Why does this shape appear at the beginning of the tool?

If you look at the picture, there is always a round-shaped tool mark where the tool started.
I want to remove the shape below.
Please give me some advice on what to do.
many thanks!

Use the new ramping feature. That will help reduce the dwell marks.


Because the Z axis tends to flex when the bit enters the wood. It’s a problem for most home duty cnc machines. I tend to use a slower feed rate there and also have the bit start in what will become scrap if it is going to cut something out. There is also some flex with the router via the mounts. The whole thing becomes a lever.

1 Like

Thank you for sharing your valuable knowledge.
I’ll try new ramping feature.

Thank you for your detailed reply. I tried to slow down the feed and down but there was still a problem. So let me challenge with your idea of including some routes in the scrap.

thanks for the awesome information.

What is your machine and how many passes are you making at what depths/speeds?
You maybe trying to cut to deep per pass or to fast and the frame is flexing. There appears to be chatter marks around the circle that appear to be due to flexing of the frame.

thanks for the awesome information.