Has anyone built a k40/50 from scratch? If we manage to get the business off the ground the wife wants to get a backup. I think as you need to replace half of it anyway (I needed a tube straight away and most of a power supply within weeks) and they come assembled, sealed and aligned badly, with low quality fan and pump, why not build it from scratch with a wooden body (dull metal plate at the bottom at the bottom maybe), sort the airflow, sealing, air assist and extraction properly, and leave room for a bigger cutting area and a 800mm 50W tube. PS I am more than happy controlling it with the standard board via Corel, I have used that since the 90s anyway.
Many of us on here have thought about this or even done it.
There are some builds in Openbuilds for a DIY laser machine.
If I was to do it again (and I may) I would build it from Openbuilds parts and shoot for 100W.
Using the stock controller may be problematic as I do not think you can make the firmware adjustments you need for size and speed and I doubt the board has enough drive.
Freeburn is the name of the project on openbuilds that should get you started in the right direction
That freeburn project mostly links to http://wiki.openhardware.co.za which gets a site not found for me