Z control for Galvo

LightBurn Software Questions
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Hey G’day people,

For the LB software engineers,
I see this question has been asked a few times but there was no real definitive reason as to why or why not this could or couldnt be implemented.

So we all know the board that comes with most galvos is not a lot to talk about so not asking for the impossible from the board itself but rather for those of us that have an external controller for raising and lowering z axis and for using the rotary which is controlled by another controller via the general fiber laser builds.

So my question is this in Lightburn, we can micro control the rotary move left move right we can micro manage the splits.

Now if we can do all this with the rotary why cant we just do the same with z axis?

Before anyone says awww we have hashed this before can’t do it.

A great introduction to the list of many things we can do with Lightburn was the cleaning pass - full cleaning pass and partial cleaning pass.

We have a simple on off switch you ether want to use one or the other then a simple add a number how often you want to do your cleaning pass, every 1 4 10 or whatever passes.

Great so thats out of the way.

How about the same principle for Z control, a toggle do you have a z controller Yes. Excellent how many micro mm do you want to step down each pass… .1 .01 .001 etc.

If you could please tell me why this wouldn’t work, if you can determine a cleaning pass every x moves why couldnt you do the same for Z control?

Z control could be limited to say 2/3/4 mm so we dont get stupid entries and they could be limited to micro control only numbers say .1 or less to a number that would be practicable and workable?

Would love an reasonable answer for this not a generic nup cant be done.

And if its just a question of coding time (because it takes too many hours to do this not worth our time) an honest reply to that would be appreciated as well.

Cheers avagreatday all and greetings from the colonies downunder.

Just as a by the by I have sat there while my laser was working doing a 2.5d engraving for an hour or so just tapping the button every 20 or so layers moving the galvo head a hair depth down. The result was exceptional in comparison to just leaving it rely on its focal depth depending on the lens your using. But who wants to stand there for an hour plus tappety tapping on the button.

There is a difference and the price of the dynamic focus galvo heads are off the planet at around 5000k USD thats not good value and exludes probably 99% of the rest of us galvo users.

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Z control isn’t strongly supported in EZCAD2 based devices - and the vast majority of galvos do not have Z control abilities (in software) as a result.

With a small dev team, we must focus on the features that affect the largest number of users. Z control simply isn’t the top of the list at this time.

With that out of the way, I hope this honest reply satisfies. We do have a Feature Request page (hyperlinked) that already has this suggested - you can vote for it here: Live Z Axis on galvo laser · LightBurn

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Hey Colin,

Thanks for an honest reply, I was rather hoping that with existing code that you have eg the cleaning passes that there might have been a way to leverage that.,

But fair enough… ty

As a by the by I have no idea but I cant log into that link you sent me. On perpetual logging in… I even switched off my vpn not happening not to worry.

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Why not just use a Nano or PicAXE controller and a relay to do this for you? A pot to control the time delay is all the control you would need.

Your Lightburn login does not work. You need to create a separate login for Fider.

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MikeyH well thats thinking outside the box… good idea…

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I am seeing a strong need for a way to do Z-steps. I’m experimenting with how successful the 300w MOPA is at cutting sheets with significant thickness. I keep going out of focus. Other than that, the main prob is the cut will slant at the same angle the beam is taking from near the center of the galvo lens to the cut, so the slant gets more pronounced the further the cut is from the bed’s center.

I do see how it would not be that straightforward to implement. My hardware doesn’t have a Z-motor.

One thought was that it doesn’t necessarily NEED to be implemented in the BJJCZ. It’s a very simple step command that happens outside of each pass, it’s not dynamic. So we could in theory have a separate ESP32 on USB getting told to issue a step pulse.

That does make some sense, because the Z also needs a manual up/down and it sure sounds nice to implement a TOF range finger to adjust the focus. But that sounds far beyond what the BJJCZ could implement, so pretty much the whole thing would be moved to an ancillary system anyways.

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Dannym,

Well this is my argument as well, there are many things that can be leveraged having a stepper controled Z Axis. Its an easy build, using the 4 pins on the back of I dare say every fiber laser out there which hooks you up to a rotary, whack an aeroplane plug (as I call them) and take the wires to a normal stepper controller give it some power add a power supply to the box, a couple of buttons and up and down she goes.

But because nobody explores beyond ahhh what do I need a motorized z for when I can wind the handle just as quick.

The code my belief is already there, whats the difference telling a rotary (which is a more complex set of codes) to do lots of wonderful tricks turn come back remember where you were last, steps, line width etc etc.

There is code already there that every X passes do a full or partial cleaning pass, no whether your telling the laser to do x y or simply now move the z distance down by .o1 whats the difference.

Your quite right regarding the cutting something Ive never really thought about because we jerry rig that with WOBBLE, lets just make the cutting wider to allow for this or that.

We dont need to hook into the fiber lasers mother board if the facility isnt there so be it. But we could be a little more inovative with other things."

At least I got an honest answer, sorry to much coding time not much interest and yup, click here make the suggestion, but the annoying thing there is to make a suggestion you have to make another login (right yup we all want to do that dont we) something else to remember, so you can well imagine people who have an interest in sharing an idea or asking for a request, (I admit like me) yup you know what Im not making another login when it SHOULD BE A PART OF THIS FORUM.

So things go no where, which is convenient and I say deliberate… but thats only my opinion.

Don’t hold your breath, unless people take up on the topic and start thinking outside of the box it wont grow legs.

The coders could though be a tad just a little bit more progressive and say you know what we could maybe do somethings with that rotary port not just x but as you suggested cutting, as well.

Sorry people not trying to be nasty I just have a different way of expressing myself.

Nice call anyways, love the idea!
Its not hard to implement my belief.
Same as it wasnt hard to add full cleaning passes instead of partial cleaning passes.