milling a 2mm slot in mild steel

[Dave TParticipant @davet19446]

Hi All,

I want to mill the above along a 4mm section of steel. The smallest cutter I've used so far is a 3mm, but was hand fed for a very short distance at maximum rpm and I was sweating all the way through (didn't break the cutter though

The cutter I've got is HSS 2 flute and as I've got a powered x axis, will be using that. Can someone give me a little help on speed/feed/cut please? I've only got the one cutter but I'd like to preserve it as best I can.

My machine is a Warco VMC.

Thanks

Dave T

Edited By Dave T on 01/06/2018 23:12:05

[Dave TParticipant @davet19446]

[JasonBModerator @jasonb]

1500rpm, 0.5mm depth of cut, 100mm/min feed.

Try it first hand feeding and if it is happy engage the feed

[Dave TParticipant @davet19446]

Thanks Jason

[VicParticipant @vic]

My milling chart says 2400 rpm for a 4mm cutter in mild steel. If you’ve got a VMC you should have a 2100 rpm option, that will do. I would sneak up on it and try a cut at 0.25mm first and increase slowly if it’s happy. 100mm/min feed is about right.

[Adam MaraParticipant @adammara]

I have a spare 1/16" cutter ex cutting plastic on a CNC router, PM me if you are in need! I have found they may not cut plastics cleanly, but seem to cut metals OK

[Dave TParticipant @davet19446]

Vic,

It's a 2 mm slot in 4mm material

[not done it yetParticipant @notdoneityet]

To avoid breaking your cutter, might a slitting saw be an alternative?

[VicParticipant @vic]

Posted by Dave T on 02/06/2018 12:17:03:

Vic,

It's a 2 mm slot in 4mm material

Ah, not sure of the speed then my chart doesn’t go that small. As said though, a slitting saw may be better?

[Dave TParticipant @davet19446]

A slitting saw is a definite thought, thanks

[JasonBModerator @jasonb]

That's another reason I don't bother with charts – you are not stuffed if the size you want isn't on the chart. Anyway with no speed readout on my X3 it's all a bit finger in the wind

 

Thought I'd give it a go for you, used ketan's SX2.7 as that has a speed readout. Speeds and feeds as I said above but did not have a 2-flute so this is with a 3-flute, two you could up the speed and or lower the feed to keep a similar loading per tooth. Feed screw is 2mm pitch if you want to work out exact feed from my hand movements.

 

Not too shabby, single pass on left, two passes on right.

 

If your cutter is a 50p Bangood special then all bets are off.

Edited By JasonB on 02/06/2018 17:09:17

[Dave TParticipant @davet19446]

Thanks again Jason

[VicParticipant @vic]

Posted by Vic on 02/06/2018 15:15:10:

Posted by Dave T on 02/06/2018 12:17:03:

Vic,

It's a 2 mm slot in 4mm material

Ah, not sure of the speed then my chart doesn’t go that small. As said though, a slitting saw may be better?

Looking at the speed range on the VMC you’re be at it’s highest speed using a 2mm cutter and should get a nice finish.

[Dave TParticipant @davet19446]

Cheers Vic

[JasonBModerator @jasonb]

Just so happened to use the 2mm cutter last night on some cast iron, similar sort of speed but 1.0mm DOC, feed a bit of an unknown as cuts were on the R/T. Deep pockets are 4mm.

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