What did you do rocket wise today?

rharshberger said:

AFAIK, there is only FAR 101 which limits rockets mass 1500g max), propellant weight (125g max). As long as the those maximums are not exceeded the altitude is unrestricted. As soon as the rocket/motor exceeds either restriction then a FAA Waiver aka COA is required and that will have altitude limitations, plus the restrictions on flying field sizes based on impulse from either NFPA 1122 or 1127 (can't remember which).

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That's my understanding as well, just wanted to cross check.

Starting on the process of sanding/smoothing epoxy fillet/fin coatings. A few observations:

1. West System 105/207 has a shelf life of over 10 years. I have had zero problems getting it to set rock-hard on every batch. The hardener has turned a bit dark but that's no big deal. I *have* been making small batches (tablespoon sized) and find that the stuff has very reasonable mixing latitude for a hard setup. Very easy to work with, overall. The 105 resin is still water-clear after all this time. [Bought a quart kit from Chad Ring at least that long ago, maybe longer. It's a great product.]

2. West epoxy is devilishly hard when set up - but sands surprisingly well. So far, I am having good success with grinding down all the runs and drips with 80 grit sandpaper, but it is very slow going. When I get the surface smoothed, I am going to have to fill a few voids left by embedded bubbles - I will probably use Z-Poxy coating epoxy there, since it sets in a couple of hours instead of overnight. I have tested samples, and Z-Poxy over West seems to work well - no funky reactions, no excess bubbles, etc. Color differences won't matter as the whole thing is going to be painted anyway - although the epoxy coating over plywood fins looks really sharp 'in the raw.' [My Z-Poxy is marked with a buy-date in 1994 but it still sets up just fine too.]

3. Part of the slow set-up for the epoxy may be the fact that my basement build room is running about 64-65 degrees this time of year, which is on the low side for the product. There is a heat vent in the ceiling right above the bench, but the furnace isn't running enough to help...a disadvantage of our relatively efficient home. Upstairs is comfortable just under 70 and gets enough sun on winter days that the furnace doesn't start very often.

4. Just at a guess, I'm thinking that the shelf life of epoxy may be extended by keeping it at relatively constant temps (no more than 65-80 degrees) and in a dark cabinet. My stock has survived long storage and a move, 7 years ago. I certainly recommend stable storage - and writing the date of purchase on the bottles!

dhbarr said:

That's my understanding as well, just wanted to cross check.

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NFPA 1127 governs HPR; NFPA 1122 is for model rockets. The NAR and TRA safety codes are effectively included in these documents.

Just as an FYI, NFPA 1125 is a code for the manufacturing of hobby rocket motors.

And i have just exhausted my direct knowledge of NFPA codes...

jqavins said:

The altitude record is held by a team called Go Fast, who passed the Kármán line, the internationally recognized "edge of space" at 100 km*. While that's only been done once, 30 km is not terribly uncommon among the really big flyers (which does not include me). The lower (and more reasonably priced) end of the high power hobby often sees one to two km flights and four or five now and then. Low or mid power tends to reach anywhere from 100 to 1000 meters.

There is an altitude limit for casual launches and waivers from the Federal Aviation Administration are required beyond that, each waiver having a specified altitude limit. The waivers are usually obtained by leaders of clubs that organize the high power launches, who deserve more credit for their effort than they frequently get. (Thank you, waiver holders!) Others can tell you far more about that process than I can, but I know it's not as hard as is might be.

* This is where you say "Holy crap!"

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I don't suppose there are any flat earther's among you rocket people? (I was about to write "guys" but I realised thee may be some girls who fly rockets). Are there sometimes cameras on-board activated at zenith? I imagine that any weight is detrimental to performance. I guess anything over 40,000 ft will show some earth curvature? How about I fly big a kite to 20,000 ft then launch a rocket? I wonder how the rocket performance would be getting a head start. Sorry if some of my questions are a bit silly.

Bob Moore

Droceretik said:

I don't suppose there are any flat earther's among you rocket people? (I was about to write "guys" but I realised thee may be some girls who fly rockets). Are there sometimes cameras on-board activated at zenith? I imagine that any weight is detrimental to performance. I guess anything over 40,000 ft will show some earth curvature? How about I fly big a kite to 20,000 ft then launch a rocket? I wonder how the rocket performance would be getting a head start. Sorry if some of my questions are a bit silly.

Bob Moore

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If there are folks of the flat earth persuasion, they don't speak up much . Which makes sense considering a good number of us work (or worked previously) in the industry of putting space craft, satellites, and (occasionally) people into orbit.
There are women involved, though they are rare! Just at our club meeting last night there was a talented young woman about ready to fly her L3

We like cameras Example is a still from Jim Jarvis's ~170k' flight on a 3 stage rocket this year. Link to video:

It would have to be an extremely strong kite to lift a rocket and stabilize it for vertical flights. The performance would be the same as if you launched it from a 20k' foot mountain with the associated decrease in drag due to lower atmospheric pressure. Another technique called a Rockoon would use a lighter-than air lifting rig to to raise a rocket to high altitude and launch, although that has proven rather problematic when attempted (it seems to be a popular idea with college students that pop in to ask questions)

Go fly!

Droceretik said:

I don't suppose there are any flat earther's among you rocket people? (I was about to write "guys" but I realised thee may be some girls who fly rockets). Are there sometimes cameras on-board activated at zenith? I imagine that any weight is detrimental to performance. I guess anything over 40,000 ft will show some earth curvature? How about I fly big a kite to 20,000 ft then launch a rocket? I wonder how the rocket performance would be getting a head start. Sorry if some of my questions are a bit silly.

Bob Moore

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HI Bob, cameras on rockets are almost as common as altimeters anymore. But any curvature seen at altitude is because the Earth is round and flat like a pancake. Thankfully the turtles holding the disk don't mind our rockets.

And it turns out that there's an optimum weight for maximum altitude for any given rocket, based on the motor, drag, etc. I think most small model rockets are heavier than optimum, and most larger rockets are lighter. Rocksim will calculate the optimum weight for a particular design and motor combination.

Best -- Terry

rharshberger said:

AFAIK, there is only FAR 101 which limits rockets mass 1500g max), propellant weight (125g max). As long as the those maximums are not exceeded the altitude is unrestricted.

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I stand corrected. So if one could achieve miles high on 125 g of propellant it'd be OK legally. (But of course one can't.)

Nytrunner said:

IAnother technique called a Rockoon would use a lighter-than air lifting rig to to raise a rocket to high altitude and launch, although that has proven rather problematic when attempted (it seems to be a popular idea with college students that pop in to ask questions)

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About 5 or 10 years ago, in a hobby shop with lots of rocketry stuff, I met two young women, new high school grads headed to MIT, looking for a summer project to take on with the mailer tube MIT had sent them for the purpose. (I.e., "Do something - anything - with this and show up with it in September.) They intended to use it as part of a rockoon and asked me if I had any advice. I suggested that they add it into an Aerotech Initiator (mainly because the store had one on the shelf) using custom transitions as the mailer was a little larger than the kit's airframe. I suggested acquiring either RockSim or OpenRocket. I also discussed some of the difficulties of stabilizing such a platform, but they assured me that they had done that part before! I left them my email address requesting to know how the project came out, and offering to answer more questions to the best of my ability, but I never heard from them.

Found an Me163 at the National War Memorial in Canberra.

My son and I got a couple flights on our Mach 1 Exiter this afternoon. It was the first time he wanted to push the button to launch it.

OverTheTop said:

Found an Me163 at the National War Memorial in Canberra.
View attachment 370578

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When we lived in Canberra, I used to take the kids there every Sunday... My boys named all the planes in the hall of aircraft - that one was "Jessy the Messerschmidt Jet"...

Purchased a proof set of these:
https://eshop.ramint.gov.au/50th-Anniversary-of-the-Moon-Landing/10076.aspx


I had visited the actual dish used to receive the pics from Apollo 11 earlier in the week.

jqavins said:

I stand corrected. So if one could achieve miles high on 125 g of propellant it'd be OK legally. (But of course one can't.)

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Two miles ought to be doable.

24mm blue streak grains are cute!

Low/Mid launch tomorrow with the club before Blue Origin plows up our field for their vulcan factory.... the circumstance is perverse

Pink rockets are cursed! A year ago, I lost a pink Hi Flyer on its maiden flight. Today, my daughter's pink Mini Max suffered an timely death on its maiden flight. Yeah, an A10-3T is a bit much for a maiden flight, but the thing did just burn right through the top immediately off the pad and destroyed the tube. The fins are still good so I'll cut the tube and make a Max Booster out of it.

Built another Eggtimer Quantum, and my first Proton. I love it when it all tests pefect on the first try. Half a dozen more kits to go after getting the rest of mr BF order. Forget swapping avionics between rockets at these prices. Thanks Cris.

Meditating upon the possibility of a Regallo glider recovery for a rocket system. Using OpenRocket 13 something, as 15.03 no longer works on my system. 15.03 files will run a 13.x file with a harmless error that mentions a feature in a version that doesn't exist yet. Ignore, go... And going to have to use Xflr5 to see if I can match the curves.

Lucifer said:

Meditating upon the possibility of a Regallo glider recovery for a rocket system. Using OpenRocket 13 something, as 15.03 no longer works on my system. 15.03 files will run a 13.x file with a harmless error that mentions a feature in a version that doesn't exist yet. Ignore, go... And going to have to use Xflr5 to see if I can match the curves.

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Sounds like you might have an issue with whatever version of Java you have installed.

AeroAggie said:

Pink rockets are cursed! A year ago, I lost a pink Hi Flyer on its maiden flight.

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Sorry bud, that's crummy. To pour salt on the wound, after hearing your bad luck my wife said she wanted her Formula 38 painted pink.

GrouchoDuke said:

Sorry bud, that's crummy. To pour salt on the wound, after hearing your bad luck my wife said she wanted her Formula 38 painted pink.

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Go for it! It's probably just me that's cursed. Sad thing is, I actually like pink rockets. They're really easy to see.


Wait, your wife has a rocket? How'd you manage that? I think the only way my wife would say "that's my rocket" is if I made something silly, like a dolphin or a penguin or a penis.

Lucifer said:

Meditating upon the possibility of a Regallo glider recovery for a rocket system. Using OpenRocket 13 something, as 15.03 no longer works on my system. 15.03 files will run a 13.x file with a harmless error that mentions a feature in a version that doesn't exist yet. Ignore, go... And going to have to use Xflr5 to see if I can match the curves.

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Try this if you haven't already: https://www.rocketryforum.com/threa...d-mac-to-solve-all-your-java-problems.143540/

AeroAggie said:

Wait, your wife has a rocket? How'd you manage that? I think the only way my wife would say "that's my rocket" is if I made something silly, like a dolphin or a penguin or a penis.

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Yeah, I figured they'd be really easy to see. Good to know.

I cheated - I won it for her in the raffle at Tripoli Vegas' SpringFest last year. The club president wrote on the bag that it was hers...DONE!

I fiberglassed 2 4 inch LOC tubes.

AeroAggie said:

I think the only way my wife would say "that's my rocket" is if I made something silly, like a dolphin or a penguin or a penis.

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Sure, why do you think she wants it painted pink?

Made the short drive to a friends farm for a launch - 9 up, 9 down! Minor fin damage from a chute that failed to open and had to fish my Estes Star Orbiter out of the pond but otherwise a great afternoon.

GrouchoDuke said:

I cheated - I won it for her in the raffle at Tripoli Vegas' SpringFest last year. The club president wrote on the bag that it was hers...DONE!

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Sneaky! I'll keep that in mind for the LDRS raffle. I know all the major vendors will be there with goodies.

Started building the "Bull Pup" .. Finished the launch pad .. improved some wiring on my launch controller. THIRD go-round for this hobby! First time was 1970 !!

Wowzers - I dropped the 3rd stage of my Lego SaturnV trying to disconnect the 1st stage to show the kids and then spent 40mins finding all the pieces and reassembling it.. Looking at yours, it looks as though its on a ledge over a set of stairs maybe?

If so, I doth my cap to your bravery sir...

Built another Proton, LCD RX w/GPS, and a Quark. The Quantum and Proton take some time. But the Quark parts are really small......

snrkl said:

Wowzers - I dropped the 3rd stage of my Lego SaturnV trying to disconnect the 1st stage to show the kids and then spent 40mins finding all the pieces and reassembling it.. Looking at yours, it looks as though its on a ledge over a set of stairs maybe?

If so, I doth my cap to your bravery sir...

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Ha! It sits on a ledge about 10 FEET above my living room floor! The key here is that it sits VERY heavy and stable, and is COMPLETELY out of reach of ANY hands at all (or anything else for that matter!) Also .... There are NO kids here running amok so, there it sits collecting dust! At some point I will switch to "horizontal" ... keep it that way a few months, then probably switch back! Don't you worry ... I gave this location LOTS of thought before placing it there!

Flew my grid fin rocket "Further Assembly Required" on a G40 at a local low/mid power launch.