Okay, I made up a google docs spreadsheet from my local Excel spreadsheet. Hopefully it will help someone out.
https://spreadsheets.google.com/spreads ... E&hl=en_USIt's fairly self-explanatory. The only thing that might be somewhat confusing is the "Pulses per Scan Gap" table at the bottom. Basically, any of the entries in there that are whole numbers should be acceptable for scan gap entries for that steps / inch. For example, at 1,000 steps / inch, the scan gaps that produce whole numbers for the number of pulses between gaps are .254, .2032, .127, .1016, .0508 and .0254. These relate to DPI values of 100, 125, 200, 250, 500 and 1,000. I wish google docs would let me use formulas for conditional formatting like Excel does, then I could easily highlight entries that were whole numbers, but that's just not happening. Theoretically this should produce the best results for that particular steps / inch setting, as there should never be any overlap of the laser (assuming it's .001" in engraving situations) as there will always be a whole number of pulses in the Y direction for that particular scan gap setting. I haven't been able to test this yet, and this will definitely be different if your laser head isn't exaclty .001". Even if your laser head is .002", you can still use the chart, you just have to account for the fact that you'll only be able to use even values of DPI.
I'd consider working on a chart that will calculate these values based on varying laser head widths, but to be honest, I'm not sure we really have anything that will measure accurately enough to really make it viable. It really is kind of a do what works best for you type thing, as I'm sure everyone's optics are going to be slightly better or worse than others, and some folks will be better at focusing the beam and all that jazz. So, this is really just more of a theoretical idea of how good your system can perform if it's basically perfect.