Can't cut squares

[Codajet (Steve Morton)]

New user to Pro 5 4x4 with VFD Spindle. I believe my machine is square and am aware of the post from the gentleman that designed the machine that says what really matters is that the y axis are generally parallel. However, when i design a simple 4 inch square and cut it out using a contour tool path with tabs it isn’t square according to the two different squares i have. its off very slightly. Any thoughts would be appreciated !

[WillAdams (William Adams (Carbide 3D))]

First, is the machine mechanically sound? All tighteners fastened? If you put a probing pin in the spindle and push/pull on it, does anything move?

If the machine is mechanically sound what material are you cutting? Using what tooling at what feeds and speeds? To what depth? If cutting deeper than half the endmill diameter, recommend adding offset geometry and cutting as a pocket down to tab height or the penultimate pass:

Best Bit for full cut through

One which has a cutting flute length equal to or greater than the thickness of the stock — pretty much any tool should work. Big thing is the toolpaths — if cutting out, rather than just cutting a slot: [image] Offset to the outside by endmill diameter plus 10% or so: [image] [image] [image] Then cut as a pocket: [image] down to tab height or the penultimate pass: [image] then move the contour down to below the pocket and start cutting at the bottom of the pocket: [image] and…

[Codajet (Steve Morton)]

Excellent suggestions. I have tightened all the various screws on the lead screws and stepper motor s. some were in fact slightly loose. That might fix it.

I am cutting 1/2" plywood with 201 cutter at provided feeds and speeds.

I will try the pockets path you describe and report back!

Thanks!

Steve

[WillAdams (William Adams (Carbide 3D))]

A further improvement is to leave a roughing clearance and take a full-depth finishing pass.

[Codajet (Steve Morton)]

So, I tried the steps reccomended and no joy. Over the course of a 4 inch square the cutter is drifting .09 inches. The x axis seems to be parallel to the base of the work material and it seems to be the y acid that is pulling to the left as you face the machine. I’ve uploaded a jpg that illustrates the drift.

The vertical line on the right is 90 to the x axis. You can see the vertical cut off the y axis on the right is drifting to the left.

If I put a square into the right y cut and draw a 90 line across the bottom you can see how it also shows the drift.

[WillAdams (William Adams (Carbide 3D))]

Let us know about this at support@carbide3d.com and we will work it out with you.

[Codajet (Steve Morton)]

So, it turns out the machine was not square. I undid all 40,000 screws to take it back down to the 4 cross bars and aligned them better. Works like a charm now. Perfect square cuts!

Thanks for the response and sorry for the false alarm!

Steve