Using 8" x 8" wood blanks - Need input

My wife has a small baby product business making wooden toys, and we have been outsourcing some machining work to a local hobbyist, with me doing the final sanding and finishing in my shop. One of the things I want to do with my Nomad (which should be arriving this week) is start to do some small production runs of these toys in-house.

I’m brand new to CNC, so have a question regarding the best way to order my wood stock. I’m thinking it would be wise to order blanks in 8" by 8" with mounting holes drilled, so it can be directly secured to the sacrificial board on the table. From there, the idea would be to use as much surface area for my parts so as to minimize waste.

Does this seem like a reasonable approach for production runs?

For one-off jobs and more custom work (and parts that are smaller), I’m thinking it makes sense to use a smaller stock so that waste is minimal.

Thoughts? Thanks in advance.


PS - I’m also assuming that if I use blanks that match the table size exactly, that it will be easy to zero the machine since I will essentially be zeroing it to the corner of the table. Is this correct?

Hi Darren,

First, regarding zeroing, if you have a way to fixture your material, then you can leave the machine “zeroed” after setting it once based on the fixture. Therefore it doesn’t matter what size your stock board is, as long as you put it in the same place every time. Because you can repeatedly use the same offset (until you change it, then you’re stuck with the new one) you can adjust your zero position in MeshCAM or other CAM package relative to your work-piece if you want to get fancy and leave the origin at the corner or center of the table, and then position your stock deriving from that position. It means that you’re not jogging around and finding the stock every time you stick material in, but it does require much more operator precision to do it that way!

It’s a standing feature request to have a number of different pre-programmed offsets for Carbide-provided fixtures (like the flip-jig and vise when they ship), as well as the ability to save offsets for setting your own, but to my knowledge Rob hasn’t implemented that fully yet.

As for how to go about buying material, it’s generally the case that the more processing you’re having done to a piece of material before you get it, the more it’s going to cost. Depending on what your margins and acceptable material costs are, as well as what tools you have available, I would recommend getting your materials in bulk, as roughly finished as you can process.

If you have a drill-press, a radial arm or miter saw, and/or a circular saw that you can use, then it may make sense to build yourself a drilling jig and buy standard length boards to cut down and drill for mounting yourself.

Also, certain sizes in wood are more expensive per unit of volume than others, so you’re looking for the cheapest size to buy per board foot or per cubic inch of material, and balancing that against sizes that are large enough for the product. It becomes a question of how hard you want to work to maximize your yield.

You’ll also want to factor in labor savings by reduction in fixturing work if you can get multiple pieces out of a single piece of material, as essentially it’s saving operator time to not have to reload and setup the machine between every part. Alternatively, if a certain size of stock is cheaper and fits the product better, then building a fixture to swap out parts is probably going to nullify the benefits of cutting multiples out of a larger piece of material, and outweigh the wasted material you lose when you’re packing the parts and have to retain margins around them to keep them all stable during machining.

Ultimately, it’s going to depend on the shape of the product, the operations you’re doing to it, the fixturing you have/can get/make, and the number of tool-changes you’ll need to perform.

Hopefully that gets you thinking, and if you want to get more specific we can dive in a bit more on it with more specific examples :wink:

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Oooh, this is handy. I was wondering if I could just leave the x and y zeroes at the end of the table, and if the machine would remember it.

The answer is yes, you can set an origin and leave it, but then you better know darn well where you’re putting the stock material when you tape/glue/bolt it down :wink: