King Air throttles

You might ask why is a PC12 sim using a King Air throttle quadrant. Well I started out originally building the King Air sim after seeing many other builds and had this basically built when I decided on the PC12 concept. I also didn't want to limit the sim with a single engine quadrant which the PC12 has. Inspiration and basic measurements were taken and adapted from another website simucockpit.com. A french site building a B200 King Air, also using IOCards. If you don't read french, run the site through babelfish and translate from french to english, you'll be able to interpret enough to learn from this builder who has gone to great length and detail to build and showcase his sim. Again, Ron Duckworth has done another great job adapting a factory purchased throttle quadrant to his sim. Get his PDF in my downloads page.

Again scrap timber was used, such as 10mm MDF from a disused VCR stand. Once the width and height of the box was determined, a 10mm threaded rod was inserted at the proposed axis point of the levers. This would become the axle for the six levers.

 

A front view of the empty box ready for levers!

 

 

 

 

A template was then made to govern the arc which each lever would move through and the point at which they would be lifted through the reversing gate (for throttles) and the feather gate (for props).

 

 

A rough draft of the expected lever movement and positions was drawn in MS Publisher to get an idea of the arcs.

 

 

 

I then used an old nylon cutting board to make guides for my levers to travel in. Each lever has a bolt threaded through midway that follows the grooves cut into the nylon guide.

 

 

Here is a completed guide with grooves cut in. Notice the dogleg where the lever is lifted up and through the gate for thrust reverse.

 

 

 

Here are the two nylon cutouts which will sit side-by-side with a lever each side.

 

 

 

 

And here are the two mounted on the axis for the Throttle (Power) levers. You can also see the pencil marks on the inner left wall showing the expected travel stops for the throttles. The first being low idle, the second being ground idle (which I didn't end up using) and the third being the reverse point.

 

 

Here are the second pair of guides for the Prop levers. Remember that the slots for the travel guides are shorter than the Power levers as they don't have to move as far.

 

 

 

Here is a throttle lever with guide bolt in the groove. The bottom pivot hole is yet to be elongated to allow it to be pulled up and through the reversing gate.

 

 

 

Levers. Most other builders have used aluminium for their levers, I used some old shelf brackets I had lying around which I found were ideally shaped to begin with so there was very little need to mould them. They are thin steel, so more difficult to mould, but very strong and look more like the real thing. An original chrome bracket sits at the top.

 

Because the Power and Prop levers had to be lifted through their respective gates to accomplish Reverse and Feather, I cut an elongated slot at their axis. This way they would follow the nylon guide slots and be able to be extended by pulling on them when it came to reverse and feather. Just like the real thing! Here you can see the pilot holes I have drilled for the elongated axis.

 

Here is the box with some additions for the rudder trim. Also the mounting brackets for the 10K pots can be seen at the back.

 

 

 

This is the preliminary face plate I made using Paint Shop Pro and printed on a laser printer. A photo of the real thing sits next to it for design guides. The most difficult task in making the face plate is printing white text on black. Unless you want to spend lots of dollars on professional stencilling. The best result I came up with was to print it on a good laser printer (try to use one with a reasonably new cartridge). The red/white Prop feather gate was printed separately on a color inkjet, cut out and glued at the appropriate point, then the whole thing was laminated to preserve and provide a glossy finish.

This is the finished product ready to be glued onto the metal face plate and slots cut out.

 

 

 

 

And this is the metal face plate cut out and moulded to fit onto the throttle body box.

 

 

 

 

Levers mounted and some preliminary metal work at front. You'll notice also the levers are now bent to shape based on photographs of actual units. Also they're painted black. The actual levers are chrome, which you could get done professionally if you really wanted. Plastic tubing was used for spacers between the throttle lever mounts and a nylon locking nut was used to supply adjustable tension to all levers (left end of axle bolt).

 

A plan veiw of levers and actuator arms to move the pots. Also you can see the toggle switch I'm using for the flaps. I had began building a more realistic B200 flap lever with one up and two down position, but decided this would limit my flying when being used for other types of aircraft with more then 3 flap positions.

 

A closer look from the rear of pot installation and actuators. These actuators took quite a bit of trial and error to get the angles correct and ensure they don't foul each other.

 

 

A closer look at spacers and washers installed. All levers sit flush against the nylon guides so grease was used to provide an extra level of smooth operation. You can also get an idea of how the levers travel in the grooves and are lifted through their respective gates.

 

The Condition levers haven't got grooves to travel in as I wanted to get a notching effect from idle cutoff through to low and high idle. Instead I carved a shallow groove channel with deeper indents at the low, middle and high points. Round headed bolts were then installed with their heads facing the nylon guides. These heads would then travel in the grooves to give the notching effect. Also, as this is intended to be a multipurpose sim, the Condition levers can be configured as Mixture levers in piston aircraft.

 

And here are the home-made knobs painted and drying on the specially made rack(!). They are manufactured from a broom handle carved and shaped to an approximate of the actual.

 

 

Throttles almost complete. Faceplate installed and linkages finished and tested. Just need to complete the trim controls. It fly's the Aeroworx King Air beautifully! Single engine aircraft just use the left levers...no problem. All axis are handled by Leo Bodner's 8 axis joystick card.