(PR) New "econo" hybrid launch system from Pratt Hobbies

kudos to Doug.. now if we can just figure out a non-pyro actuated recovery system for hybrids, the future is now..

when is a model rocket not a model rocket? when its a G hybrid.....and weighs less than 1lb...heheheheh

shockie B)

The Minitanker Combo is a package designed to help modelers start using smaller hybrid rocket motors (in the G and H range) as economically as possible. The package includes a 5-pound tank for liquid N2O, a custom-manufactured solenoid valve, and fittings to attach to all commercially-available floating-injector hybrid rocket motors. The Minitanker Combo is priced at $195.00.

Floating-injector hybrid motors use a nylon hose to fill the motor with N2O, and a small pyrotechnic igniter to preheat the combustion chamber and release the N2O by cutting the hose. Popular motors of this type are made by RATT Works, Sky Ripper Systems, Propulsion Polymers and West Coast Hybrids.

The Minitanker Combo is easily connected to any typical club launch system that provides at least two circuits of 12 volts for ignition of conventional motors. One of the circuits controls the Minitanker solenoid valve, allowing the motor to be filled. The other circuit attaches to the motor's igniter and functions exactly as it would with a conventional solid fuel motor.

"Hybrid motors have grown in popularity over the last few years," said Doug Pratt, owner of Pratt Hobbies. "Our Modular RTLS (Remote Tanking and Launching System) ground support system has sold very well. The RTLS incorporates its own battery and electrical control system, and is an outstanding value because it is the only system that will fill and fire all commercially-available hobby rocket motors, solid or hybrid."

"However, as hybrid motor technology has matured, smaller motors have come on the market. I am very excited about the new 29mm G and H motors coming soon from Sky Ripper Systems, and the RATT Works H70 remains our best selling hybrid motor. That inspired me to think about a 'minimalist' ground support system, something that would make it easier and cheaper for folks to start flying these small hybrids," said Pratt.

If your club has a multi-pad 12 volt launch system, or you have two standard launch systems of your own, the Minitanker Combo is all you need to start flying G and H hybrids. The 5 pound supply tank is adequate for 6-8 flights of an H motor, depending on conditions. The solenoid valve is custom manufactured to Pratt Hobbies specifications and guaranteed for life. Fittings are included to connect to all floating-injector hybrids in the G-H range currently on the market.

The Minitanker is not suitable for motors that are larger than H, because there is no "dump" valve to vent the tank in the event of a misfire. When you decide to upgrade to bigger motors, you can trade in the Minitanker valve assembly toward the cost of an RTLS-M2 system, which is suitable for any hybrid motor. Complete descriptions and documentation of the Minitanker and RTLS systems are available on the Pratt Hobbies web site.

The Minitanker Combo is available for immediate shipment from the Pratt Hobbies catalog web site,

Pratt Hobbies is a small manufacturer of kits and accessories for rocket hobbyists. Now in its tenth year, Pratt Hobbies is known for being the first to offer braided Kevlar® shock cords, Nomex® heat shields, and other unique and innovative products. Doug Pratt is the author of nine hobby books, including "Basics of Model Rocketry," and is currently writing a new book tentatively titled, "Hybrid Rocket Motor Operations Manual." He plans to publish it along with revised editions of some of his earlier books through a new publishing company, Robin Hill Press.

For more information, see the web site at

Who offers G hybrids?

BTW a G33, G75, G125, F101 are all not model rocket motors either.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

"Aerotech should change it's ads from 'the future of HPR is solidifying...' to 'the future of HPR is vaporizing...' " - Bob Kaplow

When is an exemption not an exemption?

When TRA/AT/Magnum/etc/etc forsakes it.

Jerry

"Last known photo." :

ALL "sport motors" are ATF exempt.

Period.

Here's the law that shows that:

27 CFR 555.141 exemptions (a) (8) Gasoline, fertilizers, propellant actuated devices, or propellant actuated industrial tools manufactured, imported, or distributed for their intended purposes.

Here's the JUDGE's words verifying it.

"In addition, the Court finds that the ATF's pronouncement that sport rocket motors are not PADs is invalid because it was made without compliance with the notice-and-comment rulemaking procedures of the OCCA and the APA."

Here is the court order that is from:

"Even Jerry tried to steer you in the right direction! (Er... sorry about the 'even' part, Jerry... but your single post showed that perhaps you, alone, are the only person here that understands the complexities of acceleration as it relates to the REAL world!)"

- "Mark"

"Alas, the problem isn't posts FROM Jerry. It's endless posts ABOUT Jerry. They come from Phil, Fred, Dave, Ray, and even occasionally from me!"

- Bob Kaplow

"Jerry is by far one of the most long lasting and successful..."

-Steve Bloom

"Is Jerry clean as the wind driven snow? Hell _no_. Is USR trying to supply the market, which can only increase the number of Rocketeers? Yes."

- snipped-for-privacy@hotmail.com (Quilly Mammoth)

Jerry

Both RATTWORKS and West Coast Hybrids have the technology.

Good thing too.

It will soon be needed thanks largely to TRA and HPR magazine and Aerotech.

Jerry

Proof:

damn Bob what planet have u been on for the past year....?

shockie B)

Mark A Palmer

That's just truly pathetic.

The RATT Works H can be made into a G with a neat little aluminum tube that Dave gave me. It screws into the forward closure and allows the motor to vent before it is full of N2O. I tried it, and it works, but it isn't exactly elegant.

Todd Moore to the rescue! Not only is Sky Ripper developing a lovely line of 29mm motors, based on their very successful 38mm set, but Todd is responsible for a major innovation: he's molding the fuel grains. They have an interior geometry that is optimized for a hybrid's burn characteristics. Check out

Since my niche is GSE, I wanted to do something that would lower the cost of entry. This Minitanker Combo is about as "minimalist" as you can get, taking maximum advantage of equipment a club or an advanced modeler is already likely to have. And by offering a trade-in on the valve and hardware, I can stick to my "modular" philosophy of offering a system that will grow with your needs.

I did have one decision to make in the design that I'm not entirely certain of, so I'll ask. I could have made the Combo $20 cheaper by going with a 2.5 pound tank instead of the 5 pounder. What do you think? Should I offer the 2.5? A RATT H takes about .5 pounds of N2O, so with venting and everything you could expect to get maybe 3 flights out of a 2.5 lb tank (four on a good day). Since the upcoming Sky Ripper Gs are smaller than the RATT H, one can assume that you could get 5-6 flights out of a 2.5 pound supply tank. Should I have gone with that one?

Doug Pratt dad-at-pratthobbies-dot-com

I think you made the right decision. Particularly with first time users you're going to end up losing some N2O during operation. So a

I see. SO none are certified at the moment.

Over the holidays I was shopping in a cooking store, and took a real close look at the whipped cream maker thingies. NOT for the whipped cream :-)

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Whippits?

Bob, didn't know you had it in you.

Something interesting involving whipped cream cartridges is in the pipeline, Bob. Patience.

Doug Pratt dad-at-pratthobbies-dot-com

Thanks very much, Alex.

YEAAAAAAAAAAAAAA GO Doug GO!!!!

shockie B)

Is that like power to ALL the people?

Not a micro-hybrid surely? I thought the general conclusion was that while interesting, cream-whipping cartridges won't give you better performance than BP motors, let alone small AP. I've seen one fly, and the performance wasn't very impressive, though it did make a nice sound :-)

How about smaller U/C valved hybrid motors (i.e. sub 29mm). I'm sure Propulsion Polymers list 22mm on their site.

I guess you'd start running into issues with weight of motor hardware/deployment electronics reducing your performance to the point where it might not be worth it (well, apart from the obvious technical/'rocket science' aspect).

Any ideas?

The MicroHybrid is a splendid device. Rene Caldera, who as far as I know came up with it, is a very clever man. I have two of them (made by Caveman) and they are a lot of fun. That's not what we have cooking, though. Can't say more yet.

As for 22mm hybrids, Marcus Leech has indeed produced some; I have a set. They burn 1/4 inch PVC pipe for fuel. Unsurprisingly, knowing Marcus, they are excellent. I'm proud to say that I made a suggestion that led to an improved injector for them. But I'm not really happy with igniting 'em. I've lit them with pyro preheater slugs cut from EX delay grains that I cast, but that is not something I would expect a consumer to do. Marcus lights them with GOX and steel wool, which works big time, but means you have to have a GSE system capable of handling two gases...and for E and F motors, that doesn't make a lot of sense. Unless you're using someone else's system.

Paul Lavin of Deepsky Rocket Shop showed me how he makes preheater grains for RATT Works motors in the UK, where (like Canada) any amount of APCP is regulated. He has a little donut shaped mold. You mix up a paste of KNO3 and epoxy and trowel it into the mold. Stick a Daveyfire in it (they can have Daveyfires, but not APCP...go figure), let it harden and install it. Clever. Maybe that's the way to go for Marcus'

Talking to all these really smart people like Marcus and Paul and Rene...I'm running as hard as I can just trying to keep up with them!

Doug Pratt dad-at-pratthobbies-dot-com

Niall Oswald wrote:

performance

performance

technical/'rocket

constitutional

Correct.

I saw Roy Trzeciak-Hicks microhybrid (he makes them himself, see link below) and it certainly is a very nice piece of work. Unfortunately a wire broke on the MAD he was using for deployment and it, well, didnt...

Deepsky seem to be working on some combination of an Estes motor and a cream cartridge.

I guess the key to small hybrids is small electronics...

But would be legal over here, which is a major advantage!

We're also not allowed to commit an 'act of manufacture', hence all the problems with APCP starter grains and the reason you can't make 'EX' solid motors over here.