Testing Max Workspace & Diagonal Issue (?)

Hi All,

So I ran a test because I’m going to be trying to maximize the usable workspace on my A350.

In Luban, I used the square tool and made the following pattern:

Each square is 10 mm larger than the previous and I centered all of them at (0,0) coordinates. There are 5 mm between the lines of the squares (with the exception of the smallest square which I made 5mm. They proceed to 10, 20, 30, etc. afterwards)

The vertical and horizontal central lines I manually dragged to 367.4 mm.

The diagonal central lines I manually dragged to 550.9 mm in length.

On the machine itself, the two Y rails are ~13.5 inches apart. I cut a piece of carboard into a ~13 inch square (more exact measurements put it at 328.61 x 331.8 mm) and put the slightly shorter dimension running along the X-axis to give that little extra clearance between the Y-rails and stock.

I aligned one edge of the cardboard to the back of the laser platform so that it was flush with the edge. I wish I had made the Y dimension longer but hindsight and all.

I have the 10W laser and I used the 200g cardstock setting reduced to 30% power (remainder of settings the same), 1800 mm/min workspeed, 1 pass.

To avoid figuring out the exact center coordinates of the platform (and because I havent used the console commands before this (though I did play a little in prep)), I used camera capture and let the burn happen as it would, i.e. no re-positioning from the coordinate specified squares all centered on (0,0).

Here was the Luban preview with camera capture (remember the top in this pic is aligned with the back of the laser platform, the blue tape wrapped underneath):

Here was the result of the burn:

The green square is the first 10x10mm square, every square after is an additional 10 mm on a side.

If you notice, the diagonal line running from top left (TL) to bottom right (BR) is off from the center by about 9.7 mm (small red circle near center). Even the opposite diagonal line that does hit center perfectly quickly veers off its anticipated path. The larger red circles show that the diagonals did not follow the corners of the squares as one might expect.

Question: Does this highlight a possible issue with cutting diagonal lines? Would my issue be in the Y or the X? Or is this possibly an error of work speed being too fast for such a cut?

Regardless it doesn’t explain the TL to BR line being displaced so badly. The toolpath order was vertical mid line, horizontal mid line, TL to BR diagonal, BL to TR diagonal, then squares from smallest to largest. Any thoughts on this are greatly appreciated. I did upgrade my rails from the original A350 if that’s relevant.

Okay back to the other measurements.

The center line on the bottom blue tape extended beyond the largest square by an additional 18.6mm, as well as an additional 7.2 mm above the largest square at the top (visible in previous image):

Counting the lines of the squares and adding in the additional overshoot of the mid-line, I came up with the following workspace the 10W can definitely reach:

X 334.1 mm by Y 380.8 mm

There may be a little more play in the X as the final on-stock line had 4.1 mm to the left edge, but I’d wager it isn’t more much more than 335 max. Interestingly it seemed to have more off-bed range on the left side (toward the machines home position) than the right - I base that on the central mid line which stopped before the edge on the right side of the stock (despite going farther in Luban) and went off the edge on the left side of the stock.

I am hoping these dimensions are consistent for the space the CNC can reach, because that is ultimately what I am hoping to maximize along the X dimension to cut circular frames for a 12 inch mirror.

Regardless, if positioned correctly, you can definitely exceed 320 mm on the X-axis.

Welcome all thoughts and any other tests you may have done supporting or refuting my results.

Cheers all!