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Author Topic: My first attempts at laser engraving.  (Read 91517 times)

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Offline Chris.Botha

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Re: My first attempts at laser engraving.
« Reply #50 on: May 20, 2009, 05:43:50 PM »
ok read it... i think the ability to build and wire a shutter system at this point in the game is out of my league .. i have never cut anything besides wax and im not sure my spindle will handle continuous aluminium cutting either....

Im going to be frank with you here.. i see a completely different application for this and im chasing it for that...

lets say that this laser was way to powerfull for my intended needs.. lets say i was thinking about focusing to a  0.127mm (+-) spot at only maybe 70' celcius and running a finishign pass over my wax to just just surface melt the toolmarks away... fairly fast feed cuz we dont want to punch a hole thru the wax either, literally just melt the 0.127 spot at its very very least amount of time..  some large amount of experimentation with feeds will be needed and with laser temps etc.

think thats possible?

if so.. this will have a huge commercial application...  tool marks are the bane of jewellers existence... 

your thoughts?

Offline Chris.Botha

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Re: My first attempts at laser engraving.
« Reply #51 on: May 20, 2009, 05:57:48 PM »
im on this train of thought5 because a friend has a hot air blower to do similar but it  is very hard to control accurately

images of hot air method


Offline Chris.Botha

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Re: My first attempts at laser engraving.
« Reply #52 on: May 21, 2009, 03:01:42 AM »
ok first bit of farting around with laser.. nicked this off my bandsaw.. mounted to my spindle.. battery powered with a switch.. as a jeweler Y is a constant so X is the only thing i need to drive to before a cut..

Tweakie.. thanks for your inspirations dude.

Offline Tweakie.CNC

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Re: My first attempts at laser engraving.
« Reply #53 on: May 21, 2009, 03:20:52 AM »
OK Chris, I see the application - brilliant idea. If you use modulation to control the laser (0 to 15kHz say) you will be able to have full command over the amount of radiated power from the laser for any feed rate that you choose. I have not seen modulation units for sale but it would be relatively easy to construct, I think, using a 555 timer or the like to create a variable PRF of a fixed width pulse. I will give this more thought and report back.

Tweakie.
PEACE

Offline Chris.Botha

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Re: My first attempts at laser engraving.
« Reply #54 on: May 21, 2009, 04:17:04 AM »
you ROCK dude!

here is a typical path that i would like to use "melt polishing" on.. this is the actual cutting path at a 0.025mm stepover, for the melt polishing i guess stepover could be lower.. maybe by factor of 2?

this is that pendant jobby by the way, would require a 4th axis to do a flip or manually edit the code to do a flip at the A180 instruction.

not sure if this helps but this like i said is a typical path for most jewellers.

the kicker here will be where the path comes to the claws tat are 2mm or so higher than the rest, meaning the laser will be dwelling in the same place for longer in those areas while Z climbs the hill.. but no science is perfect.. there will always be some scenarios this idea will not be suitable to.

« Last Edit: May 21, 2009, 04:57:32 AM by Chris.Botha »

Offline Chris.Botha

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Re: My first attempts at laser engraving.
« Reply #55 on: May 21, 2009, 04:59:20 AM »
oops cut parameters

0.127mm flat profile edge cutter. 600mm/min, 0.025 stepover..

melt would be maybe 0.254mm at 0.075mm stepover? to make sure we overlay edges

not sure on this... thats the hassle with making stuff up.. nothing else to reference :)

Offline Tweakie.CNC

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Re: My first attempts at laser engraving.
« Reply #56 on: May 21, 2009, 07:28:52 AM »
As far as I can see the Z dwell is no problem as this can avoided by the Z inhibit function within Mach. The major problem here is that your existing toolpath makes multiple X passes between each Y move and you would probably end up producing laser marks to replace the tool marks.  :'(

Tweakie.
PEACE
Re: My first attempts at laser engraving.
« Reply #57 on: May 21, 2009, 08:46:32 AM »
Great ideas fella's!
Chris, not sure how a diode laser would work, but I can tell you my yag laser is totally worthless for polishing wax. The beam tends to bounce off or blow right through in unexpected areas; even at very low settings.  ;D
Regards,
Ken

Offline Chris.Botha

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Re: My first attempts at laser engraving.
« Reply #58 on: May 21, 2009, 03:38:01 PM »
hey Ken :), hence the thinking on a pulsing point at much lower temps.. about 90C im guessing

@ Tweakie.. ok so then make the stepover the exact diameter of the point?
« Last Edit: May 21, 2009, 04:46:15 PM by Chris.Botha »

Offline Chris.Botha

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Re: My first attempts at laser engraving.
« Reply #59 on: May 21, 2009, 04:47:47 PM »
may have to melt up some of me specail anaemic wax to test on.. its pretty damn solid in color.. not as translucent as the purple or blue stuff.....