Help with squaring lr4

LowRider CNC Advice
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Hi everyone, i need some help with squaring, as my first couple of attemps are throwing me.

I have taken the machine and homed it. The router has a v bit in it for ease of marking the point.

I lower the z until it touches the spoil board and mark the point.

Track x all the way across till it hits the far side. Repeat lowering z and marking.

Then i send it all the way to the other end less 100mm or so otherwise im off the edge of the spoil board with is a full 8’ x 4’

Repeat lowing z marking and then home x and marking at that side too.

There is currently 5mm of skew in the direction shown.

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20241207_1328291920×1440 370 KB

I have tried changing y motor 1 pull off by adding the 5mm to the pull off mm, so from 4 to 9 and the results on the next test were well off.

Am i changing the right side? Do i need to split the diffence or change it profressivly and keep checking?

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https://docs.v1e.com/lowrider/#initial-squaring

Have you had a look at that section in the docs? There’s also a video that is super helpful right below it.

I could be wrong, going from memory here, I think you add the extra pull off to the longer side.

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I understand the process but whats classed as the longer side when i measure diagonally?

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Well, good old ASCII art…

So take Y Max as up and X Max as right on your screen.

If the / measurement is longer, you need more pull-off on the left hand side, closer to Y Min.

If the \ measurement is longer, add it to the right hand side.

Naturally, subtracting from the other side is also possible.

The diagonals measurement enhances the out-of-square amount, but the actual amount of change gets diminished because the belts are outside of the cut area. Using the amount of the difference as an adjustment is a fudge, and isn’t guaranteed to get you a correct result, so you keep repeating the process. Some time ago, I did a CAD drawing that you input your machine parameters (Namely distance between Y belts), the Y length of your rectangle, and entered your diagonal measurements into and it would tell you how much to adjust by. It’s in the forums here somewhere…

How to: Square your Lowrider by adjusting the end stops with M666

Right. There it is.

Edit: M666 is the Marlin method of adjusting pull-off. We do it more individually with GRBL/FluidNC.

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Hmm, not sure how I missed this that post. I’ll try that out the next time I need to re-square. Thanks Dan!

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The side with the larger number is longer

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closing old topic to help fight spambots