#1
|
|||
|
|||
How many launch lugs?
18" Rocket , BT-80 Tube, 10.4 ounces.
How many launch lugs should I put on? |
#2
|
||||
|
||||
Comrade:
One, two inches long, centered on the CG or as close as you can to it.
__________________
NAR 79743 NARTrek Silver I miss being SAM 062 Awaiting First Launch: Too numerous to count Finishing: Zooch Saturn V; Alway/Nau BioArcas; Estes Expedition; TLP Standard Repair/Rescue: Cherokee-D (2); Centuri Nike-Smoke; MX-774 On the Bench: 2650; Dream Stage: 1/39.37 R-7 |
#3
|
|||
|
|||
Thank you!
|
#4
|
||||
|
||||
47 should do it nicely.
Just joking. Something that large I would always go with two.
__________________
When in doubt, WHACK the GAS and DITCH the brake !!! Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't ! Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY. ALL systems are GO for MAYHEM, CHAOS, and HAVOC ! |
#5
|
|||
|
|||
Yeah, I'd hate to have to say "I should have....."
|
#6
|
|||
|
|||
You can get 12" long launch lugs at Balsa Machining.
I don' t think that you'd need 47 of those, but safety first. |
#7
|
||||
|
||||
If I were me, I'd go with two.
__________________
Living life on the edge...launching C's on a B field. |
#8
|
|||
|
|||
On a relatively long design like yours, I like to put one lug on or immediately behind the c.g. and a second small lug on the forward edge of the body tube. This applies to sport designs but not to most competition designs.
My thinking: two lugs spaced apart minimizes the friction of a rocket trying to twist on a single lug, at least until it gets a little velocity started and until the top lug clears the launch rod. I also like to touch up the tip of the launch rod to make sure there are NO burrs or rough spots to snag a launch lug.
__________________
NAR 20602 used to be "powderburner" in another life |
#9
|
||||
|
||||
Quote:
You are you, aren't you?
__________________
I love sanding. |
#10
|
||||
|
||||
If performance is a concern, listen to the old guys that routinely competed in altitude. They wanted the least friction in addition to the least amount of tip-off. Most migrated graduated to towers, rails, and piston launchers (do they still allow that in any events?), but I bet they have a good grasp on lugs and rods too.
If performance isn't a concern, look at the rocket and see what makes it look good. A single longer one near the CG works. Big Bertha kits have been made like that for decades. A single long one near the aft end works. A shorter one at the aft end and another near the CG works, like with the old Cobra 1500 and Mean Machine. A shorter one near each end works if it's not a long rocket. The Cherokee-D was designed and built that way for years. In short, it won't matter a whole lot unless you just stick one short lug on the rocket.
__________________
I love sanding. |
Thread Tools | Search this Thread |
Display Modes | |
|
|