need to measure servo load

[arjay8]

Hi All,

I apologize up front for my ignorance and hope that I'm not imposing on your generosity.

I need to measure the change in down-feed force required to make a z-axis cut on a CNC milling machine to test drill bit wear. The down-feed is driven by a servo motor. As the drill bit gets dull, more down-force is required. Is there a way to monitor the servo's load to get a relative wear comparison for different drills and/or metals being drilled?

I thank you in advance.

[ALZ]

Hi:

I don't know about CNC milling machines. The voltage or power yours takes but motors take more current as they do more work. So  monitor the current of the servo motor. Before you pull anything apart, they sell non-contact meters which are low cost.

Hi All,

I apologize up front for my ignorance and hope that I'm not imposing on your generosity.

I need to measure the change in down-feed force required to make a z-axis cut on a CNC  to test drill bit wear. The down-feed is driven by a servo motor. As the drill bit gets dull, more down-force is required. Is there a way to monitor the servo's load to get a relative wear comparison for different drills and/or metals being drilled?

I thank you in advance.

[paulstreats]

also if you type "open servo" into google, there is an open servo project where they are using different methods of getting feed back from the servos, maybe you can pick up some hints and tips from there

[Admin]

Measuring current as a way of measuring torque will not work - servo current draw is not linear, not even close. Its far from being reliable.

You'd need to use a load sensor(s) either attached to your CNC, or the part being machined (the better way).

http://www.societyofrobots.com/sensors_forcetorque.shtml