Acrylic Yarn Box

An acrylic yarn box like this one not only stores your yarns but also acts a way to dispense the yarn as you're working on new projects. Clear acrylic is a great material for being able to see what yarns are stored in each box and how much yarn you have left without even opening your yarn box.

Using a laser cutter is mandatory for this project and so I made this acrylic yarn box at TechShop Detroit.

Learn more about TechShop at http://www.techshop.ws/

If you check out step 4 I've included a CorelDraw CDR file I created for this project. 

Step 1: Materials and Tools Required

It's up to you to decide how thick of acrylic you want to use and as you get thicker grades the price goes way up. For my example I'm going to use 0.093" acrylic that can be found at most Home Depot stores in the USA. I buy sheets of it not to exceed 18"x24" because that is the maximum size piece my laser engraver can hold at TechShop.

Materials and tools required:

1. Acrylic sheet, 18"x24"x0.093" thick (2 sheets required for the box in my example)
2. Acetone - smallest size container you can find
3. Small funnel
4. Acetone needle bottle / applicator (can get online, just google "needle applicator")
5. Laser engraver -> TechShop
6. Computer w/ internet access
7. Drawing program compatible with the laser engraver (I will use CorelDraw, Adobe Illustrator also common for the laser engraver)

Step 2: Determine the Kerf for Your Laser's Speed, Power, and Material Combination

The size of the box is completely up to you. In upcoming steps you will see some other things to consider in the size like how many yarns you would like to fit in the box and dispense through the holes we add.

Once you've decide the size of the box we can use the box designer tool available to us online. But before we go there, it's important to step back and discuss our material thickness and how wide the laser cuts the material, called "kerf". Kerf is important here because we absolutely need a tight fit between the pieces when we go and assemble our box. If we do not have a calculation of what the kerf is, our fit will be poor and then the acetone will not do a good job solvent welding the pieces together. You can get thicker glues that can fill some gaps like IPS Weld On, but why do that when we can have a really good fit to begin with?

To calculate kerf you need a small sample of the acrylic sheet you will use and the laser cutter you will use. The details of dong this experiment are also on Instructables so I won't repeat them here but refer you to that excellent instructable here:
https://www.instructables.com/id/How-to-Adjust-for-...

Remember you need to do the kerf testing with acrylic and not wood as shown in the linked Instructable. The laser cuts through different materials with different kerf values (as well as different speed and power settings!).

For reference, at TechShop I am using a 60-watt Epilog laser cutter and with my 0.093" thick acrylic, my kerf thickness is 0.005". Five thousandths of an inch may not seem like much but in the assembly of these pieces it makes a big difference.

Step 3: Design the Box Using a Free Online Tool

Designing the box's geometry for our overall dimensions is really easy thanks to a free online tool.

Just visit this excellent Boxmaker page at http://boxmaker.rahulbotics.com/

Enter your overall dimensions then click on the "Advanced Options" link. Leave the Notch Length figure as is and "Auto" should be checked. The value we must change is the "Cut Width" value. This is the equivalent of the kerf value we calculated in the last step. For my example, I am entering in 0.005.

My box dimensions for this Instructable are 8.5" x 8.5" x 10".  I chose these dimensions based on some common sizes of yarn balls.  I wanted to take the longest and thickest sizes and be able to hold 4 full balls.

Once you have your dimensions entered and your cut width (kerf), click the "Design it!" button.  The website will automatically send you a PDF that will download to your computer.  In the next step, we will import this PDF into our graphic editing software, CorelDraw. 

Step 4: Import and Add Extra Design Features to Your Box Design

Open CorelDraw and import the PDF file you just downloaded.  You will need to move the objects around so that the pieces fit the size the acrylic you will be cutting.  Not all of my pieces fit onto the 24" x 18" piece of acrylic, so some of these pieces will be put into a separate, 2nd file or as 2 pages as CorelDraw can also do it. 

Now that we have our overall geometry placed, it's time to add some extra features. A couple of "must have" features to add to your yarn box are some holes on one or many sides to allow yarn to feed through them, and holes for the lid. I recommend putting the yarn feed holes near the top of the box so that there's less chance the yarn gets tangled. The top of the box will be snug when fully closed, so it's a good idea to put in 2 finger holes on the lid piece so the lid can be easily removed.

Other features you can include: Holes or handle features, engrave in custom decorations, whatever you like.  One extra feature I'm adding is a removable divider that's just under 4" x 10" in size.  I also design in the acrylic guide pieces that hold the removable divider in place.  

I've included a copy of my CorelDraw CDR file if you want to see how everything is setup in greater detail.  Note that the file has 2 pages!

Step 5: Setup Your Laser for Engraving and Cut

The setup steps for the laser engraver is explained in TechShop's Safety and Basic Use course. Setup in our case means we should get our acrylic into the engraver and then set the focus.

Once focus is set it is time to start cutting! Send your file to the laser engraver using the recommended speed, power, and frequency settings recommended by Epilog for your material thickness.

Step 6: Dry Fit Your Parts Together and Clamp Lightly (optional)

Remove your pieces from the laser engraver and dry fit them together. The pieces should fit rather snug if the kerf value you used was accurate. To ensure the parts stay snug while we are solvent welding you can clamp them together. A light clamping is all that's needed, too much force and we will crack our acrylic.

A word of advice, do not use rubber bands or anything like that long any edge you will be solvent welding. What will happen if you do that is the acetone will find its way to your rubber bands and run along the flat surface area of the box instead of just in the joint areas. When you remove the rubber bands a permanent mark will remain on your flat surfaces and it won't look so good. Learn from my mistake!

To solvent weld place some acetone into a special applicator used for such things. These can be purchased from several places online like eBay, hobby shops, Grainger, etc.  Just Google "needle applicator".

For my example, I did not clamp the pieces but I did tilt the box as I applied the acetone to ensure the acetone stayed in the joint area.  Another word of advice, I recommend only filling the needle applicator about 1/4 full or less.  As you tilt the bottle beyond horizontal, the acetone will want to drip out.  Try to avoid getting acetone drips on the non-joint areas of the acrylic.  If you do, do NOT try to wipe it away.  Let the acetone drip dry on its own, give it at least 5-10 minutes.  Then you can try to wipe away with a cloth.