Simple Laser Cut Puzzle in 45 Minutes

This is a project to help students in TDE 110, an introductory college class for Technology Engineering and Design Education, learn to use the laser cutter, as well as learning how to transfer images onto wood. It is not meant to take a long time, but instead to give a general overview of these processes

Students will be able to:

• Transfer a picture onto a piece of wood using acetone
• Edit SVG files in Adobe Illustrator for laser cutting
• Comfortably set up materials settings and other print settings for Universal Laser Systems.

STELs:

Standards for Technological and Engineering Literacy or STELs are a way of categorizing and describing the instruction of STEM subjects. You will learn more about them in later classes if you choose to continue in TDE. For now though, it is enough to know that they exist and have three levels, Core Disciplinary Standards, Practices, and Contexts.

Core Disciplinary Standards are exactly what they sound like, the core ideas and standards for understanding STEM education. This project relates to the 'Core Concepts of Technology and Engineering' Standard because you will be learning to use several important tools and processes, as well as having to make decisions regarding which materials to use and how to treat your product based on the time you have available (more on that in Step 6).

Practices are important knowledge, skills, and thought processes that students in STEM need to master in order to be successful. This project relates to the 'Making and Doing' Practice because you will be, well, making and doing. This is a hands on project and that is a core part of Technology and Engineering Education, as well as this class.

Contexts are how the Standards and Practices relate to the general world, as well as how STEM classes in general relate to the world. This project relates to the 'Computation, Automation, Artificial Intelligence and Robotics' Context. Learning to use a Laser Cutter will give you context of how things can be automated, something that is often used in the real world by major production companies.

Required Items

Acetone

• Acetone nail polish remover is a perfectly acceptable to purchase this.

Basswood sheet 20cm x 30cm x 3mm

• this is a standard size you can find online, other sizes will work, you will just have to adjust the size of your picture file and puzzle file

Picture slightly larger than your intended puzzle printed with a laser printer

• If you use an inkjet printer this project will not work. Check your printer, most residential printers are not laser.

SVG puzzle file

• I have supplied a file for a 7x10 inch 117 piece puzzle, if you need a file for a different puzzle size you can find one online.

600+ grit sandpaper

cotton ball or paper towel

Optional Items

roll of blue masking tape

Clear nail polish

• Another finishing product can be used, using them may take longer than 45 minutes

Cost:

Acetone costs roughly $5 for 9oz if you buy it as nail polish remover, or approximately $9 for 32oz from a hardware store.

Basswood sheets vary in cost, but you can find packs of 5 online for $8.

Printing a picture costs between 10 and 30 cents, depending on where you go for the service.

600 grit sandpaper can be purchased in a 10 pack for $7 at a hardware store, and one sheet will last you much longer than you think.

Clear nail polish costs between $2.50 and $10 depending on brand and store, while other clear finishing products start at around $5.

This project can cost around $25, which is a little costly, however, with the exception of the printed pictures, all of these items are essentially bought in bulk, and you can get 5 puzzles out of that $25. Additionally, a custom wooden puzzle of the same size can cost upwards of $60. Plus you get a fun learning experience!

Prepare your wood.

• If it's not the correct size for your puzzle then you will want to cut it to size, leaving approximately an 8th of an inch margin all the way around to allow for mistakes.
• Sand with the 600 grit sandpaper it to a soft finish. This will help with making the picture adhere.
• Make sure you blow off the dust!

Gather your other supplies

If you choose to cut your picture out of the larger sheet of paper leave at least a half inch margin around the picture for taping it later

Any picture will do, but in the process of trying this out I've found that dark colors work best. Colors like yellow will not transfer well to the wood as they are nearly the same color as the wood. Additionally, if your puzzle has a lot of white space, you may experience some bleeding of the colors into the white space.

I have found these websites to be the best for free stock photos:

• Pixabay
• Pexels
• Unsplash

This is the beginning of a multi-step process that involves acetone. While acetone will not harm your skin it can harm most surfaces and is commonly used as a paint remover. In the process of creating this project I attempted to use scotch tape instead of blue masking tape and the acetone ended up dissolving/melting it. Additionally, prolonged inhalation in close quarters can cause ill effects. For more information on the effects of acetone visit this link. This portion of the project is best completed in a larger well ventilated space.

Steps 4-5 will detail the process of transferring an image

Pick a corner of your image to line your wood up to. If your picture is smaller than your piece of wood you should return to step 1 and cut your piece of wood to the correct size. If your picture is bigger than your piece of wood then that is okay as you can fold away the excess.

Fold the sides of the paper adjacent to that corner in towards the color side of the picture, as you can see in pictures 1 and 1.5.

Starting at the corner you picked, tape the picture to the wood all the way around as shown in pictures 2-5. You want it to be tight to the wood, if it isn't perfect that's okay, you just want it to stay still for the next step.

When you're done you should have all four sides and corners firmly taped down, with no tape on the surface of the wood. Acetone will not go through the tape and any part of the picture that is covered will not be transferred.

With your picture securely taped to the wood, firmly blot the backside of the picture with an acetone soaked cotton ball. Once the paper is thoroughly soaked you can rub it gently.

• Some tutorials on this method recommend using an old card or paint spreader to distribute the acetone and make sure it really goes through, but I found that this simply smeared the toner (and ate the magnetic strip off of my old bus pass!).

Continue to keep the picture wet with acetone for approximately a minute and a half. You want keep enough acetone on the surface to be able to see the picture through the paper, but not enough to have puddles.

Once the minute and a half have passed, let your piece of wood sit for 3-5 minutes or until the picture is no longer visible through the paper and the paper feels dry to the touch, whichever takes longer (the longer you can let this sit the better)

• the paper will bubble as it drys, this is okay, it won't affect the quality of your transfer

Unstick the tape from 3 sides and peel off the paper! It may stick a little, but that is okay.

If you don't like how clearly the picture came through simply lay it back down and repeat from the top of this step, perhaps rubbing a little more firmly. I find that you don't have to tape it back down to repeat the process. If you do like how it looks then remove the final pieces of tape, you're good to go!

The process of laser cutting can be hard on these small thin pieces of wood. The laser does burn through your wood and can scorch the wood around the cuts. To prevent this in most circumstances we use a process known as 'masking'. Masking is simply applying blue masking tape to the surface of your project. Image 1 displays the effects of this on the back of a puzzle, with the top having been left bare and the bottom having been masked. Unfortunately, masking the front will remove the image you worked so hard to apply in the previous step.

You can apply a finishing product to the front of the puzzles; this will add some shine to the puzzles, and protect them from the harmful affects of masking.

This is demonstrated in the 'before' picture, where the bottom third of the puzzle has been painted with a finishing product, specifically clear nail polish, and then the left half of the finished portion has been masked. The 'after' picture shows clearly the lack of scorching in the bottom left portion, and a reduction of scorching in the bottom right portion as compared to the top.

If you choose to apply a finishing coat, then simply paint or spray with your chosen product, wait for the coat to dry completely, and then tape over whichever sides you choose. Clear nail polish is the only 'finishing product' that I am aware of that will dry in under 2 hours, thus making it the only option you can use within the 45 minute limit of this project.

If you choose to tape over both sides, be sure to mark either the front or back clearly, so you know which is which.

Whether or not you applied finishing processes to your puzzle, you have to do this final preparation. Find the center of the wood. The easiest way to do this is to simply take a ruler or other long straight edge and draw a line diagonally from corner to corner. Another perk of having your wood masked is that this pencil marking will disappear, while you will have to erase it from the finished product if you chose not to mask your wood.

First things first, make sure you're on the computer that is connected to the laser cutter.

Download the given SVG file if you're using it.

The SVG provided in this project should have the correct settings already, however, just to make sure, open it in Adobe Illustrator.

First, you have to check the document color mode. Laser printers only work in RGB colors, so go to 'File' > 'Document Color Mode' and make sure that 'RGB Color' is checked.

In a puzzle, all the lines are cutting vector lines, which is designated by a specific line thickness and color. They need to be set to the RBG code 255,0,0, which is hex code #FF0000. To check that this is correct, select all the lines, either manually or with Ctrl-A, and then check the appearance panel to the right of the screen. You want to set the stroke to the correct color if it is incorrect, and then change the line thickness from what it is to 0.0001 inches. The lines will appear to disappear, but are still present.

When you're done with that, you're ready to print!

Finally, almost to the exciting step

You can print directly from Adobe Illustrator, just hit Ctrl-P. A pop up will appear, don't change any settings, and simply hit 'Print.'

From the bottom left corner of the screen you will need to open the app called "Universal Laser Systems Control Panel' by clicking on the logo, which is a small red square with a yellow diamond in it. You can see this logo in the pictures, circled in pink. If your lines don't appear as red in this application then go back to step 8 and make sure all of your settings are correct.

Next, you have to adjust the materials and cut settings. Click on the 'Settings' button at the bottom right of the screen. Then switch to the materials tab, as shown in the picture, and adjust the material to "Natural" >"Woods" > "Softwood" > "General Softwoods". Then adjust the 'Vector Cutting' setting to 50%. Note your wood thickness as 1/8", or 0.125 inches.

Once all of your settings are correct, hit 'Apply' then 'OK'.

Click on the center point of your image, then you'll be ready to go to the next step.

First, check with an instructor to confirm that the machine is turned on. You will want the hexagonal print bed in it.

Open the lid to the laser cutter and set your piece inside, lined up with the upper left corner and in the same direction as your puzzle picture. Then, leaving the lid open, use the arrows in the upper right part of the screen to maneuver your laser head. You should see a red laser pointer (entirely different than the laser that will be used later) coming out of the print head. If you do not see a red dot, make sure that the lid is open, and call an instructor over.

Line the red dot up with the center of your piece as shown in the picture, then hit 'To Pointer'. The puzzle shown on the computer screen should move to be centered on where your pointer is. If it moves drastically offscreen, make sure you're zoomed all the way out, and then make sure that you had clicked on the center dot. If both of those had happened and your puzzle still isn't displaying correctly, call an instructor over to troubleshoot.

Once all of your settings are correct, then you can start your print! Close the lid and press the green play button. Watch your print go!

While the laser is on the highest setting, it's possible it won't go all the way through. Once your print has finished, lift it up and inspect it. If it hasn't cut all the way through then put it back exactly where it was on the board in the same orientation. Go back to your settings and adjust the 'Vector Cutting' setting down to 10%. Do not adjust any other setting, particularly do not adjust the 'To Pointer' setting. Adjusting that in any way will misalign your print from the previous cut and you cannot realign them as precisely as you will need to. Then print it again. It should cut through completely after that, but if it doesn't, simply repeat again.

Fun Automation Fact:

• If you had multiple pieces of wood that were all the same size, you could easily make multiple puzzles without ever having to adjust any settings on the laser cutter, simply by pulling one out and putting the next one in.

Make sure you've cleaned up the spaces you used, throw away used materials. If you chose to mask your puzzle then this is a good time to remove the mask from each piece.

Congratulations on completing this project!