I want to mill steel with this machine.

All the tools I have are carbide. I don't have a single HSS tool laying around.

I am working in solidcam so yes HSM machining can be choosen.
I have coolingwater on the machine aswell. I looked at this video, but that is insanely fast, that could never go well with my machine. + The smoothness of motion I could also never reach in linuxcnc , it will give jerks or points where it slows. I posted a topic on this aswell a week or 2 ago and the conclusion was that linuxcnc can't do better because of lacking S curve acceleration and things like that. I had the issue that doing helix entries after every full circle it kind of halts/jerks before moving to the next circle with settings g64 p0.1 q0.1 which is my standard setting through all gcode.

Is it not so that the tool would simply break before anything else would happen to the machine or motors/carriages/guide rails.

I am used to always run above 12000rpm on the spindle. I don't really know how much power is in the lower rpm regions. Never needed to as it's always carbide tools. I know drilling has never been a problem at low feeds only drilling on my machine vises has been an impossible talk as that is a special hardened outer rim which is the hell to go through. But that's only downward action.

I use gwizard for feeds and speed in aluminium and solidcam 2d machining which complete chooses all settings for the cut after choosing what material I am working in. Only used it for aluminium and works like a charm.

On the other hand with a 160a power on the plasma on 12mm mild steel. How accurate would it be possible to make 16mm holes?

Stephanisk wrote: On the other hand with a 160a power on the plasma on 12mm mild steel. How accurate would it be possible to make 16mm holes?

Depends on a lot of things, but, around 1mm with some practice, 0.1 to 0.2 with lots and lost of practice but might not be possible due to nozzle/torch/air humidity/material/some fuzzy stuff that happens to plasma during cutting.
Rod and thefabricator might be much more helpful with this as they do some very nice holes on thick material, all i get is some oval..... so i do not bother with anything under 30mm in diameter even on thin material.

carbide has different grades the lower end carbide i think has a hardness of around 65 hrc and the higher end carbide has a hardness around 85 hrc. coatings on the tools can help with tougher material too.

i think with material 12 mm think you might get a hole kinda round but tapper is going to be hard to avoid with the hole sizes no matter what you do on thicker material. plasma is not exactly a precision process in my opinion.

12,000 rpm is pretty fast for steel. if you can get down to 8,000 or less you might have a chance but that's still pretty fast and you are going to be limited to small diameter tools at the speed.

tommylight wrote: I did say it is possible, and the rest seem to forget you are talking about routing on already plasma cut parts,

I wonder if it might be better to cut the holes with the milling cutter. Perhaps pre-cutting with plasma is not helpful?

Can you swap the spindle temporarily? The best way to cut the holes is probably with an annular cutter (as used by magnetic drills) without pre-cutting with plasma. If you could buy / rent a mag drill and mount it to the gantry, then the job would go fast and clean.

Someone else also suggested drilling them with the router, as it is a better solution, but by far the best solution is Andy's drills, they are magnificent.

@andy, yes I actually could take out the mill and I have a magcutter here. Have to make something to fit it but that's not a issue.

Is that dirll would be within 0.1 that would do the work indeed.

Still have to do the outside profile of the plate but if I would run that at 0.1mm per pass. It's only 12mm total, that wouldn't be a too lengthy job. I could use a 6mm 4flange cutter running it with coolant

That seems indeed a good idea, as long as this angular cuttur ( I believe as to what you mean is a hollow kind of mill/drill.) Is accurate enough