Plastic Parachute Replacement

 The Thrifty Rocketeer blog continues...

One thing that escaped me when first entering this hobby, was the need for additional plastic parachutes for your fleet of rockets.  

I naively thought that since one came with each kit,   I was good to go for good... forever.

Let me burst the newcomers' bubble right now...

There are such things as rocket eating trees, thorn bushes, sharp objects and sun-fading weakening plastic in our world.  Never mind that we're working with hot gases to push our payload and chute out of the body tube.  The risk of damage to a thin plastic chute is almost inescapable.  Sooner or later, you're going to melt, rip or tear your plastic chute.

And while some limited damage can be avoided or dealt with...you will eventually need to replace a plastic parachute.

Most all rocketeers worth their salt have constructed a thin plastic chute on their own. It's almost a rite of passage for the hobby.  And it teaches you some basic skills. But there's another way.

Now Estes and other companies have conveniently packaged individual chutes for sale at most hobby shops or Hobby Lobby.  You'll find them slightly over-priced but complete on the pegboard for anywhere from $2 to $4 each. (And there are more expensive nylon chutes, but that's not what we're discussing here.}

There are essentially two types:  

1. Completely assembled, with all lines, sticker and parts... ready to go right out of the package.  For some, this is the most convenient and best choice, especially if you're out in the field at the launch site and need to swap one out.  You may want to store one in your range box at all times.

2) Some assembly required.  And by this, I mean, all the parts are included, but none of the assembly has been done for you.

Typically, the second type have brightly printed stripes laid out in a bullseye or dart-board pattern, along with instructions printed in the corners of the plastic sheet.  There are often three "rings" of dashed lines at various diameters allowing you to cut varying sizes of chute from each sheet... 12", 15" or 18"  but not always.

The discerning rocketeer may have a preference for which size chute goes with which of his rockets, but it's safe to say that you want to replace your damaged chute with one of the same size...unless you're going for a specific effect...  say, a faster descent... or a lighter weight rocket.  (Specific wind conditions of the launch day may influence your choice.)

***[When I first bought replacement chutes, I immediately whipped up three sizes, cutting them out, assembling them, powdering them, folding them up, and storing them in snack-sized Ziplock baggies in my jump box or range box.  Ordering a bulk pack of 10, after ten years, I think I'm down to my last unassembled chute now.]

I know if I try to give you instructions on which chute is best, or which rigging is best, we're going to have a difference of opinion.   And if this is posted on the internet or in Facebook, an argument is going to erupt.

Now, there are purists who say the best way to replace a chute, is to take a thin, light garbage bag and create your own.  This also requires finding the right string or thread to make shroud lines.  And there is a value to doing this scratch build.

I myself, have fallen into salvaging those bright red plastic flags that you get from the lumber yard to flag the end of protruding loads, wooden boards or other hazards when loading.  I find that plastic ranges from thin mylar to thicker sheets, printed with the name of the store on them.  Just drive around any such lumber store near an expressway entrance ramp, and you're SURE to find a half dozen that blew off or tore free from the end of the load, where they were stappled on.  

(This leads to another topic, that I'll briefly mention here. If you do attempt to salvage one of these bright red plastic flags, look carefully at where they have torn free. You likely have a hole or tear in the middle of the sheet that should be planned for when cutting out your pattern...  You may be able to incorporate a torn snag into a spill hole, or perhaps it will be close enough to the edge that you can cut away the hole and recover the rest of the plastic.  Either way, be aware of this.)

You might also approach your lumber yard and ask for 2 or 3 of these sheets to start afresh. As an adult, I find I can walk out of the store, pause at the loading dock door and just help myself to one or two without being challenged by anyone. (After all, they WANT their customers to be safe when hauling their product.  And while THEY won't take responsibility for your load, they won't object to you securing it with a red flag... or two.)

The next step is to layout and actually cut out your pattern, and that's more of a build thread. I am certain to spark some controversy between different ways to do this, so let's leave this topic for another day. (And I do intend to post a build thread very shortly.)

There are two points that I think we can all agree to here, right now.

When cutting out a pattern for a plastic chute, cut slowly and smoothly. If using scissors, try not to leave a "notch" between successive closings of the blades. That is, if you're not careful, each time you start another cut with your scissors, you can leave a little snag or cut, where the angle of the cut minutely changes, and can cause a notch.  This is bad because under the stress of deployment, the notch effect may cause a rip or tear to start right there, especially with thinner plastic.

Second, when you've completed your chute and are ready to store it, always powder your plastic with something that will reduce any inherent tackiness.  Examples include: Baby powder, flour, corn starch, talcum powder, and probably a host more substances.  I know people will argue over which of these is best, but I've never heard anyone speak badly of baby powder as easily applied, readily available and convenient in a shaker top bottle that lasts for years.

That's about enough for this posting.  I hope I've got you thinking about creating a spare or two for your jump box.  This has been the Thrifty Rocketeer saying "Powder your chute. You'll thank me later!"