Dome light switch too short in '67C

[0TreeLemur]

The dome light switch in our '67C is the type that you rotate between thumb and forefinger to turn the light on/off.  As you rotate it about 1/2 turn it clicks.  As shown in the photo, the switch  is too short.   It does not protrude beyond the fixture so is impossible to use.  I took the fixture off yesterday for a look, and the tip of the switch shaft is rounded and smooth, as if it were made that way.   Now I know that this cannot be the case. 

The shaft seems to be made of plastic, and is about 1/4" dia.   Has anyone (1) had this problem and (2) come up with an elegant fix?   Of course, I would like to extend the shaft 1/2 and make it a target for a passenger to hit their head on   Other options will be considered.   Please no hijacking this thread to discuss Star Trek "Force Fieldz" and "Tractor Beamz".

[Yetti]

I would be tempted to replace it with only a slight danger to your passenger's scalp. 

[carusoam]

In 65C... there were two knobs in the ceiling for dimming, on/off, rotating knobs...

Today, people are changing over to LEDs and that takes a PWM(?) type LED dimmer...

Best regards,

-a-

[Andy95W]

The interior lighting on the Enterprise was really cool looking and seemed to work well.  Touch sensitive on/off as well.  I wonder if there was ever a mod to use something like that in a vintage Mooney?

Of course, I'm talking about the Enterprise NC-1701-D, not the original.  IIRC, the original had toggle switches.

 

A cheaper option would be to call LASAR and get a used replacement switch.  The light is pretty easy to remove and disassemble.

[RLCarter]

Looks like the one in my 65 E, but it is push on/off type

[0TreeLemur]

Does anyone else have the rotary style switch?   If so, please tell me how far the shaft protrudes down from the fixture?    Oddly it doesn't seem that this is broken, rather it looks like it was intentionally made too short...  I'll take the plastic headliner down and see about installing a replacement, or retrofitting with a pwm dimmer as @carusoam suggested.

 

[carusoam]

Fred,

If the axle/stem that is coming out of the dimmer switch is plastic....

Look for a tiny hole running down the middle of it axially...

If the axle was cleaved off exposing a micro hole down the center...

Long story short...

The molding process of plastic pieces often leaves a vacuum hole down the center...

If it breaks, the hole is exposed...

The cause of the vacuum hole... density change from a hot liquid polymer melt, to a semi-crystalline cold solid.  The outside of the part cools first, leaving a vacuum hole in the center last....

 

This is a technical explanation, in search of a technical challenge...

In the 60’s it probably wasn’t popular to use small thermoplastic parts... injection molding was in the early beginnings in that decade... Expect any low cost plastic parts made in that decade to suffer from brittle failure at the end of their life...

We have come so far... 

PP thoughts only, not a mechanic...

Best regards,

-a-

[0TreeLemur]

Thanks @carusoam I'll look at the center of that plastic shaft- I suspect you are correct- it feels different in the middle.  Replacing the switch is most certainly the way to go it seems.

On a related note- I luckily had my headset on when this big honkin' thing fell off the ceiling and hit me in the head.  This knob extends/retracts the dorsal air inlet, and is machined out of a 1" thick piece of solid aluminum.   Pretty heavy for what it does.   I'm starting to look hard at how to improve the interior...  It looks pretty tired.

[carusoam]

Aaaaaahhhhh...

Two knobs in the ceiling, one for dimming the overhead, torpedo, lights...

The other is the vent control.

Thanks for the clarification... (I mixed up a detail... the other dimmer switch for the instrument panel is up front on the panel...)

If the knob fell off... check the set screw on the side... it may be still retaining what is left of the axle that it was attached to.   

Best regards,

-a-

[0TreeLemur]

3 hours ago, Andy95W said:

The interior lighting on the Enterprise was really cool looking and seemed to work well.  Touch sensitive on/off as well. 

@Andy95W you just used the past tense to describe something that does not yet exist...

[0TreeLemur]

Followup- in my a/c the headliner is installed over the light fixture, so I had to take the headliner out to take a look.   The switch is an integral part of the dome light fixture, which would make it a bear to replace.   Can't tell why the shaft is too short, it just is.   Maybe it just broke off, or someone hit their head on it and made is shorter.   The fix will be to put another switch somewhere out of the way.  Maybe a switch like the one that @Yetti shows above...  A good, compact and robust SPST switch is called for.   Anybody have any cool suggestions for fixes that exist and would be lightweight, compact, robust, and parsimonious?

[rbridges]

On 1/19/2019 at 3:29 PM, Fred₂O said:

Thanks @carusoam I'll look at the center of that plastic shaft- I suspect you are correct- it feels different in the middle.  Replacing the switch is most certainly the way to go it seems.

On a related note- I luckily had my headset on when this big honkin' thing fell off the ceiling and hit me in the head.  This knob extends/retracts the dorsal air inlet, and is machined out of a 1" thick piece of solid aluminum.   Pretty heavy for what it does.   I'm starting to look hard at how to improve the interior...  It looks pretty tired.

yeah, mine looked like crap, too.  I ordered new black ones from tedds.com .  I went with black.  I tried to find some that matched and of similar size.  

https://www.tedss.com/2051000153

https://www.tedss.com/2051000125

The larger knob has an indention, but my son has a 3d printer and made a washer to fill the void. You could probably do the same with some type of nylon washer.  I also had new placards made for the lights and trim indicator.  They're plastic, but are holding up well.  Much better looking than the originals.  I don't have good pics of the knobs unfortunately.

[0TreeLemur]

Photos taken this weekend with the headliner down and dome light fixture removed.  Given the shape of the end of the switch, it seems that perhaps somebody cut it off, then filed it to an irregular cone shape.   It is definitely too short.

[0TreeLemur]

Solved.  Wound up re-wiring the entire headliner.   It was a rats nest.  Now everything (speaker, electrical for lighting) is connected via two Molex connectors.

[1967 427]

After reading about your switch, I wondered what mine looked like, I couldn't picture it in my mind.  I found that mine had the same issue as yours.  The previous owner solved it with a short piece of rubber tubing. 

[0TreeLemur]

That did not occur to me.  The switch shaft in ours pretty much fills up the hole in the cover plate.  I guess drilling the hole a bit larger to allow the tubing to fit looks like what your prior owner did?

[FloridaMan]

1100 hours in my 67F and never knew that was a dome light. I always just wore a lamp on my head as an emergency safety thing anyways. 

[Bob_Belville]

I've never turned on the baggage light in this plane though I recall running down the battery in my first '66E leaving that light on. Of course I used to fly at night all the time and now I don't. 

[Shiny moose]

Mine is also short, i did cut a slot in it and use my mooney key size screwdriver to turn it on and off, and master must be on to use it. If it was any longer I would have a hole in my head exactly the same size.