Scratch DoubleTree Pen-Roc Original Design / Scratch Built

Scratch - DoubleTree Pen-Roc {Scratch}

Contributed by Dick Stafford

Manufacturer: Scratch
(Contributed - by Dick Stafford - 10/10/01)

Brief:
Rocket PicThis is a total rip-off of the cool Bic Arcas from DesCon7. The rocket was named after the hotel chain that "donated" the pen.

Construction:
Parts:

  • one Bic pen
  • clear packaging plastic
  • thin Kevlar® twine
  • one small paper clip
  • Mylar streamer stock

Rocket PicAs noted in the introduction, this is essentially the same rocket as the Bic Arcas. The main differences are that I used clear plastic Nike-shaped fins and a Mylar streamer in place of the chute. I chose clear fins because the pen body is clear.

The "nosecone" is the tip of the pen, with the ink tube removed and the neck ground down so it fits loosely in the pen body. The rear plug was also cut down and used for the engine block. The shock cord is a piece of thin Kevlar® twine that is tied through a hole in the nose cone, run under the engine block, and then knotted. Finally, a piece of the ink tube was used for the launch lug.

I drilled small holes in the far back of the rocket and formed a small retention clip from a paper clip. The fins were made from packaging plastic. The package I used had a small lip, which made the fin attachment a snap. Because the lip is not perfectly perpendicular to the fin, all of the fins are canted slightly. The fins and launch lug were glued on with Liquid Nails.

The only finishing step was the application of American flag stickers.

Flight:Rocket Pic
The motor mount includes a thrust ring and positive motor retention so inserting the engine was easy. No masking tape here! I inserted some of the shock cord, a small piece of Estes wadding, and then packed the streamer. As with previous small rockets, I used a soldering tool with a notched end to stuff the shock cord into this tiny tube. This works great and is a permanent fixture in my range box. The DoubleTree Pen-Roc flew twice. Both flights were perfectly straight and went to an impressive altitude. Deployment was also perfect. The only issue is the clear tube is getting less and less clear. Well, since the rocket is mostly plastic, I guess I can just wash it out.

Summary:
What I think is the neatest thing about this rocket, is that almost the whole pen is converted to rocket parts - very efficient! It is simple, easy to build, and it flies great. After re-reading the Bic Arcas review and getting a mental picture of what I wanted to do, mine only took me about a half-hour to build.

Other:
A soldering tool with a notched tip makes stuffing a Kevlar® shock cord into a small airframe (i.e. Micro Maxx sized) a LOT easier.

"Bic" and "Round Stic" are registered trademarks of the MM Bic Corporation, Milford, CT. Bic Corporation does not own or market these rockets, their name is used purely to accent the source of some of the rocket's components.

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