Hydraulically controlled CNC axis
Hydraulically controlled CNC axis
(OP)
Hi,
I'm looking to build a 3 axis cnc machine about the size of a van.
All 3 axis will be controlled by hydraulics and actuators will consist of 2 hydraulic motors (x axis), 2 rams (Y axis) and 1 hydraulic motor (y axis).
I was thinking of using rotary encoders connected to each axis and fed back to a motion controller. The motion controller will convert G-code to +/-10vdc pwm signals to control proportional hydraulic valves.
Can anyone point me in the right direction for suitable hardware / advice?
Many thanks,
Jim
I'm looking to build a 3 axis cnc machine about the size of a van.
All 3 axis will be controlled by hydraulics and actuators will consist of 2 hydraulic motors (x axis), 2 rams (Y axis) and 1 hydraulic motor (y axis).
I was thinking of using rotary encoders connected to each axis and fed back to a motion controller. The motion controller will convert G-code to +/-10vdc pwm signals to control proportional hydraulic valves.
Can anyone point me in the right direction for suitable hardware / advice?
Many thanks,
Jim





RE: Hydraulically controlled CNC axis
What position control do you need +/- 0.00?
How quick do you need it to be? In other words, how quickly do you want to go from 0 to say 1000mm on each axis?
What force and torque are you anticipating needing on this?
RE: Hydraulically controlled CNC axis
Position control accuracy to 0.25mm
Torque and force not calculated yet.
Hydraulic circuitry & design not a problem, I can calculate and build this when required.
I'm more focused on the electrical side of things at this stage of the design. I have experience with electrical CNC machines (lathes / mills etc), a lot of experience with hydraulic circuit design and implementation. Designing a hydraulic CNC will be a first for me, but considering I know both separate subjects well I'm hoping it should be easier to grasp.
My main questions are:
1. What CNC motion controllers (PWM or analog (+/-10vdc) are available that are compatible with hydraulic proportional valves?
2. Method of feedback? Rotary encoder to motion controller? Spool LVDT sensors to controller?
Thanks,
RE: Hydraulically controlled CNC axis
The theory behind any system will be the same, but the power and control requirements will drive the cost up.
Linear transducer attached to a slide way
Rotary transducer connected to a ball screw
Position fed to a controller. A digital or analogue controller that will measure position and provide output current to the actuator. A PID controller most probably.
The level of precision and control needed will dictate the cost of the controller and the software needed to drive it.