Lauch Lugs

[Hospital_Rocket]

As I was digging thru my stuff today getting ready for our upcoming launch (and my L1 cert) I ran across a Copperhead ignighter, and was wondering...

Has anybody ever used that nifty little tube it comes in for launch lug material? I looks like a perfect 1/4" lug.

A

 

[Dr. Don]

I use 'em all the time!
It's maybe the only positive product you can expect
from the ignitor package.......
I have used them for many model power birds as a
standard item. And I even used the larger ones on High Power flyers, including my Crayon!!!!!!!
The price is right! But what can you expect from a guy who likes to use soda straws..............?
This is my min. dia. 54mm dude with my favorite lugs!
Dr Don

 

[Karl]

lol thats the only GOOD thing crapperheads are usefull for , there no good as ignitors They look neat aswell , and very sturdy ?
-Karl

 

[solrules]

Meh....everyone seems to badmouth the copperheads. I have used them plenty of times (30+), and have only had one failure. Now, I will admit they require lots of amps and voltage, but if you are at a club launch, this should not be a problem. I agree, some igniters are better (dipped daveyfire, firstfire, etc.), but copperheads come *free* in a reload kit (usually...my H128's came with FF's), but you have to buy other igniters seperatly, which increases cost per flight. If you follow the directions to the dot (shave off loose metal strings, bent the tip to get proper contact with propellant, etc.) they seem to be pretty reloable. Your milage may vary, however.

well, thats the end of my rant. Im going to go put some copperheads in a cluster....

 

[Karl]

Ive seen copperheads fail 6+ times in a rocket , one after another , but when a FF was inserted the rocket lit first time
Karl

 

[eugenefl]

Originally posted by solrules
If you follow the directions to the dot (shave off loose metal strings, bent the tip to get proper contact with propellant, etc.) they seem to be pretty reloable. Your milage may vary, however.

well, thats the end of my rant. Im going to go put some copperheads in a cluster....

I'm with ya on that one. They've worked fine for me. I kinda think it's an anger bandwagon. BTW, I *have* clustered with Copperheads before. (Successfully at that.) Will I keep doing it? Probably not.

Hey Hospital - those tubes are great for lugs. I typically use copper/brass tubing for lugs because they are easy to paint/finish. The cardboard ones are just easier to cut. Finishing is a little bit "hairy".

 

[powderburner]

If you like to use super-strong launch lugs in the 1/4 inch + size range, you can probably get some material for free from your local archery shop.

Lots of guys shoot arrows made from aluminum shafts. Raw shafts are sold in 31 inch lengths. Almost all shooters have their arrows cut to a length that 'fits' their size, and the leftover pieces of shaft are typically one to three inches long. These scraps are useless for any archery use, and are just thrown away. This is very high quality material; high strength, very smooth finish, very highly consistent round cross-section, very straight, thin-walled, and LIGHT. Almost all the popular shaft sizes being used today are well over 1/4 inch inside diameter and would work very well for a LL. Stop by your local archery shop and give it a try, it never hurts to ask.

 

[shinbone]

Been wondering about this:
Can a lug be too big in diameter for the rod?
For instance, what if you had a LP rocket with a 3/16" lug and put it on a 1/8" rod? Would it "rattle" up the rod or would it make no real difference?
Any experiences out there? I guess my question in a nutshell is, how closely does the lug have to match the rod?

 

[powderburner]

shinbone, it probably doen't matter if the LL is a little big. Within reasonable limits, a big LL will not interfere with any part of getting off the launch rod, and the small amount of potential mis-alignment is negligible (you get as much or more deflection due to rod-tip-whip as you would from loose lugs).

For NAR competition models, extra big LLs will cause more aerodynamic drag. But then again, for most NAR competition rockets, you will not use LLs, but towers.