Tuesday, July 17, 2018

DIY Synth and Electronics Pseudo Silkscreening using "Lazertran"--How To Do This!

I am still trying to figure out how to make low-cost, low quantity, high quality front panel silk screen art but can't solve that one out.

And: I have tried etching/fabrication services like Front Panel Express but find their CAD tools difficult to use and their services expensive for one-offs.

The good news: I have been using a water slide decal process to get me close to silk screen type front panel finishes using something called "Lazertran".

That's what this post is about. No, I don't work for these guys. This isn't an ad but is the best way to do this I have found to date.

So if you already have your metal work and want to get close to professional looking, one-off front panel art,  for about $1-$2 USD per panel, please read on.

Still with me?

First, go out and get this stuff: "Lazertran."  You can find it online direct, also at Blick Art, Amazon, and several other online suppliers.  Your local art store may also have it, or maybe can order it for you.

There is one Lazertran version for laser printer and another for inkjet. I only have tried this with the laser version. You can get legal sized sheets or 11 x 17 but here I use 8.5 x 11. I'm interested in knowing if the inkjet material works the same way as described below, if you know I'd be grateful for comments.

Before we go on: be safe! This process involves putting metal into an oven and cooking it for a few hours. I probably don't need to go over safety tips but will anyway--you have to be sensible or you wouldn't survive a week of DIY.....So please, don't be a bozo about this.

E.G.: Don't clean the panel with gasoline then put it in your oven. Don't touch really hot metal with bare fingers.  Don't use a chainsaw or small explosive device to open your stove door--just pull it open. Don't put plastic front panels in your oven (they will melt, burn, and stink up your house). And above all, never, ever listen to Barry Manilow's "I Write the Songs" in spite of how damn catchy it is.

Nuf said??

You will also need:
  • The metal front panel you want to use, ready to go. If you've painted your metal panel, make sure it will withstand a 300+ degree oven bake. So, high temperature paints, like those used for car engines, are best. I leave figuring out the right kind of paint to you.
  • You'll need an oven that goes to 300-350 degrees F. Most of us have those, or use mom's? Whatever. I imagine toaster ovens will do as long as you can control the temperature.
  • Scissors to cut out the decal. 
  • Computer software to design, modify and flip your decal--Adobe Illustrator is what I use but there are lots of programs for two-dimensional artwork.
  • Tongs or BBQ implements to handle your panel when it's hot.
  • A credit card for smoothing out tiny bubbles
  • 800 to 2000 grit wet/dry sandpaper.
OK let's go:

For Lazertran to work, the front panel has to be extremely smooth--the decal with tear and hang up on any burrs or rough edges, form bubbles, and look crappy. Also, make sure your panel is clean; the decal won't stick to oil and dirt.
Next this may be obvious, but: take careful measurements of your cleaned up panel. If you mess up your measurements you will have printed a $2USD Lazertran decal that won't fit your panel, and we don't want that.

If you really don't want to measure things: I have used a Ricoh flatbed scanner to scan a 1:1 image of the front panel(s) in question; then used the PDF output from the scanner as a background in Adobe Photoshop. Before printing I hide the background layer. As long as the original scan is really 1:1, this will work.

Another way: I first draw the front panel in a CAD program (Eagle in my case) to create a down-to-the-millimeter drawing of anything that needs panel art. Save it as PDF and then use that as the background in Illustrator or whatever graphics program you use.

Eagle BRD file of a Fracrack 2u panel

Illustrator will open PDFs and allow additional artwork to be easily added on top of the PDF background. I figure other graphic art programs will do the same? If so, the PDF background becomes an easy way to make sure the decal lines up with the panel since it's a 1:1 match. As long as the elements you see in the background are holes, drills, dimension layer outlines, and mills, they won't show up in the final panel, but can be used to design and align the decal.

About color decals: If you are doing a color panel you're in territory unfamiliar to me, I only do B&W, but keep in mind that almost all lasers and inkjets can't print white. They assume the background is white and treats white artwork as clear so it can "show through". I imagine from model making that other colors may appear a bit faded or washed out if it's like other water slide decals I've messed with. Just a guess.

For this tutorial I am fabbing a new one-off panel for a Triple Moog-like VCA clone for which I did a PCB board design, as well as the GCS/EFM/everyone-else Norton 3900 amp based Serge Waveshaper (hence the Serge logos--give 'em credit where it's due--this is a really cool bit of electrical engineering on Serge Tcherepnin's part--you can get details, boards, gerbers etc. for it everywhere, my version is here
Here's what I ended up with in Illustrator for the Serge module:

Before printing to your Lazertran decal paper, check your printer settings, print out a 1:1 of your  artwork, and lay it over the panel to see if everything lines up--you want to do this with normal paper before committing to Lazertran.

Here I've done that with cutouts of standard 8.5 x 11" paper--yep looks OK.

Now go back to your art program, select all the elements in your design and flip things, so it's 180 degrees flipped along the Y axis, like this:

Save the flipped file--we are going to need to print the flipped decal image to Lazertran.

Here's a semi hidden secret. You have to BAKE THE DICKENS out of the Lazertran sheet before you take the decal off the backing. Otherwise your decal will bubble during the baking process. The instructions say to use a heat gun for this pre-bake but that's never worked for me.  I have had to literally hold my nose and bake the decal sheet in my oven before I apply decal to metal.

For this pre-bake-your-decal-sheet process, preheat your oven to 200 degrees F and then put in the decal for about 5 minutes.  

 As the decal bakes you will smell a gross plastic burning smell. And when you take out the decal paper it will look like you tried to BBQ it:

The good news is--I learned this by trail and success??--the decal will still look OK even though the backing paper got charred. But you can overbake the sheet....then the decal won't come off, so keep checking on your decal during the prebake.

Next, cut out the decal along the panel lines:

…..and soak each decal in warm tap water for about a minute--less if you can. Warning: if you soak the decal too long the laser print may start to disintegrate.  I have seen this on occasion, but other times I have left the decal in the water for 5 minutes without issue. No idea why.

I didn't get a photo of this, but apply the flipped decal face down to the front panel by sliding it off the backing and onto your front panel.  

Line it up carefully.....

Now you've got to get rid of the air bubbles that invariably live under the decal you just applied. 

I have tried all different ways to "de-bubble" but the best way, the way I always come back to, is use my fingers to get the big bubbles out, then gently (!!) use a credit card edge to wisk away all the smaller bubbles. You will probably have to re-position as you go, that's not a problem, be gentle so you don't tear the decal.  

Again no photo for this--I was too busy trying to not ruin the decal and get rid of all the bubbles. But with a gentle touch it's not a problem.  

Hold the panel up to a light and see if you can see bubbles under the decal. If you can still see bubbles, gently repeat the process.

Last step before the bake, take a napkin or paper towel and carefully dab off whatever water remains on your panel. Then check for air bubbles again.

Once you're bubble free it's time to bake the decal onto the panel.   

With the oven still at 200, put the decal in there for 5 minutes.  Important: After 5 minutes remove your panel with tongs, and check the panel and make sure bubbles haven't formed.  If you have bubbles at this point you can quickly touch them to flatten the bubbles or pop bubbles with a pin, but in my experience after about 10-15 minutes the bigs ones are here to stay.....so set your timer and do this check.

(I have done Lazertran bakes in a pan, on tinfoil--I can't see any difference, so do whatever is easy..,) 

After the five minute check, and maybe another check at 10 minutes, you're past the bubble popping stage.  Keep the panels in the oven for another hour.  

Then increase to 225 for an hour (if you are impatient, half hour will do, but the more time you bake the better the decal looks at end), then 250 for an hour, then 275 for an hour.  At this point, you might see tiny bubbles in the decal, but they will bake out if you're patient. OK, finally 300 for an hour.  Don't go over 300--the decal might burn if you do.  Not 100% sure about this--I have gone to 350-400 without issues, but other times not. 

When this is done, remove the panel with your tongs. After your 4+ hour bake, if everything went OK, you end up with a pretty good looking panel, not quite pro silk screen looking, but really super close.  

And after a full bake if all went well, the finish is really baked on--I have had difficulty removing the decal with 500 grit sandpaper.  Yeah it's on there!

For clean up, you may need to take an X-acto blade and get rid of any remaining decal material that's sitting over a drill, outline, or cutout.  But for me after a few hours most of the decal that went over holes and milling has baked all the dookie off and any remnants are long gone.  

And....if you did end up with bubbles, you may be able to sand them off.

To finish things, I use 800/1000/1200 grid wet n' dry sandpaper to gently sand the panel to give it a more uniform look.  Don't be too rough--especially with the 800--but if you baked the decal on for hours it should withstand a lot of abuse.

Here's what I ended up with while doing this blog post:

OK that looks pretty good I think! 

We're now ready to finish things.  Bolt on the PCB, mount pots, knobs, etc.

Here is how my Serge Waveshaper clone looked when I was done.

Not too shabby?  You can get very fine details out of this process--the "1", "2", "3" by the jacks is 6 point font and is fully legible, and the "normals" illustration below the gain knobs is even smaller but came out just fine. You get the idea.

One  more hint:

If you're in the process of fabbing your panel, you might try experimenting with baking on the decal following the process above and then drilling out remaining holes and mill work.  

As long as you drill and mill carefully--a skittering drill bit will tear the decal, screw up your panel and possibly injure you--this works better than drilling/milling then applying Lasertran.  You can add x marks to your decal where you need to drill....this helps with panel symmetry and drill placement.  

OK that's it for now, give it a try and let me know what you think.  I am always working on improving this process.  Thanks.


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