Machsupport Forum
General CNC Chat => Show"N"Tell ( What you have made with your CNC machine.) => Topic started by: Tweakie.CNC on January 05, 2012, 06:43:45 AM
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This was created in acrylic from GCode produced with 'DotG' using an impact magnet. The image size is 105mm square and comprises of over 90,000 dots from over 270,000 lines of GCode and took just 2 ½ hours to complete at just over 9 dots per second. (for those that are old enough to remember - it makes a sound not unlike the ASR33 Teletype :) ).
Like all things, practice and experience is required to get the perfect final result and it is evident here that my original image had just a little too much brightness and as a result some detail has been lost. Still practice makes perfect or at least I hope it does. :D
Whilst Mach already has the Impact / Laser plugin, which relies on the LPT parallel port and the Mach engine for it’s timing DotG creates a ‘stand alone’ GCode and can therefore be used with USB and external motion controllers. Each has it’s own strong and weak points and I don’t think there is any direct comparison but it is always nice to have alternatives.
Tweakie.
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Cool stuff Tweakie!
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Thank you adprinter, most kind.
To answer a question, asked in email, the black in the previous image is created by the background it has been photographed against. Here is the same item photographed against a sky background.
Tweakie.
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Nice, Tweakie. Where do you get all these pretty ladies' photos for your works ;)
Does a clear acrylic become opaque at the impact points?
Dan
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Nice, Tweakie. Where do you get all these pretty ladies' photos for your works ;)
Does a clear acrylic become opaque at the impact points?
Dan
Hi Dan,
Yes, the impact creates a tiny conical depression which refracts the incident light and makes it opaque.
The lady is Lena Soderberg (we have discussed this one before) and her full length picture (which we can't show here) was featured as the centre fold in the Playboy magazine of November 1972. She is still an attractive lady to this day.
Tweakie.
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Hi Guys,
This effect needs a lot more trials but based on the fact that my previous example (positive image) when viewed against a sky background appears as a negative image I decided to make a negative image and then view that against a sky background.
As I seem to be getting bit of a reputation for the ladies (thank you Jeff ;D ) this image is of my little helper ‘Bertie’.
It is overcast here in the UK today and it was impossible to find a patch of blue sky so I used a white background and cheated a little by altering the contrast level towards the blue in Photochop. Interesting nonetheless.
Tweakie.
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Interesting indeed. Very cool process.
That Bertie is a precious pup.
I saved the other pic that you posted way back when.
Wondered then what the name was, but never asked.
Thanks Tweak,
Russ
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Thanks Russ,
For the full story of Lena this thread may be of interest. http://www.cs.cmu.edu/~chuck/lennapg/
Tweakie.
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Loving it Tweakie!
I remember doing a couple of these for a client about 5 years ago and he was over the moon.....as was I seeing as it was a first for me lol.
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Hi Pinky,
Do you still have any pictures of your impact work you could post please ??
Tweakie.
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Sadly no, moved away from that company awhile back to start my own.
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As a follow on from the first post in this thread....
Nothing is ever simple and something that becomes apparent when we start experimenting with impact printing from GCode files is the phenomena of ‘banding’. When an image is mathematically processed to create a halftone it must not subsequently be scaled or have the aspect ratio altered in any way otherwise banding may occur. It does not always happen but when it does the result is a spoiled product – the following image was accidentally scaled and the pictures show the result. The, otherwise nicely distributed, dot pattern has formed into groups and suddenly they become noticeable.
Although I keep trying not to make comparisons, because of the entirely different method of operation, the Mach Impact / Laser plugin calculates the halftone dot pattern on the fly so does not suffer from this problem and even pre-prepared halftone images which have been scaled get corrected by the plugin at run-time so everything turns our right in the end.
Tweakie.
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This was just a test run but I am really quite excited by the results.
The DotG generated code consists of 467,517 lines and with 4 lines of code to produce each dot, the image consists of 116,879 dots which took just 1.5 hours to complete. With a stroke length of 1mm the little electromagnet has now shown that it is capable of producing at least 21.644 dots per second (axis movement time has been ignored in the calculations), which is about double my previously achieved speed.
Instead of sounding like an ASR33 Teletype my CNC now sounds like a Gatling Gun and although not quite as quick as the Roland Metaza it is getting closer.
Tweakie.
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Brilliant Tweakie! And you always know how to best photograph and exhibit your work.
Are you saying it's around 21Hz? Then I think I was close with my experiments. Any chance you could record the sound? I would be interested to compare to mine, since I have no idea how better to estimate the frequency. How did you?
Dan
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Hi Dan,
For the purposes of the frequency calculation, I ignored the axis movement time and divided the number of dots by the total time taken.
I have already been asked to make a short video – I will post the link when it is done then the sound can be heard.
Tweakie.
btw. Nice job you are doing on that milling machine – very professional.
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Hi Tweakie,
Ah... so actual frequency is even higher. Will be interesting to hear the sound.
btw. Nice job you are doing on that milling machine – very professional.
Well... I guess the only reason it would look like a mill is it being a Chinese lathe ;) Thanks anyway :)
Dan
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Sorry Dan - nice job you are doing with the lathe. ;D
Here is a short video clip with the sound of the electromagnet. http://hobbymaro.puhasoft.hu/Tweakie/Impact1.wmv
Tweakie.
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Thanks for the video, Tweakie. Now I have a clue what 20Hz sounds like. It works fairly fast considering it stops at each dot location.
Nice smiley, by the way.
Dan
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Hello All, can somebody tell me how do i connect a electromagnet with mach3 for photo engraving
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Hi Flamuria,
There are a number of different ways in which it can be done.
The method pioneered by Robotmar is perhaps a good place to start http://www.machsupport.com/forum/index.php/topic,16446.0.html
Tweakie.
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Thank you for the quick answer
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My pleasure sir.
Please let us know how you get on and what, if any, problems you encounter.
Tweakie.
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Another forum member, PicEngraver, has asked me to test a beta version of his new softwere ‘PicLaser’ and I have posted a couple of pictures of laser created images and a brief description of the operation of the software in the laser thread. http://www.machsupport.com/forum/index.php/topic,12444.msg154465.html#msg154465
Exactly the same GCode that is used with the laser can also be used with an electromagnet (a big thank you to Andrea for the magnets) and this was impact printed into some opal Plexiglas and then filled with Rub’n’Buff. The results when back illuminated can be quite stunning and this is an example of a test piece.
Tweakie.
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Looks very good, Tweakie. Unfortunately never got around to finishing my impact head. But I am still planning to revisit it and pictures like this really give a push ;)
Dan
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Ok Tweakie, when are you going to start "Tweakie's CNC Tattoo Parlor"?
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Thanks guys.
As soon as our friend writes "PicTattoo" the Parlor will be up and running. ;D ;D
tweakie.
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Tweakie,
I'll program it if you'll do all the Beta testing. Hmmm, I wonder if disappearing ink will work for debugging? ;D
John Champlain
www.picengrave.net
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This was created in acrylic from GCode produced with 'DotG' using an impact magnet.
Is the 'Impact Magnet' you are referring to, an "Electric Engraver" tool? (The brand I have is a Wis, made in China).
The length of stroke is so small on this tool, that it appears to just vibrate. Regardless of the various stroke settings' position. I tried to mount it on my machine to engrave some acrylic. Turned into a 3 day project, just trying to get a successful design implemented on the tool holder. However, even using the surface of a freshly planed piece of oak stock, as the mounting surface for the plexiglass, the results were inconsistent. The tool would plunge so deeply into the plexiglass, that it could not complete it's strokes in some areas, while in other areas the tool tip would not even contact the surface!
I have already proven The acuracy of my machine's table, by doing engravings using the router tool into solid oak, which involves multiple passes to achieve the desired depth of cut with good results. So the inconsistencies I am experiencing with the Engraver tool MUST BE in the Engraver tool itself. What is the brand name, or supplier info of the 'Impact Magnet' tool you are using?
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The magnet Andrea and I are using together with more details of the process are shown in this thread http://www.machsupport.com/forum/index.php/topic,16446.msg111240.html#msg111240
Tweakie.