Is the DR1 the plane you are building? I think you told me once but forgot... The old WWI planes are the only reason I would get my pilots license. They are so elegant and amazing.....
Now this propane gun totally makes sense.

On a side note, do you have the plans for the guns? It would be fun to make some dummy versions of them.

Yes I have plans and yes my Plane is a DR1 full scale.
Structure is built. Hoping to order Prop, Redrive and Engine soon.(next few months)

The propane guns are dummies, they just make loud bangs.
Check out "Balsa USA" they have a wood Spandou kit. I will try to bring the one I have next time.
Other than that the propane guns will be built out of metal. I have already tinkered around with them, some , but not totally happy at this point.

If you want to see a real nice Dr1, go out to Platt Valley Air Park.(just east of Hudson)
They have one and many other WW1 (flying) planes at a little Museum hanger out there.

I got to see some old stuff down in CO Spgs at the airport. Dick Janatell owns the land the airport is on and has a collection in some of his many hangers. I did some work for him years back and he let me wonder around for a bit ogling over everything. If I could come up with $500 for fuel, he would have taken me for a ride in an original RAF jet he has. But, you know how poor college students are....

If you have plans for the guns, I would like to get a copy.

Scott, I'll use the schematic you provided, plus the one(s) I have to make one for you that has each 555 in a 556 with independent timing. Since solenoids are coils, when they're turned off, the field collapses and surges back into the circuit. If you don't use diodes (1N4001, etc.) to direct the flow, it can fry a circuit. I'll add those. Because the circuit I have requires you so select what timing caps and resistors you need to make it work, I'll take my best guess. What I will recommend you do is use a linear potentiometer (pot) to adjust the timing on one 555, then when you're satisfied, just measure it with a Volt/Ohm meter and replace it with a fixed resistor. Electronics is like rocketry. You try, it doesn't work, you try something else, then you get it to work. It's a process of learning.

Scott, I'll use the schematic you provided, plus the one(s) I have to make one for you that has each 555 in a 556 with independent timing. Since solenoids are coils, when they're turned off, the field collapses and surges back into the circuit. If you don't use diodes (1N4001, etc.) to direct the flow, it can fry a circuit. I'll add those. Because the circuit I have requires you so select what timing caps and resistors you need to make it work, I'll take my best guess. What I will recommend you do is use a linear potentiometer (pot) to adjust the timing on one 555, then when you're satisfied, just measure it with a Volt/Ohm meter and replace it with a fixed resistor. Electronics is like rocketry. You try, it doesn't work, you try something else, then you get it to work. It's a process of learning.

The teo boxes I have now have potentiometers in them.
Heres a couple of pics.

Pics are great, Scott. But I need to see a schematic on the wiring. Let's sit down at MHM, I'll bring some books, and we talk it over. A FULL SCALE FOKER!!!!!!!!!!!!!!!!????????????? 😯 If you need any through-hole components, let me know. I have a full electronics lab in the garage. Just let me know.