Good choice for VFD or servo in a Master/Slave setup

Hi guys,

What would be a good choice for a drive or servo in a master/slave setup controlling two sides of a lift? The issue is that the lift has to go all the way down to the floor and we would not be able to put a jack shaft in to drive the other side.

So we plan on using two lift motors, which each would have an encoder. Suggestions for the encoder choice would be appreciated as well.


Thanks!

John

Hi, we use the Rexroth drives with Indra Motion and Indra logic. We have built many lifts such as you describe with multiple motors and drives, as many as 8 "axes" that I know of. They work very well, and the customers that we built them for are sold on them. (Aerospace, automotive and others.) I know very little about how to write the logic (they have an embedded PLC or you can use a stand alone PLC with them. The platform is Codesys. I am an A-B user and I'm not familiar with all the setup on them. I've watched others here at my work doing this and it's not too bad. I'm doing a small project with 2 servos now and it has been a challenge for me. These are supposed to be the primo product for motion. They are expensive.



I do NOT work for Bosch-Rexroth. I work for a controls integrator that is a distributor for them. Hope this helps.

It does! Thanks so much!

I've used Fuji Ace drives in a master/slave setup with great results. The slave drive will get the extra encoder card and all of the functionality is built in based on parameters.

What HP are you looking at? Servos might be more expensive at larger sizes, VFDs with Induction Motors might be too expensive at smaller sizes. But certainly this can be done with either now. In the VFD realm, it's going to be the higher end products, not the inexpensive cheap ones. But do you also need regen braking? That might make a big difference.

Let's say it's for two 15hp motors, it's still in the design phase, but it won't be more than that.

No regen braking necessary.

I'll take a look at the Fuji drives as well.


Thanks for the help guys!

This is the only one that I would go with
they are designed for lifting and hoisting applications not just a label on a standard drive
Every lift is safety check before and after every move, a failure sets the brake and halts the move.
Been using them for years .

http://www.magnetekmh.com/

Marathon Black Max motor dynapar encoder

GaryS said:

This is the only one that I would go with
they are designed for lifting and hoisting applications not just a label on a standard drive
Every lift is safety check before and after every move, a failure sets the brake and halts the move.
Been using them for years .

http://www.magnetekmh.com/

Marathon Black Max motor dynapar encoder

Click to expand...

I took a look at it, and it's more in line with what a crane would need (this is for a standalone vertical lift). The weigh scale feature is interesting, and could be useful to us. I'll call them up and see what they can do for us.

Thanks!