Have you got any pictures? Drawings? Might be recreatable....If it could be done safely. You can get Aluminium sodastream size bottles for next to nothing. Use that size and figure out a methodology.
Hybrids 2024
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To my knowledge there were only two prefills, Alpha Hybrids, and the Aerotech. The 98mm Aerotech was more of a nitrous boosted composite. You can follow my efforts for the Aerotech hybrid revival at pcarroll2525.com , I successfully flew the 54mm on a sorbitol based grain at Balls 31. Working on a paraffin/htpb grain next.
Didn't see any injector info. Liked the BP pyro valve. Simple.
hybridfreak
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Just like Edward's design he used for alphahybrids, easy, reliable but also versatile if you want to use different injector geometries.
I built a 54mm hybrid using a SodaStream tank about 10-15 years ago. This year I want to revive it with different tank sizes and maybe scale the design down to 38mm as well (using 9oz paintball tank). Gotta get my lathe back together to so some lathein' first though
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Always suspected soda stream + custom AT top closure would be relatively simple.Just like Edward's design he used for alphahybrids, easy, reliable but also versatile if you want to use different injector geometries.
I built a 54mm hybrid using a SodaStream tank about 10-15 years ago. This year I want to revive it with different tank sizes and maybe scale the design down to 38mm as well (using 9oz paintball tank). Gotta get my lathe back together to so some lathein' first though
It is, but it's also relatively heavy as the tank is 200 bar rated. So it will fly, but with the extra weight, it's not going to be a performance item.....
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But particularly for bench top hybrid or liquid experimentation, I suspect it's the sweet spot.
You can now buy small tanks from china for rediculously cheap prices If the same thread fits them then the only limitation is the throughput of the self sealing valve. You could quite easily make the same fundamental system larger. 2 litre could be a sweet spot ...
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The injectors came straight from the data pack, you can add more ports and tune it to your liking.
What data pack. Pretend I'm an idiot and didn't see it.... Can you attech the file for all following the thread.
View attachment IMG_20231211_122927.jpg
New 2l composite tank on top, 96mm diameter, original style 1100cc tank on the bottom for the Aerotech.
I didnt find any, your best bet is to scour the internet, facebook ex rocketry groups, and find a good mentor. Leland Dexter of Micro Nitro makes some wonderful small hybrids for low power experimentation that comes with some great documentation. RCS sells the Aerotech hybrid data pack for their OOP hybrid. I used it as a platform to revive it for my ex hybrid motor.
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My wife got a sodastream about 6 months ago and I eyed that bottle immediately. I was thinking of using 1 bottle as tank connected to a 2 nd modified for combustion/nozzle section. Cut the flat end off and fit a few bits and pieces in there....
I'm not sure about composites as a tank for a potentially cryogenic liquid. I'd be concerned about the possibility of a knock giving up when it got chilled. I think I'd stick with aluminium. RattWorks uses 6061 with 3/32 wall @64 mm (2.5 inch) OD. so we know fairly certainly that anything over that is safe ....ish for up to 64 mm OD. These tanks are usually manufactured to a good standard.. They're now cheap. Cut the end off, work out how much you can machine off the OD. Machine that off a new one and hydraulically test to double the working pressure, call it 2000psi and you should have a minimum weight tank from readiliy available suppliers. In aluminium.....
I've also never found any. The best place is to find a mentor.. Hybrids are simple in theory. Fill a tank with an oxidising liquid. Start a fire in a combustion chamber containing a fuel with a nozzle at the bottom. Release the oxidiser into the heated fuel grain. Keep the combustion chamber pressure below the oxidiser tank pressure or the flame front will move to be inside the oxidiser tank........ Bad.
It is aluminum with a composite shell.
I'll spend the 10 bucks to buy one and start some sketches.
hybridfreak
Active Member
The SodaStream ones aren't lightweight at all but you can still have fun using them in hybrids
That's the hybrid I want to revive but I won't use the SodaStream anymore. I've found paintball CO2 tanks to be lighter at the same volume and they're available in nice sizes with pin valves that can be modified to work well. I also came across a tank that is basically a longer version of the SodaStream. I holds 500g of nitrous rather than 430g.
Since CO2 and N2O have such similar properties looking for CO2 tanks is a good option!
That's the hybrid I want to revive but I won't use the SodaStream anymore. I've found paintball CO2 tanks to be lighter at the same volume and they're available in nice sizes with pin valves that can be modified to work well. I also came across a tank that is basically a longer version of the SodaStream. I holds 500g of nitrous rather than 430g.
Since CO2 and N2O have such similar properties looking for CO2 tanks is a good option!
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Interlibrary loan of "Fundamentals of Hybrid Rocket Combustion and Propulsion" by Chiaverini & Kuo?
There's theory and there's doing. In theory a bumble bee cannot fly. Don't tell the bumble bee.......
Does anybody know where i can find a hypertek J-L fill stem? I built my L3 around the 75mm hypertek L motor, and got the cert with an Aerotech M1315. I have the 75mm L system, with the original 2 grains that it came with, but haven't flown it yet.
Im planning on building a GSE setup, but the fill stem is mostly what i am having trouble finding.
Im planning on building a GSE setup, but the fill stem is mostly what i am having trouble finding.
I would make a posting in the wanted section or contact Sunward out of Canada who does the hypertek stuff now. I do not know if there are any US dealers.
I believe Chris Pearson may be able to help you, or at least give you some info to work with.
drewnickel
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The technical write-ups on Aspire Space's website are good for understanding the physics. As for getting started making your own I recommend finding a commercial Rattworks, Contrail, Hypertek, etc motor (Contrail being the only vendor still making new hardware, but Hypertek still has reloads from time to time and Dave Griffith may make a reload for Rattworks motors if you reach out to him). Focus on making your own reloads for existing hardware to get a feel for how everything works together before going all in and putting together EX hardware. At least in doing that you know it was whatever you did and not the hardware to blame for any anomalies and you don't have to think about whether your hardware works.
Additionally I published my hybrid rocket simulator, HRAP, to GitHub this past year. I highly recommend reading the technical write-up included with it before trying to use HRAP, as there are a lot of different inputs and not nailing down those inputs can result in inaccurate sims (garbage in = garbage out).
https://github.com/rnickel1/HRAP_Source
Yepp. The wrong regression rate can be expensive...... Amongst other unfortunate things it can be.... I was pushing it with a 30 second burn time......
It has taken longer than I had originally planned; however, the latest WFX Hybrid system is finally nearing completion. Some background involves several of the hybrid players, and I want to acknowledge them. To start, Drew (drewnickel) contacted us and was looking to integrate monitoring of the hybrid fill system into our production wireless system. This included both pressure and strain and led to a standalone Hybrid Monitor. Afterward, John ( Voyager1) was looking to add temperature to the mix, leading to Hybrid Monitor 2.0. These boards were housed in separate boxes due to space limitations.
Over the last year, Voyager1 and I have had many conversations about up-integration into a single box. The following pictures are based a lot on conversations, mostly with the Aussies, about being able to run both standard and hybrid pads and suggestions from Voyager1 as a hybrid user.
First is the LCU64-Hybrid controller, which includes the ability to fill, purge, and monitor without losing any capability for normal access to pads and banks.
Second is the up-integrated Hybrid Monitor 3 and PBU4-W into a single box. The Hybrid Monitor 3 is a single board with the Hybrid Monitor 2 capability, a display unit, and a WIFI connection. It is physically designed to fit with the PBU4-W controller, which will allow it to be contained in a single enclosure.
In addition, there are two Digital Solenoid Saver boards that limit the current to the Fill and Purge solenoids. The DSS boards are powered from the output of the PBU4-W; the only additional connection is a ground. The output from the DSS board is fully on when activated by the output relay of the PBU board. After a delay, the output is then reduced to limit the drain on the supply battery. The DSS board has the ability to have the output adjusted by the user with current limits between 900mA and around 60mA. The WIFI was added to the Hybrid Monitor 3 to allow users to set the sensor limits without having to use any of the switches/buttons/pots, although those are maintained in this version.
Dan Fox
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Over the last year, Voyager1 and I have had many conversations about up-integration into a single box. The following pictures are based a lot on conversations, mostly with the Aussies, about being able to run both standard and hybrid pads and suggestions from Voyager1 as a hybrid user.
First is the LCU64-Hybrid controller, which includes the ability to fill, purge, and monitor without losing any capability for normal access to pads and banks.
Second is the up-integrated Hybrid Monitor 3 and PBU4-W into a single box. The Hybrid Monitor 3 is a single board with the Hybrid Monitor 2 capability, a display unit, and a WIFI connection. It is physically designed to fit with the PBU4-W controller, which will allow it to be contained in a single enclosure.
In addition, there are two Digital Solenoid Saver boards that limit the current to the Fill and Purge solenoids. The DSS boards are powered from the output of the PBU4-W; the only additional connection is a ground. The output from the DSS board is fully on when activated by the output relay of the PBU board. After a delay, the output is then reduced to limit the drain on the supply battery. The DSS board has the ability to have the output adjusted by the user with current limits between 900mA and around 60mA. The WIFI was added to the Hybrid Monitor 3 to allow users to set the sensor limits without having to use any of the switches/buttons/pots, although those are maintained in this version.
Dan Fox
KC9QZF (the FX in WFX)
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cfb_rolley
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couple of questions - and I'm sure I'm overlooking the answer for the first in a previous thread so I apologise in advance if it has....
Medical grade nitrous vs racing nitrous - I can get pretty cheap and easy refills of racing nitrous, but I know this contains sulphur dioxide to prevent abuse. does this impact performance any appreciable amount or is it fine?
Secondly - electronics for the GSE - what's the minimum needed for running a small (38mm) hybrid? Using the Contrail low cost solenoids for fill and purge, these are continuous duty, and for a small hybrid aren't on for that long anyway... so I assume a solenoid saver is not necessary, so the minimum needed would be - key interlock, continuity circuit (thinking audible tone + LED light), ignition circuit with a momentary button/switch for firing, fill switch and purge switch, and a power supply that can output enough current to run the solenoids (small 12v car or motorcycle battery?) ...Anything else? Current limiting resistors for the solenoids maybe?
Edit - 3rd question - can someone explain how the Contrail CNVA chart works please
Medical grade nitrous vs racing nitrous - I can get pretty cheap and easy refills of racing nitrous, but I know this contains sulphur dioxide to prevent abuse. does this impact performance any appreciable amount or is it fine?
Secondly - electronics for the GSE - what's the minimum needed for running a small (38mm) hybrid? Using the Contrail low cost solenoids for fill and purge, these are continuous duty, and for a small hybrid aren't on for that long anyway... so I assume a solenoid saver is not necessary, so the minimum needed would be - key interlock, continuity circuit (thinking audible tone + LED light), ignition circuit with a momentary button/switch for firing, fill switch and purge switch, and a power supply that can output enough current to run the solenoids (small 12v car or motorcycle battery?) ...Anything else? Current limiting resistors for the solenoids maybe?
Edit - 3rd question - can someone explain how the Contrail CNVA chart works please
drewnickel
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couple of questions - and I'm sure I'm overlooking the answer for the first in a previous thread so I apologise in advance if it has....
Medical grade nitrous vs racing nitrous - I can get pretty cheap and easy refills of racing nitrous, but I know this contains sulphur dioxide to prevent abuse. does this impact performance any appreciable amount or is it fine?
Secondly - electronics for the GSE - what's the minimum needed for running a small (38mm) hybrid? Using the Contrail low cost solenoids for fill and purge, these are continuous duty, and for a small hybrid aren't on for that long anyway... so I assume a solenoid saver is not necessary, so the minimum needed would be - key interlock, continuity circuit (thinking audible tone + LED light), ignition circuit with a momentary button/switch for firing, fill switch and purge switch, and a power supply that can output enough current to run the solenoids (small 12v car or motorcycle battery?) ...Anything else? Current limiting resistors for the solenoids maybe?
Edit - 3rd question - can someone explain how the Contrail CNVA chart works please
Answer to the first question: the sulfur dioxide is generally around 500 ppm, or 0.05%. It doesn't have a meaningful impact on performance, but you will notice if you are testing/flying in humid areas that any steel the nitrous gets on will rust quickly (sulfur dioxide + water = sulfuric acid).
Second answer: at a minimum you need a fill valve, a purge/dump/abort valve, and a way to light the motor. Tom sells a cheap valve manifold for lower impulse hybrids for ~$275 (https://contrailrockets.com/product/nitrous-oxide-fill-manifold-system-small-solenoid-valves). There is a cheaper option without the purge valve for smaller motors, as they can dump sufficiently fast through their vents. I believe Tom has some wired GSE available still (both 12V and 24V systems) that can operate the valve manifolds, and there is a wireless option from Wilson FX that also includes pressure and fill weight monitoring.
Third answer: the CNVA numbers are relative size corresponding with the optimum fitting to pair them with. #1 with 1/8 inch push to connects, #2 with 3/16, #3 with 1/4, #4 with 5/16. Sizes 1-4 all have 1/8 NPT threads. Sizes 5-7 are 1/4 NPT threads and go with the green/yellow/red 3/8 inch push to connects. There are also the ziggurats (2 stage, 3 stage, and so on) for the 3/8 NPT and 1/2 NPT thread injectors.
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