My laser engraver from 0 knowledge to 32.461% .... probably

[BobbyW]

Hi Art. So what i understand , soon i found a proper step per unit , don't need to be in accordance with max accel and max velocity .
Ok i understand now, i will try soon i will go home . I assume that operation force me to put all the home and limit switches to avoid crash , right ? I have only on X the limit working properly , to lazy to put all  :-[ . So i think i will be forced now to finish .
Thank you for all the answers and i will let you know soon what mistakes i will do  :D
Thanks

[BobbyW]

Hi
I got home and i start some test. So , what i understand until now from my tests. The step per unit field , i figure out is the motor tuning according with transfer rate , multiplier , demultiplier , driver config , so i take a meter , i put on my table and i adjust the step per unit until i reach the same distance of showed on the auggie screen . I assume the machine and work coordonates are represented in mm .That's correct ? Also i draw a 800 mm line in vexx and i measure on my table the travel distance . I got the same 80 step per unit as my first config. I hope i don't talking silly.

Next : I figure out " at least in my head " the maximum speed  in pokeys config is synchronized with feedrate. I put maximum speed 1000 to test and i'v seen at 1000 feedrate , on a simple circle (like cut operation), the laser reach max power on entire travel. If i increase the feedrate over 1000 i need to decrease percent to reach maximum power. That's correct ? Is fare i notice .

Also: I notice now , when my machine travel free without cutting , the speed is more higher than cutting speed. So i think that is normal now. My question is now, maximum acceleration should be more smaller than maximum speed ? Exist a math rapport for that or is about tuning , how machine respond ?

But at least , my motors are able to move more smooth and faster now , without to multiply the feedrate and percent so high. I assume in every day will become better  :)
I'm feel so lost now, i start to aggressive , and to much information on short time .
And again , sry for my english  :-[
Thanks

[ArtF]

Hi Bobby:

>>until i reach the same distance of showed on .... I got the same 80 step per unit as my first config.

Sounds correct. One easy way to make sure all is good is to simply command Auggie to move 100mm.
If it moves for example 95mm, you then use the formula

  TrueStepsPerMM =  (100 / 95) * CurrentSettingofStepsPerMM

  So its just  (Actual/Commanded) * current setting = NewSetting;

>>Next : I figure out " at least in my head " the maximum speed  in pokeys config is synchronized with feedrate. I put maximum speed 1000 to test and i'v seen at 1000 feedrate , on a simple circle (like cut operation), the laser reach max power on entire travel. If i increase the feedrate over 1000 i need to decrease percent to reach maximum power. That's correct ? Is fare i notice .

  The circle you command has a natural maximum speed based on its radius. Any axis causes jerk as it starts or stops, and in a circle it has a tangential jerk depending on speed and radius. So the radius sets the maximum speed you will hit depending on
your accel, max vel, and jerk setting.
  So if you command a speed of 1000 and the natural maximum is 1500, you will go at 1000, and your power will be
proportional to your  (speed / 1000) * power; So at 1000, this would be 1000/1000 * power or 1 * power.
But if the natural limit speed is 1500 due to jerk and accel and you command 2000, you will never hit 2000,
you will only hit 1500. So your power will at maximum be 1500/2000 * power = .75* power or 75% of the power
you request. This is easy to understand if you consider a car on a round track. If the track is 50 miles long, you can do
maximum speed of the car, if the track is 500 foot long, you cant get above 30KPH or the car will roll over. The setting
of MaxJerk and Accel set the max speed of the car on any track size and takes into account when it would roll over
and limits the max speed.

  So to set speed correctly if you want to go as fast as possible, set the feedrate to 50000, run the program with
laser power off and watch the Velocity DRO, if it averages 1250, set the feedrate to 1250 and then run it with
laser power on and you will hit 100% when speed = 1250 or above.


>>Also: I notice now , when my machine travel free without cutting , the speed is more higher than cutting speed. So i think that is normal now. My question is now, maximum accelerat ion should be more smaller than maximum speed ? Exist a math rapport for that or is about tuning , how machine respond ?

  Maximum Accel can be any number, but to set it properly, just use the jog buttons.
Jog the X axis back and forth. Note how quickly it takes off and stops. Adjust accel so the takeoff and stopping is
faily quick but smooth and not jerky. Then ignore it, Auggie will use the acceleration it needs but not exceed
what you have set.

>>I assume in every day will become better  Smiley
I'm feel so lost now, i start to aggressiv e , and to much informati on on short time .

  Experience is all that will help, as you use it youll get sued to what to change or not. I really advise you
to learn GCode. IT is really very easy and you only need to know 4 or 5 commands...

G0 XYZABC means to move as fast as possible and do not fire laser in move.
G1 XYZABC means to move at the speed in the Feedrate  DRO or program Feedrate command
                  This G1 also means to burn laser while cutting if laser is on.
M3  -- Enable laser ability to burn (Normally spindle on in cnc)
M5  -- Disable laser ability to burn
Fxxxx -- Set max G1 speed to xxxx mm/minute
G3 xyzabcij  // do an arc to xyz with i,j as the x,y of the center of the arc.

  You can type any of these commands in the single line MDI window. (MDI means manual direct input)
just select the single MDI tab, type a line, highlight it and press run. Its a fast way to command motion
for testing.

Glad to hear things are running, you'll get much better over time.. :)

Art

[BobbyW]

Thanks Art for all that information.
I'm not realy sure , so fare i understand and i saw , the maximum speed is necessary to be configured in pokeys not auggie , right ? Because not all settings made'd in auggie reflects in pokeys and not all time auggie import all settings. As example i create a new profile , and i import pokeys config. The PWM channel remain at "4" , period , and some other settings .
I manage to figure out to connect PWM at pin "20" but , like you know my stupid source have the residual voltage on analog input "0-5v" and between 10% and 20% power (set in auggie) the voltage is integrated on analog input source control only 160mv , and at 80W laser that is not quite right. I drop down the voltage on source input with a external 680R resistor but now i need to made the impedance adaptor , because a simple pc817 optocupler are not able to increase the PWM linear on that low impedance . I try with TLP705 but , i'm in france now with my job and without my osciloscope is hard to tell "blindly" what happen on laser input. I notice my source dont have TTL input , i attach below the photo of control. I didn't open the source , to see how is made the control circuit , but i didn't notice any delay of ON/Off . Whatever i will fix that in the feature .
https://youtu.be/zO68eE9Gxzo

Also as suggestion or is just a bug, on jog axis buttons -/+, sometime on a simple touch , the motors continue moving and other time need to keep pressed to move . It is the button's programed as debouncing mode ? Or just take and return value ? I don't know where to look , but i assume all are made'd in script files . I crash the axes several times , because not all limit switches was installed.

And about that step per unit the perfect move at distance is "80" at my laser , edited in engine config in auggie. If i increase speed in pokeys , and i start auggie again , my machine will move faster but with different move distance . Auggie normal ask me where to load config , auggie or pokeys . What i shoul do in that situation ? Is my motors drivers configured wrong ? Sry , but i don't know all that stufs.
Thanks for all advice's

[ArtF]

Hi Bobby:


>>I'm not realy sure , so fare i understan d and i saw , the maximum speed is necessary to be configure d in pokeys not auggie , right ? Because not all settings made'd in auggie reflects in pokeys and not all time auggie import all settings. As example i create a new profile , and i import pokeys config. The PWM channel remain at "4" , period , and some other settings .

No. You should set up a pokeys so it runs and set its inputs and outputs and such. But, you set the speeds in
Auggie, under the planner configuration there is a page for each axis. You set  the number of steps/mm and the
maximum velocity in mm/minute. Auggie will send that to the pokeys at startup changing whatever it is set to.

  The PWM channel is set by a script in Auggies library to channel 4, it can only be changed by changing the script.
You can set the PWM freq and channel by editing the Spindle-Laser library file.


>>I manage to figure out to connect PWM at pin "20" but , like you know my stupid source have the residual voltage on analog input "0-5v" and between 10% and 20% power (set in auggie) the voltage is integrate d on analog input source control only 160mv  ....

  In the planner there are three PWM settings. The first is PWM Minimum. This is for a tickle PWM, normally set to 1 or 2us of tickle. Then there is PWMMin(Power) which is the minimum burning voltage if commanded to burn. Finally PWM Max which is
the maximum Auggie will set the PWM to, this is in order to protect the Laser Tube..

>>Also as suggestio n or is just a bug, on jog axis buttons -/+, sometime on a simple touch , the motors continue moving and other time need to keep pressed to move . It is the button's programed as debouncin  mode ? Or just take and return value ? I don't know where to look , but i assume all are made'd in script files . I crash the axes several times , because not all limit switches was installed .

    The buttons are capture and should turn off jog if you leave them, but I advise you to use the Keyboard Hotkeys in the config
to set keyboard arrows as jog. The keyboard is much more responsive... I am working on making the jog buttons on the
screen more reliable. They seem to suffer from time load of the system in some cases.


>>And about that step per unit the perfect move at distance is "80" at my laser , edited in engine config in auggie. If i increase speed in pokeys , and i start auggie again , my machine will move faster but with different move distance . Auggie normal ask me where to load config , auggie or pokeys . What i shoul do in that situation ? Is my motors drivers configure d wrong ? Sry , but i don't know all that stufs.


  If Auggie asks whether to use Auggie or Pokeys, select Auggie. It shouldn't ask again unless  you config the PoKeys.
Set your speeds in Auggie , once your running you shouldnt need to config the pokeys using their software again,
the speed and accel in Auggie is used at all times. So in Auggie set your steps/unit to 80 as you found,
then set max velocity to the fastest you want your system to ever go. Set accel so its smooth at takeoff.

  Here is an example of my X axis config...

Notice...

  My steps/mm is set to 96.73
  My Max. Vel. is set to 20875 steps / minute.  ( so 20,875 / 60  = 347 steps / second max..)
  You should never exceed 125,000 steps / second with a pokeys 57.
  My Max Accel is set to 20676 steps/sec^2..

  These three values set the fast speed of your axis. Make sure they are set and always answer the question
to use Auggies data or the pokeys by answering Auggie.

Try that and see how it works out..

Thx
Art




 



Art

[BobbyW]

Thanks Art . I will check that out ,, some test will arive now ;)
By the way , i don't use any gearotic software than "free auggie " but still like that , i buy a license today , just to support you awesome work .
You deserve it .
See a later , Bob

[BobbyW]

Ok , i figure out how motors settings work . Still exist alot of improvements but , time by time i will learn them. I have a question about PWM power. In engine /planner config , you set the min and max setting of you lasser and also that set the limit of you laser power . So in laser panel the control of laser power will go on linear percentage between that settings ? Like example , my laser 100w , i config in planner/config at ,max 10 , so in laser panel if i put on 50% power  i will have 5W normal ,what i ask is  i will have linear scan in range of 10W configured in planner? The laser power variable is integer or float ?
I ask because my laser seems is to powerful on engrave and i need to play between 2.2 - 2.4% laser power , 0.1 percent will burn literal'y . I have set in planner config at max 80%.
Thank you
Bob

[ArtF]

Hi Bobby:

>>Like example , my laser 100w , i config in planner/config at ,max 10 , so in laser panel if i put on 50% power  i will have 5W normal?

Yes. PWM(Tickle) sets a tickle pulse, usually set to 2 for 2ms of tickle.
PWM Minimum is the min power at which laser will turn on.
PWM Max is max power ( Usually 95 - 100)

>>what i ask is  i will have linear scan in range of 10W configure d in planner? The laser power variable is integer or float ?

  It is integer, 0 - 100.

>>I ask because my laser seems is to powerful on engrave and i need to play between 2.2 - 2.4% laser power , 0.1 percent will burn literal'y . I have set in planner config at max 80%.

  Usually this is moving too slow. Power and speed are related to stop burning. For resolution
you want as high a power as possible without burning, the lower your feedrate, the lower you
must set your power. How fast are you going? What setting is your feedrate?

Thx
art

[BobbyW]

Hi Art . I try different feedrate's of course, still lerning in motor config , making mistakes so easy to figure out what happen inside.
My laser can go very fast , still on reverse move , the return of any axe was very brutal , can hear the motor move . I figure out is where "jerk limit " come in action . I have right ?
And about my config i put some pictures below . I manage to build a good PWM indexer for my source , " like you know that crap source have strange low impedance " but on my power source documentation is written >20Khz frequency
https://www.google.ro/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=2ahUKEwiokPXMtv7mAhW2AWMBHaACBzwQFjAAegQIBRAC&url=https%3A%2F%2Fstorage.ua.prom.st%2F913343_hy_80.pdf&usg=AOvVaw0I8535iQcYyogTljKpu6_Y
Now the question in my head , i don't know the internal input capacitance on my source , to put a good PWM , to low or to high PWM frequency set will fail in non linearity power (if the source can't manage that) but thinking at analog , if low capacitance is , will be ok .
Now i set to 50khz .
Still i need more than 300 override percent to have a good move , not very slow.
And about "tickle" , I don't realy know what's mean the word. Sry my english. But i assume is like a STB power , always keep laser prepared to shoot. Is correct ?
Now i set to "0" i didn't seen to much difference on.
Also below on the picture my first test on my wife pic  :D :D :D
Thank you
Bobby

[ArtF]

Pretty good..

  Yes, Tickle is for pre-ionization of the laser, just keeps it ready, its not
needed on all lasers. You are correct about jerk, if the axis is loud and jerky, lower the jerk limit..

PWM frequency typically wont matter, most power supplies use it only as
a voltage averaging scheme, so 20khz or 5khz will usually be the same result,
but only testing will tell. :)

What power is your laser??

Art
.

[BobbyW]

What power is your laser??

Hi Art
My laser is 80W , and ,was my mistake about the source control. Wasn't broken or bad designed, it is set internaly at 40% power when nothing connected on input. I put some photos below.

PWM frequency typically wont matter, most power supplies use it only as
a voltage averaging scheme

Yes indeed , usual don't , but , depend of internal capacitance of source input , that can give a exponential voltage or just non linear.
Also now i read on PDF is only 20ma my reference 5V output . That can give me very bad pwm>vcc .
On begining i was able to pull down the residual input voltage , and use analog input as PWM . Now i try different trick , i let the source analog input limited at 40% and i connect my PWM at TL input , and it working , but the same , i can not tell the difference . Without osciloscope i cant tell if is linear or not, mostly because i didn't work for years on this machine , i just build it for fun . Still the photo look more linear like that . Right now i don't realy know what option is better to use , analog input or on TL.
The capacitors in simulation are 100p, 1n , 100n , resistors are visible
Thanks
Bobby

[BobbyW]

I forgot to say about simulation . Like you see , is simulated 3 different internal capacitance at 5 and 20khz , also different internal resistance , and the result are very different , first on timing of VCC increase and second on linearity. I think that is my source problem not auggie or config, because doesn't matter how much i will try , seems the min-max power will change between some % of my laser panel set. I need to fix that first . I don't think is feedrate or other problem , is just no linear PWM to V caused by wrong adapting impedance .

I thinking to order that two pieces. Will give me a full control with perfect adaptive impedance set min max easy to protect laser, also rid out of that 40% residual input voltage .
https://www.renesas.com/us/en/doc/YOUSYS/document/003/r08ds0107ej0400_ps_family.pdf
https://www.analog.com/media/en/technical-documentation/data-sheets/ltc2644.pdf
thx
Bobby

[ArtF]

Hi Bobby:

  I agree with your point, and using TL is probably fine, at least your PWMing a known analogue input.
It may, in the end, be a nonlinear voltage, but its also hard to say how that affects the linearity of the
laser output.

  One good way to tell is to download a greyscale form the internet and have auggie make an engraving
for it, you can then at least see the linearity of depth between grey scale set points. Its what I do
when I want to check linearity..

Art

[BobbyW]

  One good way to tell is to download a greyscale form the internet and have auggie make an engraving
for it, you can then at least see the linearity of depth between grey scale set points. Its what I do
when I want to check linearity..

Hi Art
Yea , totaly agree with you also. I do what you say me , i never think on that , i based on my calculation . And i put some pictures below.
Like i says i dont have my osciloscope here , but i can do some test on low frequency max 50khz. And i saw the problem , " i hope will be that " , like you see in photo
the voltage from PWM don't reach the good values as in my test code. I got maxim 3 levels as you see.
In the begining of the test i has 1000 feed , 400 percent and engine are configured as 1000. Using TL input , and stable vcc on analog input "1v" set tickle as 1 (if i set 0 , same 3 levels , if i set 1 he burn a small line on the return, if i set 3 he burn continuously , to high startup). Ignoring that line burning on return axes was close to more than 3 levels.
Trying on TH ,... no way to burn in any level, only 2 levels 0 and max set in power slider.
Trying with different PWM frequency , almost same result , one more bad than other .
Im a little confused right now.
Can you send me a good GCODE that you use as grayscale test ? Maybe my is not in full range of grayscale. I generated with auggie of course. Just to eliminate that option.
I already order that DAC converter and mos optocuplers , anyway are nice IC and i can use in the feature on many app.
Thanks Art
Bobby

[ArtF]

Hi Bobby:

Enclosed is a grey scale augment and its photos.

A couple of items..

The 400% is a feed-rate override, useful if a program Gcode calls for 1000, and you want 4000. Otherwise, leave override at 100% and just type in 4000 as the feedrate, probably more accurate  that way.

2)
    Auggie can only send numbers from 0-100 as power. So when you limit it to 32% by the laser power
in auggie you can get only 32 different PWM levels. This is unfortunate for high power lasers as it reduces the
resolution as you lower the laser power %.  I use an arduino to receive the pwm and allow me to adjust its
% before it goes to the laser. The arduino can subdivide in 100 steps. SO I set laser power to 100%, then
tell the arduino to adjust down to 20%. The output is then 100 steps from 0 - 20 instead of only the 20
steps Auggie can do by itself. The arduino project is published on this board as well if youd like to make
a similar board. This allows you to override the 0-100 steps the pokeys can do to be 100 steps of any %.
  So this arduino takes in 0-100% pwm from auggie set to 100%, and outputs 0-xx% as set on a lcd
connected to the arduino and sends a new pwm to the laser.

  You can see the project in the auggie topic I think under pwm control.

3)
The faster you can go the better, I typically run at 8000 or 10000mm/min , this will allow you higher power
and thus higher resolution in power steps.

  You should see a pretty good grey scale when you sort out the pwm.. Its looking good though..

Art