Laser Engraving and material selection

Hi guys

I may have to find a way to have some panels made if I cant find another source in time for a flight event that is coming up that Im hosting, so Im looking into have a local engraver make some simple panels for me.

Some questions on lettering:

It appears that the white lettering on commercial panels is very, very close to the top of the panel surface, and Im guess that when those are lasered on, that the laser is just removing the gray paint from the acrylic, correct? If this is true, then Im also guess that it is neccesary to have an opaque material vs. a clear acrylic, right?

So, what if milky/opaque material is not available, what would be the procedure? Is it possible to paint the material with several layers of white and then paint it gray and have the laser take of just the gray?

Thanks for those in the know. I have a friend who works at the place with the laser engraver, but he's never used it and is going to try different things to see what happens.

Appreciate your ideas and thoughts,

I would use clear plastic behind the grey paint. That way when you get the engraving done, leave the inside of the lessters a bit rough so that a light behind the panel will light them up at night. A poor mans EL system.

In my prototyping shop at work we have a 1 year old laser scriber and I’m the only person who can use it and I have the keys to the unit, thus why I am making my own panels usually in the middle of the night. ( Shh!!!, dont tell the boss ;))

I have spent a long time trying to find the best combination that works, and what I do is simple.

Piece of 6mm clear acrylic, then give 1 precise coat of white, no more than 1 or you will screw up the back lighting, then a couple of coat's of satin black, this adds a barrier to stop light bleeding through, then a couple of coat's of brown or grey (AC depending) then let the whole lot cure.

The paint I use is the stuff you get from any automotive shop, here in the UK I use Halfords (but a special color mix for the top coat, but same paint type)

Once on the Laser you will need to find the best settings depending on your machine, on my machine I use a travel speed of 280mm/s laser power to 61%, laser frequency@ 4Khz, wobble 2 and when you create the "fill" on your artwork always spiral the design to center of the of each individual font, letter or image's ( Basically meaning it will draw one letter at a time then the laser will work on an inwards spiral direction to the centre of the letter before moving to the next), Never cut the artwork in a left to right motion, you will lose a lot of the clarity.

When complete give it a coat of "Plasti-Kote" clear satin acrylic for a nice matte satin finish and protects your artwork and makes it indestructible!!

If that don’t work take the clear Perspex and cover it with a piece of white vinyl type film, or the type u need to heat shrink (stuff used for model aircraft type, but I can’t remember the name). give it a quick wet and dry paper, no grade lower than P800 then paint your topcoat, I believe that can work as well but I have never tried it.

Below is one 747 rejected EFIS panel I knocked up a while ago to trial the machine and artwork befor i threw it in the bin, spot the fault with the artwork:(

http://i17.photobucket.com/albums/b5...1/DSCF2800.jpg

http://i17.photobucket.com/albums/b5...1/DSCF2801.jpg

and my machine making display PCB's for me:p,
http://s17.photobucket.com/albums/b5...rent=Movie.flv

I basically use 3 or 6 mm. acrylic which is white, and spray paint it with the desired colour in automotive laquer, and then engrave. The white gives a good readout without the backlighting, and is very good at night with the backlighting ,as well. I use a mechanical engraver, not laser, but the results will be similar.
Cheers.............Brian W.

Here it is with the backlighting...........
Brian W.

Looks fantastic Brian :) of course I already knew that :)

Thanks Matt. Hey, when are you coming over here to teach me how to fly my 'Bus ??
Cheers.................Brian W.

LOL, I thought you would be expert by now Brian :)

Boy, oh boy- This is excellent information, and well recieved. I will use this to the fullest extent possible. Thank you all for the info!

If I may suggest, having made some panels the “Boeing” way. Depending on the material you decide to use lexan or whatever, if it is clear do the following:

- prep it by giving the engraving side a light wet sanding using 800-1000 grit
- paint it white evenly, several coats. Check evenness with a light from behind
- paint the second layer clear
- paint the third layer black
- final layer your choice of color for the panel

*** Important ***

Paint a scrap piece at the same time the same way at the same time. This piece will give the laser engraver a sample to work with to set the depth of the laser. It’s better to lay the white on thick then try and come back and fill it later if the laser goes thru the white

The biggest thing I found with the laser is that it can turn the white paint a bit yellow (burnt).
At the moment I am building a CNC machine to help make some of the panels.
Anyone got ideas of backlighting? I was thinking of using flatlite http://www.e-lite.com/

Quote:

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Originally Posted by alaxus

The biggest thing I found with the laser is that it can turn the white paint a bit yellow (burnt).
At the moment I am building a CNC machine to help make some of the panels.
Anyone got ideas of backlighting? I was thinking of using flatlite http://www.e-lite.com/

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The panel people Boeing contracts to channel the base layer where the lettering is and install grain-of-wheat bulbs wired in parallel.

I have been thinking about backlighting, and will be having some panels made also. However, I'd never thought of painting them myself and having them engraved. The results look fantastic but it seems a lot of work and the cutting tools have got to be ridiculously accurate.

I was going to build a mock up of a piece of panel, and then approach sign makers hoping that they can accurately print onto some acrylic. One coat would be the light diffusion layer, and the top coat would be opaque in the colour of the bird.

As an alternative (and I'm expecting this would be a lot cheaper and easier), have a sign maker print onto an acetate sheet. I can then lay this onto an acryllic sheet and do the cutting myself (or have another company pre-cut the acrylic).

Anyone have any comments on this approach? I'm asking because I'm sure some of you guys have been here, and just wondering what the pitfalls are.

Out of interest, is it expensive to have an engraver etch out a cockpit panel?

Thanks for your help

Paul

Quote:

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Originally Posted by Paul G

I have been thinking about backlighting, and will be having some panels made also. However, I'd never thought of painting them myself and having them engraved. The results look fantastic but it seems a lot of work and the cutting tools have got to be ridiculously accurate.

I was going to build a mock up of a piece of panel, and then approach sign makers hoping that they can accurately print onto some acrylic. One coat would be the light diffusion layer, and the top coat would be opaque in the colour of the bird.

As an alternative (and I'm expecting this would be a lot cheaper and easier), have a sign maker print onto an acetate sheet. I can then lay this onto an acryllic sheet and do the cutting myself (or have another company pre-cut the acrylic).

Anyone have any comments on this approach? I'm asking because I'm sure some of you guys have been here, and just wondering what the pitfalls are.

Out of interest, is it expensive to have an engraver etch out a cockpit panel?

Thanks for your help

Paul

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Just to put into perspective, the picture I posted in my last post, the front panel cost me $9.00 to get the holes laser cut and the text laser etched. The button placards were about $1.00 ea.
This panel I did has 3 laser cut layers, which increases cost, but I was experimenting. Next panels wont be done this way.

Paul,
I've also thought about your approach. Some of the sign/graphic makers I've talked to can print on translucent vinyl, with excellent light blocking ability for the brown/blue/gray main color. They use these for quick backlit signs with incredible saturation and detail.

Since it's pretty easy to make a panel in Illustrator, Photoshop or any other drawing tool, I thought about having the printers print my brown panel with white lettering drawing on translucent white vinyl.

I could then cut out the panel graphic, glue the vinyl over an acrylic or plexi piece and assuming the brown/blue color was fully blocked, I'd have a nice backlight capable panel for cheap. Thoughts?

Steve

Quote:

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Originally Posted by sbecker777

...I thought about having the printers print my brown panel with white lettering drawing on translucent white vinyl

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Steve,
If you've not dealt with printers before, make sure they know what effect you're trying to achieve. That's why I'm thinking of taking along prototypes of each bit of panel. The should then be able to suggest the best way of achieving that effect.

FYI, if you are using white lettering over a coloured background colour in an illustration program, make sure that you create the lettering on its own layer and tell the printer this is the 'knockout' layer. This is because I'm guessing that you don't want them to print white over the panel colour, so much as 'not' print panel colour where white appears. Printers refer to this as the knockout layer (I think)

One concern I have about the 'stick on panel' approach, is that the sticky layer will end up detaching at the corners, and suffers more risk of damage than if printed directly onto the acrylic. I think a protective coat (transparent of course) would help increase longevity. Also the edges of the panel would need to be painted in the same colours scheme, so you'd need to be given the colour code or ideally some actual paint.

Good luck

Paul

Paul,

You mention "currently in Airbus colors" in your signature. Do you have color numbers, e.g. RAL codes, for these colors? Up to now I haven't been able to find them anywhere...

Thanks a lot,

Hans

Check your PMs Phil :-)