Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Dan13 on August 22, 2016, 08:09:02 AM
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Hi,
Does anybody know if PicEngrave can be used for impact engraving? If so, any reference on how to do this?
Any other alternatives aside from the Impact Engraving plugin? I know Dot-G does it, but seems a bit low on resolution.
Dan
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PicEngrave can be used for impact engraving with a Dithered image and a tool like this.
https://www.amazon.com/3-Electric-Engravers-Carbide-Tip/dp/B00EQCZWX8/ref=sr_1_13?ie=UTF8&qid=1471956840&sr=8-13&keywords=impact+engraver
It would plunge the tool to the surface in black areas for impacting and then retract in white areas. Or reversed.
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This tool is for manual engraving. It is going to oscillate at 50 Hz continuously... Not sure I understand how the process works. Or should it not be energized?
I have looked through the software, but can't see the option for this... ?
Thanks,
Dan
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You would have to mount it on your CNC machine like you would with a hand router such as a Dewalt DWP611. Those Dewalts are made for manual/hand routing, not for CNC machines. The Spindle engraving profile in PEP5 could be used like I stated with a Dithered image.
The built in image editor in PEP5 will created Dithered images, then set the min 3rd axis value at zero and zero the Z axis and diamond tip above the material so it will not impact in white areas, then the max 3rd axis value be just at or slightly below the surface to impact.
There are other impact tool options for sale that may be easier to mount. I just did a quick search on Amazon for that one.
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Got any Gcode example of the output? How is the impact achieved - by Z movement?
Any examples of work done with PicEngrave? Wonder how the quality is.
Thanks,
Dan
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It's achieved by the 7200 strokes per minute of the tool impacting the surface when the Z axis moves the tip down in Black or White areas depending on how you have the settings.
We have no examples of impact engravings, but you can generate gcode for testing with the Demo of PicEngrave. Or, are you already a registered user of PEP?
Jeff
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Thanks Jeff. Again, though, don't fully understand the need for an oscillating engraver - why the single impact itself from the Z move downwards isn't sufficient - like it's done with Dot-G?
Have a key for PEP. Not sure however, if it will also work for the current version on your website. Will see in a moment.
Dan
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Didn't work ;)
Dan
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The PEP Z axis gcodes will not impact/retract for every X&Y incremental axis move if there are continuous black areas and that is why you need an oscillating engraver to constantly be impacting.
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I cannot get PEP4 to work. I have it activated, but I don't seem to figure how to generate Gcode. I have an image loaded, but I don't see any button for generating Gcode. The manual says such a button should appear once an image as been loaded, but I just don't se it on the screen...
Also, have an error and the program crashes each time I am trying to edit the settings and save them.
Dan
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Figured it - had to click the "Load Image" button which I was missing. Having another problem - as I said, I am trying to to get Gcode for impact engraving, but the Gcode I am getting isn't suitable. I am using the "Rotary Engrave" option. Attached is a screenshot of my settings, can you tell me what should I change please. The image I am loading is dithered.
Thanks,
Dan
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Hi Dan,
I assume the gcode your getting is not suitable because of my previous statement?
The PEP Z axis gcodes will not impact/retract for every X&Y incremental axis move if there are continuous black areas and that is why you need an oscillating engraver to constantly be impacting.
Jeff
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No exactly - I am getting the whole range of Z moves as if the image was not 1-bit, but rather grayscale.
Dan
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Attached is the image I am trying to generate Gcode for. And here is how the Gcode I am getting looks like with the above settings:
X3.48 Y0 Z-0.0027
X3.6 Y0 Z-0.0027
X3.72 Y0 Z-0.1071
X3.84 Y0 Z-0.6478
X3.96 Y0 Z-0.5243
X4.08 Y0 Z-0.2114
X4.2 Y0 Z-0.571
X4.32 Y0 Z-0.1839
X4.44 Y0 Z-0.4886
X4.56 Y0 Z-0.2086
X4.68 Y0 Z-0.5627
As you can see, it's not suitable for impact engraving where there should be only two modes for Z axis - impact/clearance.
Dan
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Jeff, I just re-read your previous posts above and I now understand. I were saying that the only way PEP can do impact engraving is by using one of those heads. While I kept trying to get out of it a Gcode similar to what DotG does, which doesn't require any special tools and its output Gcode looks like this:
G0 X5.1 Y0 Z1
G1 Z-0.7 F1200
G0 Z1
G0 X5.4 Y0 Z1
G1 Z-0.7 F1200
G0 Z1
G0 X5.7 Y0 Z1
G1 Z-0.7 F1200
Thanks,
Dan
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I'm not sure why there are variable depths when using a 1bit Dithered image. I don't even have that old of a PicEngrave version on my PC to even test with. :-)
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Ok, after some thought, did you save the image after editing and resizing, reopen to dither afterwards, then save again?
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You were right Jeff - the image I attached above was not good. I did it with PEP and saved it and then subsequently was opening it and trying to produce Gcode, but apparently it was not dithered properly. I did it again and now the Gcode looks better - still not perfect for impact engraving I think as it doesn't separate the Z moves from the X and Y, but I will try to engrave and see what a result I will get.
Do you know anyone who tried to use PEP with one of those engraving attachments? I understand that to use it this way, you have to use "variable feed rate" mode, but my question is what happens if you have a clear white colour on the picture - you can't have a high enough feedrate to not leave any marks on the workpiece...
Thanks,
Dan
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No one has told us they used one of those tools with our software, but it makes sense considering the way the gcode is generated. If it does not retract the tool in common black areas, it would put too much side load on the tool if not constantly impacting with enough stroke to raise off the material slightly on each impact.
When using a dithered image and Feed Rate Change, the tool would retract and run at a higher feedrate in white areas. But looking at your settings screenshot, that version of PicEngrave does not have FRC.
We do offer a program called PicFRC that adds the Feed Rate Change to PicLaser gcode and it may work with that version of PicEngrave gcode also, but you would need to test that with the Demo.
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The version I have does have the variable feedrate option. I will play to see what I can get out of it without the head first...
Dan
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The laser variable feedrate replaces the Z with a F. The Feed Rate Change adds the Z depths and the F for variable feedrate at the end on each line of gcode.
If the Feed Rate Change feature was available, there would be an input for the feedrate percentage and a selection to add it or not. I don't see that in the screenshot.
Jeff
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Here it is.
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Does the 3rd Axis letter change to a F when selected?
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Yes.
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uccnc has a free laser engraver plugin within it
https://www.youtube.com/watch?v=XnvJQGyfuV4
http://www.cnctar.hunbay.com/Bozso777/L%C3%A9zer/Mindenf%C3%A9le/DSCI0055.JPG
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That is nice, but I am not familiar with UCCNC and won't be changing over from Mach3 to something that isn't proven in my opinion.
Dan
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Is it possible to control the resolution of dithering? I am now able to get fair results, but would like higher resolution. I am trying to engrave an image on a small pendant so the image size is about 25x25mm (1"x1"), but after the image is scaled down to this size and I perform dithering, the dots I get are very coarse and the image looks poor. With a larger image the dots remain the same size, but considering the larger image size it looks fine.
Dan
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Try increasing the DPI resolution in another image editor before opening it in the PEP editor to dither. Also experiment with the Atkinson dithering algorithm as it's adjustable.
Jeff
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Increasing the DPI using GIMP, but it affects the size of the image, so that I have to scale it again using PEP. Played with Atkinson but it doesn't give what I want.
Dan
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I use Corel Photo Paint and it lets me increase the DPI without effecting the size. Good case of you get what you pay for. ;D
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GIMP does the same - the image remains same size, but when I open it in PEP, it shows different size which seems to be derived from the DPI.
Dan
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Try compensating the size by pixels instead of inches. As you know, PEP calculates the engraving size based on the Pixel Resolution setting (step over), so calculate the pixel width & height based on that. Example: if you want it 1" X 1" and the Pixel Resolution setting is .01", the Pixel size should be 100W X 100H. Also, since your image is real small, don't rely on the dithering outcome how it views on a large monitor.