Cutting wrong tolerances/dimensions

[TobyChick]

I am constantly having issues with my Koenig K1325 cutting wrong dimensions/tolerances when cutting multiple identical parts on the one sheet. Its randomized from sheet to sheet in terms of where it goes wrong. I have ensured sheets not moved, we have replaced belts, replaced sprockets and yet still getting random anomalies as if the software is sending the wrong sizing. Seems to make no difference between sending the drawing directly from the PC or sending it to the machine first.

[Kuth (Luis Jardim)]

@TobyChick

Koenig K1325

This is a huge machine!!!

@TobyChick

Its randomized from sheet to sheet in terms of where it goes wrong.

Generally, this leads to a mechanical problem.

@TobyChick

I have ensured sheets not moved, we have replaced belts, replaced sprockets and yet still getting random anomalies

In small machines, I usually advise reducing the speed to see if the problem is related to sudden movements. Sudden movements can cause these types of anomalies.
Is the type of error in the dimensions always the same or does it also vary? For example, is it always 1mm (0.04 inch) or does the error value vary?

After this happens, if you point the laser head at a specific point, will it go exactly to that point or will it be misaligned?

[ednisley]

@TobyChick

as if the software is sending the wrong sizing

If this is a Ruida controller connected by USB, then that’s entirely likely.

While you can try various USB tweaks, the bottom-line advice is to use the controller’s Ethernet connection.

These discussions explore (in grisly detail) what to do for both Windows and Apple PCs:

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Now, if it’s already using Ethernet, then other problems rear their ugly heads, but let’s rule out the obvious cause first.

[Kuth (Luis Jardim)]

@ednisley

If this is a Ruida controller connected by USB, then that’s entirely likely.

I had no idea about that!

I always thought that if there was a faulty communication, it would cause an error in any type of machine.

[ednisley]

@Kuth

cause an error in any type of machine

It certainly will, but Ruida controllers seem to bring their very own heartache to the party.

USB was designed for “desktop” devices, not high-current machinery like lasers, and lacks the noise immunity required for “industrial” applications. That many of the controllers are, shall we say, under-engineered doesn’t help at all.

[Kuth (Luis Jardim)]

I’ll try not to forget!
I’m thankful for the clarification.

[TobyChick]

I have switched it over to ethernet and see if we get a different result. Thanks for the advice. Here are some misalignment examples - the external dimensions are all right as are the dimensions of the slot ID’s but their alignments are all wrong. Its strangely randomized - meaning cuts further into the sheet are right so it’s not like it’s all wrong from a certain point or that the material has moved.

[ednisley]

@TobyChick

their alignments are all wrong

Assuming the machine has a Ruida-flavored controller (what’s the model number?), this could be a perverse instance of the PWM Rising Edge Valid mis-configuration:

Slanted Or Skewed Job Results - LightBurn Documentation

It usually affects the alignment of engravings w.r.t. vectors, but can clobber pure vector layouts:

Image shifting and bunching up but cut out is OK

Red-Black 90w Laser Ruida controller engrave 400mm/s 25% Fill 450mm/s 20% Cut 25mm/s 65% Birch ply held down pins belts are tight so are stepper motors When doing a engrave/fill and cut I get the fill shift while the engrave bunches up, cut out in just fine. This is repeatable, and all come out the same, like it was meant to be, how do I attach image?