Built-in Cabinets - calculating materials

This past weekend I finally started cutting some plywood for this project! Before I could start cutting anything, I would have to figure out what to buy for stock. Since I modelled everything in xDesign, the dimensions for all of the parts were at my finger tips.

If you remember, I am designing some built-in cabinets for a small room in my home. I have detailed that work in a post about the project and another about the xDesign modelling.

With the cost of wood skyrocketing since the pandemic and the lack of storage space in my home, I decided to start with the 3 large shelves at the top of the unit - shown in highlight below.

The majority of this design will be built out of 3/4" plywood so I needed to calculate how many 4' x 8' sheets of plywood I will need just for these 3 boxes. Each box is made up of Top & Bottom pieces (43" x 30") and 2 side pieces (13.25" x 30"). I designed the built-ins to be 30" deep to give us more storage but also to cover the missing and broken drywall in the ceiling and walls where we originally had closets located. Most cabinets like these are 24" deep which is half the width of a 4' x 8' sheet of plywood. Since these are 30" deep, I had to pay carful attention to my cut-list and I will be trying to limit the amount of waste from each sheet.

The first thing to do is turn to the SolidWorks Maker's package and get some overall dimensions. I could have just used the measure tool to get some quick dimensions but instead I opened my assembly in SolidWorks Connected and created and printed a drawing (seen below) to reference while in the shop or at the lumber yard.


In the past I would used Adobe Illustrator to quickly lay out how the pieces will fit on a 4' x 8' sheet. Instead, @SB ​​​​​​​and @VB ​​​​​​​told me about a very cool app from Google called Cutlist Optimizer. Here you can enter the dimensions and quantities for the pieces you will be cutting and the size and quantities of the stock sheets you will be using. The app uses AI to calculate the position and orientation of each piece and tries to layout in the most optimal way. It can even account for grain direction and the blade kerf.

This app is very cool. It generates a graphic view for each of the sheets needed to cut out all of the pieces and also has an interactive cut-list that cross-highlights with the graphic views. You can try it for free with 5 daily calculations.


How many cookies fit on a backing sheet?

Maybe the MakeByMe team is looking to build similar technology into their app, but either way, this would be a powerful addition to xDesign for Makers. I can imagine using a new command in xDesign while working in an Assembly where you can select any number of faces that would represent the different pieces to cut out. When you hit Calculate, the command would automatically calculate a 2D layout that best fits into a set number of standard size (or custom size) sheets. It is fun to experiment with the number of pieces and number and size of sheets.  There are endless permutations, but similar technology could be made to work with other more complex die lines that are not basic rectangular shapes. Think of how many gingerbread men (and other shape cookies) you could fit onto a baking sheet. This could be a powerful tool for makers and integrated seamlessly with xDesign and the 3DExperience Platform.



So, this past weekend I took a printout of my cut-list (shown above) to a local lumber yard and picked up 3 sheets of furniture grade birch 3/4" plywood. While I was there, I had them make the first 2 cuts on each sheet using their large panel cutter. Unfortunately, I do not have a table saw (or room) big enough to make those 8 foot rip cuts. I brought home the ripped down panels and then needed to cross-cut everything to size. Again, due to the size of these pieces, I had to make all of these cuts on my deck using a circular saw. If you have ever cross-cut plywood, it tends to tear-out a lot. So, I did each cross-cut in 2 passes with the blade only cutting halfway into the thickness of the plywood. I would make one cut on the top side of the plywood, then flip it over and make the other cut on the bottom side. It made for a long afternoon of cutting.

Next Steps:

  • Cut dado grooves
  • Glue up and clamp each box / shelf
  • Rework the electrical on the back wall in room
  • Hang each shelf unit