[simpits-tech] RE: making your own PANELS

[Jim K.]

Batiste, Nissim,
Thanks for the offer to help on getting some panel dimensions and for the 
link to xflight.

Surfin,
CNC = Computer Numerical Control.  Its the name for the way a milling 
machine (or any other type of machining tool) is controlled by a computer 
to make parts.  You give the computer a design and it basically operates 
the milling machine automatically.   Its a way to cut down costs since you 
don't have a person running the machine manually and you get VERY precise 
parts over and over again.

Marv,
You are right the cost for an engraver is going to be in the setup and per 
piece combined price.   If I go to a large plastics company their overhead 
will be to high so they will have high costs.   Not to mention they don't 
want to mess with "onesies twosies".   I'm thinking a one or two man sign 
company that has laser capabilities might be the answer.   I'll have to 
check that out.  Obviously if this engraving cost is to high than its 
easier to just buy pre-made panels.  :-)

You are 100% correct about the paint thickness.  If the top panel surface 
is painted its thickness needs to be fairly accurate for the engraving 
process as you mentioned.   I didn't originally think of that.  So maybe 
painting is not the way to go.   I'll have to think about this a little more.

In my disassembly of a real NVIS illuminated panel here is what I 
found.   I'm sure you have taken one apart but for those that have 
not.   The overall light panel is made in what seems to be 3 layers.  There 
is the outer panel (shell), a transparent filling and a backplate.   The 
outer panel is made out of some sort of transparent plastic.   The plastic 
is covered with a white "paint" layer and then the final black colored top 
coat.   The outer panel is 1/4" tall.  This panel is hollowed out.   Its 
tough to tell if this outer panel shell is machined or molded.   The mfg 
can't be making more than a few thousand of each panel so I can see these 
being made with a machining process.   But if they have their own in-house 
tool maker than making mold tooling for something like this would be pretty 
easy and not very expensive.

Anyway the outer panel shell is filled with some sort of transparent 
plastic that is just slightly "milky" in color.   Its tough to tell if this 
"filling" and the outer panel was made from just one piece of material or 
if indeed the filling is "poured" in later.

So when you look at this panel its black in color on all sides.   On the 
top of the panel the black layer is etched to reveal the white undercoat 
which makes all the lettering.   On the back side there are threaded 
"nutserts" placed into the filler material which will allow a backplate to 
be screwed on.   There are also some round holes drilled partially into the 
filler material.   This is where the LEDs will go to light the panel 
up.   When you look into those holes you can see the black outer layer, the 
white undercoat and the transparent filler material.   I'm calling it 
filler material for now but I know that this filler and the outer panel 
itself may all be one piece.   But to me it looks like this filler was 
"poured" into place as a secondary step and then milled down flat.   Those 
nutserts sure do look like the material flowed around them as opposed to a 
compression insertion fit.   I'll be seeing a large group of molding 
companies next week for another project so I'll ask them for their opinions.

Then finally there is a very thin backplate.   The backplate is 0.035" 
thick, including the circuit layout.  It seems to be made out of 
plastic.  On one side of the plate there is a very simple circuit layout 
with the LEDs surfaced mounted.   Each LED has a green colored plastic cap 
filter over it so that the LED shines as a green color.   This backplate is 
screwed onto the 1/4" panel using those nutserts.

Overall a very nice design.

To make your own I think you need to eliminate the circuit layout on the 
backplate.   While its an easy circuit it does add steps and cost to the 
panel.   I would just wire the LEDs up and place them in those little holes 
and have two wires sticking out the backplate.   Not very elegant but it 
would be easier and cheaper than making a circuit layout.

I think the tough part is getting the paint layers correct so that you can 
etch the lettering in and of course the cost for that etching.

Now I am NOT saying that I'll try this.  I'm just thinking out loud here to 
see what other ideas and opinions come out of this.   It may or may not be 
easier and/or cheaper to just have an existing panel maker make them for 
me/us.  :-)))))

Jim