Firmware to drive X-Y galvanometer

... I'm using fiber-lasers with 1070nm wavelength and much better beam-quality (smaller possible spot diameter) than a CO2-laser.

This cheapish chinese galvo-scanners and drivers aren't really meant for precise application, but your image shows a totally 'overdriven' system ... try to reduce the scanning speed to something around 15kpps or even lower.

My galvos were stated as 25kpps-types, but were only usable with max. 20kpps.

And with the servos as scanner motors I'm much slower than with galvos (something around 1m/s compared to 20m/s) but much more accurate/precise and beter suited for high power laser applications ...

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Viktor
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Thank you so much. Fiber laser is the best choice.

i bought a not standard galvo, the potentiometer is opposite of standard, and the supplier didn't send manual for me. I turn wrong adjustment potentiometer, and now it so terrible @_@.

I use arduino mega with marlin firmware to control galvo, and i don't know exactly how many speed of it (kpps). I think clock speed of arduino mega 16MHz don't have enough for galvo. Maybe i will think about servo, galvo prefer for laser show than precise application. What kind of servo you use?

I want to make some loop for gcode but i'm not a programmer. I read that reprap firmware have a mcode for loop ( M41) but i don't see the code @_@.

This is my board, i use mcp4922 and TL084.

... I have really expensive geared DC-motors with 500x-encoders, so 2000 'clicks' per motor-rev, but 400000 clicks per mirror-rev, so something like 0,0009 degs resolution.

But most encoder-servos should do it when enough accuracy+speed and an appropriate controller ...

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Viktor
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Hey VDX

That is a very very nice setup, had no idea you can use normal steppers, kinda obvious when you think about it...which I didn't.

What are you using for mirrors?

My interest is a very large 1M x 2M SLS bed

Since you've moved to steppers, what "format" do you use to generate your "toolpath" and convert in PWs?

... the mirrors are surface-coated metal mirrors out from old copiers.

My 'toolpath' is - "Pictures by PC" as CAD/CAM, exporting the NC-code as Isel NCP and processing it with Editasc10.

For a really big working area you'll need a laser with superb koherency and/or gigantic mirrors for a diode setup, as the focus quality is linear depending on distances and diameters in the optical head -- e.g. with a beam diameter of 8mm at the focussing lens in 15mm distance to the diode I'm receiving a really 'bad' focus of 0.4x0.01mm in 150mm distance ...

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Viktor
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Hi, Vicktor.
I solved most of my problems of galvano software by you! Thank you.
I want to ask some questions, since I don't know anything.
1. I'm trying to use
[www.aliexpress.com]
this galvano scanner. and it would be okay? how much will be the active range?
2. What board should i use? arduino shield?
Thanks.

... the galvo-head is OK, but the mirrors are designed for CO2-laser wavelength -- which laser do you have?

You'll need a high-speed analogue driver with up to 16Bit resoultion, what's not possible with an Arduino ... I'm using a dedicated driver for ILDA lasershows, but you can find proper electronics for this scanners at the manufacturers site too.

My PC-software is BeamConstruct with a self-programmed driver (here you'll need a programming license for 500€) ... check, if you can find a driver already installed in BeamConstruct, this would be the best way ...

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Viktor
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hello, vicktor. I'm having serious problem of my sla printer hardware.
I tried to use the galvo head at my previous post, but it's too expensive.
well, so i don't have what servos, mirrors, and how should i connect the mirror to the servo//
also, if you know a cheap galvo head, please notice me...

... look here - this are common galvos with drivers for show-laser applications, but the smaller/cheaper systems could be good enough for scanning UV-lasers too:

[www.mylaserpage.de]

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Viktor
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VDX,

I have a Synrad DH marking head that uses the ISA FLCC controller card. However, I have no software to run it. I noticed you were developing a driver for beamconstruct for another project. I was going to do the same for the DH head.

I can find info for plug in development for Beamconstruct, however I cannot find any info on driver development.

Beamconstruct is nice as it has built in slicing intended for laser use. Controlling the FLCC is easy, but a driver must be developed for Beamconstruct. SImply streaming XY coordinates in hex to address 330h is all that is required for positioning.

Can you possibly point me to some info on driver development for Beamconstruct , or possibly offer some help in this endeavor?

I imagine one of the existing drivers could be modified fairly easy if the source is available for at least one that is close.

It would be worthwile to develop a driver for this older hardware as it is becoming more available to hobbyists as companies replace them with newer equipment.

Thanks for your help in advance, and any is much appreciated.

Regards

... you have to program a flow-plugin with the DLL-calls for your specific controller board.

I've done this then for an USB-controller called "Easylase LC USB" - specs stated here: [www.mylaserpage.de]

You'll need the programming license for this, which is not free ...

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Viktor
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hey vicktor
I'm finally trying to buy a galvo system.
so, can you help me please?

okay if you search"40kpps galvo" at ebay, some galvos are there which i'm trying to purhcase.
um... so please make me a list about the best one to the worst.
there are some requirements; above 25kpps(i would really like 35 or more)
and.... cheap. I just do not want to buy over 200 euro/// and please add the postage at the price.
oh! also which laser can i use? which progam shoud i use to control the galvo board??

if you read this, thank you, and if you may make me a list... I will be very thankful to you haha

Edited 1 time(s). Last edit at 01/10/2015 11:19AM by geniouskotaro.

... I've only tested the chinese galvos for comparison and playing with the idea of a cheap system -- so no real experience with types or vendors ... my other galvos are from comercial systems.

For using diode lasers with galvos you'll need proffessional beam-shaping equipment -- so better get a CO2-gas-laser or an older NdYAG or fiberlaser, if possible ...

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Viktor
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d

Edited 1 time(s). Last edit at 01/11/2015 07:33AM by geniouskotaro.

hey vicktorrrr
cna i use 405nm 20mw blue laser [www.ebay.com]
at this? [www.ebay.com]

Quote
geniouskotaro
hey vicktorrrr
cna i use 405nm 20mw blue laser [www.ebay.com]
at this? [www.ebay.com]

i'm going to use at sla printer, so is the laser strong enough to cure the uv resin using a fast galvo?

... no, this diode is not strong enough and with a very bad beam profile, so the focus shape in distances bigger than 100mm will result in a distortet oval, not in a spot! - this 405nm-diodes can be found with powers of 200mW or 300mW, removed out of BluRay-writers ...

First comefcial SLA machines used HeCd-gas-lasers with a really good beam quality and focus distances of up to 500mm, I'm getting big problems with 2W@445nm-diodes and 150mm

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Viktor
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Just to keep littering comments in all the threads I'm reading I had this idea:
To deal with different focus points maybe you could move the mirror while rotating it? So while you are rotating the mirror also moves closer to the laser in order to reduce the length of the beam. Of course the mirrors would have to be larger. Not sure if it can actually work, but maybe it's as simple as attacking the mirror on the outside of a drum. You would of course also have to adjust the coordinates in the firmware to deal with this "moving mirror".
EDIT: Upon further reflection (pun intended) this idea would never work! But moving the laser might.

After seeing the coils used on the peachy printer (and the link above) I wonder if it wouldn't actually be rather easy to build your own cheap open loop galvos.

Thanks for all the info in these threads!

Edited 4 time(s). Last edit at 04/05/2015 01:21PM by Dejay.

Viktor, I know this is an old thread, but I was wondering if the custom driver you made was for the Lasershark? I have one of these boards, had it for a while. If the driver for beam construct is for lasershark, would you be willin to share with me? I'm willing to pay if need be. I just feel the lasershark hardware is great and is perfect for this!
Thanks,
Adam

Quote
VDX
... the galvo-head is OK, but the mirrors are designed for CO2-laser wavelength -- which laser do you have?

You'll need a high-speed analogue driver with up to 16Bit resoultion, what's not possible with an Arduino ... I'm using a dedicated driver for ILDA lasershows, but you can find proper electronics for this scanners at the manufacturers site too.

My PC-software is BeamConstruct with a self-programmed driver (here you'll need a programming license for 500€) ... check, if you can find a driver already installed in BeamConstruct, this would be the best way ...

Hi Adam,

no, it was for the "Easylase LC USB" - [www.mylaserpage.de]

... and the SDK needed to program BeamConstruct-plugins is free, if used for non comercial projects

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Viktor
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Thank you for the answer! Is the driver now included in beam construct? I am far from a software engineer. Lol

Adam

Hi Adam,

no, this was a 'private session' for my last employee and not finished completely, so status of a 'working prototype' ... and now collecting dust in my basement

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Viktor
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Hey VDX Im try to Build an Sla Printer for School i don't wana go the easy way With a 500 dollar beamer istead i want to go With a galvo and a Fiber laser i read throu this treat and i was wondering which one was the best galvo from [www.mylaserpage.de] : The kn25 The Litrack or The Raytrack 35+ . I think for controll i settelt on the Easylase LC USB (it woud be great if you coud upload the Beamconstruct Drivers for it ).
thx

-Sammy

Edit:
I want to use this Laser : http://www.kalecnc.com/index.php/product/405nm-600mw-uv-laser-module/ woud that work and if yes what kind of lense woud i need ? thx

Edited 1 time(s). Last edit at 10/03/2016 09:12AM by Speatzle_.

Hi Sammy,

my BeamConstruct plugin was a bit special and not completed for "real use", so not simply adoptable to other systems.

Maybe the Helios DAC could be a better alternative - [pages.bitlasers.com]

The 405nm-diode could be good enough, reading the specs ...

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Viktor
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Im actually most worried on what galvo to use because i know that the laser works but i have absolutely no experience with galvos.
thx

-Sammy

... I tested with the cheapest available chinese galvo-set, which was sold for around USD200 - and I've got it for 100 Euros as used. It worked with my changes, what was mostly higher pixel counts (50k instead of 3k) and much slower moving speed.

But the 6mm-mirrors were too small for my 50Watts-laser, so I changed them to 10mm, and later to 15mm, but too shot them in pieces ... so changed to servos and 45x40mm mirrors.

For the 405nm-diode the small mirrors are stable enough -- but for beter focus quality you could too change them for 12 to 15mm ...

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Viktor
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I don't get how the size of the Mirror makes a difference. coud you explain? that woud be wery helpful.
thx

-Sammy

... an expanded/wider beam will give a smaller focus ...

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Viktor
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How about voice coils to drive X - Y scanning?

... this was done for simple testing too - you'll need something with high accuracy, speed, "traveling way" and linearity ...

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Viktor
--------
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Call for the project "garbage-free seas" - [reprap.org]