Plywood Optimization

Breaking down the plywood for a cabinet job can be a very time consuming part of the project, which is why a lot of cabinetmakers speed up the process by using software to optimize their parts into as few sheets as possible to save materials, and to create cutting diagrams to save time at the saw. Plywood optimization programs can optimize all of your parts in just seconds, allowing you to get on with the cutting as quickly as possible.

CabWriter facilitates the use of plywood optimization programs in two ways, both of which allow you to use low cost, but effective third party applications for optimization. There are a great many optimization, or nesting, programs at a number of different price points to fit any budget.

One very good, low cost solution for plywood optimization is CutlistPlus fx, which is described in more detail here, particularly if you aren’t planning on using a CNC to cut your parts. In addition to advanced cutlisting features, it can take the parts on your cutlist and optimize them onto plywood sizes of your choice as shown at the right. CabWriter is tightly integrated with CutListPlus fx and can output a compatible file at the touch of a button.  This is the preferred solution if you are cutting the parts manually because dimensions are provided to make your cutting easier.

If you choose not to purchase a program like CutlistPlus fx, there are other programs on the market that will optimize your plywood for you. Most of these programs fall into the category of nesting software which try to optimize the layout of a set of parts onto as few sheets as possible. They typically read the parts in as DXF files to perform the optimization, which CabWriter CNC is able to export as shown below or on the CNC Integration page. Originally developed for the CNC industry, they are also a great way to optimize for manual cutting by simply printing the sheet diagrams. While these programs typically will not also print labels for you, there are other options available such as label printing programs or the mail merge feature in Microsoft word. Many nesting programs are quite expensive to purchase, but there are a number of rental options on the market that allow you to pay per use. If you only do nesting, or plywood optimization, infrequently this can be a great option as it often costs only a couple of dollars per use. See below for instructions on how to do this using NestLib Online.  A solution like this is much more optimized for CNC because cutting dimensions are not typically provided on the resulting diagrams.

Plywood Optimization Using CutlistPlus fx
Plywood Optimization Using NestLib Online

NestLib provides a program called MyNesting that you download to your computer and use to nest, or optimize, parts. You can use the software to nest as many parts, as often as you want, for free. If you want to output and print the optimized diagrams as a PDF or DXF, you’ll need to pay a fee. You can either subscribe on a monthly basis, or pay per nest as shown at the right.  If you are optimizing for cutting on a saw, a PDF will be sufficient. If you are nesting for a CNC, you’ll need a DXF output in order to tool path the parts.

Choose File -> CabWriter Production Documentation to open the dialog box. Prior to this, set up the scene that you would like to use for the DXF files; in this case, we’re just exporting the the 1/2″ and 3/4″ pre-finished plywood carcass parts. Make sure “DXF By Material Name and Thickness” is check and hit OK. A folder will be created in your SketchUp project folder that will contain a separate DXF file for each type of material containing all of the parts for that material type.

In the MyNesting program, choose “Import DXF Parts” and choose the DXF file exported by CabWriter for one of the material types. In this case, we’re choosing the 3/4″ pre-finished maple plywood parts.

The imported parts are listed and can be previewed and settings changed on a per-part basis before nesting begins. 

Set the sheet size for this material. In this case, we’re choosing 48.5″ x 96.5″ because that’s the typical size for pre-finished plywood; be sure to check the actual size of your plywood.

Start the nesting process. The initial optimization will happen quite quickly, but the software will continue to try to find improvements until you tell it to stop.  Notice that all of the parts were fit onto 12 sheets of plywood.

Here’s a closeup of a couple of the sheetsNotice that this type of software can easily handle odd shaped parts because the actual part shape is communicated in the DXF file; this is necessary if you’ll be using the output for cutting on a CNC.