AB Servo/VFD

I have a project coming up requiring a VFD and servo system.

The VFD motor will transfer parts up a flighted conveyor onto a rotary table controlled by a servo, which will turn slowly in one direction as the parts are dropping on to it.

A robot vision will look at the loose parts on the table and pick and place. If there are objects there but none 'pickable', the servo will rapidly advance in +ve direction followed by a sudden stop and then the same in -ve direction to shake up the parts.

I am doing proof of concept with a Pacific Scientific servo, but as these are now obsolete I need something modern.

PLC will be a small compactlogix (e.g. L16ER)

What is good in AB with E/IP for VFD and servo? Will I need an 'ER-M' (Motion) designated PLC to send servo commands? Or is the servo overkill and a simple VFD on the rotary table suffice?

You could use a 755 for both functions starting off with induction motors, and if you have to upgrade the turntable motor to a servo, it could still be the driver for it. Ethernet I/P is built in to the drives already. Plug and play...

Note though that you didn't say anything about sizes. If the turn table is fractional HP, a 755 would be over kill...

What about yaskawa.

It is fractional, the parts weigh 50g each, at any one time there should be max 40-50 parts on the table. Is there a smaller drive?

widelto said:

What about yaskawa.

Click to expand...

I will check if any of our current suppliers offer that. It's a long process to add a new supplier to the system. Does it have AOP?

If you're looking at AB, I'd look at a PowerFlex 525 VFD, and a Kinetix5500 for a servo. If you're using the CompactLogix with a servo drive you will need the "ERM" version.

-Benaiah

The first question I would ask is. Why do you think you need a servo for this application.
I don't see it. I would just use a Yaskawa A1000 with encoder feedback on everything.
Clean simple and cost effective.

For the rapid shake function. It was one of my questions too

I have done some testing on the PacSci. The rapid shake function doesn't work great. I am leaning towards VFD or an SMC (Pneu.) LER rotary table with an E/IP controller.

As I read your description, I too now think a 525 and an induction motor would work for the turn table application (and the belt feed of course). All you are really looking for is a soft start/reversing with controlled speed. The biggest issue is really the motor itself, that's tough duty for any motor. Use a good quality inverter duty motor, separately cooled or at least over sized just to help absorb the heat during that shake operation.

As to AB drive versus other brands, nothing will be simpler to integrate into an AB Logix processor than an AB drive. Some of the others offer their own AOPs, but it's not quite the same. One big benefit of using the 525s or 750s and Ethernet I/P is that should a drive need to be swapped out later, you can enable ADC so that the person changing the drive can be any grunt wireman who can't spell VFD but can still do 3 wires in / 3 wires out, then the PLC reprograms the new drive and can go back into production fast without that grunt needing to program anything.

I would scrap trying to put the "shake" function on the motor and just install a small pneumatic rotary vibrator on the table to break the parts up. That will make your motor control a little more simple.

jraef said:

As to AB drive versus other brands, nothing will be simpler to integrate into an AB Logix processor than an AB drive. Some of the others offer their own AOPs, but it's not quite the same. One big benefit of using the 525s or 750s and Ethernet I/P is that should a drive need to be swapped out later, you can enable ADC so that the person changing the drive can be any grunt wireman who can't spell VFD but can still do 3 wires in / 3 wires out, then the PLC reprograms the new drive and can go back into production fast without that grunt needing to program anything.

Click to expand...

Yup, totally agree. Our shop has switched over to all the motion drives, and it makes life so much easier on AB.