Landing Gear Switch Module

This is one of the few times in this simpit that I will utilize aluminum for construction.   I want the gear handle to have a more "authentic feel" than what would be provided by wood or plastic.  I want a satisfying "thunk" when the handle is moved into the detent and a "metal feel" to the overall assembly.

In Photo #1 below, you can see the gear handle lever arm.  It is mainly made up from a combination of nesting 1" aluminum tubing, 7/8" aluminum tubing, and a compression spring.  The end of the outer tube has been cut out to act as a mount for the furniture caster "gear handle" wheel.  The aluminum at the cut area has been flattened, the edges rounded and smoothed, and a hole drilled for the wheel axle.

Inside the end of the 1" tubing just at the point it was "cut" for the wheel, a flat washer has been epoxied into place to form a "wall" at the end of the hollow tube.  This "wall" will hold the end of a compression spring (seen in picture) that just fits into the 1" tubing.  The hole in the washer will also allow the mounting of a LED to illuminate the handle wheel area.

The section of 7/8" aluminum tubing will then slide inside this 1" tubing... and sandwich the compression spring between itself and the "wall".  This construction makes a composite tube assembly that will allow spring loaded movement in and out, with the "out" position having the "loaded" priority.

By adding a aluminum tubing "peg" running at 90 degrees to this handle that fits into a slot on the gear unit plate, the gear handle now has to be depressed in order to move it, and it will lock into detents on the unit.

You can see the hole for the pivot point and the hole for the "peg" as well as the two slots that allow the in/out movement of the handle.  Note that the slots are in different locations on the two sections...... this allows the movement.   Get it wrong... and it doesn't move.  




In the second photo, you can see the diagram of the handle positions drawn onto the 3/16" aluminum plate that forms the main housing of the gear handle unit.  The center point pivot hole is drilled, as are the four corner points for the standoff bolts and spacers that make the unit 1 "1/16" wide (I.D.) to clear the 1" tubing.


Using the handle assembly as a guide bolted at the pivot point, the position for the slot in the mounting plates is marked as are the detent positions (UP, OFF, and DOWN).  The "inset" straight lines for the detents mark the center line of the 1" tubing.




In photo #3 below, I have drilled a sequence of holes in the aluminum plates along the path of the intended "slot" and for the detent positions.  The two plates are kept clamped tightly together to keep everythjing lined up flush.  This is now the hard part of the whole thing....... cutting the series of drilled holes into a long smooth slot.  A lot of filing with a combination of round and flat files was used to get it to work OK.  make sure you make it smooth!  It doesn't take much uneven-ness to make the handle not work well.





In photo #4, you can see the two plates separated and the main structure bolts and standoffs at the four corners.  The standoffs are pieces of aluminum tubing (the rest of which will form the main structure of the parking brake handle).  If you look closely, you can just see the "peg" in the gear handle sitting in the slot.




In photo #5 below, you can see the mounting of the two momentary roller switches that will form the "gear up" and the "gear down" keypresses.  Each switch has NO and NC contacts.... so other functions are possible.  Since these pictures have been taken, I may add another switch or two for other functions.  They will be done the same way.

The switches are mounted on two short (1/8") standoffs each with tiny bolts thru holes in the side plates.  The roller arm contacts the 1" tubing near the center point of the handle tubing.




In photo #6, you can see a detail of the gear assembly from the back area showing how the "peg" runs in the slot on the plates.  To move the handle you press in slightly on the wheel and the handle comes "free" of the detents and can be rotated.  When it reaches a detent without pressure on it, it "snaps" into the detent.




And lastly in photo #7, you can see the pretty much completed gear handle unit.  The protruding handle assembly still needs a coat of the "cockpit gray" paint.  If you look closely you can see four more holes drilled through both side plates that will be used for mounting the unit into the MIP.  Now I just have to wire up the switches and get the handle illumination LED in place.




This assembly was a BIG item in the overall simpit construction.... and I am glad it is done.  I feel that it came out well.


best,

.....................john

Parking Brake Assembly

While I was working on the "mechanical" components....... I thought I'd just finish up the parking brake assembly while I was at it.  It follows some of the general design concepts from the above gear lever assembly.  It also uses nesting aluminum tubing with a compression spring for the "action".

Photo number 1 is an overview of the unit.  It will mount inside the center pedestal with a timy bit of the top aluminum tubing under the T handle above the panel facing (when the brake is "off".




In photo two you can see the real "business end" of things.  The two protruding "pegs" hit two SPDT roller switches as it "latches" onto the shelf created by the 3/4" MDF mounted on the 1/2" MDF backing plate.  The thick shelf plate has been rounded off to make the setting and release smoother.

You pull the T handle up about 4" and turn it 90 degrees to set the parking brake.  It has a nice solid feel to it.




In the last photo you see what happens when you pull up the brake handle and turn it...... the pegs hit the two switches.  I need two switches there because one will be the "keypress" in the software of the sim.... and the other will control an "external to the sim" function in my sinmpit.




It is screaming along now!


best,

...............john

Reflection of Perfection,

Thanks a lot.

It has taken a lot of work and a lot of time but it is coming together now.

I just ordered a Hagstrom KE72 keyboard encoder yesterday,... should be here by next Tuesday UPS ground... it is only coming from NY state.  So that will be the start of wiring up most of the switches.

best,

..................john

Excitement here in southern NH.

The Hagstrom KE-72 keyboard encoder card with two breakout boxes arrived this morning via UPS!!  Incredibly fast service, particularly since I asked them to mod the board by adding a header for the various keyboard leds like scrool lock , num lock, and so on. 

Unfortunately I don't have time right now to devote to the sim too much.  So it will have to wait a while before getting hooked up.

Darn.

best,

......................john


PS:  Master of Perfection and Disaster.... you should call yourself the Master of Name Changes 

On to

Part 20