What techniques are there to find the optimal wood cutting list for a project?

Question

When I've designed a piece of furniture, I need to source the wood for it. The wood is often sold in plank form that I need to cut to length when it's too long and glue together when it's too narrow.

Is there a technique other than trial and error for working out the optimal number of planks to purchase and how to cut and glue them to make the "sheets" I need?

Alternatively, are there software utilities that do this for me?

EDIT: In my particular case, the supplier can provide the wood in specific dimentions (2.5m lengths of 150mm wide planks in the thickness I need). So I really just need to work out how many of those planks need gluing side-by-side to make the wide boards in such a way as to produce the least wasted wood.

Answer 1

If you're looking for quick and easy, I am currently using CutList Plus (no affiliation) and it does everything you mentioned in your question. I don't want this to sound like too much of a software product review, but it handles storing your supply of lumber (dimensions, cost, types) and then lets you enter all of your parts. Panels can be separately created and it will break it down into parts for you. From here it will generate layouts, which you can optimize for ripping or cross-cutting, or manually re-arrange. It will also generate a bill of materials and reports on project costs. It automatically accounts for waste, blade kerf and other items that need to be factored in.

But of course, people have been building things long before there was software to create cut lists. A lot of it was probably done by trial and error, and there might have been more waste. Some strategies I can think of:

• First, consider any limitations due to equipment, space, etc. Performing a rough cut with a circular saw in your garage and further breaking down in your shop might be easier for you but will affect the final layout of parts
• Placing parts with a similar dimensions next to each other
• Starting with large parts and then trying to place smaller parts in the waste areas
• After your first attempt, try swapping certain parts around to see if it reduces waste or allows more parts per board
• If you are making multiple panels of different sizes, it might be more optimal to build a larger panel and then cut it down to the individual sizes you need. i.e. If you need one panel that is 8" wide and another that is 9" wide, but your wood is 6", it is more optimal to make a 18" panel from three 6" boards and later cut your 8/9" panels than it is to use two boards for each of the 8" and 9" panels.

Answer 2

There's a good answer for dealing with sheet goods here already but it sounds like the question is asking about solid woods where I don't think planning cuts in advance works as well.

Admittedly, I find hardwood lumber grading rules confusing but they do give some idea what I can (or cannot) count on when shopping for lumber.

For example; for my most recent project I wanted to use some maple which was locally available as no. 1 common. That grade tells me that I can expect to get clear cuttings measuring at least 4"x2' or 3"x3' from 66% of each board.

If I can plan an entire project to be built from 4"x2' or 3"x3' pieces then I suppose I can make a guess at home much lumber I need but at least for me that usually isn't the case. I end up inspecting and measuring boards at the lumber yard and re-planning my cut list based on what's available. I can usually do better than 66% but only if I can adapt to whatever knot and defect placement I find. In this case I found boards between 6 and 8' by between 5 and 10" and had to plan how to assemble panels from there based on the cuts and grain pattern I think will work well.

If there's a better approach I'd love to know about it too.

Answer 3

If you do the project in Google Sketchup, there is a plug-in that will compute a cut list. I used to do a large, custom-built book shelf successfully.