Ignition Problems

[noname]

I've redone my steel hybrid, to get the spark in a better place, and so it's more compact and easier to use. I made a new propane meter, and now it won't shoot.
Chamber volume is 787 mL.
Meter Volume is 38 mL.
According to Latke's FuelTool, I need 4.83 psi in the meter for a 4.2% mixture. According to SpudTool, I need 5.05 psi for a 4.2% volume. I've tried both without success in a 1x mix, so concluded that the fuel wasn't mixed well enough. I tried 2x mixes. I injected propane twice, then pumped the gun to 10 psi and got out my shock pump. 1 pump with the shock pump = .3 psi in the gun. I pumped once, clicked the igniter, pumped again, clicked the igniter, etc. I did this until the cannon was at 25 psi.
Any ideas?

[iPaintball]

Wouldn't it just be easier to use just a single nipple as a meter pipe instead of that whole thing?

[SpudBlaster15]

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras nec placerat erat. Vivamus dapibus egestas nunc, at eleifend neque. Suspendisse potenti. Sed dictum lacus eu nisl pretium vehicula. Ut faucibus hendrerit nisi. Integer ultricies orci eu ultrices malesuada. Fusce id mauris risus. Suspendisse finibus ligula et nisl rutrum efficitur. Vestibulum posuere erat pellentesque ornare venenatis. Integer commodo fermentum tortor in pharetra. Proin scelerisque consectetur posuere. Vestibulum molestie augue ac nibh feugiat scelerisque. Sed aliquet a nunc in mattis.

[noname]

Over here or something?


EDIT: I plugged the numbers back into both calculators and now they agree on 13 psi. I guess I'll go try it.

[iPaintball]

Maybe I'm just an idiot, but it looks to me like all the fittings up to the bigger ball valve are being used as the meter.

[SpudBlaster15]

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Cras nec placerat erat. Vivamus dapibus egestas nunc, at eleifend neque. Suspendisse potenti. Sed dictum lacus eu nisl pretium vehicula. Ut faucibus hendrerit nisi. Integer ultricies orci eu ultrices malesuada. Fusce id mauris risus. Suspendisse finibus ligula et nisl rutrum efficitur. Vestibulum posuere erat pellentesque ornare venenatis. Integer commodo fermentum tortor in pharetra. Proin scelerisque consectetur posuere. Vestibulum molestie augue ac nibh feugiat scelerisque. Sed aliquet a nunc in mattis.

[Fnord]

Ya know, it's a lot easier if you have a meter pipe that is as close as possible to 4.2% of the chamber volume. The meter on my hybrid is nearly perfect, so all I have to do is use an extra 15 psi for every mix.

Also, you did make sure it's actually the meter and not the new spark gap, right? Maybe you have a short somewhere.

If you are sure it is the meter, try running the mix too rich on purpose. 4.2% is very near the minimum explosive limit for propane(3%), so your mix might be too lean. I think the maximum explosive limit is something like 9%, so try and start there, and work your way down.

[noname]

iPaintball, yes, they are.
SpudBlaster, I'll try it.

[quote=_Fnord"]all I have to do is use an extra 15 psi for every mix.[/quote]

This is propane you're talking about, yes?
The spark plug works great, I get a 1/16" spark every time. I can check for the spark by holding the wire 1/4" away from the chamber, and the spark jumps there too, even under 30 psi chamber pressure.

[Fnord]

This is propane you're talking about, yes?

Yes, it is.
An extra 15 psi in the meter is what I meant.
As an example, for 2x I would put 30 psi in the meter, 45 psi for 3x, etc.

Sorry if my original post was hard to understand; I was tired.

[dongfang]

Hi,

Can somebody explain to me what this all is; I have never build a pressurized gas meter before (but I have built a pressureless)....

The knob on the right, is that a gas pressure regulator? Does the knob control pressure on the output side?
Is the gauge in the right on the input or output side of the regulator?

What is the gadget with the wheel thing on the left? And that long black pipe?

And finally, in my logic (of lack of it), if I were to build it I'd put a tee in one end of the meter pipe, and put air injection on one side (as close as possible) and gas on the other. In the other end og the meter pipe, the cannon through a ball valve. Anything wrong with that design?

Regards
Soren

[spanerman]

dogfang, correct me iff im wrong but are you describing a design similar to this?

iff so, yes it will work, im in the processs of building mine, but spudblaster15 has made one(he was the pioneer of this design) and it functions!

[noname]

Spanerman, read the topic or don't post in it. Simple, no?

[spanerman]

i read it ALL, im trying to help the use above me who posted a question...got a problem with that? please pm me with your isssue

[noname]

Did you manage to miss the pictures of my setup (which dongfang is describing) while reading the whole topic? Seems like it.

[spanerman]

no, i saw them but they seem unclear to me, i had to look at them for a while to see what each component was.....regulator...sock pump ect. so i thaught that i would post a simple diagram to be of some help, sorry if you feel ive done something wrong please notify me and il editmy post or request that its removed.