In this tutorial, we will be making a 3D unicorn model out of 2D pieces. It'd make an excellent gift. Please download the attached file 'unicorn parts' (both the .ai and .pdf file work).
First, I would like to give credit to chemlife from thingiverse for the CAD model I used to make the design. It can be found here:https://www.thingiverse.com/thing:925638
The CAD model was 'waffle-ized' using a software called 123D Make, for those of you interested in making similar projects. It is a free software by Autodesk that can be downloaded here: http://autodesk-123d-make.en.lo4d.com/
I have a tutorial on how to use 123D Make on my profile, so check it our if you are interested in learning how to design your own interlocking models.
Download one of the following files: the Adobe Illustrator (ai) file if you are using that program, or the pdf if you use a different graphics edittor.
Step 1: Materials and Tools
This tutorial assumes you have access to and operator's knowledge of a CNC lasercutter. As each machine's software and interface are drastically different, I'll have to assume that you know how to operate the laser cutter you will be using. The laser I used accepts illustrator files, which is why I uploaded the design as an .ai file. However, I also uploaded the .pdf for people who use a different software. Open the .pdf file in your laser's software, as pdf's are very standard file types and should be accepted by your laser's software.
You will also need calipers to measure the thickness of your wood, as 1/8" wood is rarely the nominal thickness and is typically off.
You will need a sheet of 1/8" plywood. The area of the design fits in a section about 12" by 14" in area. I used a 12"x24" sheet of birch plywood I got from a local hobby store for just a few bucks.
Step 2: Preparing Your Material and Design
Use the calipers to measure the thickness of your plywood.
I chose to use a piece of scrap plywood that measured ~.120" thick. It's important to note that the thickness of your plywood will dictate the size of the unicorn. If the thickness doesn't match up with the size, the slots will either be too small or too big for the pieces to fit together. The file I provided is meant for plywood that is .120" thick. For example, plywood that is .135" thick will result in the design file being scaled.
The entire design file will need to be scaled by: (x/.120) * 100, where x is your material thickness. If my wood is .135" thick, my scale factor will be .135/.120 * 100 = 112.5 %. This is a critical step, otherwise your pieces will not fit together. The method for scaling will vary based on the software you are using. In illustrator, select everything and go to object-->transform-->scale. If you are using a different software with a different laser, I will assume you know how to operate the software and scale the file. If you are using wood that is .120" thick, or very close to it, you may not need to scale the file at all.
Step 3: Laser Cutting the Pieces
I used a Universal Systems Laser Cutter. It has a materials data base in which you select materials and the machine then knows what power/speed/ppi settings to use. I used the material 'general medium woods' and set the thickness to .120 (using my calipers). I will have to assume for this part that you know how to use your own laser cutter, because they vary significantly from model to model.
Cut the provided file out on your laser. After cutting out your pieces, collect them all and bring them over to a work table where you can assemble them.
Step 4: Assembly, Step 1
I found the easiest way to assemble the unicorn is to start with the spine piece, or the long body piece with the tail. Then, add each of the sideways pieces, starting with the rear legs, and progressing forward with each piece as shown in the photos. After inserting all 8 of the cross pieces, you should have a unicorn that looks like the one shown in the last picture of this step.
Step 5: Assembly, Step 2
Next, we will take the two long body pieces that have legs, and add them to them to the model. Since these will be sliding into 5 other pieces, it can be a little tricky to add them sometimes. Make sure that you keep the pieces strictly perpendicular to the sideways pieces, and it should slide in well. Lastly, add the front shoulder and rear hip pieces to each side, as shown in the pictures. Keep in mind the hip and shoulder's are in the same layer, but are two separate pieces.
Congrats, you made a laser cut Unicorn! Hope you enjoy the model and liked the tutorial. If you would like to see similar projects, feel free to check out my profile. If you have anything you would like me to make a model of, leave a comment and I will do my best to make it :)
Step 6: Trouble Shooting
If you had any trouble getting the pieces to fit together, or if the pieces were way too loose, you'll need to scale the entire file by 3-4% and try cutting it again. Each type of laser is different, and yours may use slightly different settings than mine, resulting in a different kerf. This would by why the pieces might not fit together appropriately. If the pieces are too loose, consider scaling down the file and trying again. Likewise, if the pieces are too tight and don't slide together, scale the file up and cut the pieces again.
In Illustrator, select the entire design and click object-->transform-->scale. If you use a different software and are unsure how to scale the parts, remember google is your friend :)