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Executioner w/F32T: Nose Weight Needed?

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deandome

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A buddy wants a dramatic launch for a scout outing, that's what he's going with.

I'm helping him out, but I don't know if nose weight is needed or not with this luanch.

What do you think? If so, how much?

Thanks
 

Donaldsrockets

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Since the Executioner is a fairly tall rocket with a decent amount of fin area, I wouldn't think any nose weight would be required.

I've heard of quite a few people flying stock Executioners on the AT F21 24mm Econojet motor and holding up just fine.

But since the F32 is a Blue Thunder motor, he better make sure that he's got some decent fin fillets on there.;)
 

patelldp

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Since the Executioner is a fairly tall rocket with a decent amount of fin area, I wouldn't think any nose weight would be required.

I've heard of quite a few people flying stock Executioners on the AT F21 24mm Econojet motor and holding up just fine.

But since the F32 is a Blue Thunder motor, he better make sure that he's got some decent fin fillets on there.;)
F32 is a WL motor. F72 or F101 is a BT motor.
 

eugenefl

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I'd personally recommend a White Lightning motor for its flame, smoke, and noise. The Blue Thunder motors are somewhat lackluster until you get into the larger motors that can produce mach diamonds or visible blue flames.
 

deandome

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He wanted "big" over dramatic, and...oddly...there aren't any other F-power options in 24mm single-use (my RMS 24mm has several). And I think Blue Thunder is the loudest AT propellant, though certainly not smoky.

I offered to 'roll one' for him ;) w/my RMS, but he didn't want to risk being on the hook for the $$ case, and Al's not only had the new F32 in stock, but they're on sale for about $10!!

I got one, too!

He actually built the rocket without talking to me first...we'd been talking about a 29mm Skid in an AT or LOC kit.
 

DaveHein

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I've flown the Executioner on G80 motors, and I had to add some nose weight. I don't know if nose weight is needed for an F32. According to the EMRR Cp library, the Executioner's Cp is between 28.55" and 30.7" depending on whether the Rocksim or Barrowman method is used. I would go with 28.55" to be safe.

This means that the Cg should be 26" or less from the tip of the nosecone to be stable. Load up your rocket and do a balance test to see where the Cg is. If it more than 26" from the nosecone then you will need to add weight.

Note: These numbers assume that your Executioner is the standard length of 38.5 inches.

Dave
 

Mikus

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I flew F39's in mine with no additional nose weight. Executioners love F39's. :D
 

shreadvector

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Wow, a lot of cunfusing answers referring to a 29mm G80! (but the first reply was pretty good). Let me give it a try.

The Executioner is designed to be perfectly stable with an Estes E9 motor. The F32 is dimesnionally identical to the E9 (OK, it has a cool nozzle extension, but it fits the motor mount perfectly).

So, your only concern is if the F32 weighs more than the E9 and therfore might require that you add nose weight to bring the c.g. back to a safe location.

http://www.nar.org/SandT/pdf/Aerotech/F32T.pdf

65 grams initial mass.

http://www.nar.org/SandT/pdf/Estes/E9.pdf

64.8 or 64.9 grams initial mass. Let's call that 65 grams.

Identical.

Make sure it's got good glue fillets and then kiss it goodbye.
 

RocketMonkey

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Yea, what he said.
But if you want a really cool flight the F-39 is nice and LOUD!!!
Just my $.02
 
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DaveHein

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Wow, a lot of cunfusing answers referring to a 29mm G80! (but the first reply was pretty good).
...
Make sure it's got good glue fillets and then kiss it goodbye.
Oh, did I forget to mention that I modified my Executioner a little bit. I split mine in the middle and built three different versions of the motor mount/fin can. I had the standard 24mm motor mount, 29mm mount and a dual 24mm motor mount.

I used a zipperless construction with an ejection baffle, and I split the upper part into a parachute section and a payload section that could carry a camera or an altimeter. I modified the nosecone so I could easily add nose weight. Hmmm, maybe that's why I had to add nose weight when I flew it on a G80.:rolleyes:

I have a description of the Mod X (MODified eXecutioner) at http://home.swbell.net/davehein/ModX/ModX.html .

BTW, the info I posted on the Cg and Cp of the Executioner is still valid even though my Executioner didn't exactly match the standard configuration. Also, the Exectioner uses through-hole fin attachments, so I wouldn't worry too much about losing fins.

Dave
 

El Cheapo

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WOW!!!!! That's pretty enthusiastic. Is there any reason you didn't just make a 29-24mm adapter as well as interchangeable motor mounts for the 2x24mm?
 
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deandome

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I'm guessing it's cuz paper tubes rings & balsa fins are cheap & building is fun. 29 to 24mm adaptor makes sense, though...but you can't have interchangeable mounts cuz the fins are TTW.


WOW!!!!! That's pretty enthusiastic. Is there any reason you didn't just make a 29-24mm adapter as well as interchangeable motor mounts for the 2x24mm?
 

powderburner

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If you want to "impress" the scouts, and if you just have to use a big motor, why not make an upscale version of Art Applewhite's saucers or Qubit?

Maybe it's just some silly thing but I don't like having and "expert" come in to set an example for a class of newbies, and then see him launch something with a monster motor on a one-way mission. I just don't think that is a responsible way to fly.

My two cents--
 

El Cheapo

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I'm guessing it's cuz paper tubes rings & balsa fins are cheap & building is fun. 29 to 24mm adaptor makes sense, though...but you can't have interchangeable mounts cuz the fins are TTW.

Oh...Copy That. I'm unfamiliar with the kit. That makes sense then.

I've got plans for a 4" kit where the engine bay will actually be a 3" stuffer so I can still do TTW fins as well as use all my existing 3" interchangeable motor mounts from single 29 & 24mm APCP to 2x and 3x 24mm for BP motors. I haven't even put it on paper yet but that's the plan.
 

DaveHein

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WOW!!!!! That's pretty enthusiastic. Is there any reason you didn't just make a 29-24mm adapter as well as interchangeable motor mounts for the 2x24mm?
I built the 24mm version first, and I mostly flew it on E30 motors. Then I thought it would be fun to use bigger motors, so I built the 29mm version later on. At some point an energetic ejection charge blew a hole in the side of my 24mm booster. After that I used a 24mm adapter in the 29mm booster when I wanter to fly smaller motors.

And deandome is correct. Paper and wood is fairly cheap, and it's fun building stuff.

Dave
 
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