Alright… after a day of much hair-pulling and most of a bottle of Merlot, I’ve (I think) figured out how to duplicate the RAMPS laser modulation signal with a mini-RAMBO board. I still need to actually hook it up to my MPCNC and do the engraving but, judging from the signals I see with my scope, I should be good to go. I’ll post those findings later.
But, since we’ve touched on “scopes” and their suitability for the low-frequency work we’re cussing/discussing here… here’s a “sales job” for those of you so inclined – a side-by-side comparison of a $20 Banggood scope and my ~$300 Rigol DS1102E while running the Garfield raster engraving file…
The setup… mini-Rambo, displaying a +5v version of the FAN1 signal, remapped to Z-MIN
Close-up of same…
Now to go hook it up and test it on the MPCNC 
– David