Z control for Galvo

LightBurn Software Questions
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81

You are right on a number of fronts there, they do claim compatibility with Lightburn lol…

The diode portion of it works :slight_smile: which is something.

Their software is no where near the quality of LB but having said that it does do a good job when slicing a depth map.

Yes it took nearly 12 hours to engrave a 40mm brass coin but having said that it did an exceptional job if not a better result than one would have gotten with LB.

Reason I say that is their software allows for the z height to be dropped by various ranges but it will allow for a 0.01 drop per layer so if you work that backwards through 256 layers about correct weight and the coin did look super nice.
It was a deep engrave nothing missing it was just slow for a low powered unit which is being tested it was more than ok.

So I hear what your saying gcode allows for z drop..

My argument is that LB operates a rotary.. same thing Z drop or Rotary there is no difference as far as the stepper is concerned it moves it left or right or up or down.

So if LB can operate a rotary left or right but we have the rotary port hooked into a stepper driven tower raising and lowering the tower for us lazy people that dont want to wind it up or down.

So LP5 has in its software slice the greyscale and then by what increment do you wish to move the stepper down after each slice.

LB can move the rotary left or right as well why cant it be written by the mighty coders that for every slice we do the same move the stepper to lower Z by 0.01 or 0.02 I cant believe that this is that hard or out of the relms of possibility??

I have to date not heard an argument that says it cant be done.

The benefits to Galvo users is enormous!!! I dont know if you realise how big an impact that would make for fiber laser users.

Its almost like having a 6k fealtek galvo without the active focus and apart from the fealtek being sooooooooooo over priced its not funny.

You would be able to do all your 2.5d work so easily it would be 1000% better than relying on the focal depth of the lens being used.

It would allow for much better use of a lower focal depth lens eg a 70mm and be ok for a 2.5d engraving due to being able to lower the z height in increments.

Yes no am I dreaming?

It sounds simple at least I am convinced it is until shown the boot in the behind and told otherwise.

I just cant see it not being possible you can control a rotary in exactly the same way already..

sigh…

82

I’ve implemented in my hacky in house software, works great. May end up making it available to the world after some code cleanup and usability fixes

83

Fins do tell more!!!

Arduino? Timer?

You’ve heard the term about curiosity and pandora. You have opened the box time to spill the beans lol..

How has it effected engraving etc?

Benefits any ? or none ?

84

That’s always the issue, but it’s not. Especially when you realize the lack of knowledge of the different control boards.

Each type of control board is different, so what you know about board A may not represent board B.

If you think the Lightburn people are not very bright, you can continue on down this path. If this was any kind of any easy fix, it would have been done, at least a couple years ago as this has been in discussion since the galvo version has been released.

I don’t know how you think the software would know it’s time to change the Z axes. From what I can tell the rotary on a JCZ board operates differently than other boards. As far as I can tell with the JCZ control board, there is little communications back to Lightburn.

We would all love this, if you know how the controller works along with how to simply implement a Z control, I’m sure Lightburn will listen and you should send an email to support on how to implement this. I’m sure they’d be delighted.

Maybe, maybe not… on the Laser Pecker 5.. they, apparently, can’t really control the rotary either on that machine.

@fins how does your Z control know when to step?

:smiley_cat:

85

Something to consider, the screw mechanism in the typical laser tower is pretty far from CNC quality. 0.01mm resolution is probably not achievable/ repeatable without some additional parts/work.

86

Fair comment but to buy another screw for the tower is a small cost an easy upgrade.

87

I would assume that fins would use a timer.

88

A quality ball screw assembly the correct length and a counter balance device. (And some fabrication!)

89

this isn’t really the case. you can get feedback from the controller. it’s less than optimal to wait for each individual mark command to complete to send the next one, but with batching lists of commands in a structured manner you can get a useful result.

I’m using galvoplotter’s spooler as a way to mark up until i want to step z, then step it, and start a new job on the spooler to continue marking; trivial for 2.5d stuff.
I agree a stepper on cheap ballscrew ain’t gonna cut it for a true 3d setup, or anything requiring a very high Z resolution. In my current 3d build I’m using higher end ballscrews and rails.
To get a true 3d cut (i.e. simultaneous fast positioning in x,y,z), the moving mass has to be minimal, so something in the optical path is the only thing that makes sense. I think I recall seeing an inline adapter available, specifically for adapting a standard galvo head, but it was in the $lol price range.

path planning, and the whole thing is written from the ground up to be 3d-first. it’s way easier to get 2d from 3d than 3d from 2d!

1 Like
90

I’d like to do this with my JCZ fiber controller… can you tell me how? A link to any documentation that explains this or is in use would be great.

That would mean a re-write for Lightburn, as it’s really 2d?

:smiley_cat:

91

wait_for_machine_idle is described in GitHub - meerk40t/galvoplotter: low level command system for ezcad2 lmc-controller galvo lasers as blocks until machine is idle, spooler must have fully sent, and laser must give a finished status.

get_list_status will get you the raw status, but the whole point of the library is to abstract this to usable levels.

Can’t speak to the internals of Lightburn, but it would appear so. I’m writing from scratch by necessity; within the year I’m aiming toward integration to my 6-axis robot arm, so writing ground up modular code that’s 3d first makes sense. Can’t see my use case being supported in Lightburn any time soon!

92

Thanks… I started reading it.

I know a re-write is not likely, but I’m not with Lightburn, so I don’t know what they have in mind. I do know this has been batted around ever since the galvo support appeared. If it was easy, I’d suspect we’d have it.

Thanks for the info… bookmarked it.

:smiley_cat:

93

Man ok,

We have in our 3dslice, a cleaning pass.

If we can send instructions to LB that after every layer do a full cleaning pass.

Surely we can tell the rotary port/ z tower move down xxx.

So we know there is a way to issue a command after every layer.

Why not after every pass do X …

If you can do it with the rotary its moot point to do it with z height .. Its a stepper motor be it whatever axis it doesnt care it gets a do this or do that command.

It doesnt matter how the JCZ controls the rotatary there is a communication of somesort.

94

Its more the case if enough people want it then they look at it.

Otherwise if you dont ask you dont get.

95

I get what you are saying about the rotary. Maxce IndexX uses the rotary port to move their linear platform using Lightburn on a Fiber with an Ezcad 2 board, so why can’t the rotary port be used to move the Z axis (if fitted with a stepper). This seem more a programing thing with lightburn, that if it can do it with a normal marking file why not a 3d file? If you have haven’t see the Maxce IndexX Maxce IndexX Set - Maxce | laser marking accessories and a youtube video explaining how it works https://youtu.be/-J6DHxKTJMQ?si=1ogBawFAY8wVczlB

1 Like
96

First, I’m a new laser engraver. I purchased the machine directly from a Chinese manufacturer on Taobao. My machine has a motorized Z axis and an additional driver for the fourth axis. It uses a clone EzCAD2 Board Lite. They claimed that the machine can perform 3D engraving, similar to 3D printing. This means that the program will slice the photo into 256 layers, and the galvo head will move down slightly after each layer or two.

However, I need to rewire the motorized Z axis from the original drive to the fourth axis driver. The original Z driver is not controlled by Pul Dir, while the fourth axis driver is. After that, I need to download another program called iirc LaserEmboss and configure the motorized Z axis as the fourth axis. LaserEmboss is another program based on EzCAD2, similar to LightBurn. After a few attempts, I managed to get the settings running smoothly.

As a machinist, I have retrofitted a few CNC milling machines, so I believe I may understand how they work. If EzCAD2 can control the rotary axis, it can certainly control the Z axis moving up and down. Since the software instructs the board to send the signal to the stepper driver as Pul Dir, it should be possible to control the Z axis.

If the LightBurn developer needs more time to add the Z control feature, and how much time do you think it will take, please let me know. However, please don’t make statements like EzCAD2 doesn’t support Z control, implying that it will take an eternity to add that feature. I would be happy to pay a reasonable price for the Z control feature, of course.

97

No argument from me there, the perhaps official word from LB is that not many people want this, making requests for addons is jumping the hoop. As you need a different login to make an offical request.
If linear works, rotary works, quack like a duck then it must be a …
Come on mr and mrs lightburn get with it.

Even the pecker things and new laser kickstarter models all are coming out with AI something Auto something else … a little z control would be nice.

It already exists for Co2!!
Hey G’day,

Thank you for buying into this topic its appreciated. I have held the belief that this is an easily enough feature to add.
I come from a CnC background as well.

Do you have a link for LaserEmboss? I’m sure others following this thread would be interested in seeing it as well.
Is laseremboss free or paid?
Cheers..

Common Mr and Mrs Lightburn bods you know we love you.
It seems enough people are interested in this feature to warrant the courtesy of a reply..
We promise to behave and not demand a beheading :stuck_out_tongue:

98

Do you have a link for LaserEmboss? I’m sure others following this thread would be interested in seeing it as well.
Is laseremboss free or paid?
Cheers..

Common Mr and Mrs Lightburn bods you know we love you.
It seems enough people are interested in this feature to warrant the courtesy of a reply..
We promise to behave and not demand a beheading