Scram x 1.3 (oz8403)


Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - plan thumbnail

About this Plan

Scram x1.3. Radio control sport model, for .61 power.

The Scram (oz2578) was originally designed by Ray Heit and published in the July 1938 Flying Aces. It had an 83in span, weighed only 3lbs and placed 8th in the 1937 US Nationals limited engine run event. This here is a later version, enlarged and adapted for RC assist.

Quote: "Lately it seems that there is an increasing spread of nostalgia through the group of the older (or should I say more mature?) modelers almost worldwide. This may be due to real nostalgia, or the fact that these vintage type models really are relaxing to fly and, consequently, are perfect trainers and confidence builders; or just that they are great models to take out on a balmy afternoon or evening. I really cannot say, but I did enjoy the hours of flying and thermalizing that I did last season with a Majestic Major (1.4 x junior 60) powered by a Merco .61 2-stroke engine.

This is very economical flying since most of the time the engine is doing little more than idle. 25-30 minutes on a 6 oz tank is quite usual, and with the big Merco silencer, very quiet too. However, I think I got hooked on flying this vintage model as a refreshing change from scale - not as an alternative, but as an adjunct - so that I can fly and relax sometimes.

My local flying field is in Windsor Great Park, you can see Windsor Castle from the take-off area. I'm privileged to be a member of the association permitted to fly there. It really is a splendid flying site, with a very large mown grass take-off area, maintained by the park authorities. Due to the entire area being quite open to the general public and to comply with the United Kingdom CAA regulations, models weighing over 11 lbs are not permitted to be flown there. However, I like large models, so I build them light. The large Scram weighs 8 lb 6 oz ready to fly, with a Merco .61 2-stroke. Of course it's a natural for a .60 4-stroke engine or even a vintage engine like a Super Cyclone or similar. It has around 10 square feet of wing area, so is a real floater.

I spent some time trying to decide what to build - I needed a model pleasing to the eye, mine at least (beauty is in the eye of the beholder) and with a good pedigree. (Scram was designed by Ray Heit and appeared in the July 1938 Flying Aces, had an 83in span, weighed only 3 lbs, and placed 8th in the 1937 US Nationals' Limited Engine Run event.) It also needed to be acceptable for the UK SAM 35 competitions (we are allowed to scale-up for radio assist). Anyway, I liked the model, and proceeded to acquire a set of drawings from John Pond, who is the main source of vintage drawings in the USA, and drew them up 1.3 x size.

Inevitably some changes were made to the structure, but nothing that affects the model's image or character. For example, the trailing edge of the wing was originally solid, and I introduced some vertical struts between the diagonals of the fuselage sides, as the distance between them was too great to be unsupported. I elected to split the wing in the center, as in my view, this is the lighter and more conventional way to go. Of course, some changes were made to the tailplane and the rudder to provide movable control surfaces.

If you think you would enjoy some really relaxed calm weather flying, being able to take off, gain height, search around for a thermal or two, then bring the model in to land and taxi back to base, then this is for you! Let us begin with the fuselage.

Construction. Fuselage: This, in line with most vintage models, is a very conventional box structure which needs little comment. Do not omit the 1/16 balsa gussets at the top of the rear spacers since these add considerable rigidity to an otherwise flexible structure, as do the diagonal braces. You can refer to the photographs if you are in doubt. Do not omit the wire tension links from the front wing band dowel down to the ply former F-15, as these transfer the lift loads down to the main structure..."

Update 29/11/2018: Added further article, from R/C Model World, April 1988, thanks to RFJ.

Supplementary file notes



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Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - model pic


Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 003.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 004.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 005.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 006.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 007.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 008.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 009.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 010.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 011.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 012.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 013.jpg
Scram x 1.3 (oz8403) by Dennis Tapsfield 1987 - pic 014.jpg

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User comments

Hi, a couple of photos of my Scram 1.3, powered by an Enya 80-fc [model photo & morepics 005-009]. An excellent floater, can be flown very slowly. Weight is about 4 kg.
Dietmar Langenohl - 15/10/2019
Beautiful work, there. Many thanks for the photos.
SteveWMD - 15/10/2019
This is a Scram that was partially built from a fella who passed away some 34 years ago [pics 010-014]. Our local hobby shop gave it to me and my boys in hopes that someone would finish it and enjoy it as per the family’s request, and as you can see it flies quite nicely. We could not have finished it without Outerzone plans because there were no accompanying plans with it, so thank you so much for your site.
Martin Kolm - 06/04/2023
Apart from down thrust is there any wing incidence required to be set between wing and tail plane surface? or can they be 0 - 0 i.e. parallel to each other.
Thanks, John N -0
John Nanson - 08/06/2023
There is an evident wing incidence in this plan. You have to consider the "angle of attack" concept. In each airfoil the angle of attack (that determines the incidence) is the cord line between nose point of leading edge and trailing edge. So also if the wing lay flat on wing saddle, with apparently zero incidence, in reality has a positive incidence. Sometimes, for various reasons, it's necessary to increase that angle acting on fuselage design. Note how is high the LE nose in this airfoil compared for example with Clark Y. Pit
Pit - 08/06/2023
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