Help please! 1st time surfacing 🚨

[Gerry]

I refuse to be kind… but the file looks fine anyhow:)

@gdon_2003’s comment regarding the bit slipping is definitely something to seriously consider. I’ve had this happen with a faulty 6mm collet and it went directly through the stock to the wasteboard in about 50mm of horizontal travel.

Your surfacing bit is presumably a new bit you haven’t used before, and perhaps it needs to be tightened a little more firmly?

Also, if (for example) it’s a 6mm shank and you’ve a 1/4" collet it will feel like it’s in place but won’t be. Other things that might affect grip are dust in the collet or some sort of lubricant on the bit or shaft.

Note that you can always do a dry run with your pattern. Put something else in the router, even a pen or pencil (don’t turn it on in this case), then zero and back off the Z axis by 0.5mm and rezero.