Only just picking up this thread. Excellent input from Carl and others that are progressing through it.
I had dealings with one around 10 months ago and purchased one off a friend that didn't get on that well with it.
It was a stock unit and no mods. I looked around to do research and how too's
No sure if anyone has seen the g+ communities. Excellent form of advice.
The laser k40
https://plus.google.com/communities/118113483589382049502
I upgraded mine so that I can use open source software, best thing I ever did. I mainly use laserweb amongst others
Lasweweb G+
https://plus.google.com/communities/115879488566665599508
I put the cohesion 3D board in mine. Not a simple plug and play but once worked through it. Works really well.
Cohesion 3 d G+
https://plus.google.com/communities/116261877707124667493
smoothie G+
https://plus.google.com/communities/111870450664099533727
One word of warning with the K40 that has never been talked about in this thread, they are a dangerous piece of kit and tend to set on fire if you are not carefulll.
What I would say is never leave it alone when it's in operation as if the belts fail then it's curtains..
Also, when the job has been completed don't just lock the shop up and leave it, there may be embers still inside the body that catch fir. Stay with it and make sure nothing can catch fire.
I did all the mods that I see Carl has done, apart from motorising the Z axis bed table.
I didn't go for the light object jobs as posted to the UK they work out mega bucks. So ended up making all my own stuff.
Will post some pics when I get back from annual leave.