Shock Cords and Other Delights!

The Thrifty Rocketeer blog continues....


This weekend, I scored a couple of victories. 

Not only was the weather perfect.... into the mid-70s with low humidity and no clouds, but there was a low turn-out at our club launch.  (It seems a lot of people decided to go "Dancin' in the Streets" as Martha Reeves used to sing.

Anyway, the point is the leaves were almost all off the trees, and I got a chance to walk off into the woods at the end of our launch field.  The silver rocket that Joel had lost and left in the tallest tree appeared to have vanished. So I headed for it, easily spotted in the woods as the one oak that still had its brown leaves.  It served as a point to navigate to and could be spotted from pretty much anywhere else in the mostly balding trees in this copse.

As I descended the steep slope and approached it, I kept looking up and scanning around to see if I could spot a clue to its location.   

Sure enough, as I approached the small trickle that marked the bottom of the creek that had carved this ravine...I spotted it.  A shaft of such bright silver, it looked to be an aluminum bar laying across the creek, but not in the water.

I made my way gingerly toward it as my pulse quickened. Yep, it had two launch lugs and looked like there was a fin missing.  (All of them, actually.)  I was thrilled to have found the body tube of his rocket which had been dangling in that tree top for only the last month.   But there was no nosecone, no parachute.  I recalled seeing a blue checked parachute as part of the rocket dangling 50 to 75 feet over  the forest woods at last launch.

I started to look further, assuming that when the shock cord snapped, the chute and nosecone either got snagged again, or floated downwind in the (high) wind that had freed it.  The land sloped much more gently here, and I looked farther afield.  Then I spotted it.

A red plastic bag was poking up out of the leaves, drawing me near.  As I got close, I realized it was a red checked parachute, and picked it up, shaking the leaves off it, and revealing a brilliant red nosecone underneath it.

Stunned, I stared at it, looking for some marking or indication of what it was.  I could have sworn that chute was blue checked.  But I was happy to have found it.  The more I looked at it, the more I thought the brilliant paint job looked familiar, right down to the splotch of baby blue paint on the inside shoulder of the plastic nosecone. Could it be?

I started scanning around and reasoned if it had fallen from the tree, the fins may be nearby, so I started looking for black fins among the leaves...and then I spotted it, about 15 feet further down wind... black fins and something red sticking up out of the bed of leaves.  I walked over and picked up the red rocket with black fins.

It was my own missing rocket that had been in the trees for almost 6 months.  It WAS my nosecone and chute and here was the undamaged body, waiting for me.  I was thrilled.



I circled back, reasoning that the other nosecone and chute must be in the area, but I never found it.

Upon closer examination, I realized both shock cords and snapped right were the rubber strap had exited the throat of the rocket body tube.  And the nosecone also had a short stub where one had been knotted against the plastic.

So I was left with a puzzle or two:

  1.  Where was the missing nosecone and blue checked chute.
  2. Why had the rubber shock cords snapped
  3. How could they be replaced
  4. Would Kevlar be a better choice
  5. And how could Kevlar be added to the mix, considering the rocket was already built?
The answer came to me as I was shopping tonight.  
In the cleaning supplies aisle were paper towels (my target) and garbage bags. Hanging from a pull-tab hanger next to the garbage bags were several dozen "Garbage Gripper" products.  That is, each card had a blister pack of what looked to be a large rubber bands.  Two of them!



I quickly realized that these were essentially rubber shock cords in an endless loop.  I could severe one and have a length of shock cord at my disposal.  Depending on the length, I could have TWO from one circle.

I stopped and reflected for a moment, thinking how much stronger and secure a Kevlar string might be, and thought that might be the way to go.  And then it occurred to me... if I had had Kevlar in the rocket to begin with...I still wouldn't have my parts back.  It would still be hanging from that tree out of reach until the cardboard tube had rotted or disintegrated.

I decided for all their faults, the rubber shock cord was in fact designed to fail... and maybe that was a good thing.

When I got to the check out scanner, I was a little shocked to see how much this pair of rubber bands rang up... but when checking on it at another store, I found a SINGLE rubber band ran $2.99 so my pair for $3.99 may be pricy for the raw materials, but at least I had a couple of options and a supply.... one for both rockets.

Now to find that other nosecone and fashion some other fins for Joel....

This has been the Not-So-Thrifty Rocketeer with a tip for salvaging that recovered rocket in the future!

Comments

  1. LonnieNovember 9, 2020 at 5:55 AM

    I finally realized the advantage of rubber cords when my Mercury Redstone got caught on a telephone line. It was hanging just low enough for me to attempt retrieving it with my telescoping pole. I caught hold of the airframe with the pole but could not lift it over the line, so the only thing I could do was pull the airframe down toward me in hopes the nose cone would flip over the line and come down. The nose cone hung on the line and would not flip over, so I had no choice but to yank the airframe in hopes of breaking the shock cord. The cord snapped and the airframe landed in the grass and fortunately, the nose cone and parachute broke free of the power line and floated down a few feet away.

    Braided elastic shock cords *might* last longer than rubber but had I put one on that rocket it would still be stuck on that line. I made a point of replacing the cord with elastic but tying on a short piece of rubber between it and the nose cone for next time (and there will always be a next time).

    ReplyDelete
  2. Kirk G - The Thrifty RocketeerNovember 9, 2020 at 9:19 PM

    Excellent comment, Lonnie. Thank you for sharing!

    ReplyDelete

Post a Comment

Popular posts from this blog

The End of the Line

Image
 The Thrifty Rocketeer blog continues... Well, for years, the state of the model rocket industry relied upon plans and patterns that were photocopied or printed out, and then applied to standard sheets of balsa to be cut out. Eventually, the various parts for various sized rockets were packaged in groups or blister packs, and sold at hobby shops across the nation.  The emphasis was on home brew or building a rocket to specifications and plans. Eventually, entire kits were pre-packaged, with all the parts that one would need.  And then, laser cut shapes, fins or parts were already pre-cut, doing away with the need for most of the patterns and tracing. So what happened to all those bags and bister packs of parts of rockets?  That is, a baggie of various nose cones... or connectors... or transitions or more ?   Many of  those packages remain at your local mom and pop hobby store, just waiting for someone to come in and buy some of their pegboard stock....
Read more

sleeping with the enemy

Image
 The Thrifty Rocketeer blog continues... First thing I did when they put in a Hobby Lobby in my smaller metropolitan town, 40 miles away, was to grab an application to work there.  Now I know what you're thinking... "How could you?  Who would want to work for that conservative corporation?".. as my daughter would say.  And you'd be partially right. I saved the application and took note of the mailing address. Within the first month or so, most of the initial buying frenzy was over, having sold out of some things, but not everything.   But it seemed nothing new was getting restocked. So, I got on my word processor and wrote a letter to the store management, THANKING them for bringing the store to our isolated metro area. I pointed out that many of the items had sold through completely, and how much we had appreciated their stocking rockets. Then I also encouraged them to restock and consider expanding the display, pointing to the fact that as rocketeers grow...
Read more

Death of a Hobby

Image
 The Thrifty Rocketeer blog continues... No, this is not a column about how Model Rocketry is a dying hobby.  It's actually about another sister hobby that sometimes overlaps into Rocketry. I'm talking about Amateur Radio. Just this last weekend, our local Ham Radio club held a "swap meet" which is commonly called a Hamfest.  These gatherings to buy and sell used equipment, parts and visit old friends typically happen just once a year and in the absence of the late Radio Shack, is one of the only places to find parts and electronic elements. There is also testing held to advance to higher licenses. The admission varies depending on the club, their overhead, expense of renting the hall or venue, and the number of tables that they can sell to area vendors who will drive across state with their wares to set up for the half day show. It's not uncommon for amateur radio operators to drive across state to attend, pay admission and get a single entry into the door prize ...
Read more