Master and slave electronic gearing

[rainman]

Hi all,

Currently I'm constructing a master and slave gantry servo system using a single axis from the controller.

Controller-> X Axis Master->X Axis Slave (via high speed encoder A and B)

I'm not quite sure is the master is controlling the slave axis (or the slave axis is just being pushed/pulled by master axis)

When my master axis is deliberately disable, the slave axis is relatively torqueless even it is still hardware and software enabled.

Anyone has any opinions or suggestions?

I'm using copley xenus for the electronic camming.

Thanks.

[vger]

Hmmm... Ok, so you have the encoder on the master side connected to the Xenus on the slave side (master encoder input) for control? And the slave side encoder connected back to the feedback on the Xenus on the slave side, right?

Do you have a seperate encoder just for feeding the slave? Or is the master feedback encoder paralleled to it?

Steve

[rainman]

Originally Posted by vger Hmmm... Ok, so you have the encoder on the master side connected to the Xenus on the slave side (master encoder input) for control? And the slave side encoder connected back to the feedback on the Xenus on the slave side, right? Do you have a seperate encoder just for feeding the slave? Or is the master feedback encoder paralleled to it? Steve

Hi Steve,

Yes I have a seperate encoder for the slave axis, the master axis encoder signals that goes back to the CNC controller are parallel connected to the slave's command input (High speed A and B signal)

Since the 2 motors are bridged together before my testing, there is no way I can tell if the slave is following the master correctly. (I do a CAM table)

Deliberately I disable the slave axis and configure my master axis as slave and I noticed the torque is very limited even if it's enabled. (A little more push will cause following error)

I'm expecting the slave axis to have equal stiffness and torque as the master (to perform as a gantry system)

Is it how a master and slave gearing should work for copley xenus, master has good stiffness (with closed loop on CNC controller) and slave as weak stiffness when idling?

Or does it mean I have to do intensive in-drive PID tuning for the slave axis?

Thanks.

[vger]

Which Xenus do you have? Panel or micro panel?

I assume you are using analog input from the CNC controller. And that you are using CME 2 to do the setups on both drives.

Steve

[rainman]

Originally Posted by vger Which Xenus do you have? Panel or micro panel? I assume you are using analog input from the CNC controller. And that you are using CME 2 to do the setups on both drives. Steve

Yes I am using XTL xenus drive and CME 2 software for the setup.

Master has been configured as current - analog. Slave configured as position - camming.

I'm using DAC output (+-10VDC) from my CNC controller. The position loop is closed at the controller side.

I has performed auto tune (current loop) on both drives, on seperate occasion.

My point is slave appeared to be "torqueless" when it is set at camming mode, is this normal?

Rgds.