Rough estimate of the force applyed by spindle on the gantry

[snow]

Hey
Im trying to understand for the last week now :
how can i estimate the force that the spindle applying on the gantry during cutting?
(lets say aluminium 6061 is cut with HSS tool with diameter of 10mm, feed 100mm\min and depth of cut 2mm)

[Kitwn]

HSMadvisor calculates this for you. It's in the 'Cutting Data' tab.

https://hsmadvisor.com/

30234

[routercnc]

Strange that they quote it in kg (mass), rather than N (force). Not a big deal to x10 though !

I've always used the following as a guide:
Wood 10 N
Alum 50 N
Steel 75 N

These were quoted by a forum user a long time ago, and I've seen 'similar' values quoted from a company that make force sensing equipment and had kitted out a milling machine. Of course it depends on F&S too, so just a start point.

But remember these become moments when applied to the gantry so are a force at the tool cutting edge x the distance to the gantry bearings. Yes this will try and bend the gantry, but it will apply a much bigger twisting force and this will dominate the total tool deflection (in terms of how the gantry reacts).

This is also just the mean static force. There will also be vibration on top of this which will add a bit more to the total force applied.

[Kitwn]

But remember these become moments when applied to the gantry so are a force at the tool cutting edge x the distance to the gantry bearings. Yes this will try and bend the gantry, but it will apply a much bigger twisting force and this will dominate the total tool deflection (in terms of how the gantry reacts).


This has always been one of the reasons for having two ballscrews on the long (X on my machine) axis. Cutting forces cannot twist the gantry horizontally even when using ralis/bearings with a little give in them like the continuously supported rails I use. They can still bend it, twist it vertically and make it lean if the structure is not rigid enough but the worst effect (or probably largest amplitude effect if you prefer) is taken care of.