2,460 Feet on an E-12-8

[PDawg]

That was Fun! My Scratch Built rocket "Please Don't Cato" surprised me. No holes in the BT but ejection was just after Apogee.

 

[OC-Patrick]

Were you able to keep it in sight the whole time?

 

[cls]

what a great feeling! nice paint job, no wonder it flew so well.

now go do it again, chad stage D12-0 to the E12. good luck !

 

[PDawg]

Were you able to keep it in sight the whole time?

Barely. Conditions were perfect and the sky was clear. A fellow Club Member said he also followed it the whole time. The 8 foot reflective Streamer looked like it was 1 mm, took a while for it to come down. I was hoping for 2000 ft.

 

[SolarYellow]

Now chop down that body tube and gain a few hundred feet.

 

[lakeroadster]

Now chop down that body tube and gain a few hundred feet.

And add nose weight? Trading Peter to pay Paul.

 

[NTP2]

And add nose weight?

But then you lose the 100ft!

 

[SolarYellow]

It's all about the sim work. MD rockets often go higher with nose weight.

 

[NTP2]

It's all about the sim work. MD rockets often go higher with nose weight.

How?

 

[SolarYellow]

Search, like my avatar says, on "optimum weight."

Also, download OpenRocket and play with it. A lot.

 

[NTP2]

Search, like my avatar says, on "optimum weight."

Also, download OpenRocket and play with it. A lot.

no, how in physics terms does it work you increase the mass the more mass you have to push right? Edit I did I don’t see much by searching.

 

[tsmith1315]

no, how in physics terms does it work you increase the mass the more mass you have to push right?

And the more momentum you have during coast phase.

 

[NTP2]

And the more momentum you have during coast phase.

I see thanks.

 

[asm109]

Toss a whiffle ball, Toss a baseball with same effort. Which goes further?

Balance drag forces and momentum during coast.

 

[BABAR]

And the more momentum you have during coast phase.

And often the less finnage and length needed for stability. Think Badminton shuttlecock.

hence each rocket design has an “optimum” mass. Exceeding it or failing to reach it BOTH will result in lower max altitude compared to optimum..

from a rocketry flight Perspective, any mass you need to add in a rocket which as built is below optimum mass should be as far forward as possible, preferably near nose cone tip.

tungsten, being denser than lead (but far more expensive) would be an optimum choice.

 

[BEC]

...but of course the relatively porky Estes altimeter served as some of that added mass in the original post

@PDawg I'm glad you got a reading. Usually on those Estes units it's either 0000 after a flight or a pretty reasonable result.

 

[PDawg]

...but of course the relatively porky Estes altimeter served as some of that added mass in the original post

@PDawg I'm glad you got a reading. Usually on those Estes units it's either 0000 after a flight or a pretty reasonable result.

Thanks! It was my first time using one. I understand it didn't likely take its reading until ejection, and if I drilled holes in the body it might've read higher. Body tube got a little kinked so I chopped off 5 inches and I'll see what it does with a D-12-7. I've built these rockets shorter, but the flights became straighter once I reached 17 inches total length. I figured a few extra inches of body tube doesn't weigh much and top priority is a good straight flight.

 

[bjphoenix]

I was curious about that altitude so I plugged an Estes Alpha into OpenRocket, extended the main tube about 5", and got 2577 feet. I'm surprised it is so close to what you got!

 

[PDawg]

Search, like my avatar says, on "optimum weight."

Also, download OpenRocket and play with it. A lot.

I was curious about that altitude so I plugged an Estes Alpha into OpenRocket, extended the main tube about 5", and got 2577 feet. I'm surprised it is so close to what you got!

I've never used Open Rocket believe it or not. If I ever get into High power I will. I like most Rockets, but Minimum Diameters will always be among my favorites. Someone here put in an F-15-8 Sub Min diameter rocket I built (29mm lower half, BT50 upper half) and it showed 2850 feet, I suspect my straight 29mm version went even higher.

 

[bjphoenix]

I've never used Open Rocket believe it or not. If I ever get into High power I will. I like most Rockets, but Minimum Diameters will always be among my favorites. Someone here put in an F-15-8 Sub Min diameter rocket I built (29mm lower half, BT50 upper half) and it showed 2850 feet, I suspect my straight 29mm version went even higher.

Aerotech used to make a 24mm F72, maybe they still do occasionally. Put that in your rocket and try it, you can probably break mach with it.

 

[Spacedog49Krell]

Great flight, PDawg. Start using Open Rocket, now. Become familiar with it, dial it into your construction characteristics, with your launch altitude and temperatures. When you fly Min Diameter HPR, like I do, you'll spent less time in the learning curve for Open Rocket. You might need to invest in a radio location finder for your Min Dia HPR rockets. I have several G powered that fly to 4,000 - 7,000 ft altitudes and they are very difficult to visually track.

 

[SolarYellow]

Great flight, PDawg. Start using Open Rocket, now. Become familiar with it, dial it into your construction characteristics, with your launch altitude and temperatures. When you fly Min Diameter HPR, like I do, you'll spent less time in the learning curve for Open Rocket. You might need to invest in a radio location finder for your Min Dia HPR rockets. I have several G powered that fly to 4,000 - 7,000 ft altitudes and they are very difficult to visually track.

What he said.

I got sucked into the whole BAR thing by simming a Hi-Flier in OR, realizing it's a pretty lame design, and OCDing on how to improve it. You can learn a lot, much faster, by hacking around in OR than by actually building rockets. Then your rocket building time and expense is put to much better use. For example, I really meant that you're hundreds of feet shy of where you can be with an optimized BT-50/E12 combo.

I've only managed to sim two means of breaking mach without crossing the HPR line. Two-stage F44s (needs a Blue Raven for airstart) and the CTI 144G65. Either one sims to around Mach 1.3.

 

[PDawg]

Aerotech used to make a 24mm F72, maybe they still do occasionally. Put that in your rocket and try it, you can probably break mach with it.

Probably not, those fins are surface mount Balsa. This thing is very flimsy and the tube I used from BMS is thinner than Estes tubes.

 

[PDawg]

What he said.

I got sucked into the whole BAR thing by simming a Hi-Flier in OR, realizing it's a pretty lame design, and OCDing on how to improve it. You can learn a lot, much faster, by hacking around in OR than by actually building rockets. Then your rocket building time and expense is put to much better use. For example, I really meant that you're hundreds of feet shy of where you can be with an optimized BT-50/E12 combo.

I've only managed to sim two means of breaking mach without crossing the HPR line. Two-stage F44s (needs a Blue Raven for airstart) and the CTI 144G65. Either one sims to around Mach 1.3.

I understand, I won't get into High Power without it. I've played around with it and it defianitely is a quick way to learn a lot.

 

[Spacedog49Krell]

I've only managed to sim two means of breaking mach without crossing the HPR line. Two-stage F44s (needs a Blue Raven for airstart) and the CTI 144G65. Either one sims to around Mach 1.3.

For the history buffs. This is probably the first F powered rocket to go supersonic. It flew on an experimental 18mm X 70mm PlasmaJet F80 at Lucerne Dry Lake in 1978.

 

[PDawg]

For the history buffs. This is probably the first F powered rocket to go supersonic. It flew on an experimental 18mm X 70mm PlasmaJet F80 at Lucerne Dry Lake in 1978.

Thanks for that, very Cool.

 

[PDawg]

...but of course the relatively porky Estes altimeter served as some of that added mass in the original post

@PDawg I'm glad you got a reading. Usually on those Estes units it's either 0000 after a flight or a pretty reasonable result.

The Estes Altimeter added 12 grams so I switched Nosecones to shave off 7 grams to compensate. I'm happy it got a reading, I was prepared for disappointment.

 

[PDawg]

We'll see how the next one does in a week if all goes well. 3 grams heavier, 4 fins, and uses a plastic Fin can . The fins are about half as thick. This has flown twice but was rebuilt after it was run over by a car (missed the Fin can).

 

[cwbullet]

That was Fun! My Scratch Built rocket "Please Don't Cato" surprised me. No holes in the BT but ejection was just after Apogee.

Pretty impressive.

 

[jqavins]

And often the less finnage and length needed for stability. Think Badminton shuttlecock.

hence each rocket design has an “optimum” mass. Exceeding it or failing to reach it BOTH will result in lower max altitude compared to optimum..

from a rocketry flight Perspective, any mass you need to add in a rocket which as built is below optimum mass should be as far forward as possible, preferably near nose cone tip.

tungsten, being denser than lead (but far more expensive) would be an optimum choice.

Density of Tungsten: 19.28 g/cm³
Density of Osmium: 22.5 g/cm³

I mean, if you're going to go all spendy, why not go all the way?