(by Bob Harrington - 08/31/05)
Brief:
This is a mini engine powered downscale of the Centuri ESS Raven contructed out
of cardstock, featuring streamer recovery. This was one of my favorite designs
of my younger days that I never got a chance to build. The two plan sheets give
you all the parts needed and then can be assembled using the plan set from Jim
Z: http://www.dars.org/jimz/cen5312.htm
Construction:
Components consist of two plan sheets that should be printed on 65 lb. paper.
(Plan Sheet 1 - 892K;
Plan Sheet 2 - 371K)
There is a lot of unprint area on the sheets and that will be used to laminate
the parts to make them sturdier. In addition a 12" length of 1/8"
elastic was used for the shock cord, a 1" X 10" streamer cut from a
plastic tablecloth, and a small ball of clay for nose weight..
The parts were cut out and the wings, main fins, stabilizer, wing support,
stabilizer support, landing gear, sensor pod, and scoop were glued onto the
excess cardstock and placed between wax paper on a flat surface under a heavy
book until dry.
The body tubes were pre-rolled by placing them printed side down on a mouse
pad and rolling a dowel over them until they started to take shape. Expended
motor casings were used to roll the body tubes. I rolled the tube until it just
started to overlap and then spread Elmers white glue over the exposed tab with
a Q-tip and finished rolling. If you're careful, the edge should just match the
color seam line. Place them aside to dry.
I pre-rolled the body tube coupler, nose cone shoulder and engine block and
placed them inside the completed tubes to check for size before glueing them.
When the flat parts are dry, cut out the parts and glue together the top and
bottom wing parts, left and right main fin, top and bottom stabilizer, scoop
support and place them back under the book to dry.
The nose cone is formed by rolling and glueing the shroud piece, rolling and
gluing the shroud doubler inside, and forming the cone section. The cone
section is glued to the shroud, lining up the printed cockpit, and the shroud
glued to the short forward body section and the nose cone shoulder glued into
the body tube leaving 3/4 of the length outside the tube.
From this point, the downloaded instructions can be followed. Make sure to
put a launch lug on before gluing the nacelles. When attaching the wings, line
up the pre-printed markings. This model uses an engine block. Glue is smeared
in the body tube about 1 1/2" inside the rear tube with a Q-tip and the
block pushed in with an expended motor until 1/4" is exposed. remove the
motor immediately.
The prototype required 4 grams of clay nose weight.
Finishing:
The finishing of this model couldn't be easier. Everything is pre-colored and I
used a couple coats of gloss clear to seal the ink.
Flight:
The model is light enough to use 1/4A through 'A' 13mm mini engines. There
really is no need to use A10-3T's in this light a model as the A3-4T has plenty
of power. I used a 1/2A3-4T for the first flight. The motor is a friction fit
using masking tape. I used two squares of wadding but cut each square in half
because of the small body tube. The launch was straight and fast. I almost lost
sight of the model against the overcast sky. I was able to pick up the streamer
in the air for a successful recovery. The streamer really isn't needed and is
there to help spot it. The second and third flights were repeats of the first.
Recovery:
The streamer probably isn't needed but helps in locating the model both in the
air and on the ground. There is not a lot of room in the body so packing the
shock cord and streamer must be done carefully.
Summary:
I really enjoyed making this. The model looks a lot like the full size Raven.
Pro's - good looking, uncommon model. Inexpensive to make and fly. No
painting except clearcoat.
Con's - small body tube is difficult to pack.
Other:
This was one of my first attempts to recreate some of the classic models in a
small easy to handle size.
- Post a Comment -
What You Can Do
- Link to this Page -
You can link to this page using the following HTML or BB Code.
Text Link in HTML (for web sites)
<a href="http://www.rocketreviews.com/scratch-ess-raven-by-bob-harrington.html">Scratch - ESS Raven - Review by Bob Harrington</a>
Text Link in BB Code (for forum posts)
[url=http://www.rocketreviews.com/scratch-ess-raven-by-bob-harrington.html]Scratch - ESS Raven - Review by Bob Harrington[/url]
Select the appropriate above text with your mouse then "right-click" and select "Copy." Then, paste the text into your web site's code or a discussion forum post.
