Lakeroadster's Estes Logo Rocket

[BABAR]

Cutting and Installing Fins

S.O.P.: Cut the fins using the scroll saw, sand the fins using the table top disc / belt sander.

These aren't really TTW fins, but the grooves should provide a good strong attachment with the fin tabs. I peeled the paper off the fins at the tabs.

View attachment 585547View attachment 585548View attachment 585549View attachment 585550​

Not that I am likely to emulate this, but how did you do the grooves? It’s a really great idea.

 

[lakeroadster]

Not that I am likely to emulate this, but how did you do the grooves? It’s a really great idea.

Fin Slots R Us

 

[lakeroadster]

Created the silhouette of the rocket using paint.net to visualize the Estes Logo....

meanwhile... glue fillets.

​

 

[neil_w]

Sorry if I missed this but... is that the way you wanted the grain direction to go? It looks like it's parallel with the trailing edge. What's the thought process there?

(aren't those drawn lines the grain direction?)

 

[lakeroadster]

Sorry if I missed this but... is that the way you wanted the grain direction to go? It looks like it's parallel with the trailing edge. What's the thought process there?

Fins are symmetrical... so it doesn't matter. 6 of 1, a half dozen of the other.

1/8" papered basswood... this rocket is a beast, strength wise.

 

[lakeroadster]

Sorry if I missed this but... is that the way you wanted the grain direction to go? It looks like it's parallel with the trailing edge. What's the thought process there?

(aren't those drawn lines the grain direction?)

I guess I could have pulled a Tommy Flanagan and stated:

"Fin grain direction is based on the trailing edge surface on rear eject rockets, yeah, that's the ticket. It's because the ground impact is backwards from a normal rocket. Just ask my wife, Morgan Fairchild".​

 

[lakeroadster]

I did another swing test, with no nose weight, just to see if the fins alone brought stability to the rocket.

The test without nose weight revealed the rocket is not stable, just as the previous test did.​

I then installed the nose weight that was used in the previous swing test that made the finless fuselage stabile.

The test with the nose weight revealed the is stable in this configuration. The test was not however as stable as the previous test without the fins. The Open Rocket simulation also shows higher stability without fins.​

​

I anticipate additional nose weight will be needed once the spool, the motor and the recovery hardware are installed.​

​

 

[lakeroadster]

Recovery Spool and Launch Lug

Using 1/16" corrugated cardboard for the centering rings on the BT-50H spool, and a BT-3 for the launch lug.

​

 

[BABAR]

Cardboard. Love it. Reminds me of a cadet saying (the commanding officers didn’t appreciate it)

“ if the minimum wasn’t good enough, it wouldn’t be the minimum.”

 

[lakeroadster]

Cardboard. Love it. Reminds me of a cadet saying (the commanding officers didn’t appreciate it)

“ if the minimum wasn’t good enough, it wouldn’t be the minimum.”

And that cadets name was: Lester R. Moore, you can call him Les.

These rear eject spool centering rings really have virtually no load on them.

Thrust of the motor is a buckling load on the BT-50H motor mount tube and at ejection the spool basically just falls out the back of the rocket.

An E20 motor (or even an F32) located with 1/16" cardboard centering rings. It does kind of bring a grin to one's face, right?

 

[jqavins]

Are you going to treat the forward face for burn resistance?

 

[lakeroadster]

Are you going to treat the forward face for burn resistance?

Good question. I will apply wood glue across the internal face, after the nose weight is installed. I'm holding off on installing the nose weight until I do a swing test of the finished rocket.

I'm planning on applying CA to the rings this afternoon, that should help them with fire resistance. The front ring face will see the flame and burning hot bits of the ejection charge also, be it just for a fraction of a second.

Stability is wonky on this one, as previously discussed.

 

[lakeroadster]

Spool Updates and Super Glue Day

I decided to go ahead and install a motor hook, I prefer them over tape fitting the motor. I made the hook out of a piece of stainless from an old set of windshield wiper refills.

Next up was applying CA. @neil_w mentioned the use of a cotton ball for applying CA. Armed with that I decided to use a couple Q-Tips to apply CA to the spool centering rings and to the edges of the fins. This worked great.... in the past I've always just dribbled the CA right out of the bottle, and runs ensued. Tip of the Hat to @neil_w.

​

 

[lakeroadster]

Nose Ballast and All Up Flight Ready Swing Test

I cut & temporarily installed a 2 ounce nose weight into the rocket and then loaded the parachute and E20-4 motor into the spool for a swing test.

Test shows it is stable. Not overly stable though, on one of the tests it danced around quite a bit until I got it up to speed.

There's plenty of room to add more nose weight if needed in the future. I glued in the nose weight, and used wood glue to coat the counter bore face as a fire retardant.. thanks to @jqavins reminder.

She's ready for primer and paint.

​

 

[BABAR]

Nose Ballast and All Up Flight Ready Swing Test

I cut & temporarily installed a 2 ounce nose weight into the rocket and then loaded the parachute and E20-4 motor into the spool for a swing test.

Test shows it is stable. Not overly stable though, on one of the tests it danced around quite a bit until I got it up to speed.

There's plenty of room to add more nose weight if needed in the future. I glued in the nose weight, and used wood glue to coat the counter bore face as a fire retardant.. thanks to @jqavins reminder.

She's ready for primer and paint.

View attachment 586208View attachment 586209View attachment 586210View attachment 586211View attachment 586212View attachment 586213

​

I’m convinced!

 

[lakeroadster]

Primer

Sprayed on some Rustoleum Automotive Primer 2 in 1 Filler Sandable. That old redwood is mighty thirsty, takes quite a bit of primer.

I really love the simplicity of this build. A true 3FNC if there ever was one.

 

[Daddyisabar]

3-4FNC rocks!...and rules too!

 

[BABAR]

3-4FNC rocks!...and rules too!

3FNC!

Darn my stupid lysdexia!

https://www.rocketryforum.com/threa...n-spirit-of-america-successful-flight.160086/

 

[lakeroadster]

CWF

​

 

[Daddyisabar]

CWF

View attachment 587592​

Smooth as glass!

 

[lakeroadster]

2nd Coat Of Primer - Ready To Paint

​

 

[lakeroadster]

White Flat Paint

​

 

[BABAR]

What is predicted pad weight and how big a chute can you reliable pack (and more importantly deploy!) on that spool?

I am sure I missed it, but how do you attach shock for to body in a manner that doesn’t roast it nor interfere with spool ejection?

 

[lakeroadster]

What is predicted pad weight and how big a chute can you reliable pack (and more importantly deploy!) on that spool?

11.1 ounces Flight Ready using an 18" Parachute = 13.6 mph ground hit.​

​

Prior to swing testing the rocket I packed the 18" chute around the spool. In reality, a 12" chute would work just fine since it's rear eject. The rocket will descend nose first, and those 0.16" thick fins are hell-for-stout. This rocket would recover undamaged form a lawn dart... the entire body is solid wood.​

I am sure I missed it, but how do you attach shock for to body in a manner that doesn’t roast it nor interfere with spool ejection?

300# Kevlar attaches to a screw eye in the nose cone. The Kevlar runs through a straw that is glued through the forward spool retaining ring. The Kevlar does see an offset impingement of the ejection charge momentarily. The Kevlar is easily replaced... but it's Kevlar... that's why we use it, holds up well to toasty ejection charges.​

​

I used 100# Kevlar (which is like heavy sewing thread) on my Columbine... it's powered by a D12-3... and the Kevlar was undamaged. These rear eject spool rockets have a lot of area for the ejection charge to dissipate into.​

​

​

 

[Daddyisabar]

13.6 mph impact at altitude?

Just checking...

 

[lakeroadster]

The Black Stripes

I tried something different on this. Normally I would have spray painted the black but I wanted to try to use a brush for this. Came out pretty nice.

Sure... I could have used a piece of electrical tape for the stripe... I'd rather try something new.

​

 

[lakeroadster]

Clear Gloss

​

 

[Cape Byron]

Very, very nice.

 

[lakeroadster]

Can you spot what's wrong with this? As Dr. Evil would say... S h i t !

​

 

[Pinetree]

Sometimes, ya just gotta send it.