Dimensioning Lumber with a CNC

[Randall Houghton]

Does anyone dimension lumber with their cnc? Seems like it would very similar to flattening a spoil board.

[Kevin Jenness]

I've flattened and thicknessed slabs but it is too slow to be worthwhile for anything small enough to process with conventional milling equipment.

[Bruce Page]

I'm flatting some cherry as we speak. I sold my planner and joiner when i bought my cnc because of space restrictions. Dimensioning on the cnc is a painfully slow process. JMO

[Richard Coers]

You can use a CNC, but you have to shim every board you run to take out twist, cupping, or bowing. You will also not get a high quality surface finish because of the rotary cutter.

[Ronald Blue]

I've done a considerable amount of slab flattening and like Richard said you have to shim to minimize waste and machining time. This is only on large pieces usually to wide to process any other way. I wouldn't consider it worthwhile to dimension lumber on it. If it's the only thing you can do it on maybe as a short term solution. However you can prep a pile of boards with a jointer and planer in the time you are getting set up on the CNC.

[Wes Grass]

A friend has a warehouse of walnut slabs, Claro, Bastogne, most from the Sacramento Valley. Absolutely gorgeous stuff. Very few of them small enough to fit on a 'normal' size, 4x8, cnc router. He uses a power planer and his eyeballs/hands to clean them up to be sale-able.

I have a few 'cants' chainsawed from chopping them down to fit on the chainsaw mill. Odd shapes, hard to figure out what to do with them... but too damn pretty to throw away.

Something, someday....

[Maurice Mcmurry]

I'm flatting some cherry as we speak. I sold my planner and joiner when i bought my cnc because of space restrictions. Dimensioning on the cnc is a painfully slow process. JMO

I stumbled upon some you tube videos of CNC sawmills . They are not for surfacing, but do amazing edging.

[George Yetka]

I'm flatting some cherry as we speak. I sold my planner and joiner when i bought my cnc because of space restrictions. Dimensioning on the cnc is a painfully slow process. JMO

You need 2.

I cant i'm only 48x32 but have flattened cutting boards before.

[Jim Becker]

Yes, you can do that...and I have. It's certainly not practical for "ordinary" material dimensioning but absolutely valuable for unusual material or larger and very heavy stuff that can't be handled well or at all with a normal jointer and thicknesser. Folks who do a lot of slabs often have a separate, simpler system for flattening that may look physically similar to a large CNC, but it basically an induction motor on a gantry that can swing a big fit-for-purpose cutter with either manual and/or automated movement on two axis. Matt Cremona has one of those in his big barn building at this point for serious slab prep. I have a smaller manual flattening system from TruTrack in my shop that's larger than my CNC, but was inexpensive to acquire compared to getting a larger CNC, even though I now have the room for a larger CNC. But I still will put big stuff on the CNC when they fit within the boundaries because it's easier to do the deed than with the manual flattening system and much, much, much cleaner due to dust collection. I've done cookies and slabs of various sizes since I got the CNC. It works. I try to use the tool that "in the moment" does what I need done the most efficient way including considering restrictions of the machines that might be employed.

[Steven O Smith]

I'm just finishing a medicine cabinet made from baltic birch. It was all cut on my cnc, with no sanding and only a little cleanup to remove edge fuzz. It would have been a lot of work for me to get this edge finish by hand (likely not as good), and to exact dimensions? Nope. The pieces went together with no gaps (exception to follow) and the shelf ends almost exactly aligned with the dado end when clamped. The exception to fit was the dado slots, they were a little too wide due to my error in the CAD drawing.
I agree that surfacing would take some time, but I think using the cnc to surface would be preferable to a manual router sled for a large piece.