Match-Stick (oz2270)

About this Plan

Match-Stick. Radio control sports model for Cox .020 power and 2 channels.

Note the Matchstick and Rivets (oz11679) both appeared in the same article in RCME 1984 titled: "Why not try Suitcase Scale?"

Update 04/11/2019: Added article, thanks to RFJ.

Quote: "Pull-Out Plans for Suitcase Scale. Two micro R/C models for 0.020 motors and two function R/C. Matchstick and Rivets, by RCM&E staff.

Two Pull-Out Plans: Hopefully having whetted your appetites, take a look at the two full-size plans accom-panying this article. Both designs are suitable for the Cox 'Tee Dee' .020 or G Mark 0.03 motor, both could be considered scale as the 'Matchstick' is an approximately 1/2-size Ugly Stick (oz5175) and the 'Rivets' is fairly close to scale. The 'Matchstick' provides a very good starting point for this style of model, it is boxy, easy to construct and a stable flyer allowing a little practice with such small models before moving on to the undeniably slightly more difficult area of scale models.

Matchstick: Construction of this model is very simple, fuselage sides are cut from 1/16 balsa with diagonal grain 1/32 balsa doublers back to F3. Drill wing dowel holes before assembling fuselage through both sides simultaneously. Cut out formers and assemble F2 and F3 between the fuselage sides then sheet the wing bay area underside of the fuselage. Pull-in the rear fuselage sides and glue together, followed by fitting the nose former 1/8 sq balsa reinforcements. Cut the tailplane and elevator from 3/32 balsa, the fin from 1/16 balsa adding the anti-warp strip to the fin as shown on the plan.

Now complete the fuselage top and bottom sheeting noting grain directions and glue tailplane and fin into place. Fit the scrap 1/16 ply cross-piece onto the fuselage nose and make up the battery hatch.

Servo mounts are hard balsa, the elevator push-rod is simply a length of 18swg piano wire with a 'Z' bend at the servo end and a mini horn, clevis, etc. at the elevator end. If you really trust your wire bending accuracy, the elevator connection can be a simple right angle bend with the push-rod very positively sprung into place.

The wings are equally simple. Cut a plywood template for the ribs and make 18 identical 1/18 balsa ribs. Cut the trailing edge bottom sheet and chamfer as shown on the cross-section. Assemble all the ribs onto the trailing edge, add the top spar and leading edge and the upper trailing edge. Remove from the board and fit the second wing spar. Add the wing tip profiles and triangular gussets, sheet the centre section with 1/32 balsa and cut out the hole for the servo. Note that the servo output shaft projects through the wing upper surface and it is necessary to position the hard balsa servo mounting beams so that the top of the case is against the top sheeting. Sand the complete wing ready for covering.

Covering: We used 'Solarfilm' and cut up the sections to produce the colour scheme and assembled these on my work-bench before applying to the wing. This technique worked well, only a 3/18in. overlap is needed and providing you don't use too much heat when shrinking the covering, these overlaps will hold. Covering this way saves the weight of a double layer of film where trim colours are applied.

Both elevator and ailerons are hinged with 'Solarfilm'. Cut a 3/8 in wide strip and lay the elevator flat down on the wing trailing edge. Film over the aileron and wing trail edge then fold down the aileron into its functioning position and now seal the top surface with a second 3/8 strip. The engine is fitted with 2 x 8 BA nuts and bolts and with 100mA battery Futaba Micro AM receiver and two servos the model weighed 7.5 oz ready to fly and balanced right on the main spar.

Flying Small Models: Firstly fix yourself up with some 20% Nitro fuel, a 1.5 volt glow battery (A 1.2AH Ni-Cad cell is fine) and choose a calm day. Fuel up the motor and use either hand-start or the spring starter. Don't use your normal hi-torque 12-volt starter! These small motors nearly always need a prime through the exhaust to set them off.

Set the needle valve with the nose slightly high and be very delicate, open the needle ever so slightly from the optimum 2-stroking setting and check over the controls before launching. Do have someone experienced to launch the model, neither a full-blooded hurl nor faint-hearted drop are going to help!

Once airborne, don't allow the model to get too far away, particularly downwind, far better to continually fly upwind (and out of the sun if possible).

If the engine does go off song from being over-rich then putting the nose up will some-times lean out enough or just as good, cause it to cut!

Once the engine has cut you will find the glide quite fast and landing approach has to be planned and executed smartly. With a little practice you will find that you can land the model at your feet 'deadstick' every time.

Roll rate of these tiny models is usually very fast, but surprisingly they are not usually twitchy. With a wing loading of less than 8oz/sq ft the models are not prone to tip-stalling either.

Next month - What's available in the 'Suitcase Scale' market place."

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