Homemade desktop CNC - cutting 0.8mm mild steel out the question?

[HankMcSpank]

Well, I just had a go - I only had a 4 flute 2mm dia end mill to hand - I went with 4 cuts @ 0.2mm cut depth per perimeter run, squirting a bit of wd40 (it was all I had!) once in a while - the end result was very reasonable (though a degree of deburring will be in order. I couldn't bring myself to use the higher feed rates, so went with 150mm per minute.

That said, I could telll that my machine/spindle wasn't particularly happy (I understand it better than my wife now) - it's used to acrylic! But at the end of the day, there was no real drama (unlike with my wife). Material clamping is an issue though, ie that last bit where the part is fully cut out from the material - it's tin helmet time. Not pleasant.

Nice to know though - ie that for the odd thin steel widget, my humble DIY machine will grudgingly comply.

[Robin Hewitt]

a degree of deburring will be in order... that last bit where the part is fully cut out from the material - it's tin helmet time.

Is the part particularly small? No possibility of running a couple of bolts through it?

If I had to guess I'd say the last .2mm of your tool is now exceedingly blunt and flex in the system is giving you a stop-go cut as it builds up a cutting pressure.

If you haven't got/can't use a bigger cutter I'd suggest, wind the speed down to about 1500rpm, the feed down to 60 mm/min or less, cut clearance on your sacrificial plate so can cut in one pass to a cut depth that uses the middle of the flutes and invest in a bottle of Rocol RTD liquid (apply generously) :naughty: