pneumatic circuitry sanity check
pneumatic circuitry sanity check
(OP)
Howdy folks.
I have a fairly simple requirement. I need to test a linear actuator (stepper with a lead screw) against a fairly constant load in both directions (~20 lbs, but possibly *also* 200lbs; trying to assess the needs of my team).
Pneumatic were suggested by the PM, sounds overly complicated to me, but I'd like to play... I've done a fair amount of hydraulic design, and I'd like to get some experience with air too.
can this be done with pnumatics? see the sketch.
thanks!
I have a fairly simple requirement. I need to test a linear actuator (stepper with a lead screw) against a fairly constant load in both directions (~20 lbs, but possibly *also* 200lbs; trying to assess the needs of my team).
Pneumatic were suggested by the PM, sounds overly complicated to me, but I'd like to play... I've done a fair amount of hydraulic design, and I'd like to get some experience with air too.
can this be done with pnumatics? see the sketch.
thanks!





RE: pneumatic circuitry sanity check
linear actuator speed:
~1 in/s
will also be using precision position feedback, and likely a load cell.
the test is to assess the motor(s) for use in a precision positioning application, to better than .001" repeatability, against ~20# of seal friction.
RE: pneumatic circuitry sanity check
Pneumatic system will give the basic kinematics, but the system "as drawn" will not be controllable to level you need.
Also, the directional control valve you have drawn will be very rough with either air or oil. If you want really precise control, you'll need a proportional control valve.
If the system will be highly transient, the gauge in the position will not be much good at all.
Cheers
HPost CEng MIMechE
RE: pneumatic circuitry sanity check
it will not be very transient.
that being said, I do want a fairly constant, repeatable load through the full travel. travel will be about an inch.
RE: pneumatic circuitry sanity check
RE: pneumatic circuitry sanity check
You could use a closed loop E/P transducer to pressurize the cylinder.
For 20 lbs you could use a glass body cylinder so that it's own seal friction doesn't skew your results.
You have to define the resolution/repeatability you need from your variable load to say if any of this will work.
All that said: Weights and pulleys sound a lot simpler...
RE: pneumatic circuitry sanity check
the PM is an very focused on the control side (read: an EE), and I like to play with valves and pistons.
but this application sounds like a complicated way to get worse results for more money. I am not on the state payroll...
cheers