SpudFiles

I am having trouble igniting the gas with piezos. They are really unreliable and frustrating. (is this normal?)

I have been thinking of using a tiny glow plug from an RC boat, by scewing it into the back of my chamber's pipe cap.

When attached to the power source, the coil of the glow plug starts to glow red/orange/white hot.

Do you guys think this would be a decent way of igniting the mixture?

I am having trouble igniting the gas with piezos. They are really unreliable and frustrating. (is this normal?)

Let me guess: your spark gap is like an inch?
Close down the gap to less then 1 mm and you'll be fine.
Also you could try camera flash or stungun ignition.

Do you guys think this would be a decent way of igniting the mixture?

It will ignite the mixture, but, this has a small delay right?
I don't think it is a decent way because it takes a few seconds and then suddenly fires. It is safer to fire right as you click it.

No, the spark gap was small.

I don't mind the delay, as long as it actually fires consistently.

To be honest, no.

Yes, it will ignite the fuel.

But..the timing of this is VERY unpredictable. It would be difficult to tell when it would ignite, not to mention the delay before.

Glow plugs are intended to be kept hot by repeated combustion, and ignite when the mix is correct rather than by a timing.

There are other methods..camera flash (electric grill ignitor), flyback, marx, tesla coil, flux capacitor, match, lantern sparkler..list goes on.

There are better ways of doing it, but this is just so much simpler.

I just need to make the grooves for the plug, and the only downside is that I might have to wait a few seconds. It takes the glowplug about a second to get to full heat.

I will go ahead and try it out. I'll report any results here.

If it's terrible, I guess I'll get a camera flash ignition.

Alright, it'd be interesting to see. Be careful with the camera flash, there's an article on the wiki about how to wire them up. Electronic grill igniters are similar to camera flash circuits. The camera flash MAY damage your spark gap, if it does then consider using a car ignition coil..

good luck

Deterrent wrote:There are better ways of doing it, but this is just so much simpler.

mmmmmkkkkkkk

If you're going to the trouble of threading for a glowplug why not go one stage beter and try a small RC engine spark plug. There's a number of them available now for the small four stroke RC engines.

Or go the whole hog and get the ignition coil to match them.

The point is that the delay is unsafe. You will no longer have control of the exact firing moment.

Which is why I was suggesting a spark-plug and coil set up from an RC 4-Stroke engine, given that the Op knows RC stuff I thought he might have either experience of them, or at least have a friendly local model shop.

I've thought about using them myself as they're small, ready made, and seem perfect for spudguns (I reckon the Tippman combustion launcher is using something just the same personally), but the nearest RC shop to me is 100+ miles away and I don't want to order online without being able to see the stuff in the flesh.

no wont work. i have tried it.

inonickname wrote:flux capacitor

Yeah, doesn't work.

OK, I'll pile on...Don't fool with them. You might get some ignitions with them...they have been tried before and generally rejected because of reasons mentioned.

You're initial stipulation that piezos are unreliable also isn't accurate. Are you using a spray and pray cannon? hair spray? propane? It's more likely that you have a mixture problem than a piezo problem.

I'm using propane.