Working with mild steel.

[Neale]

I've been cutting steel with my router for a while now, on the basis originally of "What could possibly go wrong?" Mainly bright mild (EN1) but more recently EN3B or similar from my local stockholder. The kind of general-purpose mild steel as desctibed by Wal, I suspect.

Key thing for me was finding cutters rated at 8K RPM or more (in the small sizes - 2-4mm - that I normally uae), some kind of coated carbide, usually 3-flute, and also recommended to be used dry, no lubricant or coolant, which is great for someone with a wooden bed machine. The usual 3HP spindle really doesn't have any grunt worth talking about at much under 7K, and I have done more damage to cutters running too slowly and slowing the spindle (you can stall it with a 3mm cutter...) than I have done with cutting faster. I get my cutters from Cutwel.

You need a stiff machine, I suspect. Mine is all welded steel, profile rails, ballscrews. I don't think that rigidity is as big a problem as resonance - if I were building another machine I would go heavier than the 3mm box that I used just for damping.

Not exactly a high-volume production technique but you use what you've got!

[Wal]

I've been cutting steel with my router for a while now, on the basis originally of "What could possibly go wrong?"

Heh - pretty much identical to my thought process..!

Yep - second the three-flute recommendation - the little carbide 3/3mm has done loads of full depth edge milling and it's quite happy to do some more. I did use a 6mm uncoated carbide two-flute on this pair of riser blocks - once again - thin cuts, softly softly to begin with - for the second block I cranked up the feed a fair amount and it was still pretty happy to get on with it.





Brian - the two machines (pics below) I've got are my first build fixed gantry mini-mill - it's quite small and uses supported rails rather than profile, but it's proven to be a very reliable machine - the larger moving gantry style router was largely built for me by CliveS (I stood around drinking his tea, eating his biscuits and asking the stupid questions) and the design of it leant very heavily on what JazzCNC builds. Once again, a very capable machine - I have a few upgrades planned to both, but in all honesty they work very well as they are... Both run off the same control box (I have a new digital driver box on the bench for the router, but I need to gather up the enthusiasm to set up the Mesa card for it...)



Wal.

Edit: I see Dean has contributed above �� - it really is a very capable machine - continues to serve well and impress..! ��