5 axis milling

gerry wrote:

M130075D-1,6KW(for X);
M130060D-1,5KW(for Y+Z) and
M110020E-0,6KW(for A+;

Have you found any documentation for the drives? I had a look and couldn't see any, or any indication of how they work

gerry wrote:

have a look at: www.gskcnc.com/Support/DA98B_ACDriver.pdf www.gskcnc.com/Support/DA98A_ACDriver.pdf

OK, you can drive that any way you fancy in EMC2. It takes +10V to -10V input for analogue speed control, but also supports step/direction, up/down or quadrature pulse trains.

You could hook those drives up to a parallel port with just wires, if you wanted.

wizard69 wrote:

gerry wrote:

I am new to linux;
new to emc2 (its running );
new to cnc

That is an awful lot to tackle all at once!

I started from there a couple of years ago, so it is doable.

The proper hardware depends on many factors and the bigger the machine the more likely that good engineering upfront is in order. For example to size the servos you need to know how fast you want to go, acceleration, mass, inertia and other factors affecting the operation of each axis..

It is certainly worth trying at least basic speed/mass/acceleration calculations. The servos linked do look pretty big, though, rather larger than the ones in the Youtube clip.

Sample calculation, for the X gantry.
Initial guesstimates.. (change to suit)
Mass 200kg, 5m travel, end-to-end time 5 seconds, distance to reach max rapid speed 100mm.

end-to-end time suggests 1m/s max speed.
Motor max rpm 3000, means 20mm per motor rev.
v^2 = 2as means required acceleration is 5m/s^2
F=ma means actuator force is 1000N
With an actuator lead of 20mm the mechanical advantage is 2*pi /20e-3 = 314.
So, that suggests that a 3Nm rated motor will be close to giving you that performance.
(you can transiently dip into the intermittent rating for accels to rapid)
1000N (200lb) cutting force seems reasonable, that force would push a cutter through foam even without a spindle motor.
200kg might be an over-estimated or under-estimate of gantry mass.

precastengineer wrote:

very good at computing stresses deflections etc!

We could have done with you on IRC last night, trying to explain why 10x10x20mm extruded aluminium would be an awful lot less than half as stiff as 20x20x40 and wouldn't make a decent mill frame.