Controls

1. Building and installing the control columns

(7th April 2006) The first image shows the joysticks which are linked together by bronze bushes through holes in steel fittings in the central welment, and a lower pushrod of hexagonal section. The rod end bearings of this push-rod are adjusted to get the sticks parallel. Image 2 shows a threaded rod end from the rear elevator pushrod ready to be drilled to take 8 pop-rivets. To find where to drill, I used a piece of thick paper (red) which I wrapped around the rod and marked with 8 equally-separated divisions. Drilling must be done with a drill-press ans a piece of "V-section" wood which nicely holds the rod. The thinner rod in image 4 attaches to the control stick assembly and drives a bellcrank which in turn drives the thicker pushrod to the elevator horn. These pushrods are are light and strong. They need to be primed both inside and out.

(15th-22nd April, 2006) The elevator bellcrank assembly and spacers (Img 5) were finished, constructed and dressed over this time while I was working on other fuselage small pieces. they were all primed in one go. Note that the elevator servo pushrod has to be spaced away from the bellcrank (I am holding it in place - Img 6). This is done with two washers when the link is finally bolted in place. I lifted the sheet covers from the seat ribs and removed the small rib pieces which allow access to the control column pivot attach points. I then used AN3 bolts and nuts, with washers as spacers, to fit the pitch control rod in place. I then bolted together the roll control hex rod and rod end bearings and threaded this whole assembly into position parallel with the pitch control rod ("Fitting control columns"). The final photo is a close-up of one attachment point of the pitch control rod. I found that laying the fuselage on its side facilitated positioning washers, bolts and nuts, because gravity was then not an issue!

Joysticks

Measuring rod end holes - elevator push rod

Circumferential

Drilling

Elev Bellcrank

Elev AP servo rod

Fitting control columns

Pitch control fulcrum fasteners & spacers

(29th October 2006) One job to do once the wings are mated is to add the aileron trim control. I have the manual version which I installed over about 2 hours today. Image 1 shows the teflon block which provides friction to hold the trim control shaft in position. It is marked up for drilling two AN3 bolt holes. it was shamfered to fit in the mounting bracket (image 2), and the bracket was clecoed to the RH floor sheet where it coveres the two central floo ribs (Image 3). These were then drilled to take the control shaft (image 4) and the mounting bracket was finally primed (hardware spray pack - image 5).

teflon block drilled &

mated to bracket

match drill to floor skin

hole for shaft

primed

The trim works by means of an arm, the position of which is set by the control shadt and indicator. This arm needs to be bent a little (image 1) before being inserted into the teflon block (image 2). The shaft is drilled in two positions, First, 1 1/16" hole is trilled to take a cotterpin which hold a retaining washer (not shown). Second, the shaft iand indicator arm are both drilled 3/16" to take an AN3 bolt to secure them together (image 2-4). AN3 bolts are inserted through mount bracket and teflon block to secure and provide variable friction to hold the shaft position. This was temporarily screwed in place, until the floor sheet is eventually installed (image 5). Eventually the actuating arm will be connected to AN3 bolts securing the control sticks to the aileron pushrods by wire and strings. Altering the indicator arm will move the actuating arm and alter the resting position of the joysticks via the springs. All good fun!

bend it a little

and drill for

AN3 bolt

and cotter pin/washer

installed

 

Rudder and Tail Wheel

The rudder cables pass along the fuselage walls through plastic bushes. They connect to the rudder bar pedals by four 0.50" steel plate connectors (see image 1). I need to prime them, but you can see how simple it is. At the back, there are two lengths of chain and two compression springs which link the tailwheel to the rudder position. I think those chains and springs look OK, even though they probably cost a knot or two. Some builders use a mechanical arm which presents much less parasite drags and looks sexier.

rudder cable

tail wheel