Spoilboard surfacing plan?

I’m about to embark on the journey of surfacing my spoilboard - due to a bunch of newbie glitches, it’s already pretty scarred up and getting hard to ensure the 1/4 baltic ply I’m using for projects lies flat.

So my question is: what is the best way to set up a program to surface the spoilboard? Should I just draw lines in fusion 360 and have the machine follow them?

Am I overthinking this?

No need to draw lines, you can use a 2D Facing tool path.

  • In Fusion 360, create a box that represents the length and width (X,Y) of your working area…height does not matter.
  • In the Manufacture workspace create a setup with no additional stock.
  • Add a 2D Facing toolpath.
  • Add your wide bit and feed and speeds to the toolpath.
  • In the Height’s Tab, set the Bottom to minus whatever you want to cut. So say you want to cut 0.3mm from the top, set the bottom to “-0.3”.
  • On the Passes Tab, set the stepover. I used half of my bit diameter.
  • I would run the toolpath above your spoilboard first (perhaps at a faster feed) to make sure that your toolpath does not extend beyond the limits of your machine when set to your specified origin.

It wouldn’t hurt to do a facing run on a piece of scrap to get your feeds and speeds right before you surface your spoil board. A wide bit has more potential for deflection resulting in scalloping, and some test runs will figure this out. I ran my surfacing much slower than I would have with a smaller diameter bit. Also surfacing will show if your machine is out of tram (router not perpendicular to the spoil board), so you may have a tramming step followed by a more minor surfacing after your initial surfacing of your spoil board.


Woohoo! This is exactly what I was looking for. Thank you for the detailed and we’ll thought out answer. After work today I will follow this through.
Thanks again!