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Where do I put the launch lug?

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Bone Daddy

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Hmmmmmmmmmmmm I meant to post this question awhile back...like before I painted it. At least it's not completely finished.

Anyway, where should I put the launch lug?

It's BT50 to BT60.

I want to avoid a standoff if possible.

Launch vehicle post.jpg
 

MarkII

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Launch it off a piston or from a tower. You could also install launch lugs inside the tube fins (on the sides opposite the body tube), but it might be a good idea to add them to two or three of the tubes, and then launch it from a specially constructed pad (or pad adapter) that has two or three rods. My concern is that if you use just one lug mounted inside of a tube fin, it will be so far off center that it will interfere with the boost off the pad. Not to mention the fact that mounting a single lug so low is a bad idea anyway.

A third idea is to use a pair of wire loops on the ends of stems, one mounted just above a tube fin and the other mounted just below the payload section.

MarkII
 

Bone Daddy

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Thanks for the great feedback. As I type, this problem is being upscaled to a Bt-60 to a Bt-80. I built this one with parts on hand while waiting to get all the parts for the bigger version. I obviously need to pay more attention to the whole launch lug thing.

I figured that the easy solution of mounting a launch lug on one of the boosters might be problematic. I like the idea of mounting one inside a booster. I just bought some 8" lengths from Semroc which sound like just the ticket.

Do you thing a pop off wire loop system could work? I've been reading about them and have been interested in trying it. I'm guessing the wire would have to be pretty stiff since it would not run flush with the body?
 

Viperfixr

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From inside one of the lower tubes? That's what my Fliskits Overdue does.
 

powderburner

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You guys are all being disappointingly polite and helpful with your answers. I mean, there is sooo much potential fun with a question like this.

Oh well, I guess I'll have to behave myself then. Bone, you already have some good answers, and I know you said you wanted to avoid a stand-off, but if you want the LL at/near the longitudinal cg you may just have to use a standoff. (Is the cg somewhere behind the start of those tube fins?) You could minimize the appearance by using a clear piece of thick plastic sheet, and maybe even find a clear piece of plastic tube to use for LL material. You could use a piece of music wire sticking out the side (protruding through both sides of the local BT, to brace it in position) and bend a LL-sized loop in the free end. You might be OK with one lug on the front end and one lug inside a tube fin at the rear (if you can keep them lined up, without the nose turning out of position) but you would still have a "transient" as the rocket clears the launch rod where it is hanging on only by the lower lug (just for a moment, but that may be all it takes to twist and bind).

We gotta launch somethin. Soon. I'm having withdrawal symptoms. I am going to launch a few test shots from my own yard but the big schoolyard/field that I used for big stuff is now under construction for a new Benbrook middle school. Torn up from one end to the other. (CRUD) There is a little space for possible launches over by the south TCC campus on I-20 in south Ft Worth. Weren't you trying to tell us there is a spot over by 360? We gotta get together again and launch somethin.
 

Bone Daddy

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I have a few things I want to pierce the sky and touch the face of God with myself.

This Saturday is AllCon in Dallas, but Sunday would be great. The field by TCC of 360 is really nice, but I'm open to pretty much anything.

Next Saturday is the DARS launch, but again the Sunday would be great.
 

Bone Daddy

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Well, finally solved this problem.

I figured the place to look was the rockets design to loft eggs and hit paydirt. I found plans posted by Mr. Gassaway (homepage.mac.com/georgegassaway/.../eggloft_duration.htm) that had a launch lug mounted on the fin and the egg capsule.

I put a longer launch lug on the BT-60 just because I thought it looked better. I used a spacer to glue the launch lug onto the fin. These pics are before painting.

This Saturday will be her maiden voyage at the monthly DARS launch. She'll fly on a D. This is my first D powered rocket.

launch lug on fin post.jpg


Launch lug on BT-60 post.jpg
 

ScrapDaddy

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A "D" the estes D12 or the composite D13w D24 or the D10? iv been playing with F motors for a while
and if you really wanna build that super roc you might need somthing as large as an E I'm taking a calculated risk with the D

And to be perfectly clear is she a 24mm bird or 18mm?
 
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ScrapDaddy

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Launch it off a piston or from a tower. You could also install launch lugs inside the tube fins (on the sides opposite the body tube), but it might be a good idea to add them to two or three of the tubes, and then launch it from a specially constructed pad (or pad adapter) that has two or three rods. My concern is that if you use just one lug mounted inside of a tube fin, it will be so far off center that it will interfere with the boost off the pad. Not to mention the fact that mounting a single lug so low is a bad idea anyway.

A third idea is to use a pair of wire loops on the ends of stems, one mounted just above a tube fin and the other mounted just below the payload section.

MarkII
I second the piston idea sunward says they are SU but they will last quite a while
 

Bone Daddy

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24mm.

I planning on using a D12-3.

I'm building an adapter that will let her fly in a C.
 

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