Z axis changes during a rectangle cut.

[DonCP]

I have cut rectangle with 1/8 carving bits many times with no issue. I tried using the 60 deg V and the finish of the rectangle dropped in depth and gouged the end of the cut.

Tried another with an 1/8 in bit and noticed that it is doing I a little now also.

Any ideas on what to check? only 30 hours on machine.

Thanks

[bergerud]

Did the bit drop in depth or did the board raise up? It seems more likely to me that the board raised up. (If that is the whole board in the picture, it would not have stayed under the rollers.)

[DonCP]

I had It in a Jig I had used before. I will try it again with the Universal Carrier.
I have done another with it but used an 1/8 in bit and shows the same thing except a lot less.
I will try this again with the UCB. Good experiment I think.

Thanks

[bergerud]

If the board is warped a little, the ends can spring up. Make sure it lays in flat.

[DonCP]

Based on your thought on the bit slipping I tried two things. Used another 60 Deg v Bit and your Universal Carrier instead of my old jig.

It worked! Thank you very much. Next carve will try the original bit. But will use the UCB from now on.