Hotrok (oz14181)

About this Plan

Hotrok. Control line FAI Team Racer model.

Quote: "The Hotrok is a pretty typical team racer - don't expect any miracles. It won't be 20 mph faster than everything else on the field, but it won't be slower either.

If this is your first team racer, build it as shown on the drawing. I'm sure you'll have some variations you'll want to try but save them for the next plane because everything on the plane has a reason for being. You may not agree now, but with experience you might very well come to the same conclusion. I don't intend to give complete building instructions. Building the airplane should be dead easy for anyone with just a little experience, but there are some options that I'll discuss.

Control Sytem: Up to this year all of my airplanes have used a circular bellcrank and button connectors in the wing. The advantage of the circular bellcrank is that the leadouts can run in tubes, thereby simplifying wing construction. The button connectors are housed in a cutout near the wing tip which is open at the bottom. A cover is usually put over this cutout when flying.

This year's plane uses button connectors on the bellcrank thereby eliminating the cavity at the wing tip. It requires the cutting of wide slots for the leadouts. Also this type of bellcrank cannot be purchased. (The bellcrank is detailed on the drawing for those who wish to make one.) If you can't find someone to make a bellcrank or buttons for you, go ahead and use regular line connectors outside the wing. The difference in flying speed is probably quite small.

For the wing, choose straight, light balsa. Cut the planform and inset the spruce in the leading edge and the 1/64 ply in the trailing edge. Taper the thickness to 3/16 at the tips but be sure to leave the center section untapered. This allows the wing to be easily aligned with the fuselage.

When using aluminum tubes in the wing I usually rough shape the airfoil. Then I cut the slots, glue in the tubes and cover with balsa strips. When dry, the wing is given its final shaping.

Fuselage: The fuselage begins with the bass crutch which is cut to shape and has the 3/8 bass wing spacer glued on. The mounting holes for the engine mount are drilled, and the crutch is hollowed out. Pin the engine mount onto the crutch and glue on the 1/16 " ply floor. Now put a motor on the mount and finish chewing out the crutch so the motor will fit.

Finish the lower block to the correct thickness (this will vary with engine height) and saw it out for the engine and cooling duct and glue onto the crutch. Cut out the duct floor and install the blind nuts for the landing gear cover. Glue the cover on the pod. Be sure to coat the inside of the pod with epoxy. Now using the crutch and the pod floor as templates, the sides of the pod can be given their final shape. The amount of sculpturing done to the nose is determined by the engine to be used.

Roughly cut out all the blocks needed for the fuselage and tack-glue or attach with double-sided tape to the crutch and motor mount, and carve and sand the fuselage to its final shape. Be sure to keep the 50cm x 100cm x 39cm2 fuselage cross section at the pilot's location. Take the blocks off and hollow them out. Glue the wing and stab onto the crutch and install the controls. Now glue on the blocks making sure the controls are still free.

Form a canopy around the hatch block. Hollow out the block and glue on the canopy. Mount the pilot in the hatch where he can be seen from all around. Exact mounting of the hatch depends on the type of motor mount used.

I have two #3-48 screws located between the engine mounting holes with a locating pin at the rear of the hatch. I have used various types of wing tip skids and have found that almost anything will work satisfactorily. My recommendation is to use .075 wire on the outboard and 1/16 aluminum tubing on the inboard. Why the inboard? Because when catching the plane the inboard tip is often scraped on the ground. Also when the airplane is being refueled and started, the inboard tip must be kept on the ground. If a landing plane snags your wires and your tip is off the ground, you're disqualified. Note that the tank vent is on the outboard corner to allow refueling with the inboard wing on the ground.

Bend .075 music wire to fit around the wing tip so that it lightly squeezes the wing. Wrap and solder the end. Epoxy around the wire. Do essentially the same on the inboard with the 1/16 tubing. Flatten the tubing where it bends around the leading edge. Fasten the two ends together at the trailing edge by pushing a V-shaped piece of 1/32 music wire into the tube ends.

Install a leadout tube in the wing tip. If you can, use a piece of 5/32 drill rod with a 1/8 hole. Harden by heating red hot and quenching in water. If you use aluminum tubing, the wire will quickly wear a slot in it which may cause binding..."

Hotrock from MAN, June 1975.

Direct submission to Outerzone.

Supplementary file notes

Article, thanks to RFJ.

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