L3 Project Build Thread - Performance Rocketry Competitor 4

'' O .....yeah!"


You already have a name....

chuck5395 said:

How about naming it "Fred"?

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Say, where did you get that idea?

blackjack2564 said:

'' O .....yeah!"


You already have a name....

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"O yeah?"

Hey, how about "The great epoxy and rail button debate?"

Ready to accept.



After pouring expanding polyurethane foam from TAP Plastics. Great stuff, this is.

That looks like fun. I've never tried the foaming trick. I've never been convinced of the necessity.

jackman said:

That looks like fun. I've never tried the foaming trick. I've never been convinced of the necessity.

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It is fun indeed! I do it on most of my builds (with the exception of Binder kits, since they come with the modular fin can assembly). The foam is lightweight and very solid when cured. Makes for much stronger fin attachments, IMO.

Even if you have firmly filleted through-the-wall fins, the airframe can flex. However, a dense foam in the space between motor mount and airframe will help reduce that flexing.

Used a hacksaw blade to cut off the excess cured foam, then carved out a bit with an exacto knife.


Aft centering ring epoxied into place. Can't wait to put this fin can project to bed...

Will you be using your tracker on this one as well? I should be at most of the launches this year... I hope, so my Garmin will be available again if you need it.

I am working on a Comp 4 for my L3 as well... L3 Cert drag race? :wink:

Darren

Demonian said:

Will you be using your tracker on this one as well? I should be at most of the launches this year... I hope, so my Garmin will be available again if you need it.

I am working on a Comp 4 for my L3 as well... L3 Cert drag race? :wink:

Darren

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Hi Darren, great to hear from you! Yes, I will have my 900 MHz Beeline GPS onboard, though I am coordinating with Vern Knowles to see if he can put Kate onbaord my flight. I'll be at most of the launches as well, so I will definitely take you up on the Garmin offer! You were a life-saver at NXRS last year.

How about a 3-way L3 cert dragrace? My good friend jackman is doing his L3 at NXRS with a 4" fiberglass rocket, as well.

AlnessW said:

How about a 3-way L3 cert dragrace?

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Ménage à Cert?:dark:

Sounds good to me.

Man I still have a lot of work to get done before June. Less time on forums, more time on rocket. :kill:

Got it!

Demonian said:

Ménage à Cert?:dark:

Sounds good to me.

Man I still have a lot of work to get done before June. Less time on forums, more time on rocket. :kill:

Got it!

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Sounds good to me too!

I've got plenty to do as well... Though I did the first set of fillets today.

Prepped and ready for epoxy.


A quick pour of West Systems does the trick!

More goodies in the mail, this time from fellow TRF member Ken at Performance Hobbies. Excellent guy to do business with, and very fast service - I had placed this order on Friday and everything arrived on Monday!


Inside is a 36" piece of 4" airframe for my main parachute bay, as well as a few altimeters.


"Weapons of choice" for recovery - A Missileworks RRC3 for the primary, and a Perfectflite Stratologger for the backup.

Well, still no responses, so I'll keep updating you all.

Last night I went to go wash the new piece of airframe that had just arrived, but with the recent freezing temperatures here in Portland, I discovered that the garden hose had frozen. So I washed and scrubbed it in the shower instead - there is always plan B!

Now that I have that last piece of airframe I needed, I can now do a full assembly of the rocket:

I have to say, this thing is looking sexy now!

No response implies full endorsement. Good show Wilson and thanks for sharing!

jackman said:

No response implies full endorsement. Good show Wilson and thanks for sharing!

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+1. Been watching the whole time. Please keep posting; I'm quite enjoying this thread! Got a paint scheme in mind?


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jackman said:

No response implies full endorsement. Good show Wilson and thanks for sharing!

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rocketgeek101 said:

+1. Been watching the whole time. Please keep posting; I'm quite enjoying this thread! Got a paint scheme in mind?


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Thank you both for the kind words! Much appreciated. I shall indeed continue this thread right up until the button is pushed!

Sebastian, still debating a name and paint scheme. As of right now I think I'd like to do at least 2 colors, one of which metallic.

I've been watching. Great build. Whatever colors you pick the metallic should look very cool.


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I'm still watching as well! Looking good and thoroughly enjoying watching the build and the difference between how you are building yours vs. how I am building mine.

As for paint...



Rough idea of what I have in mind, though without making a separate tube in OR, I can't get the fin area of the lower tube black, like I am thinking about doing...

Not sure about the red, yet.

Metallic... hmm :wink:

<edit: What engine are you planning to use for your cert flight?>

Looking good bud.

And I still think you should name it "Fred". Flashing Rear End Device is already taken. I need to come up with something else....
"Fabulous Rocket w/Excellent Deployment?"
"Field Remote Expeditionary Device" (From Stargate)
"Forward Ranging Electronic Device"
"Freaking Radical Engineering Design"

conman13 said:

I've been watching. Great build. Whatever colors you pick the metallic should look very cool.

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Thank you Connor, great to see so many people following my build!

Demonian said:

I'm still watching as well! Looking good and thoroughly enjoying watching the build and the difference between how you are building yours vs. how I am building mine.

As for paint...

Rough idea of what I have in mind, though without making a separate tube in OR, I can't get the fin area of the lower tube black, like I am thinking about doing...

Not sure about the red, yet.

Metallic... hmm :wink:

<edit: What engine are you planning to use for your cert flight?>

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Your paint job looks awesome! Love the flames up by the nosecone. Yep, I was thinking about metallic mostly because I have lots of gold/silver spray paint in the shop, plus it sparkles nicely in the sky...

I will be using the Aerotech M1297W for my cert flight. Classic L3 motor, plus Red Arrow Hobbies has their $170 cert special on that reload.

chuck5395 said:

Looking good bud.

And I still think you should name it "Fred". Flashing Rear End Device is already taken. I need to come up with something else....
"Fabulous Rocket w/Excellent Deployment?"
"Field Remote Expeditionary Device" (From Stargate)
"Forward Ranging Electronic Device"
"Freaking Radical Engineering Design"

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Thank you Chuck, and great to see that progress has resumed on your X-Plane rocket.
Clever idea there, making an acronym that spells "FRED." :roll: I think Azinger would be honored...

Another update - I have been thinking about leaving the forward bulkhead out of the booster section, and just attach the drogue harness to the forward end of the motor (via the eyebolt). That way, not only would I not be limited on motor length, but the tapped forward closure with eyebolt would just seem like a stronger load-bearing attachment than an epoxied bulkhead.

Thoughts?

That's exactly what I am going to do.

With the 75/6400 motor in there, it is almost an anti-zipper design by it's self.

Isn't there a CR at the forward end of the anti-zipper, between the MMT and BT?

I attach the harness there -- then loop though the eyebolt.

Always recommended to attach to the motor -- it's the heaviest thing in the rear.
However, I like to attach to the airframe too.

AlnessW said:

Another update - I have been thinking about leaving the forward bulkhead out of the booster section, and just attach the drogue harness to the forward end of the motor (via the eyebolt). That way, not only would I not be limited on motor length, but the tapped forward closure with eyebolt would just seem like a stronger load-bearing attachment than an epoxied bulkhead.

Thoughts?

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That's what I do.

Demonian said:

That's exactly what I am going to do.

With the 75/6400 motor in there, it is almost an anti-zipper design by it's self.

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Yes, I measured my booster section and discovered that is is only slightly longer than the 75/6400 case.

FredA said:

Isn't there a CR at the forward end of the anti-zipper, between the MMT and BT?

I attach the harness there -- then loop though the eyebolt.

Always recommended to attach to the motor -- it's the heaviest thing in the rear.
However, I like to attach to the airframe too.

Click to expand...

Yes, but the forward centering ring is only about 1/4" wide - not a whole lot of room to attach anything to.

jackman said:

That's what I do. View attachment 161477

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Securing the eyebolt via a wire seems like a good idea, to keep it from un-threading.

Yes, but the forward centering ring is only about 1/4" wide - not a whole lot of room to attach anything to.

And TN is less than 1/8" thick.
Cut a slot in the CR on each side of the MMT and slip the TN through the slots.
Wrap the TN around the tube and tie or sew it together.
Epoxy in place.

FredA said:

Yes, but the forward centering ring is only about 1/4" wide - not a whole lot of room to attach anything to.

And TN is less than 1/8" thick.
Cut a slot in the CR on each side of the MMT and slip the TN through the slots.
Wrap the TN around the tube and tie or sew it together.
Epoxy in place.

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Ah, I see. I though you meant put an eyebolt there, or something. Didn't you say you incorporate the tapped forward closure into this method, as well?

Didn't you say you incorporate the tapped forward closure into this method, as well?

Yes -- loop the TN though the eyebolt on the motor.
This way it holds onto both parts.

FredA said:

Didn't you say you incorporate the tapped forward closure into this method, as well?

Yes -- loop the TN though the eyebolt on the motor.
This way it holds onto both parts.

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Got it.

Just to let you all know, I'm leaning heavily towards not gluing in a bulkhead at the forward end of the booster and attaching the shockcord to that. In all honesty, I'm a bit worried it wouldn't be strong enough to hold the weight of the booster (and motor)...

This way I'm also not limited on motor length.