanks for the quick response. i like the size and power of full scale cannons. Massive hybrids were built by DR, jesse spellman, etc...both of which were sch80 pvc. I would like to build a 3" metal hybrid which could also be used as a regular combustion cannon for recreation.
I understand the spark plug now. Generally, do people make their own or will an automotive spark plug work? Also, one electrode of the ignition source would need to be attached to the metal chamber, correct?
Most people are using galvanized sch40 steel. Personally, I hate the way it looks. What about cast black iron? |
|
| Back to top |
|
|
| _Fnord |
| Posted: 03/27/2008 12:37 PM Post subject: |
|
|
reenigne
Joined: 13 Feb 2007
Posts: 1212
1739.50 Spud Bux
|
| Quote: | i am going t use my hybrid at 10x so metal is good to 9999999x if you got thick enough
|
By the way, 9999999x in an average size hybrid would be equivalent to a 20,000 pound propane-air (thermobaric?) bomb going off, but with 10000 times the energy density .
To answer your questions...
Sch80 pvc was generally abandoned after noname had a hybrid blow up at 2x. It was concluded that pvc fatigues over time because of its brittle nature and will usually fail at some point due to microfractures.
It's still fine for remote firing, but metal is only slightly more expensive and has almost zero chance of failure.
I've always preferred not to use spark plugs, as they require a fairly large hole to be tapped as opposed to one or two small holes (In which case, you would make your own "spark plug" and run wires to it through the holes instead of having the plug itself sticking through the chamber wall.
Edit...
Black iron is basically the same as steel, just with a different enamel/
Last edited by _Fnord on 03/28/2008 14:16 PM; edited 2 times in total |
|
| Back to top |
|
|
| SpudFarm |
| Posted: 03/27/2008 13:20 PM Post subject: |
|
|
Hybrid Guy
Joined: 04 Nov 2006
Posts: 2083
1166.72 Spud Bux
|
the "normal" spark plug will be fine..
then i think he can tap a hole like that in steel since he stick to 6x..
if you find a pipe that fits inside your main chamber you can sleeve it and go to10x |
|
| Back to top |
|
|
| DYI |
| Posted: 03/27/2008 18:28 PM Post subject: |
|
|
Rear Brigadier
Joined: 07 Jul 2007
Posts: 2263
1009.48 Spud Bux
|
Steel is, believe it or not, actually cheaper than PVC for a given size. Whereas PVC fittings have to be bought, steel fittings of nearly any description can be made simply with plates.
As for the safety of sparkplugs; my prototype hybrid has a 1.75" plate on the back where the holes are tapped, so I'm really not worrying. |
|
| Back to top |
|
|
| spudman029 |
| Posted: 03/28/2008 11:48 AM Post subject: |
|
|
Private First Class
Joined: 19 Mar 2008
Posts: 35
85.02 Spud Bux
|
| _Fnord wrote: | To answer your questions...
Sch80 pvc was generally abandoned after noname had a hybrid blow up at 2x. It was concluded that pvc fatigues over time because of its brittle nature and will usually fail at some point due to microfractures.
|
Thanks, that cleared it up for me.
| _Fnord wrote: |
I've always preferred not to use spark plugs, as they require a fairly large hole to be tapped as opposed to one or two small holes (In which case, you would make your own "spark plug" and run wires to it through the holes instead of having the plug itself sticking through the chamber wall.
|
Instead of using the insolated wires as the electrodes for the spark, what about using 2 insolated machine screws or something similar? As long as they are isolated from the metal chamber wall, shouldn't they should be fine in producing a controlled spark inside the chamber?
It would be like using 2 spark plugs meeting each other at the ends, rather than a spark plug sparking against the inside of the chamber.
Also, most people have their meter system connected to the end of the chamber via a threaded reducer or reducing bushing. With this closing off the chamber other than from the barrel, how is it possible to vent the spent gasses quickly enough for another shot? Can you still use a chamber fan inside of the enclosed chamber? Even so, it would be difficult to repair the fan if it broke. |
|
| Back to top |
|
|
| SpudFarm |
| Posted: 03/28/2008 11:53 AM Post subject: |
|
|
Hybrid Guy
Joined: 04 Nov 2006
Posts: 2083
1166.72 Spud Bux
|
just try your ignition system on a steel plate and find a selution that is good for you  |
|
| Back to top |
|
|
| spudman029 |
| Posted: 03/28/2008 12:03 PM Post subject: |
|
|
Private First Class
Joined: 19 Mar 2008
Posts: 35
85.02 Spud Bux
|
| Ok...any ideas about the exhausting? |
|
| Back to top |
|
|
| SpudFarm |
| Posted: 03/28/2008 12:46 PM Post subject: |
|
|
Hybrid Guy
Joined: 04 Nov 2006
Posts: 2083
1166.72 Spud Bux
|
if you mean burnt gasses just rush the chamber in 1 second from your air source.
on a hybrid you don't need to vent but you get a weak(er) shot if you uses just the compressed air. |
|
| Back to top |
|
|
| Jared Haehnel |
| Posted: 03/28/2008 12:58 PM Post subject: |
|
|
Colonel
Joined: 19 Feb 2008
Posts: 613
164.28 Spud Bux
|
| Quote: | | i am going t use my hybrid at 10x so metal is good to 9999999x if you got thick enough walls. |
You can do that with just about any materials as long as it "thick enough"
Any one tried using wood before? |
|
| Back to top |
|
|
| LikimysCrotchus5 |
| Posted: 03/28/2008 13:27 PM Post subject: |
|
|
Brigadier General
Joined: 04 Sep 2007
Posts: 1017
2412.72 Spud Bux
|
| Well IIRC, i think spudfarm made a wood combustion, but i know a wood combustion has been made before. |
|
| Back to top |
|
|
| starman |
| Posted: 03/28/2008 13:51 PM Post subject: |
|
|
Big Daddio
Joined: 12 Dec 2007
Posts: 1492
2901.57 Spud Bux
|
|
| Back to top |
|
|
| LikimysCrotchus5 |
| Posted: 03/28/2008 13:53 PM Post subject: |
|
|
Brigadier General
Joined: 04 Sep 2007
Posts: 1017
2412.72 Spud Bux
|
Ahh thats right the pink elephant
Thx, i remember now.
Last edited by LikimysCrotchus5 on 03/28/2008 14:57 PM; edited 1 time in total |
|
| Back to top |
|
|
| SpudFarm |
| Posted: 03/28/2008 14:32 PM Post subject: |
|
|
Hybrid Guy
Joined: 04 Nov 2006
Posts: 2083
1166.72 Spud Bux
|
haha i started thinking when i saw that i had maked a wood combustion  |
|
| Back to top |
|
|
|
|
