My adventures with Auggie.

[tweakie]

Something that may be of interest?

Glass is a 1 bit material so 8 bit images are usually reduced to 1 bit and dithered (to create the illusion of shade) but there are alternatives. Paint is not a 1 bit material so painting the glass then lasering an 8 bit image on the paint produces some interesting results.
In this example the paint and image have been done on the rear of the glass.

Tweakie.

[ArtF]

Amazing how the horse looks almost to be in color..

  I did a similar one to the cat on the back of a mirror as a test.
Worked out pretty good at the time.

Nice work,
Art

[ArtF]

Tweakie:

  The Auggie install was just updated to correct the 1Khz limitation, it will now go down to 10hz.

Art

[tweakie]

Excellent news, thanks Art.

Tweakie.

[tweakie]

I have just been sent this picture by a good friend of mine in Hungary. He has copied a section of the A square and pasted it by the B square and done a similar thing with the B and A squares to prove that the shades of the two squares are indeed the same.

Looks like we are both impressed with Auggie?s ability to allow shades to be laser reproduced with such accuracy.

Tweakie.

[tweakie]

I am in need of a little help please.

I would like to be able to do a couple of things?

1) Add a command to the M3 script to also turn ON the Pokey?s Direction 4 (DB-25 Output pin 9) and in addition add a command to the M5 script to also turn OFF the Direction 4.

2) Add a command to the on-screen ?Laser Power? button to turn ON the Pokey?s Step 4 (DB-25 Output pin eight) at the same time as the relay is energised and turn it OFF when the relay is de-energised.

I have looked at the documentation and I am really confused so some guidance as to where to start and the direction to take would be most appreciated.

Tweakie.

[ArtF]

Hi Tweaky:

>>1) Add a command to the M3 script to also turn ON the Pokey?s Direction 4 (DB-25 Output pin 9) and in addition add a command to the M5 script to also turn OFF the Direction 4.

  Ok, to do this there are many ways. The best way to make sure an M3 turns on an output
or does an additional task to is modify the M3 script for the library your using. Since you want
this ( I assume) to happen only when using a laser, we'll modify the LaserSpindle library
which calls for the spindle to be turned on, but only when using that library as your spindle controller. (One can have many different named spindle libraries. The one you have currently selected is under Gcode libraries named "SpindleLib-Laser"

  So use the LIB button and select that library name, and press "Local Edit"

In the script MDI window the scripts for the spindle appear.

//the following function does only 1 thing for spindle on, it sets the
real-time PWM output to ON. The rest is automatic as Auggie now knows to
power the PWM as a result of grey scale, or speed or in binary depending on other options you may have selected.

global SpindleOn = function()
{
    //turn on pwm realtime mode
    //called by engine , so no need to tell system
    SpindleControl.SetRealTimePWM( true,
                                  LaserPWMPeriod,
                                  LaserAxis,
                                  LaserPWMChannel );
    print("Laser Spindle RT engaged");                               
}; 

  You wish to also turn on DIR#4.  Now when dealing with output you have to understand
a bit about a Pokeys 57CNC . It has a normal pokeys in there, and you have access to all its pins,
however, they added an external motion engine, which has 8 axis output, but uses some
of the pokeys pins to control that engine. You cannt really access those pins used for engine
control. You can use anything exposed to you.

  Looking to the test IO connected your referring to as the db25, I see the pin you describe,
is the DIR4 pin or the A axis direction pin. You have no real access to that pin, its simple the
external motion cards output for the A direction axis. Thats not to say you cant make it
do what its intended to do though, you could move the A axis forward by .01 mm's, thus making the DIR pin go high, or move -.001 to make it go low.

  Or, you could pick a pin you have access directly to such as pin16 labeled as PIN45, the pin
number tells you its a native pin to the pokeys, and you control it.

Lets assume you really need  DIR4 on pin 9 to toggle. You can add a Gcode motion for
the A axis to make it happen. Change the spindle on function to


global SpindleOn = function()
{
    //turn on pwm realtime mode
    //called by engine , so no need to tell system
    SpindleControl.SetRealTimePWM( true,
                                  LaserPWMPeriod,
                                  LaserAxis,
                                  LaserPWMChannel );
    print("Laser Spindle RT engaged");
    Engine.FeedTo( NULL,NULL,NULL, 1 ); 
    print("A Axis set positive");                           
}; 

and the spindle off to
global SpindleOff = function()
{
    //turn on pwm realtime mode
    SpindleControl.SetRealTimePWM( false,
                                  LaserPWMPeriod,
                                  LaserAxis,
                                  LaserPWMChannel );
    print("Laser Spindle RT dis-engaged");
    Engine.FeedTo( NULL,NULL, NULL, -1 );  //move A in neg direction.
    print("A Axis set negative");   
   
}; 

  Now the A Axis direction pin will reflect what M mode your in.. though
you may want to add something to make it always 1 on startup or something..


If , instead, you wish to use a digital pin.. you have pin45 on the DB pin16 or Pokeys pin20
on pin14. You could use

mypokeys = Motion(); //get a varibale to the pokeys device
mypokeys.SetPinDig( 20, 1 );// to turn on pin 20 or ,0 to turn it off.


Let me know if this confuses..

On more note, on checking this for you I noticed I must have broken the
motion script capability recently, I fixed it as I went and a new Auggie install
in uploaded as a result. Download a new version before changing your
scripts and you should be OK.

>>2) Add a command to the on-screen ?Laser Power? button to turn ON the Pokey?s Step 4 (DB-25 Output pin eight) at the same time as the relay is energised and turn it OFF when the relay is de-energised.

  Step4 you cannot control. It is from the motion engine and will only provide a step output
when the A axis moves. There is no configuration for that. Youll need to find a signal, ( like
pin 20 or 45 above) to use as digital control signals or feed one from another plug on the board.

  The laserOn button,  is a system variable button. It was placed on that panel with a variable name of ExtRelay1, so when its called, it automatically toggles that pokeys device. To modify that you'd have to remove that button from the panel, and place a new one with a script attached to it. This will take a fair bit of explanation as its the most complex use of Auggie screen designer and a bit odd to handle. Theres a few videos on scripting the panels and screens but it may be more of an education than youd like. 

  In looking into your questions, I found a few bugs, make sure you redownload the new .005 version. I notice in screen editing that the panels and screens take a very long time to swap here, I suspect it was upgrading it to a new compiler last month that made this happen. Ill be looking into auggie updates shortly to fix those annoyances..


Art
 

[tweakie]

Thanks Art, an excellent tutorial and solution ? I am most grateful.

My difficulties arise because I don?t want to change anything regarding my existing machine set-up so Auggie / 57CNC has to work with a DB25 connector and my existing pin number allocations.
My previous mod. to the ribbon cable connector works well so I could swap 16 in to 8 out and as you say use Pin 45 Out from the 57CNC re-directed to Pin 8 of my machine. Unfortunately I can?t use Pin 20 Out because is already carries the PWM signal and from what you have said I am guessing that I can?t use either Axis Enable X or Axis Enable Y.
Plan B suggests to me that my ribbon cable connector is now going to have 2 input connectors thereby giving me access to more, available, configurable, Pins. The more I think about this the more it seems to be turning into a homemade BoB  :)

Tweakie.

[ArtF]

Hi Tweaky:

  Yes, I agree. Its best to have a DB25 cable coming out thats attached to the Pokeys at more than 1 plug. That TestIO plug is fine for a simple 3 axis system, but to unleash the power
of what a Pokeys can do, its best to use all the signals you can get access to.

  I mounted several DIN terminal strips to a rail so I could then pick and choose what outputs
to use in the final DB25 to run the machine. (My machine is dedicated to Pokeys, so I then
got rid of the DB25 altogether, but in units like yours where you wish to keep compatibility
to the db 25 format, its worth doing custom wiring at the pokeys end to make up the pins of the db25 and swap as you  wish.

  I highly recommend the din rail approach if you see any on Ebay or anything. You can get din rail terminals of every plug type so that all the exposed pins can be easily used.

[tweakie]

I am a little disappointed with the performance of my electromagnet, particularly after Art has spent time at my request increasing the available PRF range of the PWM signal. I was expecting to get up to 80Hz response from my magnet but have found 50Hz to be the limit and even then I have to reduce the travel to 0.5mm which does not give my expected weight to the impact. Reducing the PRF to 40Hz will allow me 1mm of travel and possibly sufficient weight to the impact but the feed-rate needs to be reduced to about 500mm/min., which is painfully slow. Unfortunately everything is a compromise.
In the light of this experience I am going to re-design my electromagnet ? I have a couple of different ideas in mind and it will be interesting to try different designs against each other and hopefully find the optimum.

In the meantime I am back to using the laser and I am just so impressed with the performance of Auggie and all the various effects that can be so easily produced.

Tweakie.

[ArtF]

I have to say thats one of the best photo engravings Ive seen in terms of texture and color
blend. Nicely done.

  Let me know if I can help in the impact area as you go, I have a bit of flexibility in the code
for various things. Id imagine youd need a very fast impact driver to make it work well, Id suggest
a very short stroke.

Ive never done it, but I had an idea once while toying about in another project..

  Youd need a very sharp and hard pointed shaft, in a solenoid with a rubber
hose pressed on the shaft where the point is with the hose extending .2mm
past the sharp point. This would allow the point to drag on the granite or whatever
without scratching it. This also means the shaft only needs to punch .2mm before
impact and needs no return spring as the rubber hose acts as both a limiter and a
return spring. The strength of the hose will limit the speed of travel as its return
strength will dictate the time to retract from a hit.

  As travel time of the shaft will be the main variable in the equation of time
of impact and return, Id think that would allow the max frequency to be much higher.
The frequency Id think would be highly dependent in the inertial moment of the 
shaft and the distance of travel. In testing such a theory here once, (in a very different
context) I used a fuel injector from a car. I could repeatedly do a 1ms stroke time
(and that was in mach3).

    Now if that same solenoid was taken apart,the shaft extended with a carbide
tipped point and held off the stone by .2mm or so
by a hose.. that should allow for 1khz vibration with chips produced.
  I think if the shaft was extended upwards as a place to add small weights one
could tune depth vs hz more easily as the moment of inertia would have a
not insubstantial effect on penetration.

  I could be way off on all of this of course, Ive only played with fuel injector
timing in cnc as a way of making a water curtain..but it occurred to me at the
time that it would have made a fair impact hammer.  I include a picture of
what I was thinking at the time as a time optimized impact hammer. May be
all rubbish though, I don't even know what exactly was inside the injector
as a solenoid.. but I did intend to try it at some point as an experiment..
never got there yet.. its 8,877,846 on my list of interesting things to try.

Art

[tweakie]

Hi Art,

Thank you for your suggestions and assistance (I certainly like the rubber tube idea).
Up until now I have only been able to use Frequency Modulation of the dot pattern (as is used with 1 bit dithered images) and I am reasonably happy with my magnet performance operating in that mode.
However, Auggie has changed everything as it allows Amplitude Modulation of the dot pattern (the duty cycle of the PWM controlling the impact weight of the solenoid and thus the dot diameter). The advantage of this halftone technique being that otherwise 1 bit materials (such as soft brass, chrome, aluminium, etc.) become 8 bit materials and support 8 bit images (without dithering). Roland are probably the market leaders with this impact technology and they use a legacy 8 wire print head from an obsolete dot matrix printer. Although they only use one of the 8 wires their firmware allows selection of another wire when the one in use wears out ? their print head virtually has 8 lives. Not sure I want to go that route but, at this stage, I am considering as many different designs as I can possibly find ? hopefully, something will stand out as being the way to go.

Tweakie.

[ArtF]

Tweakie:

  Interesting.. I wasnt aware of the roland print head thing.. thats kinda funny.. given the cost of
their technology.

Art

[kit]

Gents,
I'm completely ignorant on this kind of technology but can't help thinking that to get something heavy to move that fast it would best be part of a mechanically resonant system which has the 'hammer' continuously oscillating with a gap between it and the actual tool doing the cutting. making a dot then requires a spacer to be pushed into the gap to make the hammer move the tool. This moving spacer and it's associated solenoid could be much lighter than that required to actually punch the tool directly. You might even get really clever and have a wedge shaped spacer to get depth modulation.

Obviously there's an issue with synchronising all the movements and controlling the amplitude of oscillation with and without strikes. Just thinking out loud.

Kit

[ArtF]

That sounds like a reasonable idea.. though maybe a bit complex. It
DOES sound like a good way to modulate a lot of power though.

Art