Multiple axes shares same control output


#1

Hello

First of all, this is my first project that requires hydraulic motion.
I have been searching the internet for this topic and kept getting back to Delta Motion and articles written by Peter Nachtwey, so I thought here would be a good place to start.

We are currently working on a project where we need to control 6 hydraulic cylinders, where 2 cylinders will act as 1 axis (master/slave). All cylinders has quadrature feedback.
My problem is however that there is only 2 control valves for all 6 cylinders (one for the master and one for the slave). This limits control to 1 master/slave at a time, which is no problem, but I would really appreciate some help selecting the hardware when they share the same control output and/or maybe some tips.

I will just say that this is an old 20 year old machine and our customer does not want to update the hydraulics, as it was recently shined up.

EDIT
Forgot to mention that I tried downloading the programming software and it does not seem to be possible the configure axes with the same control output.


#2

Claus,

To switch the outputs, I suggest creating an Outer Loop axis for each axis of control, and then creating a control axis with no feedback. An Outer Loop axis is just like a normal control axis, except that is doesn’t have a physical Control Output. Then, you would make a single-step user program that always runs, and copies the Control Output from the desired axis to the output only axis. You will need some logix in there to choose which axis the Control Output is copied from.


#3

Don’t think in terms of gearing the slave to the master. We have a Synchronized move absolute where both axes are geared to the same target position.


#4

From a hardware standpoint, Attached is probably the cleanest way to go.

There must be some other valves directing the oil from the prop valves to the appropriate cylinders. If the RMC needs to do this then you would need some digital I/O as well.
Share Valves.pdf (109 KB)


#5

Hello all,

Thank you for your replies.
Think I will be going with the solution with outer loops as sugested.