Tag Archives: laser cut

107: Thick Acrylic

A few months ago, my friend Arty got in touch with me and said he had “some thick acrylic” left over from a recent storefront revamp at a mobile phone store. Not really knowing what I was getting into, I said “hey any scrap material that I can laser is good with me!”

This stuff is so clear it's almost hard to see.
This stuff is so clear it’s almost hard to see.

Much more recently, I went to pick up the acrylic that he’d been graciously holding onto for me. As it turned out, the acrylic wasn’t just thick. It was far thicker than I could process with the laser, with 7/8″ as the thinnest edge. But there were several chunks of uniformly cut acrylic, and every surface was smooth enough that you could see clear through to the other side. This was material worth experimenting on!

The first engraving test confirmed that it was cast acrylic.
The first engraving test confirmed that it was cast acrylic.

I first determined whether it was cast or extruded acrylic by doing a surface engraving featuring some art deco frame stock. The surface engraving was powdery and white, which was perfect—cast acrylic engraves in a much more visible manner than extruded acrylic.

The second design didn't really convey the "frosted ice" look I was going for.
The second design didn’t really convey the “frosted ice” look I was going for.

The second design I tried was based on a “frosted ice” theme I developed while working with a client a couple of years ago. While it looked great on the snowflake shapes I used originally, the effect was lost on the square chunk of acrylic, and the “FROSTY” text I added didn’t really come out clearly.

Two different sizes of blocks "comprised" of tetriminos.
Two different sizes of blocks “comprised” of tetriminos.

I revisited some tetrimino patterns from a very early 52LASERS post. Using three different engraving techniques, I created a pattern that highlighted certain shapes with fills and deeper cuts. The result not only looks awesome from straight on, it created some really stunning effects when looking through the unengraved side of the acrylic.

Looking through the clean edge shows off each "deep cut" tetrimino.
Looking through the clean edge shows off each “deep cut” tetrimino.
Any fan of Tetris will recognize these shapes!
Any fan of Tetris will recognize these shapes!

I still have plenty of stock of these blocks left, so if you can think of any more creative ways to jazz up the acrylic’s surface, let me know in the comments!

Quite a supply of material too thick to cut through!
Quite a supply of material too thick to cut through!

100: Pyramid Holograms

The pyramid, taped and ready for the phone.
The pyramid, taped and ready for the phone.

A few months ago,  Jennifer had me order some unusually thin 1/32″ transparent acrylic to try out some kind of “phone hologram” trick she read about on the Internet. The material arrived in a shipment of a whole bunch of other inventory and was mostly forgotten, until just last week Eagle Engraving’s resident laser ninja Monica brought up the same concept and basically demanded I make it happen. So thanks for helping us reach the big 1-0-0, Monica!

A close-up of the pyramid.
A close-up of the pyramid.

The pyramid hologram uses four pieces of thin transparent acrylic taped together in order for it to be placed either on top of or below a display—in this case, a mobile phone. A specially formatted video is then played back and the image is reflected “into” the pyramid, resembling one of those old Sega arcade “hologram” machines.

There are plenty of templates out there on the net to make your own, but I followed the graph paper measurements from Demilked. The laser did the dirty work, replacing the most often recommended x-acto knife work on a CD jewel case. The finished plastic was very clean, but my questionable tape job connecting the four trapezoids left things just a little sloppier. Even with the pieces taped, the pyramid is a little wobbly, so I had to be gentle when balancing the phone on top.

Tiny minions make jokes underneath my Moto X.
Tiny minions make jokes underneath my Moto X.

While you can also rest the finished pyramid on top of your phone, I opted to set the phone on top so I’d see less of the originating video. There are several videos on YouTube to demonstrate this trick, and you need to choose “screen up” or “screen down” versions to make sure the hologram is displayed correctly. With the phone on top, I selected a playlist of screen down videos and set it going. Minions, anime girls, and a very motivational Shia Labeouf all appeared in my tiny pyramid and danced around. All in all, it’s a neat little trick, and didn’t take much time; perfect for a busy holiday season!

Hatsune Miku shows off a double image effect that's hard to avoid.
Hatsune Miku shows off a double image effect that’s hard to avoid.

98: Breaking the Interlock

One of the projects I’ve been working on this week involves some pieces of wood that are far bigger than my laser bed allows. While I’m not finished with the project yet, I thought I’d take a moment to talk about the front door on my VLS 4.60 laser and a fairly simple trick to defeat their magnetic interlocks in cases where you have to engrave something too long for the laser bed.  First, here’s some quick information about the project.

Here are some screenshots of the original box.
Here are some screenshots of the original box.

Those big long wooden pieces are for a custom frame design (by If These Walls Could Talk; check ’em out!)  meant to fit a picture of the Leg Lamp from A Christmas Story. The test piece given allowed me to perform a handful of engraving tests to determine how best to replicate the fragile (it must be Italian!) label on the Leg Lamp’s box.

Several engraving tests have convinced me that I need some spray paint.
Several engraving tests have convinced me that I need some spray paint.

One immediate issue was that the surface of the wooden frame pieces was darker than the inner wood, so even engraving at a high power and low speed to char the wood resulted in text that wasn’t appreciably darker than the wood, while the source material was black spray paint on lighter wood.

Color fill seeped under the masking paper too easily, so spray paint is my next test.
Color fill seeped under the masking paper too easily, so spray paint is my next test.

I then tried some paint fill, but the strong texture of the wood meant that my transfer paper wouldn’t prevent the color fill paint from seeping. My next step will be to try a light spray paint over another paper masked engraving; it should more closely approximate the look featured in the film.

The three edges of the frame I am to engrave. One is a tight squeeze, and two more won't fit at all without leaving the front door open.
The three edges of the frame I am to engrave. One is a tight squeeze, and two more won’t fit at all without leaving the front door open.

But the biggest trick here was figuring out how to fit those larger pieces of wood into the laser. When we were first looking into buying the laser, another laser owner mentioned how the front door interlocks could be defeated to allow people to engrave larger items—like boat oars—if necessary. I never heard from him how to do so and the manual doesn’t mention it at all. Doing this is considered a potential safety hazard, too, for quite a few reasons. The manual explains the following:

DO NOT OPERATE THE LASER SYSTEM IF ANY SAFETY FEATURES HAVE BEEN MODIFIED, DISABLED OR REMOVED. This may lead to accidental exposure to invisible CO2 laser radiation which may cause severe eye damage and/or severe burns to your skin.

The left interlock magnet, tricked by a badge magnet.
The left interlock magnet, tricked by a badge magnet.

With that in mind, defeating the magnet interlock is something you do at your own risk. Do your best not to look at the laser or stick any body parts in there. Also recognize that the exhaust system will be compromised to a certain degree as it’s no longer a closed system.

The right interlock magnet and some of the wood sticking out of the front door.
The right interlock magnet and some of the wood sticking out of the front door.

The front door is held by one magnet on each side, and there is a sensor behind each magnet that detects whether the matching magnet built into the door is present. While some of my weaker magnets weren’t able to trick the sensors, a pair of stronger badge magnets, positioned just right, were able to convince the machine that the front door was closed. My counterfeit badge magnets were attracted to certain parts of the laser body’s magnets, and when I let them slide into where they wanted to go, the sensor could no longer pick them up, so I had to arrange them sticking out (as shown in the pictures) in a very specific position. With this in mind, be very careful when processing your long materials, as nudging the magnet just a tiny bit can cause the laser to realize the door is open and stop the job immediately. For all the trouble that might cause, I’m certainly glad it’s designed to shut jobs down if the doors are opened mid-process.

I hope to write a follow-up post about this project once the frame is built around the Leg Lamp picture; I haven’t even seen the piece it’ll frame yet! Until then, have fun engraving longer materials, but be very cautious when breaking your laser’s interlocks.

97: Utilitarian Fridge Shelf

The empty fridge, absent a long lost shelf.
The empty fridge, absent a long lost shelf.

As I’ve written about before, even when there’s not much creativity involved, the laser platform allows for all sorts of functional usefulness. In this case, local friend Brenn once again provides a fun project: replacing a lost wire shelf in his mini fridge.

We measured the space and cut a prototype out of cardboard. It’s a good thing we did; we overlooked a small gap of extra space on the left side where a key on the shelf would slot in, so the second cardboard prototype (pictured) had the key built into the side.

The second cardboard prototype added a small key on the end to fit the space better.
The second cardboard prototype added a small key on the end to fit the space better.

The cardboard also helped Brenn and I realize that the initial material we’d chosen wouldn’t be thick enough for the space. Thankfully, I do keep some 1/4″ thick acrylic around, but unfortunately the only color I had on hand was black.

A snug fit, allowing Brenn to better utilize what little space is inside.
A snug fit, allowing Brenn to better utilize what little space is inside.

Still, with the shape measured twice and cut thrice, the final black shelf fit in just fine! We discussed cutting out a “grill” of holes in the center of the acrylic to make it look a little more at home, but the extra time spent cutting that entirely decorative element would have increased the price too much for such a simple project.

Brenn hasn’t had the fridge set back up long enough for us to know whether the frigid temperature is going to be an issue with the acrylic, but I don’t foresee any issues!

A close up of the keyed shelf edge.
A close up of the keyed shelf edge.