Does the scan gap affect speed?

[Adam Less]

Dumb newbie question, and I could probably find out the answer just by experimenting myself but I'm away from my office right now and thought this would actually be a decent question/answer for other newbies like me.

I'm cutting and engraving a map right now and while it looks awesome, it's taking quite a bit of time. My power/speed settings are good (like 350 for speed and 18 for power for engraving, etc) but I just realized that I haven't been checking the scam gap. Or put differently, I haven't really considered what scan gap I should use.

I completely understand dpi as I am a print designer. When I just looked up scan gap equivalents it showed .02 (which is what my default is set at) equalling about 1,000 dpi)!!! 300 dpi is way good enough for my needs, which would be around .08 for a scan gap.

So, my question is, would a lower resolution scan gap (ie going to .08 from .02) result in faster cutting and engraving. And if so, noticeably?

[Kev Williams]

Yes and yes--!

I hate the "DPI" moniker when referring to Y axis travel, because there are no "dots"--- it's LINES per inch, not dots per inch...
So at 1000 DPI (l'll call it LPI ) means your laser head is making 1000 sweeps per inch of Y axis travel. Cut that down to 350 sweeps per inch, that's 65% less lines, which equates to 65% less time to go that 1 inch...

Put another way, 1000 seconds vs 350 seconds... So yeah, big time saver! :)

There will be differentials in time due to stop/start time at the ends of the sweeps, etc, but -- by all means, use ONLY as much scan gap as necessary to get the results you want!

[Adam Less]

Ok, well I feel like an idiot. lol.

And the funny thing is, there are elements to this I can probably go even lower resolution with. So instead of the near two hours it's engraving for now, I could get this whole thing into about half an hour. Hmmmmm 2 hours = costly. .5 hour = Profitable.

Thanks and sorry for dumb questions. At least I'm learning new things. I'm hoping soon to be able to pat my head with one hand while I rub my tummy with the other. Not holding my breath on that one. :)

[Kev Williams]

NO problem!

And I hope you didn't take offense to my DPI attack, that was aimed at the industry in general :) .. And what should be called DPI they call "PPI", which is pulse per inch--at least the meaning is correct! (but to me that's the same as a dot per inch, but what do I know? ;) )

And for what it's worth, glass lasers don't fire in pulses, they just fire...

[John Noell]

And what should be called DPI they call "PPI", which is pulse per inch--at least the meaning is correct!
Well, at least on my Epilog you can set BOTH DPI and PPI. But yes, overall you are quite correct that there is a lot of slightly off-kilter terminology that obfuscates.

[Bert Kemp]

heres a conversion chart with explanation+
http://www.checkmatelasers.com/docs/layout/ScanGapDPIConversion.pdf