Tag Archives: yellow

112: Three-Ply Acrylic

It’s kind of amazing that it’s taken me this long to get to this project; when 52 Lasers was first conceived, using three-ply acrylic was on the first draft of our potential projects list. Now, more than two and a half years later, I finally have a project that requires this unique material!

Rowmark's convenient visual representation.
Rowmark’s convenient visual representation.

Three-ply acrylic is similar to the two-ply acrylic I use very often, except the thin cap layer is applied to both sides of the main acrylic substrate. While most of the badges, magnets, and other pieces I make only need one side to be engraved, certain items like medallions or coins might need both sides engraved, and this is when you’d use a three-ply option. This month’s project is a great example.

 

A bunch of SCA tokens celebrating an elevation.
A bunch of SCA tokens celebrating an elevation.

A couple of dear friends of ours are part of a group called the Society for Creative Anachronism. While I’d like to explain what that is for you, I couldn’t possibly do better than the SCA’s excellent portal for curious newcomers. Dave got in touch and explained that his husband Jim was going to be recognized for his accomplishments in the Society, in a ceremony called an elevation. For the event, they wanted to distribute small tokens, in SCA appropriate colors, featuring Jim’s moniker in Chinese (凱曾, Kai Tseng) and the triple rapier logo of the Order of the Masters of Defense. I’ve always used wood for tokens that need both sides engraved up to this point, but it was far easier to get the colors Dave and Jim wanted by using the three-ply LaserMax acrylic from Rowmark.

When you’re engraving two-ply material, you don’t really have to worry too much about the back face; people aren’t going to be scrutinizing a blank back surface, so imperfections caused by the manufacturing process aren’t a big deal. That’s why two-ply materials only ship with mask on the front surface. Three-ply material has mask on both cap layers, and while you want to remove the mask from the side you’re engraving first, you definitely want to leave the mask on the bottom side. That’s because those vector cutting scars—plastic residue, honeycomb table impressions—are going to damage that side if you don’t. It’s okay to engrave the reverse side with the original side unmasked because you won’t be doing any high power vector cutting in that final step; it’s just surface engraving, which doesn’t cause those kinds of issues.

Red tokens placed upside down in the makeshift jig.
Red tokens placed upside down in the makeshift jig.

Conveniently enough, just cutting the shapes out in the first pass automatically creates a makeshift jig—or template—out of the leftover material. As long as you send the second half of the engraving data in the same exact positions as the first, all you have to do is flip the shape over and engrave again. Now, this requires a symmetrical shape, or else you’ll have to take flipping into consideration and cut extra pieces out of the material that will form the jig. You also want to remember to take the mask off of the flipped token’s new front side before engraving; firing the laser through that thin plastic layer will usually create a sticky mess.

With all of that in mind, it’s fairly simple to process three-ply material in a clean manner. You’ll still have to wipe down the edges with a light alcohol or a solvent similar to Goo Gone, but that’s usually the case with two-or-more-ply acrylics anyway. For how simple the whole process is, I still managed to muck things up, and I lost a whole set of twenty yellow tokens on the first pass due to a technical issue with the laser that I still haven’t figured out.

Unexpected markings ruined a whole batch of tokens.
Unexpected markings ruined a whole batch of tokens.

Once in a while, when raster engraving, the field I’m engraving will be speckled with tiny additional engraved dots. I can never predict when it happens, and just rebooting the system fixes it, but it always loses me a piece or two.

Token stacks.
Token stacks.

I also noticed with this project that my laser alignment isn’t perfectly perpendicular to the engraving surface currently; if you look a the picture of the token stacks above, you’ll notice the slight skew in the 1/8″ thickness of the tokens. I think this is due to a misaligned mirror #3, but it’s difficult to know for sure and I might end up having to replace the mirror #3 assembly with a factory-calibrated one.

If any of you have any tips for cleaning the laser-cut edges of a two-or-three-ply piece, any ideas on what might cause the rare engraving field speckling, or any suggestions on how to realign the beam path across the surface, let me know in the comments below!

44: Ready Made Files

I’m smitten, totally smitten by this awesome bee puzzle.  Yes, we made it on our laser, but no, this is not our design.  This week I want to talk about the wealth of resources available for laser cutters, in the form of ready-made files.

Bees! (3 of 6)

 

The learning curve on a laser can be a bit daunting sometimes.  In drawing, you can just pick up a pencil and go to town.  For collage, scissors and glue are your best friend.  Lasers?  Well first, you have to learn a a design program that can make a file that the laser understands before it will even start to work.  And that’s just the start.

The individual bee pits - you can see how they connect!
The individual bee bits – you can see how they connect!

You may notice most of my work is flat – I am not yet totally comfortable in taking flat objects and know how to assemble them into 3D space.  I’ve attempted making some pendant lamps before, but never was wholly satisfied.  (It’s on the list to try to perfect for a week in the future, I promise!)  So creating something like this bee would be way out of my comfort zone.

The lamps worked well, in theory.I was never satisfied with my materials or the bare bulb.
The lamps worked well, in theory.I was never satisfied with my materials or the bare bulb.  Photo is from my very first Renegade Chicago, back in 2009!  Thanks to my awesome booth helper, Brenn.

Luckily, many other laser users that have shared their awesome projects on-line, for free!

liscence bee
Creative Commons License

This bee was originally shared by Thingiverse user Mutsuki.  If you check out the project page, you’ll see that original, laser cutter files are available for download, and the Creative Commons license tells you how you can use this project.  The string of icons in this case indicate it is under Commons Commons (the CC), that is must be attributed to the original artist (the person icon), the project cannot be used commercially, only privately ($), and you are more than welcome remix or build on the idea, but it must have the same licencing as the original (the circling arrow.)

Because Mutsuki shared the design for remixes and improvements, I actually downloaded the design from sahrchitect, who modified the design to work with 3mm material, among other things.

Some great places to get free projects:

– Thingiverse is probably my favorite.   They have a good sense of community, the liscencing is clearly stated and the files are easily downloaded. They do focus on 3D printed projects,  but just do a search for “Laser” or “lasercut

Trotec, a laser manufacturing company out of Michigan.  What better way to show off your machines than having projects ready to go! You can find them under “Samples.”  The laser engraved rolling pin is quite awesome!

Epilog is also another popular laser manufacturer.  The Sample Club is full of ideas – even a laser cut 3D T-Rex model head.  How awesome would that be mounted to your wall?

My personal DOs and DON’T for free files

– DO look rights and usage.  Many projects are for personal use only.  Respect this.

– DO give attribution to the original designer.  You know they did something awesome, give them credit.

– DON’T redistribute shared files without permission.

– DO use the files to try something you haven’t before, or the get an idea how something works.  Building Mutsuki’s 3D bee helped me see how it was designed, and I can use that knowledge for potential future designs.

– DO use the files as a springboard to make your own amazing.

The connections were so loose on the first bee, he couldn't keep his face on!
The connections were so loose on the first bee, he couldn’t keep his face on!

– DON’T expect files to work immediately and perfectly.  I had to cut three bees before we had one that slotted together tightly. Designers post what works for them – material thickness and laser powers vary by user.

– DO share your own designs, or designs that you have improved.  Unless you need to protect your livelihood (hence why I don’t share Isette or Beadeux designs) sharing your knowledge helps make the laser community that much better!  (I’m planning to go through our 52 lasers posts to sort out what was for fun, and what was for business.)

DO add dramatic lighting to picture.  Dead bee!  Oh no!
DO add dramatic lighting to picture. Dead bee! Oh no!Bees! (2 of 6)

Where are my specimen pins…

Bees! (6 of 6)
The florescent yellow was great for this project! (Unlike Week 13 : Alcohol Inked acrylic)