line handles are not just ordinary tools. For a beginner there may not be
much difference which kind of handle he is starting his first laps with.
But the advanced pilot surely makes some demands on the type of handle he’s
using. After all this is where he feels his airplane, and he wants to feel
VERY comfortable while flying.
aluminium centre layer 2mm
having had some doubtful experience with various examples, and since suitable
handles are not available at the model shop next corner, I finally decided
to build my own. This allowed to consider my own wishes and demands. The
requirements for design were:
1) the handle should fit the control system used in all my airplanes. Since I always use the same system and dimensions, I can use the same handle for all airplanes. My bellcranks are 100 Millimeter long and so is the handle. While quite practical in some cases, I do not feel a fully adjustable handle an absolute necessity, so I renounce this feature.
2) I’m not exactly a Schwarzenegger type. Long overhang requires quite some muscles to steer sharp corners , especially in wind. I prefer to have as little overhang as possible.
3) I prefer to have a flat but wide handle ( wide in the direction of the lines ). Unlike those thick grips a flat handle can be fully enclosed by your hand and cannot move in your palm. Especially with sweaty or oily hands a well shaped handle is helpful.
4) I like to be able to adjust the lines during flight. When trimming a new airplane I don’t have to wait for the next flight to dial in a little more Up or Down. If you have only one handle this feature is necessary to adjust the handle to different models. I have more than one handle now, but I still like this feature. Especially in strong wind and/or with cold hand I seem to be happier with one more Down “turn” for those nerve wrecking inverted pullouts.
these thoughts in mind I tried to find the optimum handle shape. For this
purpose I picked an old English Davis Charlton grip which is a very narrow
item. I mixed some epoxy putty and put it around the handle. With a thin
plastic glove on my hand I grabbed it and held it quite firmly in a way
which I would when actually flying. This gave me the perfect final shape
which was to be copied on my real handle.
|Construction of the handle is not too difficult. The adjusting system consists of a runner riding on a threaded rod within an aluminium channel.|
|First a knurled nut ( 6 ) is soldered to the threaded brass rod ( 9 ). A small keeper ( 8 ) with M3 threaded hole is held between two washers ( 7 ) soldered to the rod. I have used a short piece of 10 X 10 mm aluminium channel ( 5 ). The inner width of this channel is 8 mm. So the runner ( 10 ) is made to fit precisely and slide without any friction in the channel. The control cable is some kind of lead out cable; I use bicycle Bowden cable. Be sure to get some really flexible stuff. It is soldered to the runner, then the end loops are made. Fix keeper ( 8 ) to the channel with a short M3 bolt. If you prefer you can add another keeper at the bottom end of the channel. I haven’t found this necessary. After all, the horizontal load is taken by the curved channel of the center layer ( 1 ). That’s why this bend should be really even and smooth. Before gluing all layers of the handle together, carefully apply some grease to the cable to keep it from getting glued in solidly !|
centre layer ( 1 ) is sawn from 2 mm aluminium. The next two layers ( 2
) should be made of 4 mm plywood because they have to support the front
ends of the handle. Together these three layers add up to 10 mm which is
the thickness of the channel. You Imperial guys will have to calculate other
dimensions for what is available in your surroundings. The top layers (
3 ) are made from whatever thickness and kind of wood you like. Sketch (
4 ) shows the schematic construction.
|At last file and sand the wooden layers to a shape which feels comfortably in your hand. Check repeatedly until the fit is perfect. Work the exit of the cable extremely carefully. In emergency reactions ( = movements ) the cables might be bent sharply here, so there shouldn’t be any sharp edge.|
that the technical part is completed let’s turn to the really important
step. What follows is that essential aesthetic treatment by applying a most
tasteful design to the handle surface. Only artful wood-carving, craftsmanlike
fine-milling, as well as classy inlay art ( Northern Kenyan mahogany preferred
) can satisfy our elevated demands. A final UV barrier clear coat is wet
sanded with 9000 grade linen and highly polished with Australian blue diamond
powder. It goes without saying that such a jewel can only be handed over
in humble attitude, presented on a white velvet pillow wetted with Eau de