Hmm - is it unrealistic to use feed/speed calculators on home built machines?

[komatias]

Agree with you Jazz, not my video though.Just the first one that came up as diy cnc trochoidal, will note that next time. Basicly wanted to show what can be done even with a light frame router.

When I rough i try to get 0.8 mm of axial offest from the total depth and about 0.5mm for finishing sides. 8mm 2-flute or 3 flute is my preferred choice with at least 3mm of step over going at 700mm/min only because i am limited to the rpm on the old KRV.

editing to add a photo of last weeks job
:

[Washout]

I'll add to the chorus here. Since getting trochoidal/adaptive CAM in Fusion 360 I've all but but given up using slotting in aluminium, even when doing cut out paths.

Although i have yet to run some "tests" to see where the limits of my machine are I'm getting 5mm DoC from a 6mm 3 flute rougher at 2.4mm stepover in 6082 T651 ali and it doesn't seem to be any where near moaning about it. Whereas when slotting I've found that the "window of safety" is small enough that you only need something in the recipe to be inconsistent e.g. a gummy spot in the aluminium or something slightly off with the machine that day and what normally runs well with a good spray of chips the day before, becomes the howling chatter marked cut from hell.

There is of course operator error on my part as well, so a wider margin of error is always welcome :)

[sinnsvak]

Slotting is about the worst cut you can do, especially in Aluminum. The best cutters I use for that are 1 flutes 3mm, they are almost impossible to gum up, because there are so much space for the chip to go.

Using two or more flutes require the cutting flutes to be really wet in order to prevent gummy aluminum chips to stick to the bit. This is the case for my 6040 anyway.


To answer your question, I have found feed and speed calculator to work pretty well. I tried Gwizard, and the calculations put me right into the ballpark when I selected the second least aggressive cut. (You can select between aggressive roughing, roughing, finish or fine finish)

[Rufe0]

[komatias]

That video puts in mind something very interesting actually. Something that I had forgotten about.

The spindle power.

It seems that the zero divides FSwizard does not account for reduced spindle power. Was looking at doing some facemilling with a 50mm and he was giving me spindle power requirements of 16HP! My poor KRV only has 3

GWizard did have the power tweek but my subscription ran out and I am not quite ready to renew.