irregular machining

I am machining some clamps from a perfectly squared stock.I do an adaptive 2D contouring. I machine the top part and then I turn it over to machine the part that was previously held by the clamp. The measurement comes out perfect after machining but it has a kind of offset. In theory, since the stock is a symmetrical rectangle, when turning it over it should cut in the same place, right? Can someone tell me what could be the cause?

Have you checked squareness of the part, using a micrometer measure the height in the 4 corners. It dosent look like a machine problem more like a clamping/squareness or misalignment issue. Unless you are loosing steps....

The piece is perfectly squared, I don't think it's the loss of steps, I have hybrid motors with encoders and I use very slow speeds.
I'm going to check that the clamp hasn't moved.

M4MazakUser wrote:

Have you checked squareness of the part, using a micrometer measure the height in the 4 corners. It dosent look like a machine problem more like a clamping/squareness or misalignment issue. Unless you are loosing steps....

Indeed, today I checked the perpendicularity of the clamp and the truth is that it was not right, that is why there is this misalignment in the piece. I have aligned it and now it works perfectly.

Thanks!