hybrid cartridge protoype without burst disk

[Zeus]

I shall post a schematic and some photos tomorrow by 1700hrs AEST.

[zomgwtfbbq]

Looks like Zeus went on a holiday...

JSR, I'm working on something very similar to this design (I know you are working on an oxygen-version and I hope things are swell!)

But I do have a question about this design, how do you intend to fuel your cartridge? Do you inject the mapp gas through the Schrader valve with the BB already sealed? Or do you inject your mapp gas through the top-hole before sealing it with your BB and adding air through the Schrader?

P.S. I couldn't find a tutorial on injecting mapp gas/ pressurized fuel-&-air through the schrader valve. Has this already been done?

[bradisfun]

i would think that the schrader would allow mapp to pass through it

[CpTn_lAw]

JSR i was wrong, a mini piezo igniter works, it has troubles at 8x, but until 6-7x it works. My bad (i am posting damage pics to an extinguisher in my hybrid's topic)

[jackssmirkingrevenge]

But I do have a question about this design, how do you intend to fuel your cartridge? Do you inject the mapp gas through the Schrader valve with the BB already sealed? Or do you inject your mapp gas through the top-hole before sealing it with your BB and adding air through the Schrader?

I was injecting the gas through the front where the BB sits, capping it with the BB quickly then pressurising with air through the schrader. As I haven't got ignition with this system yet though, I can't really confirm its a valid method.

P.S. I couldn't find a tutorial on injecting mapp gas/ pressurized fuel-&-air through the schrader valve. Has this already been done?

I had done this effectively with a combustion cannon, have a look here. Technically it should work for a hybrid too but again, I have no proof it will work.

[zomgwtfbbq]

Brilliant! Thanks for answering.

Here's a peek at what I'm working.

P.S. Some of the parts are still in the workshop, hopefully they will be machined soon by my ever-procrastinating friend.

[jackssmirkingrevenge]

Looking good, and on a bigger scale than mine so it's got a better chance of working What calibre? Looks like at least 1/2"

[zomgwtfbbq]

I'm impressed by your ability to guess the calibre from such a shoddy photo.

It is, sir, exactly, 1/2 an inch.

[jackssmirkingrevenge]

I'm impressed by your ability to guess the calibre from such a shoddy photo.

Schraders are about 1/4" and the barrel tube looked about double that so it wasn't such a hard guess

[jackssmirkingrevenge]

Update here in order to avoid hijacking CpTn_lAw's topic, in the light of his observations I've made a new prototype with as tiny a spark gap as I could manage, basically identical to my first prototype but with an added piece of piano wire:



... to be tested soon.

In case it doesn't work, would a hot wire/glow plug type ignition work well?

[CpTn_lAw]

Hey I wasn't mad at you for hijacking the topic lol , it's nice to talk .

On a more related note, I think some kindof glow plug might work. plus there is no problem concerning the energy required for a spark to jump a gap. It just has to be very hot to ignite the mixture!

Looking forward to hearing from you and your testing.


P.S.: Oh, what does your job consist in?

[jackssmirkingrevenge]

Hey I wasn't mad at you for hijacking the topic lol , it's nice to talk

Fair enough, but it's good to have everything under the right thread anyways, it helps with future searching and referral

On a more related note, I think some kindof glow plug might work. plus there is no problem concerning the energy required for a spark to jump a gap. It just has to be very hot to ignite the mixture!

daccel seems to have hads some success with steel wool ignition in his BACH design. I need something more maintenance free though, I have various types of nichrome wire in my spares box, mostly from scrapped heat guns/hair dryers, which should do nicely. A short length of effective "gap" will get very hot even with relatively low current across it, the important thing is that it survives intact because given the... well, "permanent" nature of the cartridge construction, you need to destroy it to access the wire... unless I come up with something that attaches to the stem of the schrader, hmmm...

P.S.: Oh, what does your job consist in?

I manage the laboratory for a pharmaceutical company manufacturing APIs, in short I test expensive white powder for a living

[inonickname]

P.S.: Oh, what does your job consist in?

I manage the laboratory for a pharmaceutical company manufacturing APIs, in short I test expensive white powder for a living

I knew it! You're the non-animal testing of our drugs. Now I know where the constant mutation arises from

[jackssmirkingrevenge]

I knew it! You're the non-animal testing of our drugs.

I wish I could test on some of the animals I work with but sadly I'm confined to using ridiculously expensive and precise instrumentation, namely HPLC, GC, FT-IR and UV

edit: fuçksocks, the seal didn't cure properly. 'couple more hours then

Here's a couple of views of the finished product, in that position the BB can hold around 30-40 psi, pushed further in it will hold at least 200 spark is good, testing scheduled for later today.

[zomgwtfbbq]

Wow the diameter is 1/4 inch? That's really small! And 200 psi is really sexy.