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Good point, I hadn’t thought about that. I slouch corrected!
Ultraman VTOL Plane (Space Booster Version)
- Thread starter BigMacDaddy
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Conservation of momentum would suggest that the rocket would be propelled forward in proportion to the weight of the ejected engine... not sure which micro-force will be more substantial. None will be as substantial as the drag of my poor quality primer job...
Fill, sand, repeat.
Today I finally had a chance to test a couple of rockets I have built over the last several weeks...
The rocket was pretty stable and impressive with a pair of C5 engines (I was hoping to launch with a pair of C6 engines but needed to use 2x C5's due to weight). However, as forecasted, it arched over the top quite a bit (does 180 degrees = quite a bit?) due to the uneven drag... I should have gone ahead and launched it at a 45 degree angle or something to let is arch up. I guess I do need to make those bottom drag elements to even things out some.
Not enough time for parachute to deploy so hard landing and broke a wing. Need to decide if I will bother to rebuild and add bottom elements.
The rocket was pretty stable and impressive with a pair of C5 engines (I was hoping to launch with a pair of C6 engines but needed to use 2x C5's due to weight). However, as forecasted, it arched over the top quite a bit (does 180 degrees = quite a bit?) due to the uneven drag... I should have gone ahead and launched it at a 45 degree angle or something to let is arch up. I guess I do need to make those bottom drag elements to even things out some.
Not enough time for parachute to deploy so hard landing and broke a wing. Need to decide if I will bother to rebuild and add bottom elements.
Congratudolences. The flight seems to have gone, frankly, better than I expected, and it's too bad about the damage. What was the delay on the C5s?
Incidentally, launching at 45° violates the safety code; 30° is the maximum aloud.
Incidentally, launching at 45° violates the safety code; 30° is the maximum aloud.
lakeroadster
When in doubt... build hell-for-stout!
Just find a 15 degree hill... then launch it at 45 degrees relative to the hill. Eazy Peazy..
Thanks -- yes, mixed feelings... Stable but arching is hard to decide how to feel since the result was not surprising but still pretty dramatic.
These were C5-3's - ah I guess I can launch at 30 degrees then. If I put the bottom fuel tanks and continue ringtail around bottom of rocket like the earlier idea it might arc less (although these details would be closer to rocket)...
Just find a 15 degree hill... then launch it at 45 degrees relative to the hill. Eazy Peazy..
Haha... got it -- ready to go...
The ring all the way around is less funky looking. How about:
Someone suggested putting a small fin / edge on the nose cone or front bottom of rocket to cause downward drag... Not sure how to measure the drag effect of front vs. rear asymmetrical elements like that.
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Amazing build!
Just a thought but how about a very small asymmetric inclination on the wings/pods or a small fin tab to cause it to corkscrew and average out the arc to give true flight overall. Think it would only need to be a tiny amount tho.
That would preserve the great look and could even give it a nice flight characteristic.
Various designs introduce the corkscrew intentionally and many unintentionally but I always love seeing the trail!
Just a thought but how about a very small asymmetric inclination on the wings/pods or a small fin tab to cause it to corkscrew and average out the arc to give true flight overall. Think it would only need to be a tiny amount tho.
That would preserve the great look and could even give it a nice flight characteristic.
Various designs introduce the corkscrew intentionally and many unintentionally but I always love seeing the trail!
Agree - The last version I had mocked up before I built the unmodified version had these bottom drag-inducing elements and an asymmetric continuation of the ring tail\...
Thanks - I do actually like to try to spin asymmetric rockets to create stability so this is a good idea. In this case I would like to straighten it out some as well if I was going to redo it.
A totally different option -- what do you guys think about me loading a mini engine in that top booster engine mount? How much power do you think I would need? A10-0? I guess ideally I would want a plugged engine. I am not sure if they make any other mini engines without ejection charges besides an A10. Keep in mind main engines are C5-3s so quite a bit of power and weight in this rocket.
I actually made all three of the booster engine spaces sized for mini-engines. I could drop down my main engine size and put 3x mini engines in there... Maybe I should just super-glue that plywood back together and do another test
I actually made all three of the booster engine spaces sized for mini-engines. I could drop down my main engine size and put 3x mini engines in there... Maybe I should just super-glue that plywood back together and do another test
Oops -- posted in wrong thread...
I think it wouldn't solve your problem because it only has any effect until it burns out.
I was thinking this -- would only solve it for the first .8 seconds of flight...
lakeroadster
When in doubt... build hell-for-stout!
Spit-balling here: An overly simplistic method you could look at:
(the frontal area of each piece) x (the frontal distance to the center of gravity) = moment arm for that piece
Ideally, these are all equal with a rocket that is symmetrical
If it isn't symmetrical, add something that makes the numbers cancel each other out.
Which would help, thus allowing the rocket to gain altitude before it starts to arc over.
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Mindsim blue screen of death! Can not compute...self destruction sequence initiated.
Yeah -- no clue how big or how far out those bottom elements need to be to offset that ring fin and the tail portion. I assume it is actually the ring fin that has the largest impact but as was pointed out -- a huge round ring fin just does not look as cool. I repaired the rocket tonight and made the bottom elements with a complete ring fin - the big compromise is that the bottom part of ring fin is much closer to rocket so all this may not matter at all.
These were inspired by a moment in the Ultraman show when they loaded the Space boosters onto the VTOL Plane and there were these tanks and some apparatus that did not stay on the rocket but could have (in my mind).
These were inspired by a moment in the Ultraman show when they loaded the Space boosters onto the VTOL Plane and there were these tanks and some apparatus that did not stay on the rocket but could have (in my mind).
Ok, I must be leveling up my mindsim since this flew so straight and stable with the new bottom elements... Launched with 2x C5-3 engines like last time.
Figured you guys would start doubting I would ever launch these models if I did not get out there and get some prototypes in the air...
Figured you guys would start doubting I would ever launch these models if I did not get out there and get some prototypes in the air...
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