A320 engine start swich with DIY locking mechanism or mount for thrustmaster Airbus throttle

General description 

This is a replica of the A320 engine start switch cap this design is as realistic as possible using measurements from the original aircraft taken using the picture coin method.

Funny story, taking the pictures, I was in the cockpit of an A320 on a flight deck visit after a recent flight, I got the captain to hold the coin so I can take a proper picture and use the coin for measurements. He was the most confused Captain to ever exist

Swich cap assembly (the silver part)

The two versions of the switch cap included one that contains two parts and the other which is a single piece. Each one has both a number one and a number two head.

Originally it was designed as a two-piece model so it could be CNC machined however that did not work out the two-piece model requires you to glue the head and the stem together this creates an ugly gap where the two meet.

I recommend making the single piece version as that Gap is not present my settings are an 0.4 mm nozzle and 0.1 mm layer lines with 15% infil. There are two filament changes required during the print, white for the lettering and then a few layers of black behind it to give that black behind the letering, the rest, Gray preferably a darker silver gray.

If you're using a single color printer like the prusa mini then the colors will visible from the side of the switch. You can paint it over with a bit of acrylic paint which also gets rid of the white around the letters. Which before you point out is an accurate however it was necessary at for printing purposes. The pictures of the model you see are what was printed, no post processing (like painting the sides) has been done.

Base assembly

I refer to the base as the black part at the bottom of the switch which the silver head is attached. On the real switch it has a locking mechanism at the bottom I have designed two designs

Desighn 1: Trustmaster airbus throttle

The first design is for the thrustmaster Airbus throttle found in the captain pack and the first officer pack, the base is a direct replacement to the original switches which I found inaccurate.

First remove the original switch cap, there's a pin on the side, after that when the base is printed out place the base on to the switch press it in place and put the pin back in. Often the pin is not necessary friction fit will keep it in place.

Design 2: Custom locking swich

The second design consists of a custom locking System to replicate the original locking switch of the aircraft.

I found that the Locking switches are available for purchase I'm very expensive. I am not paying 24 euros for a single switch! I decided to make my own mechanism, it is relatively simple design and wiggles a bit but it is perfectly adequate for home simulators.

The materials required go like this:

One small toggle switch just like the ones you can find literally everywhere most electrical shops have them for cheap. Picture in gallery

ballpoint pen spring

M 2.5  screw or grub screw

The base consists of multiple components.
first there's the base case, this is the black component which houses the spring mechanism and is where the silver swich head is attached.
Next is the spring stop, a small component which goes over the top of the internal switch stem (pictue attached) and has a grub screw to be able to hold on it restrains the spring and allows the spring to push against something when the switch is lifted.
Then there is the locking mechanism bottom, is the part wich goes on the panel, there are two versions, one that includes a demo case which shows how to use it and how to install it in the panel and put it to together and one that is a standalone unit, to be used in the design of the panel.

This component is also uploaded in a different printables model with free to use license, allowing you to use it freely in your panels and to be able to upload them to printables independently (if you do, could you please credit me in the description and put a link to this model page, thanks!)

Link to swich locking mechanism bottom:

To Assemble, print out all the necessary components, install the switch into your panel as shown on the demo panel (screw it into a hole in the panel, do not use the nut as it will impedemovement), put the black base (there is a version for short grub screw and one for a regular screw) on it then insert the spring which has been cut to the appropriate size. Finally put on restricting color and tighten the grub screw you can now put on the silver switch head and test it to make sure for correct movement. Picture attached of how it should go together.

Tips and tricks

Check the tolerances to which your printer can print and adjust accordingly, my printer has quite bad tolerances so the parts may go together rather Loosely on your end make sure to adjust for this.

The Locking switch mechanism Base has pins poking out from the bottom, I recommend to print it standing up with supports (picture attached) make sure that your supports have enough clearance separating layers between the print and the support material to be able to come off correctly and make sure to remove all of them any material Left Behind will impede movement of the switch.

The black on the head of the switch can be a bit problematic. I've had the layer lines sag as it's an overhang, I've not yet fully fixed this issue as you can see on my pictures however using a multicolor printer could really help this model, however I do not have one as they are expensive. One thing that could help is higher Extrusion (Extrusion multiplier brought up) so that more material is deposited, it could make a better finish but I've not tested that thoroughly enough to come to a concrete solution.

Do not use this model in an actual a320

If you have any suggestions tips, tricks or any other information you like to share do post to make or send me a quick message, also if you have access to a real aircraft of any type, especially if it's a commercial airliner do send me a message as any measurements would be helpful.