[ablacksmith]

Hi, colleagues!
I construct and plan to manufacture a smaller, three-sided CNC router for processing soft materials, where the hardest workpiece would be an aluminum board. I made a trial version, without any calculation, and used a weaker stepper motor and I am completely satisfied with the work, so I started working on a more serious version.

The shaft of the electric motor would be coupled to the spindle shaft with the timing belt; I determined the necessary characteristics of the pulleys and adopted the belt.
I am currently calculating shaft of the main motion(spindle shaft) and I am trying to determine the force it loads when cutting, in addition to the force that tightens the belt. There is also a tangential force at the top of a milling cutter.
? So I'm interested in how to calculate the tangental (Ft) and radial (Fr) force when cutting aluminum with an 8mm endmill with 4 flutes. (There is also an axial force, but my priority is radial). The attachment is a schematic view of the spindle.

I found some literature where is shown method to calculate these forces, but there are tables with coefficients and exponents related only to steel. I didn't found any information related to aluminum cutting.
So if anyone knows how to determine these forces, I would be extremely grateful to post here.

[ablacksmith]

In one handbook I found this equations(i put them on separate document), but as I said, there is only table for steel and cast iron. I am looking for these informations related to Aluminum.

[ablacksmith]

I found very quality presentation for calculating tangental, cutting force(Ft=Fc), and radial force which loads the spindle shaft is calculated by: Fr=1.3*Ft,
If someone needs it, it's in the attachments.

Pay attention on:
Kz is specific cutting force of material and you can find it here, for every material https://www.nyccnc.com/specific-cutt...-kc-materials/
For calculating chip thickness, it's better to use equatios from this site: http://www.biancogianfranco.com/Agg%...%20cutting.pdf where ?e is ?p from the attached document.

Cheers!