machining aluminium with 1.5kW spindle

[EddyCurrent]

1. Reading the VFD manual for torque boost (need to check it has this and suspect it will heat the spindle)

This is not applicable to your issue, Torque Boost is to produce initial torque from standstill, for example to get a heavy load moving, it usually cuts out at low frequency or when the speed you selected has been reached.

[routercnc]

Thanks Eddy. I misunderstood what that was for and this afternoon (before reading your reply) I experimented with boosting the voltage by 10% in the region of 4500rpm [default was 5% at 720rpm] and also had the DOC set to about 1.5mm. It happily cut a slot 50mm long (6mm 2F Carbide bit) without problems.

Now I'm confused. If the boost is momentary until the speed is reached it wouldn't have affected the torque delivered during the cut since I allowed the tool to reach the required speed before starting the cut. Perhaps everything was cold (tool and workpiece) and I would need to machine for longer to see if this was actually better.

Anyway before I could experiment further I had to take the machine out of action to send one of the ballscrews away for straightening so I'll have another play when it returns.

Thanks for the advice - I don't think things are so drastic as I first thought.