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Check My GWizard Figures?


Hi All,

I want to cut a 50mm diameter cylinder out of a block of 6061 aluminium that is 40mm thick.  I have downloaded GWizard to determine the correct feed and speed.  My CNC machine is a 6040.

The figures entered into GWizard are:

Material – 6061 aluminium
Tool – Carbide Endmill
Tool Dia – 6mm, 3 flutes and a ‘stickout’ of 40mm
Cut depth – 4mm
Cut width – 4.6608mm (I don’t understand this bit)
KW limit – 0.8kW
RPM Limit – 24000
Min RPM – 1200
Feed Limit – 10160 (2%) (I don’t understand this bit either)

The RPM comes out at 14031 RPM and Feedrate 205.3 mm/min

All the reading are now in black but a warning re “Chipload is low, may cause rubbing!” is displayed.

Please can someone check my figutes and what will be the best way to mill this cylinder from the block?



  • Gary Williams asked 1 year ago
  • last edited 1 year ago
  • You must to post comments

Gary, I’m a bit skeptical from several standpoints.

But first, some answers to the puzzling bits.  Since the Cut Width is less than the full cutter diameter, you must cut from the outside of the workpiece in so as not to exceed that Cut Width.

The Feed limit is the maximum rate your machine can move the cutter.

Okay, now on to what makes me skeptical.  We’re on a router, I assume?  You’re asking that cutter to go down pretty deep.  In fact, you’ll need more than 40mm stickout if the material is 40mm thick.  Probably need to leave a 5mm margin or something.  That is really going to leave the cutter hanging out a long ways versus the diameter–over 6x diameter.  Since you’ve got to go in from the outside anyway, I would get a larger cutter–the biggest that fits, but maybe 12mm’ish?

Second, this being aluminum, you will need some sort of lubricant or the chips will just stick to the cutter until it breaks.  Ideally, you want to rig up a mist system with compressed air and some kind of water soluble coolant.  At the very least, lots of spritzing with WD-40 will be needed together with compressed air or some other way to blow the chips clear of the cut.

This is doable, but you’ll have to tend to some of these things for best chances.


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