Flying Ohm
Fuselage is aligned over a drawn grid (above left) to install the horizontal stabilizer and vertical fin. The stabilizer is “sighted” using an aluminum straight bar in place of the wing. After the stabilizer is dry, the vertical fin
ailerons and rip them to the dimension shown on the plans. Using the rib template make new rib sections for the ailerons. Make the end ribs for the ailerons from hard 3⁄32- inch balsa. Mark and notch the T.E. and in- stall the new aileron ribs. Now cap off the L.E. of the ailerons and sheet upper and low- er cap just as you did with the wing. Fit the nylon hinges, but do not glue in at
this time. Make a bellcrank mount for each wing panel and mount a nylon bellcrank. Make clearance holes in the ribs for the
pushrods. I made the aileron pushrods from 3⁄16-inch wood dowel. I drilled the ends on a lathe and installed DuBro Qwik links on one end and 1⁄16-inch music wire with a Z bend on the other end. I then wrapped the ends with thread and epoxy to insure no splitting could occur.
Install a small 1⁄16-inch plywood plate in
the bottom inboard ends of the ailerons to provide a mount for the nylon horn. Once you have the pushrods and the linkage from the bellcrank to the aileron established, you can fit some balsa sheeting between the ribs to allow a neat exit for the linkage. Join the
can be attached. Overhead view (above right) of the model with the stock wing. The horizontal stabilizer was covered with polyspan and checked for any warps before installing on the fuselage.
wing panels using 1 inch under each wing tip rather than the original 2-inch per panel. All the original dihedral isn’t needed be-
cause we have aileron control. After the pan- els are joined, sheet the top side and then construct the servo cutout to fit your favorite servo. I took a standard plastic mount and cut it
down to fit the micro servo, which used only one screw versus two screws for a standard servo. This worked out rather well. Lastly, I took one of those black six-star servo arms that come with some Futaba servos, the one I mostly never use, and cut off all but two ad- jacent legs. This resulted in two legs with a V shape which give some aileron differential.
Fuselage The fuselage was kept mostly stock. I
added 3⁄16-inch square balsa stringers to the fuselage inside edges of the turtle deck and at the bottom edge from the L.G. mount to the tail block. This keeps the sides from sag- ging under the fabric shrinkage and giving that starved horse look. The landing gear has minimal prop clearance. Back then we
didn’t taxi out to take off like we do today, so the prop clearance wasn’t critical. So, if desired, the landing gear can be bent to a sharper angle to provide increased propeller clearance. The original attachment was thread stitching. I used nylon straps and that re- quired a thicker balsa filler piece where the gear legs exit the fuselage. The original model used Trexler inflatable rubber wheels. Amazingly, these wheels are still available, so I procured a set for my model. They look cool as this is a vintage R/C mod- el, but any modern wheel is perfectly okay. I used a nylon motor mount to save time.
The aluminum mount as shown on the plans looks more correct. I would use one if at all possible. The removable nose hatch is not needed except for access to the fuel tank and initial battery pack installation. The cutout location is also optional and the tricky quick removal latch is not needed. I attached the hatch with blind nut tabs and 4-40 flat head screws. The cabin area is more than adequate for a modern radio. I used carbon fiber
Overhead view of the completed construction (above left). Note the elevator pushrod is installed during the stabilizer mating to the fuselage. The hatch has a groove sawn to match the inside of the fuselage sides and a piece of ¹⁄₁₆ plywood with two 4-40 blind nuts installed. Four screws
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through the sides secure the hatch. Overhead view of the completed fuselage (above right). The wing hold down dowels are installed after the basic dope and tissue work is done. Just as with the original, the Flying Ohm is equipped with Trexler inflatable rubber wheels.
MAY 2012
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