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  #1  
Old 06-08-2020, 11:19 PM
RobVG RobVG is offline
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Default How many launch lugs?

18" Rocket , BT-80 Tube, 10.4 ounces.

How many launch lugs should I put on?
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  #2  
Old 06-08-2020, 11:56 PM
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Comrade:

One, two inches long, centered on the CG or as close as you can to it.
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  #3  
Old 06-09-2020, 12:58 AM
RobVG RobVG is offline
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Thank you!
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  #4  
Old 06-09-2020, 08:44 AM
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47 should do it nicely.

Just joking. Something that large I would always go with two.
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Old 06-09-2020, 12:54 PM
RobVG RobVG is offline
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Yeah, I'd hate to have to say "I should have....."
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  #6  
Old 06-10-2020, 01:35 AM
DavidQ DavidQ is offline
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You can get 12" long launch lugs at Balsa Machining.

I don' t think that you'd need 47 of those, but safety first.
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Old 06-11-2020, 08:07 AM
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If I were me, I'd go with two.
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  #8  
Old 06-11-2020, 10:37 PM
olDave olDave is offline
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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.
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Old 06-14-2020, 05:57 PM
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Quote:
Originally Posted by Joe Shockcord
If I were me, I'd go with two.

You are you, aren't you?
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Old 06-14-2020, 06:06 PM
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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.
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