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View Full Version : AWC708C or Light Object X7 DSP auto focus



Tim Klus
03-16-2017, 10:23 AM
Hey Guys,
New to the forum and am working on my first CO2 laser build. I am hoping to wire up the electronics this weekend and am curious if anyone has set up the autofocus on this DSP controller. there doesn't seem to be much documentation on it. there is some info in the manual that tells how to enable it but it doesn't talk about what pins need to be used on the control board for the inputs.

I received an email from Marco (light object) and he said I have to hook up both limit switches for the Z axis but didn't really elaborate and was not very clear.

I am curious if it just uses the Z+ limit switch as the "focus" switch.

Thanks!
Tim

Tim Klus
03-21-2017, 4:57 PM
Hey guys,
Guess no one is using autofocus with these controllers? well I contacted the company that makes this controller and they sent me a document that describes the inputs and outputs. I don't see anything that talks about autofocus but it does have the pinouts for air blow which will be helpful.

I am wondering if the Z axis plus limit switch is what is used for the autofocus. I will be wiring everything up soon and can test that theory. I have attached the document. hopefully it can help someone out.

Thanks,
Tim

David Somers
03-21-2017, 5:39 PM
Tim,

There are bound to be a few users who make use of Autofocus, but for the most part I think most who have tried it have decided it was not worth it, and not very consistent and reliable. I think...and I could be wrong....that most just make use of a spacer guage set to the focus point of the lens they are using. Dirt cheap, simple, reliable. Have you done a search in the forum on the word "autofocus" or "auto focus"

Dave

John Noell
03-21-2017, 6:45 PM
Yep, tried it, took it off my Epilog. (If the plunger misses the work slightly, goes thru a hole in the honeycomb grid and brings the table up, crunch.) Now, I mostly use a stock Chinese red pointer (angled from one side) and a line type LED pointer 90 degrees around tube. When they both touch, the surface of the work is in focus. Quick and easy. (I do check now and then with the spacer just to be sure.)

John Lifer
03-21-2017, 10:23 PM
I use mine occasionally, but I've gotten used to the spacer it is SAFER! Just as John Noell said. The limit switches for my Z are for stopping either the auto or manual from going too high or low.
When I use the autofocus, it sets an separate calculated -Z limit a few mm above where it automatically sets the focus distance. You can't go higher than that without reset or re autofocusing.

Sam Rodriguez
09-29-2017, 8:55 PM
Hey Guys,
New to the forum and am working on my first CO2 laser build. I am hoping to wire up the electronics this weekend and am curious if anyone has set up the autofocus on this DSP controller. there doesn't seem to be much documentation on it. there is some info in the manual that tells how to enable it but it doesn't talk about what pins need to be used on the control board for the inputs.

I received an email from Marco (light object) and he said I have to hook up both limit switches for the Z axis but didn't really elaborate and was not very clear.

I am curious if it just uses the Z+ limit switch as the "focus" switch.

Thanks!
Tim


Tim,
Im endeavoring to do the same thing. All with not much to go on. I have scoured the internet for crumbs... Also Im afraid after all this I may to be disappointed in how the autofocus feature works in / on the machine.
Also, I was thinking why not just create a separate auto focus feature. like a separate circuit containing limit switches for the upper and lower Z height along with the height sensor Capacitance type. All connected to a Arduino or Rasp pie. a little software code and with a switch you could turn it on / off and or set a height position to maintain. Fire up machine insert part to be cut engraved etc... engage hight routine..... once satisfied start the laser..... done... even better. auto height... put in a curved part. let the Arduino keep track of the height. (YMMV depending on the part being cut) but it should be pretty easy to do. you in? Im gonna work on it no matter. let me know -S

John Lifer
09-29-2017, 10:09 PM
The issue that I have with my 50 and the 35mm focus length lenses is that with the stock tube and cone there is about 6-8mm between cone and the workpiece. And a millimeter does make a huge difference. Nothing that you get will be within a half a mm tolerance. Nothing. You can't make the z movement that accurate without spending bunches of money. no arduino or rasp will work. And forget capacitance, tolerance is a couple of millimeters and there is a lot of metal around to throw that off. Just do what we all do and use a piece of wood or acrylic for a gauge.

Sam Rodriguez
09-29-2017, 10:26 PM
@JL you said "NOTHING" that word is my kryptonite.. I hear nothing I work harder. sorry but your wrong. My 3d Printer is capable of getting .001 even if I get 1/10th of that Id be happy. If I stopped trying the first time I heard those words? Id be a loser with nothing to show for it. I won't say anymore as I know a flaming war when I hear one coming. Im okay with you believing its impossible . just not me "PERIOD"

-S

Dave Sheldrake
09-30-2017, 12:32 AM
set your focus exact on a test piece slip (like a piece of MDF that tends to be very flat and stable)

Fit a digital vernier rule to the Z axis,, set your zero on that, use that as your focus from measuring the materials

I have auto focus and copy follow on different lasers of mine and only ever use it on the metal cutters

Sam Rodriguez
09-30-2017, 1:32 AM
I seen another piece of equipment that used a similar technique only it used a a magnetic sensor as the slave. I think the same principle your talking about. Could I encourage some pics of one of your setups?
My controller is a X7 While I have heard good things about it I had not heard or witnessed any good portions relative to the auto focus portion. in fact little to none even from the supplier. not a schematic or logic.
down the rabbit hole I go! -S

John Lifer
09-30-2017, 11:07 AM
Go for it Sam.! I'm not about to start a war. Just telling you your are chasing your tail for no gain other than to say you did it. Just let us know when the z axis drives the table into your nozzle, k? Way too easy to use manual check. Dave has great idea for scale BTW. It's just that some things aren't worth the time, and money.

Sam Rodriguez
09-30-2017, 11:13 AM
@JL, All my success's are easily identifiable just look for the trail of failures. and I will. And I do agree manual check is so simple why even spend time using auto focus... well for me? because I can't ever leave well or easy enough alone. thanks for the warning though :) -S

Kees Soeters
09-30-2017, 4:39 PM
Just read this topic..a bit late maybe, sorry for that.
But i use the autofocus for every single thing i laser. I'm Lucky to had my hands laid on a programmable Ultrasonic sensor (distance 20-150mm) this has almost the same accuracy as a proximity sensor but works on all materials except felt (but you can lay a piece of paper on top to autofocus.
Before i used a proxi with a "iron reference block".
Before i se the autofocus i have to manually lower the bed enough. Place the material on it, move the sensor somewhere above the material (with the cursorkeys) and press autofocus.
The bed will raise till the sensor is triggered. At this point it will be perfectly focussed.
Yes, i have my sensor connected to Z+. And yes, after switching on it will only home in X and Y direction.
You have to checkmark "Use Z for autofocus"
This works perfect, every time.
Any questions? i will answer your PM
Kees