FatBoy on E... which launch lug?

[melvyn]

I'm building a Fat Boy to run on Estes E9 motors, and was wondering if I should use a larger launch lug than the 1/8" one that comes with the kit. I noticed the Executioner kit has a 1/4" lug, and wondered if I should get another one of them for the Fat Boy-E. What does anyone else think?

 

[Elapid]

1/4" launch lugs on just about everything
sure can't hurt!

 

[astrowolf67]

I'd recommend using 1/4" lugs. I've got two FB's, a 24mm version, and a 29mm version, with 1/4" on both.

 

[Adam Selene]

except that at some lauinches the wait line for 1/4 inch rods is the longest.
but i'd go with something larger than 1/8.

 

[Papa Elf]

Go with 1/4" lugs. It will also work safely on 3/16" rods (I do that all the time with my Mustang and Arreaux). So if and 1/4" rod is being used, go for the 3/16" .

 

[Donaldsrockets]

I would reccommend a 3/16 launch lug myself. That way if you're out flying on your own, you can launch it from a standard Estes Porta-Pad.

 

[DynaSoar]

Originally posted by n3tjm
Go with 1/4" lugs. It will also work safely on 3/16" rods (I do that all the time with my Mustang and Arreaux). So if and 1/4" rod is being used, go for the 3/16" .

This *is* a good idea, but if you do it you need to use either 2 lugs or else 1 long lug. It can twist and tip off if you use only 1 short one.

 

[North Star]

If I might expand a bit on Dynasoar's last comment....

A launch lug takes very little force provided you are not using it to supprt the rocket on a stand-off. I have had lugs damaged by wind while the rocket waited for a calm slot to launch. ( I no longer let the lug sit on the stand-off, I use the base of the rocket)

If the lug is just used as a launch guide, the rod only 'kisses' the inside of the lug as the rocket attempts to reach aerodynamic stability. In this case a bit of play is preferable to a tight tube which would impart forces to the joint as will 2 lugs which are slightly out of line. Look at the size of rail buttons on some of the large L3 rockets, they are tiny in comparison with lugs, particularly when the weight of the rocket is held by a cradle.

So .. if your rocket is stable and has a good motor to kick it off the pad; a shorty like a Fat Boy will be happy with one lug, at the CG point and about the length of the 2 'half lugs' combined.

 

[Stymye]

3/16 sould be plenty for a fatboy on an e-9

 

[eugenefl]

Originally posted by stymye
3/16 sould be plenty for a fatboy on an e-9

Very true except with the fact that a 24mm MMT will tempt a rocketeer to put composite motors in there. I say 1/4" lug.

 

[melvyn]

Thanks for the feedback. Guess I'll be going back to the Science Education Center for more parts. Oh, the hardship.

(I went there yesterday just for some kevlar cord and some E9's, and came out with another issue of Exteme Rocketry, a Big Daddy kit, the motors and the cord... I'm not allowed to go there on my own any more. )

 

[cydermaster]

Originally posted by melvyn
I'm not allowed to go there on my own any more.

Is that so you've got somebody else to help you carry everything? lol

 

[melvyn]

Originally posted by cydermaster
Is that so you've got somebody else to help you carry everything? lol

hehehe!! I wish.

More like, make sure I don't have too much to carry out to the car!

 

[jetra2]

Forget all your problems and put rail buttons on it!

Seriously, though, if you're only putting E9's in there, the 3/16" rod will work just fine, IMO. If it was anything bigger than a Fat Boy, I would likely put rail buttons and/or 1/4" lugs on it.

Jason

 

[DPatell]

rail

 

[cjl]

I'd go with 3/16. I've seen a fat boy on an F39 take off just fine from a 3/16 (spectacular flight to 2300 feet).