GearHeads Forum

Sounds right to me. Usually a TTL high and TTL low are just inputs to an optocoupler,
so with nothing hooked up you should get zero output..

Art

tweakie wrote: I think a simple test would be to disconnect anything connected to the TTL(H) and TTL(L) terminals of the PSU.
If the laser still fires try fitting a pull-up resistor (10k) between TTL(L) and +5V and a pull-down resistor (10k) between TTL(H) and GND.
If the laser still fires then you have a problem with the PSU.

Is not connected yet on any pin of PSU. I just made some tests. Seems the PSU input TTL \L/H are very low impedance .
Now i have two problems , First , only below 1k resistor will turn off completly the laser , and that's bad, will be necessary to change entire input circuit and design the second one.
Second is , because i want to made the limit on maxim 60w of my laser. I buy on 80w just to don't stress him on max power. So that will be a little bit tricky , wil dont work only with some resistors and transistors.
Anyway , seems to be good , i made some test on a simple square in Auggie of course, and look very nice (without cut it, are not all the mirrors placed ) , and i saw the auggie calculate the laser power according with speed and velocity on corners ,i attach a photo.
Still i have a question . Why i never reach the maximum 3V voltage during cut operation ? In pokeys work perfectly , from 0 to 2.92v and that's normal. I miss some configurations ?
And my second question  is on cutting operation, like example i cut two circles , the cutting speed is more high than travel speed between cuts . Is that normal ? Sry , i don't realy know to much about CNC , is new zone for me . :-[

Hi:

>>Why i never reach the maximum 3V voltage during cut operation ? In pokeys work perfectly , from 0 to 2.92v and that's normal. I miss some configura tions ?

  Auggie corrects for speed vs power in order to stop burning in corners. The formula though is  (actual speed) / ( feedrate commanded) * power. So if you set F50 and it reaches 50, you get 100% power. IF you command 2000 and it only reaches 100
you get very little. You adjust your feedrate command to the maximum the axis actually hit and it will hit 100% of commanded speed.


>>And my second question  is on cutting operation, like example i cut two circles , the cutting speed is more high than travel speed between cuts . Is that normal ? Sry , i don't realy know to much about CNC , is new zone for me .

  Travel speed should be the highest you can do. Its a g0 move, which means rapid. A g1 move is at feedrate and feedrate
will never go higher than rapid can. But..its hard to say how your code was written, it may be the Gcode your using is commanding it. If you show us the code I can tell you.

Art

ArtF wrote:   Travel speed should be the highest you can do. Its a g0 move, which means rapid. A g1 move is at feedrate and feedrate
will never go higher than rapid can. But..its hard to say how your code was written, it may be the Gcode your using is commanding it. If you show us the code I can tell you.

So, what i understand , i need to have at maximum desired speed feedrate "100" , and on my is 6000. That's mean , he will never reach 6000 and the power percentage will be something like 100/6000 , 1.6% of 3v  at 100 feedrate correct ? And that's mean , i need to set my motors to reach maxim speed at 100 feedrate right?
The code are just for test to understand how all that work. That settings i found to be the best move on my motors ,
I keep digging .
Thank you Art ,

Hi:

  No, you dont need to adjust motors for that, you adjust feedrate. Here is my recommended process
once you have set the proper steps/unit for your motors.

Use Jog buttons and jog axis back and forth. Adjust the max velocity and max accel in the planner config
for that axis so the jog is as fast as you think the machine should do at 100% jog speed. Adjust the accel
so the Jog take off and stop are abrupt but not too abrupt. Make sure it is very quick to start and stop
and goes fast at 100%. Then slow jog to 20% and make sure its a nice jog motion.

Now, adjust the Jerk setting to 50,000. Make a GCode program of a large square that takes up most
of your table. Run the program and see how jerky it is. If each corner seems jerky, lower the Jerk
setting, if the corners seem too slow, raise the jerk limit. Find the jerk setting for which that
square runs fast and smooth. That should make the settings proper.

Now, set a feedrate of 100 in the Feedrate DRO. Run the program and watch the tool velocity DRO.
If the tool velocity hits 100 at any time, raise the feedrate to 200 and repeat. You will find eventually
a speed where the table will not hit the actual velocity any more. That is the point where the power will
no longer hit 100% if you go faster.

  For laser burning I use the Feedrate Override checkbox so that any feedrate command in the Gcode is ignored
in favor of the feedrate and Override slider % I have set. Each program is different so I run it without laser on to
see how fast it will go as an average. If I see the speed DRO is varying around 3000 or so, I set the feedrate
to 3000 and run the program with my preferred power selected on the Laser Power slider.

  Doing all this will give you maximum performance and is important if you intend to do 3d machining by laser
which is the most complex operation you can do in Auggie.

Art

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 
Thanks

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

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

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

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