Which Hybrid do YOU think is the best for HPR???

Doug's wesbite is the best place for info:

Yes, hybrids are inherently lower thrust. Not intended for heavy rockets compared to the total impulse class.

The rocket's motor mount must be very long compared to a solid motor. I have a Rattworks I90 motor that is about 3ft long!

You will need to supply recovery electronics and your own ejection charge system. The standard method uses black powder which still requires a LEUP if you want to buy it and store it yourself.

-John

I don't know about "diminished raw power;" it depends on how you look at it. There are hybrids that will lift 100 pound rockets.

Generally speaking, though, you're right. At the present state of the technology, hybrids tend to be long burn motors, which means they deliver lower levels of initial thrust.

I've never considered hybrids a substitute for conventional motors...or anything else for that matter. They are a different type of motor that should be evaluated on their own terms. I suppose it's inevitable that we compare them to solid motors, since those are our main points of reference. But the general conception of hybrids as "wimpy" is annoying to me. That's what model airplane people thought of electric powered RC airplanes a few years ago...in spite of the fact that the world speed record is held by an electric powered RC sailplane.

Sorry to be so general. Let's get specific.

If you want to get into hybrids, your big choice is between pyrotechnic ignition and GOX-based ignition. It's cheaper to get into pyro-based ignition, since the GSE costs about half as much; all you need is a NOX tank and the first two modules of my RTLS system, or roll your own ignition and valve setup. The limitation is the number of motors available: at this time, RATT Works H, I and K; West Coast I; and Propulsion Polymers H, I and J. The good news is that RATT Works is testing an L and an M, West Coast is testing an L and some others, and ProPoly has announced two Js and two Ks. So the motor range for pyro-ignition hybrids is improving.

If you go with GOX-based ignition you're looking at more GSE, but you get your hands on the 39 different HyperTEK motor combinations, from I through M. HyperTEK motors are elegant, exciting, well-made systems that are backed up by an outstanding company. (Of course, so are RATT, ProPoly and WCH. I know all these people and am proud to work with them.) And you can use your GOX-based GSE to fire any commercially available hybrid motor.

I'll get commercial now (forgive me; the mortgage is due). I can get you into pyro-ignition hybrids for about $500, with a 20 pound tank and Modules 1 and 2 of the RTLS. For the GOX-based system it's more complicated, but as a reference point, if you wanted what I call the "everything system," including a 20 pound tank, an X-Rockets drop-down launcher, two fill stems (one for J-L and one for M HyperTEK) and all the hoses and stuff, you're looking at about $1400. You can of course spend less by getting a GOX-based system that doesn't do M motors, or uses a different setup than the X-Rockets drop-down launcher, but that's what you would spend for top-of-the-line. And I really strongly recommend the X-Rockets drop down launcher. What you spend on that you will save in the cost of replacing fried fill stems or motors that bind on the stem for some reason. I will also point out that you can start with the pyro-ignition system and add on the GOX-ignition stuff later. And of course, you can use the RTLS to fire conventional solid fuel motors.

I hope this is helpful. I've spent a lot of time over the past five years talking to people who started the conversation with, "Well, I can't get a LEUP, so I guess I have to look at hybrids." That's not the way to look at it. Hybrids are very exciting motors in their own right, not a substitute for anything. Once people see a few of them fly, the attitude becomes "I've gotta do that!" There is something deliciously NASA-ish about tanking a vehicle on the pad, and it stretches out that moment of anticipation (sometimes almost unbearably, as Robert deHate will attest!).

Doug Pratt

It's hard to tell exactly what you're asking here. Yes, the specific impulse of hybrids is lower (except when it isn't) than comparable HPR solids.

Delivering optimal performance (for some measure of performance) is based on the specifics of the "mission profile". Sometimes, a longer burn is better, sometimes a faster burn is better, depending on what you want to achieve.

In HPR "missions", Isp plays an only very minor role, since there's almost no high mass fraction vehicles out there--the differences in Isp are easily swallowed up by airframe design choices typically made by HPR designers.

Newer hybrid designs achieve Isps that are very respectable, even compared to some of the best HPR solid motors. New multi-port injection schemes used by all four major hybrid manufacturers (Hypertek, RATTWorks, Propulsion Polymers, and West Coast Hybrids) provide very good Isp.

I don't think that there's an answer to "Which Hybrid is the best". It depends. {Of course, if I had a marketting department, they'd shoot me for being so unbiased :-) }.

I started on the Hypertek, mostly because that is what I'd seen flown, and the GSE was available. As Doug said, nitrous doesn't replace AP, it adds a different facet to our hobby. It all depends on what you want to do. Max altitude? Huge rockets? Ugliest paint job? ;) Brad recently got his L3 on a Hypertek M:

Checkout some clubs and see what the local support is like. Out west here, Wanye of nowhybrids has sponsored certification flights with free grains, can't beat that with a stick. There's also FAA rules which must be followed, and a club will already have covered those. The national club web sites should have the names of local clubs.

Joel. phx

And for the headaches, take 2 aspirin and stop reading rmr! ;)

Thanx for all the info guys...especially Mr. Pratt...

I sympathise re: Bills!!

Doug, I'm beginning to get pissed off by my "annual" visits by the BATF in which I have to take a morning off to educate a newbie agent about rocketry and wonder why they're visiting me when I don't even have a magazine to inspect. But, since I fly rockets that have less-than-optimal aerodynamic properties........OK, I'll level with you, I like to fly lead sleds. Can you tell me which Hybrid can safely boost a 60 pound traffic barrel (weight before motor)?

Mark Simpson NAR 71503 Level II God Bless our peacekeepers

Ya, Doug, I guess I will have to. I might even see if you will bring me a 20# N2O tank to LDRS if your are attending next year. I know you get them from someone else, but maybe we can work a deal. People give me crap about hybrids all the time but I dont care they are fun. I got into them way before the fire or the legislation. I just liked the complixity, call me crazy but I liked it. Took me over 3 years to build my hypertek setup, because I was building it slowly. Now my club here in Mass gets the advantage of that. Thanks Doug, you helped me see the 'gas' of hybrids ;-)

Thanks Marcus, So take your simulator. Plug in some numbers and simulate away. You will find that , in general, keeping the weight down and the altitude up is the name of the game in hybrids. They are fun. Give it a try, you won't regret it.

RDH8

Jerry told you so.

Jerry

I hate the complexity, but I love watching and hearing them fly. Haven't done any hybrids yet myself but our club flies a lot of them. When I finally do my Level 3, it will most likely be on a hybrid. In fact, I plan to do a test flight first with a hybrid L.

LOL, Thats funny. Someone pointed out to me that it sounded like I was replying to Marcus. eg:" Give it a try, you won't regret it." Actually I was refering to the original post as I am sure Marcus has flown one or two hybrids ;-)

RDH8

Looks like the M960 would do the job; that's a nice motor. 2800 cc tank, baby M, pretty cheap ticket for an M flight. Several of the bigger Ms will work too. If you've got some sort of rail guidance, I would be willing to consider the L740.

Be glad to. I can usually work a deal of some sort on tanks. And you can count on me being at LDRS; it's only an hour away from where I was born (and where I intend to return some day).

I don't really get upset over all the misinformation flying around about gassers...I remember the wild rumors and wilder opinions when (gasp) reloadable motors were suggested! If some people find hybrids too challenging or uninteresting, cool...rocketry has something for every interest. I love it all, from 70 pound blue M rockets to Micro Maxx, and I only get mad when someone says that his favorite kind of rocket is "better" than another. I spent 10 years working at the AMA, and I've seen what happens when that kind of petty squabbling takes over.

By the way, talking of tanks...did I tell you I found out why we spent

The technology is improving. It took a dramatic leap when Dave Griffith put the floating-injector valve hybrids on the market, and another dramatic leap when Cesaroni took over the HyperTEK line. That's not knocking Korey or the other HyperTEK folks...it's saying that Cesaroni took their work and ran with it.

I see the big problem with hybrids as information, not engineering. The products and systems available are elegant, reliable, and excellent value. What's inadequate are the instructions. This is a problem with all hobbies...for many years, if someone asked me how to learn to fly an RC helicopter, the best advice I could give them was "find someone else who is already flying them, and make friends."

That's why I cranked up

Hybrids look like a pain in the rear.

when my doctor puts on the rubber glove and gets out the KY...that is a pain in the rear!!

:-O

The "Got No Altitude" Outcast

As an early hybrid vendor and general believer, I have to agree. ALOT more hassle than any solid.

Jerry

Plug the black wire into the black socket. Plug the yellow wire into the yellow socket. Plug the white ENOUGH! I GET IT ALREADY! Attach the blue hose to the blue fitting. Attach the red,..

hose to the red fitting,...

You can never put too much nitrous in the motor tank,...

Starrocketry and nowhybrids have also posted some excellent hypertek tips.

This is one of those paradigm things. Being in Phoenix, I sort of assume that people think about the sun beating down on the tank (and rocket for that matter). If I went to a cold climate, I might be wondering why I didn't get the performance I expected. I remember reading an article in HPR, when it existed, about cold weather flights effecting hybrid performance. The manufacture (or dealer, I forget) was in Florida, and couldn't exactly reproduce 30 degrees flight temps.

Certified Hybrid User Motor Phreak CHUMP Certified Hybrid Indulging Motor Phreak CHIMP ;)

Joel. phx

I have exactly one hybrid flight under my belt, a Hypertek one. Unfortunately that flight did not end well because of problems unrelated to the motor (I was using Pyrodex ejection charges and used too much powder, blowing the side out of my Quantum Tube PML Eclipse). 95% of the complexity is setting up the GSE. The motor is no harder to assemble than a PRO38 reload (OK, maybe a little since there are O-rings to worry about) and a lot easier than an Aerotech reload.

Step 1: Grease the O-rings Step 2: Screw fuel on to tank Step 3: Install in Rocket

Putting the rocket on the pad is different than a solid, but not difficult. The launch sequence is a lot more fun than with solids.

I like the Hypertek system for the non-pyro ignition. Lugging a large tank of GOX around is a pain however. I'm sure smaller tanks would work (don't they sell little disposable GOX tanks?). Hmmmm, how about selling disposable NOS and GOX tanks the size of propane camping bottles? Wouldn't work for anything over a K motor and would not be very efficient, but it might lower the barriers to entry. Perhaps a deposit could be collected on the bottles and they could be exchanged for full ones without a new deposit. With a Quick connect on the tank you could just snap in a new bottle after you prep your rocket.