Certainly my success has come with smaller diameter motors. I think it is incredible that the TRA record L was attained with a 14% L (114% of the impulse of a full K). That was a indeed because it is a 54mm motor vs. a 75mm motor. The TRA J record is another great example - a J570 would not normally be thought of as an altitude motor, but a more traditional altitude load, the J125 (long burn, full J) gets eaten alive by the J570.

For my part, and in my experience, I agree with the reduced diameter "school of thought". That said, Adrian is a talented and innovative flyer and his success may come other ways. I do not believe it is within my personal ability to fly any current F or G motor as high as I flew an F32 or G55.

As they say on TV - "your actual mileage may vary" 8)

I think the L330's advantage aside from the diameter is its long burn. Also some of the tweaks you used such as the really teeny tailcone and other innovations to shorten the length of the bird really help as well. While my 54mm L altitude bird has been done, prepped, loaded and ready to fly for over 2 years, I recently decided to make some changes and have decided to make it single deploy, saving nearly a foot in length.

I think Adrian has a decent shot of at least getting into the ballpark of your G flight with the Ellis G37? and the only negative there is now that Bob Ellis has passed away, the days of those long burn Ellis motors are also over once the existing stock is gone - that is unless someone buys up the rights from the estate.

Personally I find it terrible that Aerotech stopped making some of those great single use motors - the F32, F72, G55, K250, etc. etc. etc. Has anyone ever asked Gary why or if they'd ever consider going back into production? I'm sure it's a production issue. AT doesn't make anything except E15 and E30 motors in 24mm single use at all. The new K250 and its related "Loadable Single Use" motors aren't up to the impulse provided by the old motors and they're heavier to boot. Someone should start an email campaign to bring back those great single use motors. Without them or their equivalent, I doubt that we'll see some of those existing altitude records fall.

As a final note, I was looking at the Rocksim file for my E altitude record bird and realized that I flew it on an E30 and the bird was a bit underweight for optimal altitude on that motor. If I'd flown it on an E15 (same total impulse), I might have squeeked past 5K.

Having seen Adrian's altitude attempt birds and the Parrot, I have no doubt about his skills and ability to take many of the low power records. If he choses to move on HPR altitude records he's going to be someone to reckon with and we could see a number of records fall. The chief area where I have serious doubts is in records taken with 24mm motors that now cannot be flown except on 29mm motors.

Warren

Thanks for the kind words of support.

An F32 would do a bit better than an F10, but either one should be able to crush the TRA record, given an optimized rocket flying a Beeline and a Parrot.
I'm confident about that statement because Rocksim has been predicting my altitudes pretty much dead on, by which I mean that I can make the Rocksim predictions go above or below the actual value by adjusting the crosswinds, etc. within my own estimate for what they were at the time. All of the tradeoffs we're speculating about --the differences in diameters, rocket lengths, burn times, and fin size necessary for the shorter rockets-- are all taken into account in the Rocksim simulations. So when I flew the 29mm F10 to 8400 feet last November, it wasn't a surprise to me at all. I was predicting flights between about 8200 and 8600. There really isn't any mystery here, just physics. For me, the only real uncertainty is whether I can build a rocket that matches the mass and aerodynamic design and still build it strong enough to get the rocket back in one piece. So far, the answer to the last question has been no, but I'm working on it.

Getting small altitude rockets back is the biggest challenge of all. My optimal mass predictions for F and smaller barely have had room for the traditional altimeters I've been using (mostly Perfectflight MAWD's - about 24gr for board, batteries, ejection charge and ematch) and absolutely no physical room for tracking. It's been unfortunate that Robert DeHate's Picoalt doesn't pass muster for TRA due to lack of temperature compensation. It barely weighs 2 grams with the battery and is less than 1/2" square. Your 8 gram Parrot would solve most of that problem.

I propose a challenge to you Adrian. I'm going to design and build an optimized 29mm bird for the F10 (already have one actually although I have to do some tweaks to see how tight I can get things to fit and to shrink the fins a tad.) and we'll fly them head to head at one of the launches later this year. I'd like to shoot for July, but I'm desperately trying to get my L3 completed for the July launch so that might be too soon. Unfortunately I won't likely be at Oktoberfest this year so we'll have to shoot for August or September.

Even better, I'd like to extend this challenge to ALL flyers and I'm trying to put together an appropriate prize for the contest - either a kit or some kind of reload. I've got to see what Joe has in the prize/raffle bin or find something worthy of such a prize.

W

The av-bay I'm working on fits a Parrot, a Beeline, the Beeline antenna and two batteries (one for the alt, one for deployments + tracker) in a 24mm coupler tube, about 2.4" long. The boards and batteries weigh 15 grams.

Robert DeHate's 2gram altimeter doesn't include the battery, by the way.

Hey Warren,
I'd be up to it for the experience alone..... It would give me something to shoot for. No pun intended... I've been lacking on motivation to move rockets back up in pecking order.

Adrian,
Make sure batch #2 is a good one.... I just ordered one 😛

I got my tubes and some 5 & 6 oz glass, I have to go back and get some hollow cones. I don't think I can bore out the PML ones and make them work. But, I will try it anyway.....
Greg

Thanks for your order.

My wife tells me that the panel of boards just arrived from the surface-mount assembler, so I have my fingers crossed, too. It will really suck if there is an assembly error or a design problem that I didn't catch in the prototype (the version 1 Parrot had one of each).

This batch of 36 V2 parrots are selling fast enough (and took my new SMD assembly guy long enough) that as soon as I verify that things are o.k., I'll have him build up some more.

I'll take one Adrian. About time I stop talking about it and fly one in one of my birds. Can you bring one with you to the June launch?

Warren

Hey Adrian,
How much of the Beeline antenna have you cut and how far could you get a good signal? I know you said you have cut half or so off....... But, if I end up milling out the nose cone I'm wondering how much the cast plastic material will kill the signal. I was thinking about looping it back on it's self or coiled. Any input would help.
Greg

I definitely will, assuming I get done with them by then and I attend the launch. Still a little too much that could go wrong before then to make a firm promise, though.

IF - they are done by then, hold on to mine and I will get it from you at the launch too. If not, let me know and I will pick it up from you, that will save the shipping......
Greg

IF - they are done by then, hold on to mine and I will get it from you at the launch too. If not, let me know and I will pick it up from you, that will save the shipping......
Greg

O.k.

I'll give some more status update in the electronics forum.