The Thrifty Rocketeer blog continues….
Normally, this blog tries to give you some useful, positive tips.But right now, we’ll take a look at a couple of things To not strive.
Just tonight, I was chatting with some rocketry buddies by Zoom, and one of the extra senior guys holds up a couple of items destined for his high energy rocket. He’s asking for assist and recommendation on how you can proceed.
He’s obtained a medium sized carabiner in his proper hand, and in his left is a strip of what he is calling an elastic band. (It seems more like the headband that Spock wears in Star Trek IV: The Voyage Home, however regardless of.)
It’s a protracted size or skein of two inch vast elastic band that appears like it might either go in a truss, a bra, or some form of again brace.
And he’s asking, “How do I attach this to that?”
The dialogue starts and guidelines out sewing (trigger the stitches will not stretch), rivets (trigger they’ll pop each time it stretches), grommets (for the same reason) and glue, (as it won’t “give” with out cracking).
One rocketeer said, “Dump it, just get a nylon rope or related woven tube, and tie it on”, just as you’ll in mountain climbing.
We all just about agreed that the two inch width of the elastic band won’t permit for a tight knot to be tied across the carabiner, so we settle on the nylon tube/rope concept.
Now this began me thinking concerning the time that I thought of making my own shock cord out of elastic. I used to be doing a scratch construct for a recycling display on how you can turn unusual trash into a quite simple rocket and nosecone with plastic Wal-Mart bag parachute. For a shock cord, I had settled upon an previous pair of men’s tighty-whitey briefs.
I convinced my wife to lend me her pinking sheers, and i used a seam ripper to free the elastic band from the pair of shorts. In a short time, I tired of the seam ripper, and went for a straight sharp pair of fabric sheers, and just minimize as close to the waist band as I might.
Now that I had the loop of elastic free, I do not recall if I minimize throughout the appear or ripped it free, however I wound up with a single size of one inch wide elastic that still had lots of stretch in it.
Deciding that the band was too extensive, I took the fabric sheers and cut down the middle of the band leaving an equal width of elastic band, research by the staff of Benhvienvinhchau, on either aspect of the reduce. What I hadn’t counted upon was the fraying, which began immediately. The 2 elastic strips, while about 42 inches lengthy, curled and buckled, refusing to put flat.
This was symptomatic of how the elastic band would behave regardless of how I minimize it , stretched it, or steam pressed it. I learned that you simply Can’t reduce an elastic band lengthwise had have it work. (Now, for the needs of my poster board display of the elements of a rocket, it worked properly enough, but for really use in a rocket, my concept would not have worked.)
What WOULD work is the purchase of about 3 toes of slender 1/8-1/four inch elastic from Joann Fabrics or related store. Except for the run on this materials to make masks through the pandemic, this would work for smaller, low-energy rockets when you wanted to substitute a shock cord.