Quest Harpoon AGM (the way it should have been designed)

[Elapid]

here's my version of the kit

 

[Silverleaf]

Thats a fine looking rocket there, and I've always liked the grey, blue and white combination of colors.

Is that a D to a D MMT set ?

Scale..mmmm

 

[Karl]

I'd say 24mm to 18mm That looks awesome!
-Karl

 

[jetra2]

OOOOHHHHH YEAAAH! That's what I like to see there! SCHWEEET rocket Elapid!

Man...I should stay off this forum until payday...



Jason

 

[eugenefl]

Awesome modification! You had me there in the first picture. I bet it'll get some serious altitude on a D-C combo!

 

[Elapid]

E9 -> C6-5?


I got a bunch of D12-0 and one pack of C11-0 to test it on tomorrow!


thanks for looking!

 

[Karl]

Wow I didn't know there was a E9-0 motor till now ! You could always try this . CHAD stage -> D12-0->E9-0->C6-7
-Karl

 

[Elapid]

i like the way you think!
maybe i'll add some nose weight...

 

[Elapid]

Originally posted by Karl
Wow I didn't know there was a E9-0 motor till now ! You could always try this . CHAD stage -> D12-0->E9-0->C6-7
-Karl

maybe i should get an email off to vern...

 

[Elapid]

and came back!

that's always good...
i sent it up the first flight on a C11-0->B4-4

beautiful flight!!!!!!!!!

then i tried D12-0 -> C6-5
OMG!
it weathercocked a bit on launch and went abit down range, but i got it back after climbing a fence or 3...


here's a shot of it lifting off

 

[Karl]

Nice pic! Good to hear you got it back !What 'chutes where you using?
-Karl

 

[Elapid]

I put an Estes 12" chute on her

 

[JeromeK]

Way cool!!!

I just launched my Harpoon (built standard 18mm motor) for the first time 2 weeks ago and it flew beautifully! I thought it would make a nice conversion but I didn't even consider going 24mm to 18mm.

I took my time and glassed my fins (1/4oz. fiberglass cloth and finishing resin). This made a nice finish and strengthens the balsa quite a bit. I launch at a hard dry lakebed here in Southern California and it shows no mercy to our birds.. :sigh: I also built it tough with the idea of shoving a 18mm Aerotech D13 in it!

What did you use for your centering rings and tube coupler? I think I might want to try this! Any issues with the first stage gasses igniting the 2nd stage?



Jerome

 

[shreadvector]

There are no E9-0 motors. They made some, tested them, had them certified and then (wisely) determined that the average consumer would NOT be able to fly them safely. They would arc over and end up staging horizontal or while pointed down. initial thrust and average thrust are too low for the heavy long burning E9 to be used as a booster *by most average consumers*.

Originally posted by Karl
Wow I didn't know there was a E9-0 motor till now ! You could always try this . CHAD stage -> D12-0->E9-0->C6-7
-Karl

 

[shreadvector]

There are no E9-0 motors. They made some, tested them, had them certified and then (wisely) determined that the average consumer would NOT be able to fly them safely. They would arc over and end up staging horizontal or while pointed down. initial thrust and average thrust are too low for the heavy long burning E9 to be used as a booster *by most average consumers*.

Originally posted by Elapid
E9 -> C6-5?


I got a bunch of D12-0 and one pack of C11-0 to test it on tomorrow!


thanks for looking!

 

[Elapid]

on those E motors...
*average consumers* seem so dumb...i've met a few. see 'em on the road all the time...

(FWIW: E9-P (-P)=E9-0)
i built mine using the stock parts for the sustainer but left out the retainer clip for my preferred friction fit. i forget what i did for the booster. i think i used the standard 24mm MMT parts, e.g. bt50, cardstock centering rings. surface mounted fins.

the coupler is made from a split piece of body tubing

i did put a couple of vent holes in the booster to help keep things together until the sustainer is lit.

so far, 100% success for all flights.

 

[DumasBro2]

FWIW, E9-P <> E9-0. The "P", stand for plugged. Would make a terrible booster.

 

[Elapid]

that means REMOVE the plug.

in other words, an E9-P with the plug removed is an E9-0 since there is no delay charge in an E9-P.

 

[Karl]

Is the plug just a thicker clay cap?
Karl

 

[DumasBro2]

I see now (-P). Sorry. I need to make sure I have my coffee drank before reading the forums.......

 

[Elapid]

but not soft clay like the *old days*
this stuff is tough to dig out...


i guess i ought to say that i don't recommend anyone modifying model rocket engines for any reason. this posting is meant to be informational only and is not intended to promote potentially unsafe activities.

 

[Elapid]

Originally posted by DumasBro2
I see now (-P). Sorry. I need to make sure I have my coffee drank before reading the forums.......

my bad!
i need my coffee, too!



you're absolutely right, though. plugged motors make lousy boosters!

 

[Elapid]

I prepped a plugless E9-P --> C6-5
sims to barely over 2000'
32 mph (48fps) off the rod...
barrowman .99
rocksim 1.08

i might add just a touch of nose weight to move the CG forward a hair...from the liftoff speed, it appears the rocket is not underpowered. wouldn't want that!


this is an experimental flight in preparation for a 3xE9 ----> 3xE9 multi-stage multi-cluster version of my TriAgain. i'll have to find a larger field for that launch, though.


Please don't try this, it could be dangerous.