Surveying table flatness

[v3juggler]

Hi!

Theoretical question here

It would be cool to know how badly your table is uneven and I was thinking that my ender is doing exactly the thing, so… would it be possible to add probe like the one ender has and measure height in dozens o places to know what kind of difference we’re talking about?

Also how one would take those data out of the board?

cheers,

EDIT:

obviously I have found key phrase to search just after creating this topic! surface mapping! yes?

[Michael_Melancon (Mike M)]

There was a thread about this recently.

Mesh Spoilboard mapping

Hi all - i’ve got my LR4 running on a tortion table and i was wondering how flat is it and can i fix the high or low spots in software? I’m working on a script that probes the spoilboard at whatever interval and can compensate for high/lowspots by altering the gcode. (Using the telnet port to send and recieve commands in python) Here’s a snippet of a 600x600 square i probed and generated some visualizations of the bed (i intentionally made point 1 a little high to emphasie the heat map. Stay t…

Not sure if the project was ever completed

[v3juggler]

Thanks, Mike! I’ll use the other thread

[dgkeith237]

So - for me the most important thing is that the spoilboard is coplanar with the spindle plane of movement. And with a CNC, you can just surface the spoilboard to ensure this is the case. I’m not sure a surface mapping routine would carry the same value.

Obviously with wood movement, there could be changes over time, so a surface mapping routine to tell you when to re-surface the spoilboard could potentially be helpful?

Also - my spoilboard is only flat the day I install it, after that it has grooves all over it. I wonder how that would effect the mapping, unless you could ensure none of the measurement points occurred in a groove.

[v3juggler]

I just started to think about carving, and I will need to surface my spoil board. I’m afraid that step down of 0.5mm may become 10mm 2500mm later - and I thought it could be useful to run such survey to know where to start your surfacing.

Anyway, as I said it was just theoretical question - I will just crash course it

[Michael_Melancon (Mike M)]

@v3juggler

and I thought it could be useful to run such survey to know where to start your surfacing.

I just used a 6ft level as a straight edge to rough guesstimate where my high spots were.

Marked it, Zeroed my Z height at that spot, and then just ran the surface job at 0.5mm down.

After that, I at least knew it was all knocked down, and surfaced it again in increments until it was all done.

Just scribbled in pencil over the whole thing and surfaced til the pencil was gone.

Surfacing isn’t quick, but running an extra surfacing job is probably still quicker than developing something that can accurately tell you where the high point is first

[barry99705 (Barry)]

I used different surfacing directions each time. That way you can see the pattern.

[Bigfoot16 (Dan Harley)]

I just surfaced my spoil board with a cutting area of 1225 X 2570. I used a 1/2” dovetail bit, 1mm DOC, 40mm/s, Kobalt router speed 4. It had no trouble at all with that bit . I started at 20mm/s and kept increasing the speed while cutting until I was comfortable with everything. I used the GCODE Generator, so the cutting was all from one direction. Time to finish was just under three hours.

My method of checking high spots on the spoil board started with a 4’ level. Checked X and Y directions and marked high spots. Then I probed a few high and low spots in various places to calculate how much I needed to remove to get a flat surface.