Full Version: Trick to engrave granite?
From: Ken D. (KDEVORY) [#2]
8 Sep 2005
To: David (SEETHESUNRISE) [#1] 8 Sep 2005
Like marble the quality of granite varies from piece to piece.
For lower grade material increase the values used in "Unsharp Mask"
If you find the easy magic solution, LET ME KNOW.
From: Pedaler (ROYBREWER) [#3]
9 Sep 2005
To: David (SEETHESUNRISE) [#1] 9 Sep 2005
David,
As Ken suggested, there is no magic solution. I also, as an Epilog rep, have a few beautiful sample photographs on granite in my display. What I don't have on display is all those I screwed up (probably worse than yours!).
On the other hand, this is what I have found works the best for me. Don't be too alarmed when others respond with seeminly opposite instructions. I scan/save or resample the photograph at 200 dpi and leave it in color up until the last moment. I massage the photo to get it to "lend" itself toward being laser engraved. I use PhotoGrav. I engrave at 200 DPI (therefore quite fast).
Depending on the "properties" of the granite, I'd suggest starting at 80%speed and 55% power on your 35watt Mini. Especially on Granite, I'd lie to Photograv on the dot size (tell it larger than it is, since the dot on the granite will be larger than the dot in the artwork).
IMHO, however, you'd be better off to pay the high price for the pure (or near pure) black marble and charge more for it.
HTH,
From: Cody (BOBTNAILER) [#4]
9 Sep 2005
To: Pedaler (ROYBREWER) [#3] 9 Sep 2005
Roy,
I'm curious now...
What spot size do you tell Photgrav that you have?
Do you use those same settings on black marble (dpi, speed/power)?
We have done several marble pictures, and they're "good"...but I can't help but think that we could improve on them.
Thanks!!!
Cody
From: Pedaler (ROYBREWER) [#5]
9 Sep 2005
To: Cody (BOBTNAILER) [#4] 9 Sep 2005
Cody,
As always, experiment with it a bit, but I recommend telling PhotoGrav the dot size is at least 50% larger than it really is. On your TT (and the Mini18) the dot size is between .0055 -.006" so tell it .008 or .009. The Mini24 and all larger/newer Epilog's spot size is just below .004" (with the new Radiance Optics) so I use .006 or .007 for "kissing" marble and a little more if I'm hitting marble hard or doing granite.
HTH,
Edited missed question: Your TT is faster than the Mini; I might recommend dropping your speed to 65-70% as a conservative starting place ---- as we all know, we can go over it again if the properties of the marble (or granite) dictate, but espcially on marble if you "wash it out," you throw it away.
EDITED: 9 Sep 2005 by ROYBREWER
From: Cody (BOBTNAILER) [#6]
9 Sep 2005
To: Pedaler (ROYBREWER) [#5] 10 Sep 2005
Roy,
I will definitely try that.
What about the dpi settings...would you use 200 dpi on marble (will it have the same effect)?
Cody
From: Pedaler (ROYBREWER) [#7]
10 Sep 2005
To: Cody (BOBTNAILER) [#6] 10 Sep 2005
Cody,
Again, you'll hear many who do more engraving than I, say to use 500/600dpi, but like the effect and the speed of 200dpi.
From: Cody (BOBTNAILER) [#8]
10 Sep 2005
To: Pedaler (ROYBREWER) [#7] 11 Sep 2005
Thanks again, Roy.
I'll make it a point this next week to play with those settings.
By the way, we'll be exhibiting at the Hopkins County Fall Festival this next Friday and Saturday. If you happen to find yourself on the east side of the metroplex either of those days, stop by the Civic Center and visit with us.
As you know, we'll be taking the Epilog out there this time to do on-the-spot engraving. This is our first time to do something like this, so we're VERY excited!
Cody
From: Engravin' Dave (DATAKES) [#9]
10 Sep 2005
To: Cody (BOBTNAILER) [#8] 10 Sep 2005
Cody,
Take notes and give us a play-by-play observation of your experience. We will all be waiting with baited breath.
EDITED: 10 Sep 2005 by DATAKES