spoil board surfacing bit

Sorry for all the recent questions. Can you recommend a spoil board surfacing bit? I have the 660 so I can go as high as a 1/4 inch shank.


Right now, I am looking at these and not sure which route to go. Obviously I would like to save money where possible and the 2nd one is cheaper.





I don’t typically surface my waste board, I will surface my part if needed or a small block if I am doing something with a critical Z depth (rare). Surfacing usually leaves a indent in the work space, this tends to cause more issues than surfacing solves, so if you do this make sure you make a block that you can entirely surface.


You are taking a very tiny amount off, so you can go as large as you want…the downside is the larger the bit the more accurate your tools perpendicularity needs to be or you will get scalloping.

This is the one I have. I can surface the whole spoil board. Some of the stuff I engrave on is already finished, so I can’t surface it.


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I used this one:


My spoilboard is about half an inch smaller than my full cut size on the MPCNC. If you use screws to hold your spoilboard down, make sure they’re recessed enough to keep from hitting them with the cutter. I found out my 660 is slightly off of vertical as I ended up with the slightest scallop, but it’s not big enough to affect my cuts.

I did a 1mm pass and kept speeding up the cut speed until it had a good sound. My 24"x24" board took over an hour to level.