Howard Ike DGA-5
Fin and stabilizer are mounted on the fuselage, and balsa blocks have been installed and sanded to shape to match the taper of the fuselage (above left). Text describes how to install temporary spacer blocks so you can shape these fairing blocks without the fins in place. Close-up of the wing mount block
a ¹⁄₁₆-inch or similar drill bit and thread the elastic through the top of the fin, the stab, the bottom of the fin, stab, and back up to the top of the fin in one loop. Pull this loop tight and cyano the ends into place. For the wing we have to get a little more creative since the thread here must be re- movable with the wing and landing gear. Pass four lengths through the wing rigging blocks and fasten them to the fuselage and wheel pants with small wire hooks on the ends of the threads and small eyehooks or wire loops anchored in the fuselage and wheel pants. Since the landing gear is split, the wire between the wheel pants must also be installed this way. After a lot of searching I found some very
small eyehooks at the hardware store but even these looked too large and out of place on the model. I finally settled on making an- chor loops by bending short lengths of fine music wire over on itself (like a bobby pin) and pushing this into the wood with a drop of cyano. For the thread hooks I used ¹⁄₁₆- inch aluminum tubing to make short crimp ferrules which I used to fasten a small mu- sic wire hook to the ends of the thread.
installed in the fuselage (above right). The wing block has been drilled and tapped to receive the 10 –32 nylon wing bolt. The wing should be fitted into position and the block test-fit and carved to match the bend in the wing joint before gluing into position.
Control and power Small servos such as the Hitec HS-81,
with 36 ounce-inch torque, 16 gram weight, are perfect for this size model. As stated above, a 150 W motor and a 3S1P 2200 mAh battery are ample power. My prototype flies on an APC 8–6E prop turning about 8000 rpm and the flying speed is quite realistic, but I would consider this the minimum for a model of a racing machine. I’m flying mine
on a homebuilt 1100 Kv motor, but scanning the specs shows that motors such as the Scorpion 2212-22 from Innov8tive Designs
www.innov8tivedesigns.com, or an AXI 2212-20 are very suitable. Look for a motor/ prop combination that will result in a pitch speed of 45–55 mph (i.e., 6-inch pitch pro- peller turning at 10000 rpm). To guard against overheating I like to oversize my speed controllers so I recommend installing a 20-25A unit even though you will only be pulling about 15A with the suggested power system. Mount the ESC away from the re- ceiver. I mounted mine just behind the bat- tery, ahead of the servos, and I mounted my receiver on the tray behind the servos using hook and loop fastener.
Setup and flying Once all the equipment is installed check
the balance point. It should be right over the wing spar or a little ahead of this. My pro- totype is balanced about ¹⁄₈ inch ahead of the front edge of the spar cap and I am flying with the elevator trimmed about ¹⁄₈ inch up. Move the battery back and forth as required to achieve this balance and fasten it in this place with hook and loop tape. You might find, as I did, that to fasten the battery se- curely when it is located 2 or 3 inches behind the firewall is not very easy. To get around this and make battery re- placement easy I made note of the correct battery position and then constructed sim- ple blocking to locate the battery in the right spot every time. I glued a balsa block to the battery tray behind the battery, a couple of firm balsa sticks across F2B and F3 to hold the battery up against the tray, and a strip of balsa along the tray to hold the battery against one side of the interior. Instead of fastening the battery directly to
the tray I attached a ½-inch square balsa stick with hook and loop tape to the tray in front of the battery to stop it from sliding
The bones of the DGA-5 with the fuselage partially sheeted and all control surfaces in place (above left). Three-quarter view of the finished model (above
24
right). The markings really set this plane apart from the others, and the flying wires are an easy addition that add a lot to the looks. Don’t leave them off!
MARCH 2012
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