.
in general learning from others using the machine from decades of use is to use the biggest cutter possible and with a 20 hp machine the chips come off quick at 20 - 50 ipm especially using big dia cutters.
The "thats how we've always done it" excuse.
I've spent a lot of time finger banging some 3 axis Mazatrol. Its handy for simple holes, and simple parts, beyond that, its really pretty crappy.
Its really a 2axis interface trying its best to work in a 3D work space.
I'd say its perfectly fast and functional for 25% of parts (in my experience), the rest.. hello CAM.
You don't need a big cutter to pull big HP #s. I was screwing around with some high speed type paths a few months ago, annealed
4140. I figure my spindle is rated 22.5hp for 15(or is it 30) minutes. So ignoring the fact that I know it will start to bog at
23 cubic inches a minute(old spindle drive), I shot for 27. Ended up backing it down into the 18 cubic inch a minute range, I
didn't get to play much, only had 6 parts to do, and that is with a 1/2" $50 endmill.
I too was taught, biggest cutter, on the manual mills with R8's that meant 3/4" tooling all the time, when I got into the world
of real machines, it was still biggest cutter...
I've completely changed my tune on that. Why use a big $150 cutter when I
can simply change the way I attack a part (more efficient tool paths and use of the endmill),
use a much cheaper and smaller cutter and get insane amounts of tool life, and get the parts out the door quicker.
I apparently haven't ordered any tools since January, and we've been moving a good bit of metal, 13-8 304 4140, 4340 etc..
And apparently I didn't even need the tools I ordered then, and it was only 8 endmills, 2 of which are still in the package.
From January 17th.
Hi Curtis.
I need some APKTs, 16mm.
3 boxes, Whatever will work well in 4140 and 4340 at around a 38-40C.
All the other stuff showed up Monday and Tuesday, just in time... BUT the tools I already had were so damn good I didn't even need them.
1/2" Titan, previously used, then chewed on 304 for 2 days, then still pulled out 300pounds of 4140 at 900sfm and 150ipm before calling it quits.
Really quite amazing what going at a part in a slightly non-conventional/more modern way can accomplish. Crazy metal removal and crazy tool life.
I'm sure I could have gone a little faster and eaten up a bunch more tools, but I always try to find that magic sweet spot. Basically just
a stable process that I can leave running and not worry about.