Plunge too fast

CNC Machines Shapeoko
1

I start my very first job after testing a few things. The job was really simple using Birch Plywood 5/8. Here is my setup;

Shapeoko 3 XXL
Birch plywood 5/8 16" X 14"
3 Toolpaths, two pocket holes and an outside cut

I used default settings as plunge and feed rate. I set material to soft wood.

The job start well untill it start to do the last Toolpath, the outside cuts. It start ok and all of a sudden the plunge and feed rate increase. I stop the joob as soon as I could.

Should I set it to hard wood or any other recommended feed rate?

2

Please double-check the CAM settings for the last toolpath — did you make an error in entering them?

Post the source .c2d?

If it was only the plunge getting too fast I’d suspect insufficient belt tension and the endmill / gravity pulling the bit down.

Does the machine still move too far / fast along the Z after powering it back up?

3

@Mat
Yes, you should reduce your feed rate.
Please refer to the chart:
http://carbide3d.com/shapeoko/feedandspeed/

Plywood is not the same as “Soft” (Pine) wood.

Screenshot 2016-12-10 18.03.28.png1010×314 67.1 KB

Woods are the most difficult to machine predictably without some testing.
Even board to board you will get variations in density, moisture and grain.

4

Thanks for the quick reply. I read about increasing the router speed and did a second test. That time it went fine. I reduced the speed rate of the third toolpath from 75 to 50 too.

Thanks again, you guys rock :slight_smile:

1 Like