So it's fair to say machining isn't always the greenest thing in the world so I try to make every little effort I can.. Mainly reusing materials as much as possible etc. One thing that used to bother me was the amount of wd40 type stuff I used to get through in the shed.. It's useful stuff for freeing seized stuff, penetrating and loosening rust, cleaning parts and also blowing swarf out of holes etc... However its expensive, uses hideous propellant's which I'm a bit sensitive too and definitely not green. So the solution! Well I've long known that diesel is an amazing penetrant so a mix of a few hundred ml of diesel and then a few drops of engine oil creates a mix that in my opinion is as functional as wd40 and I even occasionally use it as a cutting fluid. All you need to do is find a hand pumped spray bottle... I favour this princess hair detangler one as the vibrant pink is easy to spot in the clutter!
So just had a very quick 15 minute CNC session as time is a bit short at the moment! I've been meaning to see how it is to rout cardboard (CNC router as poor mans laser). After a quick play its OK.. Nice to be able to cut a material in one pass and pretty darn quickly in terms of feed speed. I was worried that it may tear material rather than cut but this wasn't the case and even the smaller ring which is only 3mm wide didn't distort when cut. So it's good.. However it does have the disadvantage of leaving a small burred edge which you don't get with a laser. Also, obviously, your sacrificial material has to be something that can be cut/touched at the same keep and of feed rates or else you may break tools! So I fancy when time allows playing with some 3d print slicing software to see if I can slice a 3d model into layers/contours and then cut from card..