Sunday, February 22, 2009

A picture of the Master Caution

As I promised a few days ago, this is a picture of the MC.


You can see the two squared pipes, one inside the other. The upper handles will be fixed to the cockpit frame. The two springs at the bottom keep the two pipes in the right position and allow to press the button. A switch at the bottom left side catches the pressure of the button.

Now the difficult part is to fit the leds in the upper side. I have already shaped a little holes card to fit in the big pipe. The card will be hold by a set of screws in order to keep the leds upon the hole and avoiding the lights to pass through the holes of the pipes.
At the present I plan to put 4 red and 4 yellow leds in the holes. Over the card of leds, I put the plexi and over it a little piece of white paper with the written.

I hope the final result will not be so bad. As I said, at the present I have the impression that the movement of the button is not as smooth as I hoped at least compared to an electronic switch. I will go ahead building that button but I am still not 100% that this tool will never be part of my cockpit.
in fact last week I went to conrad and bought a squared button where it is possible to fit one led. I am investigating if it is possible to fit two colored leds inside the button and if I succeed I will probably choose this second solution even if the button is not as big as I wish.

Monday, February 16, 2009

Master caution again

The master cation frame is finally ready, I will post a few pictures one of these days.

The final version is slightly different from the original design, in fact the two springs had to be put between the two lower brackets. It means that the two springs push the brackets away one from the other instead of pulling. I have tested the movement of the button and it works even if it is not as smooth as I wish. I guesst I have to put some oil between the two pieces of aluminium but it can never be as smooth as an electronic switch.

There is also another problem due to the windows made in the outer windows to let the upper brackets pass outside of the pipe to fix the button to the cockpit frame. The windows will be a problem when the leds are on because the light will pass also throught the windows creating an undesired game of lights. I have thought to two possible solutions and I will probably adopt both of them:

  1. mount the button in such a way the window will always be below the frame (in this way I guess the light will be much less because the wood will naturally stop it; I should probably add a fisical protection like a piece of dark gumi)
  2. try to mount the led in the upper most side of the outer pipe with a dark gumi in the back (for this implementation I should investigate the usage of special very little leds like those used to light handy phones; the light will probably be inserted into the plexi; particular caution must be applied while cabling the leds because they move together with the outer pipe whenever the button is pressed or released)

In the mean time I think it is time to start designing the right side of the cockpit. I have to put there more commands usually found in the upper side of the real cockpit like fior example the trust control, the gear lever and so on. I have submitted yesterady an order to opencockpits getting a new master card a few switches and the gear lever of the 737 (I had found a 767 model too but was really too expansive).