Strange Z-axis problem: bit moves z- or z+

@crew wrote:

So I am still trying to get my first correct cut from my Shapeoko.

the x, and y are doing great but I can’t seem to fix the z (using a Dewalt DWP11)

My first problem was that I don’t get enough depth. It was supposed to cut through the material 9.3mm, but instead but would cut about half that. I did some tinkering and stuff, and after a few unsuccesful tries here and there, I noticed that the bit would be deeper into the Dewalt after the job. I guess that the bit was not locked in tight enoough, so that it recesses deeper inside the dewalt, when it should instead be digging deeper down into the material, or that my feed rate was too slow and it was not spinning fast enough to withstand the forces from the wood when it is cutting.

So I tighten the router as hard as I could, and slowed down the depth per pass, and increased the RPM to make sure that the bit breaks down the wood faster when it plunges. Now it cuts all the way through. The problem however is that it cuts through my wasteboard!

And when I look at the router, the bit not extends farther down than before! I understand if the wood pushes the bit up the router, but I am not quite sure why it can also pull it out?

Any advice on what just happened?

Here are some details if it helps:

Original attempt (not enough depth):
Material: Soft Wood
Bit:
Flat end, Single flute, 3mm diameter, 8mm flute length.
Depth per pass: 0.927
Stepover; 1.1350
Feedrate:551.180
Plungerate: 551.180
RPM: 15000

last attempt: (too much depth)
made following changes
Depth per pass: 0.300
Feedrate 480.060
Plunge rate; 240.030

Posts: 6

Participants: 4

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