I have, after just over 14 months finished my K40 build on RAMPS 1.4.
My grinding and resonance issues have all been resolved now I found a post on A4988 pololu copies. MS3 jumper on the RAMPS board does not work and it ignores it. Set MS1 and MS2 as the copies only support 1/8 microstepping not 1/16. Reverted to the MK4Duo default firmware with only a couple of changes and it’s smooth, quick and quiet.
New laser head from lightsource was well worth the money - the original lens corroded and I bought a cheap chinese head from ebay and new lens rather than pay excessive shipping from lightsource. This was a false economy. New one from lightsource arrived, transferred lens and it’s working beautifully. Just need to realign and I’m ready to use it. It’s been a long journey but I now know a ridiculous amount about RAMPS systems now. No ghosting any more - the ghosting was caused by the cheap chinese laser head due to poor machining. You get what you pay for…