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 front panel silk screen art but can't figure 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.  And no, I don't work for these guys. This isn't an ad. It is the best way to do this I have found to date however.

So if you already have your metal work done, 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 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.  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 it does I'd be grateful for comments.

Before we go on: be safe! This process involves putting metal into an oven and cooking it for several hours.  I probably don't need to go over safety instructions 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 the 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??

Lazertran is not cheap--about $2 US per sheet--$20 for 10 sheets....but that's way cheaper than one-off silkscreening services or other solutions....

You will also need:
  • The metal front panel you want to use, ready to go. Since we are going to bake the panel in an oven, plastic, wood, parchment, etc., panels won't work. 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. Most of us have those, or use mom's? Whatever. I imagine toaster ovens will do as long as you can reasonably control the temperature.
  • Scissors to cut and trim the decal.
  • Computer software to design, modify and flip your decal--Adobe Illustrator is what I use but there are lots of programs you can use to create 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 1200 grit wet/dry sandpaper.
OK let's go:

First: Deburr and clean the metal panel thoroughly beforehand. For Lazertran to work, the front panel has to be very smooth--the decal with tear and hang up on any burrs or rough edges. 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 Lazertran decals that don'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 scan 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.

But more recently I found 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 Lazertranning. Save it as PDF and then use that as the background in Illustrator.

I'm not going to go into details about using Illustrator here, it's beyond the scope of this post, and there are tons of Adobe Illustrator tutorials online, also you may wish to use another program.

Illustrator can natively open PDFs and allow panel artwork to be easily added on top of the PDF background. As a bonus, the PDF background becomes an easy way to make sure the decal details line up with the panel since it's an exact duplicate. 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.

A bit of an aside: 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 waterslide decaling.  Thus I tend to stick to black on an aluminum metal background, but you may wish to try things here.

OK what panels will this work on? I am going to go out on a limb and say--pretty much anything made from metal that's not a completely crazy shape? It's hard to hold Lazertran down--this stuff really works!

In my DIY studio, I use Paia FracRack 3U boxes as a tip of the hat to trusty old PAIA.  These guys got me started in DIY many years ago and the measurements of FracRack (1u = 1.5" x 5.25" with 1/2" grids for pots and jacks etc.) are extremely easy to calculate.

BTW, I have PDFs and eagle BRD files that can get you FracRack guys started, comment below and I'll post 'em somewhere but I figure most DIY synth readers use Eurorack or something else like it.....

Eagle BRD file of a Fracrack 2u panel, with 6x pots and 12 3.5mm jacks

Ok getting back to it: Using your favorite illustration program draw your text, images, cartoons, logos, rounded rectangles, and save in native format.  

Here 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:

Hint: Before printing to your $2 a sheet decal paper, check to make sure all your artwork fits your panels!! So: 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.

OK once everything is to your liking, 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.

Once you're sure everything is going to line up properly, put a piece of Lazertran in your printer (it needs to print to the shiny side of the material) and print that puppy out.

We're not quite ready to apply the decals yet however. 

Now 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 225 degrees F and then put in the decal for 5 minutes.  

 As the decal bakes you will smell a gross plastic burning scent. And when you take out the decal paper it will look like you tried to Barbeque 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. Whew!

Next, cut out the decal along the panel lines:

…..and then soak each decal in warm tap water for about a minute--if you've ever made model airplanes or whatever the water slide process will probably be familiar to you.

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 to gently (!!) use a credit card edge to smooth all the bubbles out and then reposition the decal.  

Again no photo for this--I was too busy trying to not tear 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 credit card process.

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

With the oven still at 225, put the decal in there for 5 minutes.  IMPORTANT!!  After 5 minutes remove your panel with tongs, and check the panel and make sure tiny or larger bubbles haven't formed.  If you have bubbles at this point you can often quickly touch them to flatten the bubbles or pop bubbles with a pin, but in my experience after about 10-15 minutes they are there to stay.....so set your timer and do this check.

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

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

Then increase to 250 for an hour, then 275 for an hour, 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. It seems to me that the longer you bake, at around 300 degrees, the better the decal sticks to the panel.

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 off and is 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 an even 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 millwork.  

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 decaling.  You can add x marks to your decal where you need to drill....this helps with panel symmetry and drill placement.  Again this is due to the toughness of baked on decal.  

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.


No comments:

Post a Comment