Tutorial Presented By Member Buddy Mooneyhan (BuddyM)
Let me start off by saying that I am not a machinist, or a draftsman, and I don't have much experience (yet) at cockpit building. I do love to tinker and build things, and I am always looking for a way to build a needed component in a manner that fits my budget. This tutorial shows how I contsructed my landing gear lever and switch assembly for my A320 build.
The operation of the assembly is simple. It's not very accurate as far as how the real lever works, but it it does work very well, and is easy to build. The lever pivots at one end with the handle at the other, and in the middle is an acorn nut. It's called an acorn nut because it's spherical on one side and looks like an acorn. At the full extent of travel at both ends of the pivot, the lever presses against the roller/lever assembly on a microswitch, which is wired to whatever input controller you use. The acorn nut mounts someplace in the middle of the lever. A hole slightly larger than the round head on the acorn nut is drilled in the appropriate location on the switchplate so that when the lever is moved to one end or the other, far enough to trip the switch, that the head of the acorn nut drops into the hole and holds the lever in place. The pivoting end of the lever is mounted slightly offset from the switchplate with a couple of metal washers and a rubber washer in between them. This provides for a tight but flexible fit that allows the lever to ratchet in and out of the holes in a comfortable and familiar way.
The Parts List
My gear lever and switch assembly consists of these parts:
- 1 piece of rigid plastic for the switchplate, lever, and handle discs.
- 2 micro switches (leaf-type).
- 1 acorn nut.
- 2 angle brackets.
- 1 barrel or “sex” bold with matching screw.
- Assorted screws, washers, and nuts.
Making the Switchplate
Start off by cutting the switchplate from your plastic sheet, or whatever material you chose. Your switchplate dimensions might be slightly different, My switchplate was designed to with enough distance between the 2 microswitches to allow the lever travel the full length of the cutout on my MIPs landing gear slot.
Cut out your gear lever and the handle discs.
Drill the holes in the switchplate for the acorn nut and all of the mounting holes for the microswitches, the gear lever pivot, and the angle brackets.
Drill the holes in the lever for the pivot screw, the acorn nut, and the handle disc screw. Drilling holes for the acron nut and the mounting holes for your microswitches will take a little playing around, since your dimensions and switches might be different.
Mount the acorn nut on the gear lever. I chose to mount mine 1.58 inches from the center of the pivot screw hole.
Mount the gear lever to the switchplate with a screw and the washers as shown to allow the lever to flex a little at the pivot scew.
Now hold one of your switches against the switchplate and decide where to place the switch so that the gear lever will trip the switch when the acorn nut is sitting flush in the hole. Mark your mounting holes and drill them. Repeat for the other end of lever travel and mount both switches.
Now mount the angle brackets that will hold the gear lever assembly in place behind your MIP.
Assemble the handle discs on the end of the gear lever. I used a barrel screw so that it would be flush on both sides, but a normal nut would work.
Lastly, wire your switches and test with whatever I/O card you have. I've tested mine with my Iocards mastercard, my Bodnar card, and my Mjoy16.... it works great with all 3! Note that I have my switches wired to connect to 2 different inputs and a common ground. This allows me to move the lever from UP to DOWN. If you only have one input left you could also wire them to a single input and simply toggle the gear as though pressing G on the keyboard.
I am sure that there is room for vast improvement on the design of this gear lever assembly. Some things that come to mind are using a section of spring-metal to mount the acorn nut on a dog-leg so that the lever does not need to flex, instead allowing the lever to remain stationary and the spring-metal to give way enough for the acorn nut to pop out of the hole and allow the lever to travel. Another idea is to assemble the unit from aluminum instead of plastic. You could also assemble the lever from 2 sections of plastic and route a wire slot inside to allow placing plexi handle discs at the end with LED in them to illuminate the handle. I am sure you will no dount have many other ideas and improvements.
I hope you find this tutorial helpful. Please fell free to drop me a note with your ideas and improvements.