Sure - bug me at CEOldAmroc@me.com and I'll get around to it. I'll probably hoist a video of me disassembling it and commenting as I go. You'll need access to a lathe and a milling mating to do it right.
@deaftodd Nitrous Oxide was the oxidizer used by SpaceShip One when it won the X-Prize. I use gaseous O2 in this motor because it's easy to transport, and easy to resupply. It also allows me to control the motor - and there are no safety issues when I start with just the O2 running and no combustion.
@deaftodd No worse than burning any other hydrocarbon. CO2 is the main output.
Also, I'm burning it with pure O2 so the combustion is pretty complete. Also, that's why I recommend cast vs. extruded acrylic - the extruded acrylic as polystyrene added and during incomplete combustion it releases a lot of carbon - like burning an old model airplane.
@Scorpion85629 Simple - we shut the company down in 1995. We were working towards the launch of a 250,000 lbf thrust sounding rocket under a $25 million TRP partnered with Lockheed Martin and United Technologies. We had to raise matching funds, LM and UT could use Government funds. When the US decided to allow the Russians to dispose of their SS-23 missiles by turning them into commercial launchers, the funding evaporated - we closed the company within 30 days of that decision.
@jpourkav Yes - a converging sub sonic on made from Carbon which you can get from Ohio Carbon Blanks. It was about 1/2 dia on the inside and 1/4 inch on the outside with a 45% angle section connecting them.
Laminar flow is when the flame is long and not turbulent. When the O2 flow is increased the flow is turbulent, and the combustion goes up. In this case we got very close to supersonic flow - it looks like there might be shock waves in the exhaust - the blue against the dark doorway.
I cant understand what you are saying there? ( something like: laminar flow ??) Is the long flame because of oxidizer flow rate is small and short flame because of high flow rate? And i guess she one with short flame has more thrust, right ?
How is it possible that you can see the combustion of the fuel and oxidizer? Is the acrylic left exposed, or is it surrounded be something? if it is exposed why doesn't it just burn away? Great vid, thanks.
That's the beauty of a cast acrylic fuel element - you can see though it. It will burn through at the full rate shown in the video after a couple of minutes - makes a great demo - because I can demonstrate the fundamental safety of a hybrid - you can turn it off! Astronauts who have seen the demo love this feature. Really.
Sorry for the delay. The erosion rate is a function of the mass flow of oxidizer. In this case I'm running the regulator at 30 psi and I can go a couple of minutes before I burn through. Had I been running at 60 psi at full throttle I would have been burning though the wall of the cast acrylic somewhere around a minute. I don't have hard data on the regression rate of cast acrylic and GOx.
was the ignition method simply GOX and a spark plug ignition system? no steel wool, pyro, or gaseous fuel added? We might be building a demonstration motor for our space design class.
The ignition device is a small piece of steel wool between two copper wires - you can see them coming out of the white piece of plastic that holds the wire. You can see that I get the GOX flowing gently, I then press the contact in my left hand to run 9 volts from a standard 9 V battery across the steel wool. I typically wiggle the wire to get that first spark, was lucky this time, and finally you see me remove the alligator clips on the ends of the wires. I then play with the GOX valve.
Thanks for the response back. The go ahead was given for a hybrid propulsion system and we are in the design stages for an labscale demo motor with GOX and PMMA. One of the issues I was running into was finding appropriate a and n values for GOX/Acrylic. What typical values did you use for this combination? I've also been looking through AIAA papers and have not found those values in particular for this combination. Any help would be greatly appreciated!!!
This is a "pony" bottle of oxygen available at any welding supply that carries gases. You need to get the bottle, a regulator, and a hose. I have a quick disconnect at the bottle end of the system.
I can't remember the price of the bottle, but a refill is $15 to $20 and is good for 5 plus firings.
At laminar flow there is no thrust at all. That is simply the combustion of the vaporized plexiglas and the GOx. This particular motor can generate about 3 lbf - running the GOx at 60 psi and having a "Fresh" nozzle. I have gotten super sonic flow with standing shock waves from this motor - but that was about 100 firings ago on this nozzle.
I meant to ask the man in the video for the parts and tips I need to attempt making my own hybrid rocket. Hopefully you can get back to me soon.
heyarnoldpoop123 10 months ago
Sure - bug me at CEOldAmroc@me.com and I'll get around to it. I'll probably hoist a video of me disassembling it and commenting as I go. You'll need access to a lathe and a milling mating to do it right.
InsoliaShoe 10 months ago
can you make a list of everything you used to make this
heyarnoldpoop123 10 months ago
What happen if you use liquid nitrous oxide?
deaftodd 1 year ago
@deaftodd Nitrous Oxide was the oxidizer used by SpaceShip One when it won the X-Prize. I use gaseous O2 in this motor because it's easy to transport, and easy to resupply. It also allows me to control the motor - and there are no safety issues when I start with just the O2 running and no combustion.
bgrh 1 year ago
is burning acrylic bad for the air?
deaftodd 1 year ago
@deaftodd No worse than burning any other hydrocarbon. CO2 is the main output.
Also, I'm burning it with pure O2 so the combustion is pretty complete. Also, that's why I recommend cast vs. extruded acrylic - the extruded acrylic as polystyrene added and during incomplete combustion it releases a lot of carbon - like burning an old model airplane.
bgrh 1 year ago
So, why is he the "former" AMROC CEO?
Scorpion85629 1 year ago
@Scorpion85629 Simple - we shut the company down in 1995. We were working towards the launch of a 250,000 lbf thrust sounding rocket under a $25 million TRP partnered with Lockheed Martin and United Technologies. We had to raise matching funds, LM and UT could use Government funds. When the US decided to allow the Russians to dispose of their SS-23 missiles by turning them into commercial launchers, the funding evaporated - we closed the company within 30 days of that decision.
bgrh 1 year ago
is there a nozzle on the end of that?
jpourkav 1 year ago
@jpourkav Yes - a converging sub sonic on made from Carbon which you can get from Ohio Carbon Blanks. It was about 1/2 dia on the inside and 1/4 inch on the outside with a 45% angle section connecting them.
bgrh 1 year ago
whats the fuel ?
hybridpyrotech 2 years ago
Cast Acrylic. 1 1/2 inch diameter - 3 inches long, 1/4 inch hole at start.
Tip: Don't use extruded acrylic - it has styrene in it which leads to black wisps of plastic during start up and shut down, and a funky smell...
bgrh 2 years ago
thanks. let me ask this way. the long flame is because of low oxygen flow rate, right? great video. thanks.
roboticmehdi 2 years ago
Correct - low O2 flow, laminar flow, long, smooth flame - like a propane lighter. Increased O2 flow, increased combustion, turbulence and a short flame.
bgrh 2 years ago
what do you do to change from long flame to short but powerful flame ???
roboticmehdi 2 years ago
Laminar flow is when the flame is long and not turbulent. When the O2 flow is increased the flow is turbulent, and the combustion goes up. In this case we got very close to supersonic flow - it looks like there might be shock waves in the exhaust - the blue against the dark doorway.
bgrh 2 years ago
I cant understand what you are saying there? ( something like: laminar flow ??) Is the long flame because of oxidizer flow rate is small and short flame because of high flow rate? And i guess she one with short flame has more thrust, right ?
roboticmehdi 2 years ago
thanks for the response. What were you demoing this to the astronauts for? just out of curiosity.
russianboi711 2 years ago
They were there. I was trying to get NASA interested in the technology and I've fired this motor in NASA HQ a dozen or more times.
bgrh 2 years ago
How is it possible that you can see the combustion of the fuel and oxidizer? Is the acrylic left exposed, or is it surrounded be something? if it is exposed why doesn't it just burn away? Great vid, thanks.
russianboi711 2 years ago
That's the beauty of a cast acrylic fuel element - you can see though it. It will burn through at the full rate shown in the video after a couple of minutes - makes a great demo - because I can demonstrate the fundamental safety of a hybrid - you can turn it off! Astronauts who have seen the demo love this feature. Really.
bgrh 2 years ago
cool stuff, we had the same demonstration during a tour in lockheed missles and firecontrol
soapy05 3 years ago
effective and visual demonstration. what material did you use for the nozzle?
TopGunMan 3 years ago
The nozzle is straight up graphite - as you would purchase to cut an EDM mold. It was cut into a 1/4 inch converging nozzle.
bgrh 2 years ago
What is the erosion rate of the fuel? You ran it so long I am shocked it didnt burn through or melt.
r0ck3tsm0k3 3 years ago 2
Sorry for the delay. The erosion rate is a function of the mass flow of oxidizer. In this case I'm running the regulator at 30 psi and I can go a couple of minutes before I burn through. Had I been running at 60 psi at full throttle I would have been burning though the wall of the cast acrylic somewhere around a minute. I don't have hard data on the regression rate of cast acrylic and GOx.
bgrh 2 years ago
was the ignition method simply GOX and a spark plug ignition system? no steel wool, pyro, or gaseous fuel added? We might be building a demonstration motor for our space design class.
doc34thumper 4 years ago
The ignition device is a small piece of steel wool between two copper wires - you can see them coming out of the white piece of plastic that holds the wire. You can see that I get the GOX flowing gently, I then press the contact in my left hand to run 9 volts from a standard 9 V battery across the steel wool. I typically wiggle the wire to get that first spark, was lucky this time, and finally you see me remove the alligator clips on the ends of the wires. I then play with the GOX valve.
bgrh 4 years ago
Thanks for the response back. The go ahead was given for a hybrid propulsion system and we are in the design stages for an labscale demo motor with GOX and PMMA. One of the issues I was running into was finding appropriate a and n values for GOX/Acrylic. What typical values did you use for this combination? I've also been looking through AIAA papers and have not found those values in particular for this combination. Any help would be greatly appreciated!!!
doc34thumper 3 years ago
how much does a small cylinder of Gox cost
damcorp 4 years ago
This is a "pony" bottle of oxygen available at any welding supply that carries gases. You need to get the bottle, a regulator, and a hose. I have a quick disconnect at the bottle end of the system.
I can't remember the price of the bottle, but a refill is $15 to $20 and is good for 5 plus firings.
bgrh 4 years ago
high IQ's!
tkktkt 4 years ago
looks like one too
blazerblast 4 years ago
sounds like a light saber lol
blazer9559 4 years ago 2
What's the thrust difference between full blast and "laminar flow?"
TDanza8 4 years ago
At laminar flow there is no thrust at all. That is simply the combustion of the vaporized plexiglas and the GOx. This particular motor can generate about 3 lbf - running the GOx at 60 psi and having a "Fresh" nozzle. I have gotten super sonic flow with standing shock waves from this motor - but that was about 100 firings ago on this nozzle.
bgrh 4 years ago