Author Topic: Impact engraving plugin  (Read 235732 times)

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Offline robotmar

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Impact engraving plugin
« on: November 07, 2010, 02:22:12 PM »
Hi

As you know I like to make accessories to enhance the potential use of CNC machines, we would surely have seen in my Youtube channel (http://www.youtube.com/user/RobotfactorySRL # g / u).
Well now I have made up his mind to add a new accessory "Photography".
For accessory "Photography" I decided to use the DLL "Engraving" that Art has done.
I've read all the messages on both the Yahoo forum that the Machsupport forum concerning the topic.

For those who want to revise the topic:
http://groups.yahoo.com/group/mach1mach2cnc/message/74912
http://www.machsupport.com/forum/index.php/topic, 11996.msg87152.html # msg87152
http://www.machsupport.com/forum/index.php/topic,12981.0.html

The first problem was to find a way to drive a magnet through the signal "Digit Trigger".
After many trials I found a way to use a magnet with which I can use the DLL developed by Art, for this I used a stepper motor drive for connecting the magnet to a single phase leaving the other free.
Since the signal "Digit Trigger" is very short, this is the only simple system possible for proper operation.
With this system I can have a feed rate of 300 mm/min, not much but enough if you consider that it works.
Up to here all is well ...
The problem is probably that the DLL is not working properly, you can see it in the first photo.
The picture would also be good with many shades of gray ...

The image is slightly offset, this is because at the end of the path of the X the trigger array is empty.
When you move to the next line in Y, the start is correct.
And so on until the end.
This is proportional to the X-axis travel (it seems that the values are rounded to lose data, and then the road is longer and more data are lost).
You can see it in the second photo.
I am working in mm!

Perhaps the problem is in this passage from the message of Art:

############
The triggerlength is an array of 1's and 0's which represent the image's density in one scan line. Its limited to 1000000 , so thats
1 million steps. The trigger array is equal to the number of steps you will move in the X each scan line.

omission .....

Think of pixel size this way. If the program knows there is 120 steps in each pixel of the X line of image, then it will put a variable pulse rate
for that first 100 steps that is representative of the density of that first pixel. During the next 120 steps, another pulse pattern will come out
representing the density of the next pixel..ect.. So if theres less than 20 motor steps / pixel, you wont get much of a density pattern.

omission .....

The way it works is basically this , a buffer of bits is created, the length of the number of steps that the photo will scan in one line.
So in a 5000steps/unit system, on a 8 x10" photo, there woudl be a scanline of 5000 * 10 or 50,000 bits.
Each bit may be set to 1 or 0. that 1 or 0 is put out on the DigTrigger output during the scan of the motor as it traverses the X axis.
This means acceleration is taken into account and each of the 50,000 bits will correspond to the motor position exactly. Now in this example, if the loaded photo is 1024 x 768, then each of the 1024 pixels in the image X will match up with 50,000 / 1024 = approx 50 triggers. If the image was 20" , then we'd have about 100 trigger positions per pixel. Question now, is how best to handle the filling of the possible 50,000 trigger points.
############

You can see the same problem of mine in the third picture (Top right) when you use the DLL with the laser.
Surely no one noticed because the Y stepover of the fault is less than what I use (0.2 mm)

Now I'm asking for HELP!!!

Art, poppabear, or any person who is able to program in VC++ can help me to solve my problem?

I use the DLL created by bdock (http://www.machsupport.com/forum/index.php/topic, 11996.10.html) on July 29, 2009, 05:22:37 AM,
because he have added a "Maintain Aspect Ratio" checkbox to keep the image the correct shape.

If you need the sources code, these are in the link above.
Or the originals in Machsupport Plugin.

Please help me to solve the problem!!!

Andrea

Offline robotmar

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Impact engraving plugin - construction
« Reply #1 on: November 08, 2010, 12:16:30 PM »
Hi

Thanks Art for the reply...

When you say  "There didnt seem to be much interest in such a thing" I think it is very difficult to drive a magnet with a signal so fast, but now it is possible with my system.

Now I will explain in detail how I did it, so that anyone can use your DLL.
And of course you can do the tests if necessary.
This is because I believe that now there will be much interest in your DLL.
I have used a "pinch solenoid valves" the pinching device is moved by a solenoid operator and cuts off the fluid by pinching or releasing a tubing in soft silicon (or other soft material).
I believe that any magnet can be used...
Take a magnet (photo Magnete_1) then disassembled into its parts (photo Magnete_2).
Please note that final assembly is mounted to the back (photo Magnete_3).
This is because is the spring that will give you the energy to beat and not the magnetic force.
Take the middle (the core) and you make a hole, in this hole is inserted a metal bar with a hard tip at the end, the metal bar is fastened with a screw (photo Magnete_4).
Attach the magnet to a stepper motor drive, connecting only one phase (photo Magnete_5).
The stepper motor drive are setting to full step.
Attach the magnet to the Z axis of your CNC (photo Magnete_6).
For convenience I have used the stepper motor drive of the fourth axis (A axis).
On photo "MotorOutput" there is a setting of the A axis, and on photo "OutputSignal" there is a setting of the Digit Trig.
Start Mach3 and run Impact/Laser Engraving.
I used the photo "Andrea", and this is the dialog window that appears (photo PhotoEngraving).
Please note that photo is negative because magnet is inverted (when not working is excited as a stepping motor).
Start job and wait until the end.
I hope I have done what is pleasing to many and that my experience might be useful.

On my Youtube channel you can see a video http://www.youtube.com/watch?v=PcNRF0y6h_E

Sorry for my bad English.

Thanks,
Andrea


Offline robotmar

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Re: Impact engraving plugin
« Reply #2 on: November 08, 2010, 12:18:30 PM »
More photo

Offline robotmar

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Re: Impact engraving plugin
« Reply #3 on: November 08, 2010, 12:19:41 PM »
The latest photos

Offline Dan Mauch

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Re: Impact engraving plugin
« Reply #4 on: November 09, 2010, 10:50:53 AM »
Cool ! Why couldn't any spring loaded  solenoid modified to hold the stylus and be compabible with the voltage of a step motor driver work?

Dan Mauch
www.camtronics-cnc.com
low cost cases for Gecko products.
Kits and an assmebled systems

Hi

Thanks Art for the reply...

When you say  "There didnt seem to be much interest in such a thing" I think it is very difficult to drive a magnet with a signal so fast, but now it is possible with my system.

Now I will explain in detail how I did it, so that anyone can use your DLL.
And of course you can do the tests if necessary.
This is because I believe that now there will be much interest in your DLL.
I have used a "pinch solenoid valves" the pinching device is moved by a solenoid operator and cuts off the fluid by pinching or releasing a tubing in soft silicon (or other soft material).
I believe that any magnet can be used...
Take a magnet (photo Magnete_1) then disassembled into its parts (photo Magnete_2).
Please note that final assembly is mounted to the back (photo Magnete_3).
This is because is the spring that will give you the energy to beat and not the magnetic force.
Take the middle (the core) and you make a hole, in this hole is inserted a metal bar with a hard tip at the end, the metal bar is fastened with a screw (photo Magnete_4).
Attach the magnet to a stepper motor drive, connecting only one phase (photo Magnete_5).
The stepper motor drive are setting to full step.
Attach the magnet to the Z axis of your CNC (photo Magnete_6).
For convenience I have used the stepper motor drive of the fourth axis (A axis).
On photo "MotorOutput" there is a setting of the A axis, and on photo "OutputSignal" there is a setting of the Digit Trig.
Start Mach3 and run Impact/Laser Engraving.
I used the photo "Andrea", and this is the dialog window that appears (photo PhotoEngraving).
Please note that photo is negative because magnet is inverted (when not working is excited as a stepping motor).
Start job and wait until the end.
I hope I have done what is pleasing to many and that my experience might be useful.

On my Youtube channel you can see a video http://www.youtube.com/watch?v=PcNRF0y6h_E

Sorry for my bad English.

Thanks,
Andrea



Offline robotmar

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Re: Impact engraving plugin
« Reply #5 on: November 09, 2010, 01:17:04 PM »
Hi Dan

In fact, I literally said "I believe that any magnet ( read solenoid ) can be used..."

I used a 24 V DC solenoid, and one of my stepper drive ( http://www.robotfactory.it/CncBoard/StepperBoard.htm ) setting on 2A 35V full step.

And everything works as shown in the video...

Andrea

Offline Dan13

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Re: Impact engraving plugin
« Reply #6 on: November 09, 2010, 02:19:04 PM »
The third picture in the first message - isn't it Tweakie's laser engraved image? Looks exactly the same:

http://www.machsupport.com/forum/index.php/topic,12444.msg110555.html#msg110555

Dan

Offline ART

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Re: Impact engraving plugin
« Reply #7 on: November 09, 2010, 04:08:14 PM »
Andrea:

  Very nice work.

 Ive looked to the code and I thin maybe I see what was wrong. Try this one, I can't guarentee it will be better but Id like
to know if its worse or better..

Art

Offline robotmar

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Re: Impact engraving plugin
« Reply #8 on: November 09, 2010, 05:54:15 PM »
Hi Dan13

Yes it is.
That photo was included to highlight the same problem of my (as I said verbatim).

Andrea


Offline robotmar

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Re: Impact engraving plugin
« Reply #9 on: November 09, 2010, 05:55:36 PM »
Hi Art

Well, thank you.

Tomorrow I'll try the new DLL and then I can tell you...

Thanks,
Andrea