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View Full Version : Why hybrids? From hybrid yahoo group


X-wooshprez
03-15-2012, 02:16 PM
I thought I'd share this. It relates to many of the reasons why I like to fly hybrids.
It's a challenge to fly them and many shy away from more complexity. I say that if you do not work in a few roadblocks in your hobby when do you expect to see growth in your knowledge and experience?
Scotty


What attracts hybrid flyers?
I've been following the conversation about the dwindling number of hybrid flyers. One thing I think important is considering what it is about hybrids that attract flyers in the first place.

If it weren't for hybrids, I wouldn't have gotten back into rocketry at all. I flew Estes/Centuri as a kid, dropped out as an adult, but became aware of high-power stuff around 2003. I considered participating, but frankly, APCP seemed just another whoosh-pop - Estes rocket on steroids, especially the single use motors that were in vogue at the time. I'll acknowledge some structural complexities as velocity and mass increase, but it's still pretty straightforward. Engineering, not art.

Once I became aware of hybrids, I jumped in - and I really don't fly anything else. As Todd's website says (or used to say) the "quirky complexity" of hybrids keeps me interested, focused, and keenly aware of the potentially large effect of small changes. If it weren't for the wacky stuff that happens I'd probably be bored stiff.

There have been a number of points made about what keeps people out of hybrids - cost of GSE, lack of on-field support, system complexity, lack of hybrid ready kits, long (overstable) rockets, etc, etc.

For me none of these things has been an issue, and some have been attractions. The cost of the GSE spread over a number of flights is pretty reasonable. Knowing there's no on-field support I ensure I have *everything* I need to fly in advance. I love designing and building rockets and launch control systems, so who needs kits?

As long as I've been flying hybrids, I've heard (repeatedly) what's wrong with them. I take that input and use it as the next design goal. If someone complains that hybrids have wimpy thrust or lousy sound I'll pitch a flight using one of Contrail's 38mm xfast motors in a minimum diameter airframe.... hurts the ears and the neck. The complaint that the rockets are long is true enough - if you use the techniques found in many APCP kits, especially for dual deployment. Innovate and rethink the process, and try something new!

When I started in hybrids I learned about the 'garage' nature of most rocketry businesses. That led me to gather enough reloads to keep me flying for quite a while, just in case. I have a reserve of more than 50 loads for Ratt, Skyripper, and Contrail motors, G through M.

These days, however, I find myself far less interested in flying large numbers of rockets, and far more interested in flying more complex systems. I have only one flight planned for this year - a 3xK525 cluster in a 5.5" rocket 80" long.

Next year will be another attempt at staging.

With all that said, I'm suggesting there is a certain mindset and approach common in hybrid flyers - including intense planning, patience, curiosity, attention to detail, a need for complexity, the ability to learn from your mistakes, and a good sense of humor. Because of this I suspect the number of folks drawn to hybrids in the first place are relatively few.

In the long run I suspect the pool of hybrid flyers will be small but relatively stable - people will come and go in small numbers. Those of us flying can continue to show the public that they can be flown and are great fun. Write about your efforts when time allows. Answer questions from folks on other forums.

And be ready to be the discouraging voice when necessary. I got into a conversation with a college student on one of the pyro forums. He led off by asking "how much thermite should I use to light a second-stage M-class hybrid motor?"

Turns out they were planning to put an M motor on top of a commercial O solid booster. However, they had no working hybrid motor bigger than G, no flights in single stage mode, no working vehicle, and a timeline of 9 months. I rather discouraged them.

Kevin OClassen

Bill
03-15-2012, 03:23 PM
Next year will be another attempt at staging.



How would someone stage to a hybrid unless using the AT motor with the preloaded flight tank? Are those still certified?

The question about the popularity (or lack thereof) of hybrids came up at the last club meeting. It is commonly believed that the bottom fell out when we won the APCP lawsuit.


Bill

chadrog
03-15-2012, 03:48 PM
Any chance you'd be willing to give a "class" on the subject Scott? I have some 29mm sky ripper motors I'd like to blow the dust off of, but as of now I'm clueless...

chadrog
03-15-2012, 04:04 PM
Actually, I think they're Ratt Works.

billspad
03-16-2012, 06:15 AM
How would someone stage to a hybrid

Kevin used a custom top bulkhead that was made by the motor manufacturer and approved by TMT and S & T that allowed him to fill the top motor through the bottom one.




unless using the AT motor with the preloaded flight tank? Are those still certified?



They are still on the certified motor list even though their certification should have run out. TMT (and S & T on motors it certifies) has the option to extend certification and the last time I asked they had no plans to remove them from the list.

X-wooshprez
03-16-2012, 04:00 PM
Any chance you'd be willing to give a "class" on the subject Scott? I have some 29mm sky ripper motors I'd like to blow the dust off of, but as of now I'm clueless...

I've offered to buy Mike Vandebunt's 29mm. hardware off him but he is using the stuff as a paperweight and the ceiling fan is always on high speed. :rolleyes:


I think education is the key to getting more flyers interested in flying hybrids.
I read plenty about them but until I had the hardware in my hands and built the GSE with Brian White I had no idea how they worked.
We found plenty of ways to fail along the way but it seems pretty easy to prep and fly a monotube hybrid now.

I'd like to do some more hybrid flying this year. Showing the rest of the club what it involves is a good idea. Let's put this one down right after we do the RSO/LCO training.

X-wooshprez
03-16-2012, 04:02 PM
Actually, I think they're Ratt Works.

Do you have loads for them?

chadrog
03-16-2012, 04:25 PM
Yes, and the solenoid filling apperatus thing. 'm working on getting some pictures up now.

chadrog
03-16-2012, 04:40 PM
Here they are.