Scratch - Upscale Mosquito (320%) {Scratch}

Mo' Skeeter Upscale

Scratch - Upscale Mosquito (320%) {Scratch}

Contributed by Chris Gonnerman

Construction Rating:
Flight Rating:
Overall Rating:

Published:	2010-12-24
Manufacturer:	Scratch
Style:	Upscale

Brief

This is my Mo' Skeeter, a 320% upscale of the classic Estes Mosquito. It's a rear-ejection model, which avoids the visible nose cone line that most Mosquito upscales suffer from.

Components

This rocket consists of a Baby Bertha cone, 6" of BT-60, 6" of BT-20, two 20-60 centering rings, a thrust ring, engine hook, and retaining ring, a launch lug, and a shock cord consisting of a Kevlar leader and a length of elastic; I use a standard Estes or Semroc chute with it, attached via snap swivel.

The fins are 3/32" balsa, cut using a 320% upscale of the standard template downloaded from JimZ's site.

Construction

I cut the pointed part and attachment lug from the nose cone, bored a new hole to attach the Kevlar, and epoxied the cone in place on the BT-60 tube. I came to regret that decision a bit later.

After notching the centering rings (inside for the engine hook on the rear ring, outside for the shock cord for the forward ring), I installed the thrust ring, engine hook, and retaining ring into the BT-20. I still had some epoxy mixed up, so I used that to secure all these parts. After gluing the aft centering ring in place using yellow glue, I put the forward ring on the tube and inserted the assembly into the sustainer, pushing it in until the aft ring was just inside the BT-60 tube. Doing this pushed the upper ring into the exact position it needed to be in. I pulled the inner tube out and applied yellow glue to secure it.

Next, I glued the fins in place using yellow glue and the usual "stick it on, pull it off, let it dry a bit, glue it on for good" method. Here's where I regretted gluing the nose cone on first... I had to hold the rocket for probably twenty minutes before I was sure the glue was solid enough to stand the rocket on its fins.

When it was all dry, I applied several fillets of white glue (less shrinkage than yellow) then attached the launch lug with yellow glue.

Finishing

I brushed the fins with thinned Elmer's Carpenter's Wood Filler. I also brushed it over the body tube spirals and into the nose cone line. When dry, I sanded the filler smooth; then I started the usual prime-and-sand loop.

When I was happy with the surface preparation, I painted it yellow using a cheap store-brand rattlecan (I don't remember where I got it). Several light coats followed by the rotisserie treatment resulted in a deep shiny coat; I gave that the usual week to dry (as is usually required with the cheap paint), then masked it and applied Wal-Mart Colorplace Fire Red.

I created the decal myself using the GIMP and some clipart I found online, and printed it using a color laser printer. I didn't clearcoat the decal before applying it, and it suffered a little bit of flaking before I got clearcoat on the rocket, but it hardly shows. Laser printed decals sound like a good idea but the current laser decal paper has some deficiencies. Still, the rocket looks pretty good overall; I'm particularly pleased how well the red decal matches the Fire Red paint.

Construction Score: 4

Flight

At our 4-H Club Launch on the 9th of July, 2009, I got to launch the Mo' Skeeter for the first time, on a B6-4. It flew well and recovered nicely, albeit on the roof of the landowner's machine shed. Thankfully, we were able to recover it in good shape.

I got to fly it again at the SPARC launch on August 22, 2009, on a B6-4 again. It was a perfect flight and a perfect deployment. It came off the rod too fast to photograph, which is surprising for a rocket with as much base drag as this one. There were some minor dings to the paint on the fins.

On September 18, 2010 we had a launch at the neighbor's. I flew it on a B4-4 for the first time, and WOW do I like that. It took off with more authority than I expected, and recovered beautifully.

Recovery

The nose-down recovery of this rocket tends to protect the fins from major damage. Though it rigs differently than other rockets, I have not suffered a deployment failure, nor any damage to the chute. And note, this rocket does not require wadding, since the upper ring shields the chute from exhaust gasses.

Flight Rating: 5