Hybrids 2023

[G_T]

Swapping CGA320 valve over to CGA326, and installing high flow siphon...

Procedures? Is a new hydro test required after doing the swap? Looking at getting a B35 cylinder but what I've been finding are all set up with CGA320 (CO2) rather than CGA326 (N2O).

I've found B20 set up for nitrous but it's not quite a big enough tank for the somewhat larger EX motors I'm considering in the future. A B20 will handle my baby M but probably not a large M and not an N. I don't want to deal with transporting a B50. Too heavy. Unless I get into EX hybrid O motors in which case there is no choice but to go big. A B35 would get me through this year and next and still be manageable. That's why I'm looking for that size.

Thanks,
Gerald

 

[ContrailRockets]

We are busy and innovating. A certified N motor not an ex motor is being tested before TMT certification.
Hollow cone injectors with 2 gallons per second of NOS flow are being machined not jut for testing but for addition to our website. Lower cost NOS valves for L1 L2 motors. The .375 orfice CFF 1/2 NPT Solenoid valve. This Continuous duty solenoid valve uses only 11 watts of power.
There are no problems it is just that you have not yet found the solution. When you hit that problem reach out.

 

[kramer714]

Dumb question, but anyone know of a source for stainless braided jacket PTFE lines with brass 4AN fittings (or 4AN on one end and perhaps NPT on the other) rather than the colorful anodized aluminum fittings? I don't trust aluminum fittings for repeated installs and removals.

Thanks,
Gerald

McMaster https://www.mcmaster.com/products/high-pressure-hose/fitting-material~stainless-steel/

 

[kramer714]

I've been wanting to get into hybrids for a long time, but was always put off by the cost of GSE. Then, the other day, I found a 10lb NOS bottle in town for 160 canuck bucks.

"It's an older bottle, sir, but it checks out."

View attachment 556551

When you get it hydro tested, have them put in a siphon tube, most likely it doesnt have one. You can use the Nitrous in it if it doesnt you just need to hold the tank upside down.

 

[samtc]

Although I only made one Hypertek J flight in 2022, I love the challenge. I did my Level one and Level two flying an Aurora with a Hypertek J. That was a long time ago before the rules changed. I flew my Level 3 on a Hypertek M. Nothing beats an almost 10 second Hybrid M burn.

My goal this year is to build a launch trailer that will easily support both Hybrid and AP flights. I plan to minimize the hybrid setup as much as possible, but still make AP flights easy. We have a basic design and I have found a vendor to build the trailer. I have two M projects, one repair of 6" project and a 5" project. I plan to fly the 5" on the last MFX Grain I have with the large 5478cc Tank. (M1040). I'm shooting for 20K feet if I can keep the weight down. All of my 54mm up to 4" are designed to fly on either Hypertek or AP.

I highly recommend the challenge!

For those interested, I have a bunch of Hypertek documentation.

 

[maddmaxx11]

We are busy and innovating. A certified N motor not an ex motor is being tested before TMT certification.
Hollow cone injectors with 2 gallons per second of NOS flow are being machined not jut for testing but for addition to our website. Lower cost NOS valves for L1 L2 motors. The .375 orfice CFF 1/2 NPT Solenoid valve. This Continuous duty solenoid valve uses only 11 watts of power.
There are no problems it is just that you have not yet found the solution. When you hit that problem reach out.

Are the lower cost valves on your site yet? How much?

 

[G_T]

I now have a certified B-50 cylinder, with lots of help from Tom. Waiting for dolly to arrive early next week, and then will see about getting it filled. Since it is over 100lbs filled, the dolly is mandatory! One more step completed towards relighting THRP-1 at URRF-9.

Gerald

 

[ContrailRockets]

Aluminum cylinder and high flow CGA 660 valve.

 

[P_Carroll2525]

I see a lot of discussion about U/C valves but I think the prefilled motors would be more attractive to the occasional flyer as they require the same ground support as AP motors with only a little more prep on the forward end.

 

[info_dFj]

Contrail Rockets N-4000 98mm Hybrid. Pad video shows Ring of Fire pre heat required to burst the 1/2 inch nylon fill line. THe 1/2 inch PTC used as an injector is ported to a full 1/2 inch. In the NOS tank is a 4 stage Ziggurat creating a hollow cone of NOS.

 

[cfb_rolley]

Hey, hoping this is the right place for a little bit of help.

I've been flying on a micro-hybrid rocket motor for a little while now and seriously enjoying it, but I'm hoping to get in to a contrail hybrid motor system later this year (38mm x 16 inch motor). Unfortunately, I'm in Australia - meaning that by the time exchange rate is applied, shipping stuff from the US is insanely expensive. There's no way around spending over $500 AUD on a motor and some reloads. There is some relief though, I should be able to purchase everything I need to build my own ground support gear locally. To do this though, I need assistance. If someone to go over what I have planned it out it would be greatly appreciated.

The current plan is to use a 5lb automotive nitrous oxide bottle (I can source automotive stuff at quite a good discount), a -4an line from the bottle to a fill valve connected to one part of a 1/8" NPT tee, and on the other parts of the tee, a dump valve and a PTC fitting for the nylon hose that goes to the motor. I'm unable to find a 100% duty cycle solenoid here, so the fill and dump valves I was thinking of using something like this: https://www.halfcatrocketry.com/sabv. Building the electronics side of a controller for operating the servos for the valves and for ignition should be no problems at all for me.

From my understanding, these valves will fit the job without the need for expensive or hard to source solenoids, avoids pulse-filling the motor, and with this setup I would just need to change the PTC fitting depending on the size of hose that is supplied with the reload.

Is there anything else I need to consider or include, or am I already on the right path here?

 

[info_dFj]

The 38mm x 16 motor with slow nozzle is $160.00 USD and reloads in a 3 pack for the G-100 are $54.99 USD.
The basic fill manifold with two solenoid valves with fittings and fill line from tank to motor.
https://contrailrockets.com/product/nitrous-oxide-fill-manifold-system-small-solenoid-valves $274.99 USD.
This is a basic fill system for small hybrid motors. It uses the .062 orfice solenoid valve for both filling and purge. This valve is designed for a 5 minute duty cycle so it is not designed for larger motors. It has a connection for a CGA326 NOS tank valve and a 1/8 PTC to connect your fill line. The 1/8 inch nylon line is rated with a 3400 psi burst with a .078 ID. The solenoid valves have 120 volt plugs for easy connection to a UL rated cord from the valves to your GSE. Also included are coupling adapters from the fill line to either a 1/8 or 3/16 inch motor fill line. This is a great starter set for 38mm L1/2 motors.
If you have a small NOS tank it should have a CGA 326 valve.
I do charge 25% Shipping and Handling for International orders.
The internals from the 38mm fit into the larger tanks so if at some point you want to go for a L-1 or L-2 we could help with that as well.
I do not know the conversion to AUD and we do not pay any customs, duty or VAT.

Tom Sanders

 

[cfb_rolley]

The 38mm x 16 motor with slow nozzle is $160.00 USD and reloads in a 3 pack for the G-100 are $54.99 USD.
The basic fill manifold with two solenoid valves with fittings and fill line from tank to motor.
https://contrailrockets.com/product/nitrous-oxide-fill-manifold-system-small-solenoid-valves $274.99 USD.
This is a basic fill system for small hybrid motors. It uses the .062 orfice solenoid valve for both filling and purge. This valve is designed for a 5 minute duty cycle so it is not designed for larger motors. It has a connection for a CGA326 NOS tank valve and a 1/8 PTC to connect your fill line. The 1/8 inch nylon line is rated with a 3400 psi burst with a .078 ID. The solenoid valves have 120 volt plugs for easy connection to a UL rated cord from the valves to your GSE. Also included are coupling adapters from the fill line to either a 1/8 or 3/16 inch motor fill line. This is a great starter set for 38mm L1/2 motors.
If you have a small NOS tank it should have a CGA 326 valve.
I do charge 25% Shipping and Handling for International orders.
The internals from the 38mm fit into the larger tanks so if at some point you want to go for a L-1 or L-2 we could help with that as well.
I do not know the conversion to AUD and we do not pay any customs, duty or VAT.

Tom Sanders

Conversion rate for AUD is pretty garbage at the moment. That $274 USD turns in to over $500 AUD and that’s before even buying a nitrous bottle to fill from. Buying everything locally sets me back just over $500 AUD and that’s including the nitrous tank.

The motors and reloads themselves are still pretty damn good value though considering the internals are interchangeable between tanks, the other option for us here is to try and source APCP motors which like finding a unicorn - as an example, there’s only 2 H motor reloads available that I know of at the moment, which would run me $200, plus the case for it which would be another $200-300. And after that, there’s no ETA on any more APCP motors. $500 for *two* flights…

Hybrids at $40-$50 AUD per flight and plenty of reloads available? Much better option imo.

 

[rocket_troy]

Hey, hoping this is the right place for a little bit of help.

I've been flying on a micro-hybrid rocket motor for a little while now and seriously enjoying it, but I'm hoping to get in to a contrail hybrid motor system later this year (38mm x 16 inch motor). Unfortunately, I'm in Australia - meaning that by the time exchange rate is applied, shipping stuff from the US is insanely expensive. There's no way around spending over $500 AUD on a motor and some reloads. There is some relief though, I should be able to purchase everything I need to build my own ground support gear locally. To do this though, I need assistance. If someone to go over what I have planned it out it would be greatly appreciated.

The current plan is to use a 5lb automotive nitrous oxide bottle (I can source automotive stuff at quite a good discount), a -4an line from the bottle to a fill valve connected to one part of a 1/8" NPT tee, and on the other parts of the tee, a dump valve and a PTC fitting for the nylon hose that goes to the motor. I'm unable to find a 100% duty cycle solenoid here, so the fill and dump valves I was thinking of using something like this: https://www.halfcatrocketry.com/sabv. Building the electronics side of a controller for operating the servos for the valves and for ignition should be no problems at all for me.

From my understanding, these valves will fit the job without the need for expensive or hard to source solenoids, avoids pulse-filling the motor, and with this setup I would just need to change the PTC fitting depending on the size of hose that is supplied with the reload.

Is there anything else I need to consider or include, or am I already on the right path here?

I've used ball valves for N2O GSE for maybe 10-15 years - currently using NOS solenoids though, but there's absolutely nothing wrong with ball valves. So long as the servos have enough grunt to reliably actuate them, they'll be fine.

TP

 

[cfb_rolley]

I've used ball valves for N2O GSE for maybe 10-15 years - currently using NOS solenoids though, but there's absolutely nothing wrong with ball valves. So long as the servos have enough grunt to reliably actuate them, they'll be fine.

TP

Wicked, thank you. Guess I better get moving on some GSE then!

 

[ContrailRockets]

I've used ball valves for N2O GSE for maybe 10-15 years - currently using NOS solenoids though, but there's absolutely nothing wrong with ball valves. So long as the servos have enough grunt to reliably actuate them, they'll be fine.

TP

Valves are to fail to closed. Ball valves are a bit harder to fail to closed. In event of loss of communication to pad or battery power loss valve could remain in open position. Ball valves can be done but requires more than just power to a servo to meet safety requirements.
Tom

 

[cfb_rolley]

Valves are to fail to closed. Ball valves are a bit harder to fail to closed. In event of loss of communication to pad or battery power loss valve could remain in open position. Ball valves can be done but requires more than just power to a servo to meet safety requirements.
Tom

Fair point. Spring return is fairly easy to add in though, ensuring the valve closes if there’s a power loss. Communication loss isn’t a problem though, with the arduino program I can set up, it’ll only have the valve open if it sees the switch closed. Any other state (eg, cable disconnection) and the valves will close. Combined with a spring return, that should meet safety requirements?

 

[ContrailRockets]

Valves are to fail to closed. Ball valves are a bit harder to fail to closed. In event of loss of communication to pad or battery power loss valve could remain in open position. Ball valves can be done but requires more than just power to a servo to meet safety requirements.
Tom

If servo pulls against spring adds unnecessary work for servo. At power or communications loss valve remains open. Spring solves nothing if servo has valve locked open.
Tom

 

[A-ron]

The mad scientist in me has always wanted to clone a RATT.

Left: R.A.T.T. Works 29mm H/I hybrid
Right: My 29mm full-G hybrid design

 

[ContrailRockets]

NOS for Spaceport 2023 on my website.
New drop-down menu under Accessories.

 

[Hobie1dog]

I love this stuff. You guys make it sound simple.

 

[Rocket_Col]

Hi, been using hybrids in the UK for years, I now have a RATT L/M combo hardware only
Does anyone have any information on the size of the grains?
I have 1 from a RATT K240 and looks like polypropylene??
any infor on wall thickness and nozzle form please.
Thanks

 

[OzHybrid]

I've used ball valves for N2O GSE for maybe 10-15 years - currently using NOS solenoids though, but there's absolutely nothing wrong with ball valves. So long as the servos have enough grunt to reliably actuate them, they'll be fine.

TP

Teflon seal, stainless body. Like this. https://www.valvewarehouseaustralia...ainless-steel-ball-valve-1-piece-full-flow-ff
rated 1000psi. The brass ones are generally not rated for either pressure or low temperature N2O can get to. There's no significant price difference.

Norm

 

[OzHybrid]

Hi, been using hybrids in the UK for years, I now have a RATT L/M combo hardware only
Does anyone have any information on the size of the grains?
I have 1 from a RATT K240 and looks like polypropylene??
any infor on wall thickness and nozzle form please.
Thanks

The L/M reloads were polypropylene. Aerocon used to have some RattWorks reloads until I bought them all..... Many years ago. RATTWorks.net has some fuel grain/injector test results for the K240. These seem to show that ABS would be a better fuel grain with a type4 injector (see attached)
Natural ABS prints well in a warmed chamber with a 105 degC bed. So printing a reload is more doable than machining one as you'd need a biggish lathe. And extrapolating the K240 test results for an L or M is an interesting idea. From the test results, it might be a good idea to have a top bulkhead insulator. Or at least the injector exit holes further away from the bulkhead of the #5 test. I'll dig out the nozzle and measure it. I don't have radius gauges, so I'll have to approximate the inlet radius. You can PM me if you want more info.
Norm

 

[cfb_rolley]

that ball valve is perfect, thanks!

Also, on ABS grains - I’ve recently started testing some 3D printed ABS grains with my micro-hybrid with really good results so far. It opens up so much flexibility in port geometry as well, spiral ports, twisted star grains, mesh grains - there’s not much you can’t do and that’s pretty awesome.

 

[OzHybrid]

that ball valve is perfect, thanks!

Also, on ABS grains - I’ve recently started testing some 3D printed ABS grains with my micro-hybrid with really good results so far. It opens up so much flexibility in port geometry as well, spiral ports, twisted star grains, mesh grains - there’s not much you can’t do and that’s pretty awesome.

@Rocket_Col If you are in the UK, Screwfix should have something similar with lower postage.

 

[G_T]

What sort of regression rate are you seeing with ABS?

 

[G_T]

Adding to the questions, does anyone know if any of the various liquid rubber coating compounds such as liquid roof EPDM will bulk cure? Or only when put down as a membrane?

 

[rocket_troy]

Adding to the questions, does anyone know if any of the various liquid rubber coating compounds such as liquid roof EPDM will bulk cure? Or only when put down as a membrane?

I don't know 1st hand (although I have a pale sitting there for years), but Anthony Cesaroni says the stuff like Proguard doesn't bulk cure well.

BTW: I'm happy to run a test on casting a block if you can give me a size and it's not too big.

TP

 

[cfb_rolley]

What sort of regression rate are you seeing with ABS?

I’ve only done one flight on a straight port grain, but I'm getting a bit over 1mm/s average. It’s difficult to measure accurately for more complex grain geometry rather than straight port, but star port definitely had a decent increase in performance. I need to do a bunch more flights to properly quantify how much of a difference there is.

@ContrailRockets, by the way, do you still make 29mm motors? I see they're on the site but no reloads for them, is it something that users make their own grains for? A 38mm G130 puts me right at the absolute maximum height I'm able to fly at my usual launch area according top Openrocket, I'm thinking a 29mm x 16 inch motor on 3D printed ABS grains might be a better option for flying in that area.