Working with mild steel.

[Wal]

Hi all,

I've always shied off working with anything ferrous - until fairly recently, where I've had to cut a few parts from steel - I can't tell you exactly what grade, it's fairly generic mild steel covered in mill scale that you'd typically buy off ebay, or that's issued when getting profiles flame-cut etc. Nothing exotic.

First thing to say is that yes, you have to be realistic with cutting parameters and you're simply not going to run as quick as what you'd perhaps like to, but since most of us aren't in production and in no real hurry, then whatever - as long as the parts get made, right?



Here's a vid of a bit of adaptive clearing and a finishing pass on the flange nut shown above:



And here's the finishing pass on the flat spanner:



Even managed to make myself a suds tray with a 1000x500x1mm sheet - this was a bit slower/trickier to machine, but still yielded some decent results:



(Gaps were filled with Chemical Metal before paint).

Anyway, my point is this - I was massively surprised at being able to make myself decent useable parts in steel using my mini-mill and my router. Drilling was fine at 8krpm on the spindle plunging at 0.15in/sec using a 6mm drill bit - three flute and two flute carbide end-mills intended for aluminium worked just fine. Yes, yes - it's all a bit of a hack, but it's a place to start and I'll be buying some more relevant tooling and refining my methods as I go. Pretty cool though.

Wal.

[Kitwn]

Wal,
That's very encouraging. Gives us all the confidence to try.

[Voicecoil]

Check out the "Nano coated" cutters from APT - I found they work very well on steel if you have a spindle that doesn't give much poke at low speeds.

[Wal]

Cheers. Will add a couple to my next order...

[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!

[BDH]

That's very interesting Wal, could you give some idea as to the machine you are using?
Brian

[JAZZCNC]

Looking good Wal as usual, Is that still with a single screw on my baby.?

[JAZZCNC]

That's very interesting Wal, could you give some idea as to the machine you are using?
Brian

Hi Brian,

I'll answer this because Wal might not like to say much about the machine without my permission.

The machine he did the spanner on, not sure about the nuts.?, is one of my designs and is pretty much identical to this one but without the front panel.
Thou I didn't build it, Wal built it with Clive S help cutting parts with my permission using Code I provided in return for all the Help Clive and Wal have given me.

They made a cracking job and Wal makes excellent use of it considering it was only ever designed and sold on basis of only cutting woods and plastics with occasional light aluminum work. Think I'll have to make him Chief stress tester... ( And that's on the Single ball screw version, there is a stronger twin screw version which Wal as had all the bits with modified plates sitting on the shelf, which I'd wager he hasn't swapped out yet..)

[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..! ��

[Wal]

Dean - you're 100% correct - here's the extra screw and the new control box as they are today...



A combination of laziness and being quite happy with my current set-up... I'm mostly not very busy at all, but guaranteed the second I take the router apart someone wants something doing...

Wal.