Polar direction between two cylinders

[reilly]

How can we control the output of two cylinders in opposite directions continously?

We are using two Festo solenoid valves right now. We got them to go in reverse of each other: for example say piston A goes in , and piston B goes out but this happens only once unless we manually reverse the tubing to the exhaust [2 to 4].

[Mike Betts]

Originally Posted by reilly

How can we control the output of two cylinders in opposite directions continously?

We are using two Festo solenoid valves right now. We got them to go in reverse of each other: for example say piston A goes in , and piston B goes out but this happens only once unless we manually reverse the tubing to the exhaust [2 to 4].

I'm not sure I understand your problem... Try this... Use one Festo. put a T connector at both its port 2 and port 4. Now hook one of the port 2 outputs to cylinder A front and the other to cylinder B back. Hook one of port 4 outputs to cylinder A back and cylinder B front.

See is that does what you want... If not, please describe what you are trying to do in more detail.

[Jeffrafa]

I can't say i completely understand your situation either - do you want both those to function toether, just opposite? - if so, this can be done with only one solenoid valve as mike mentioned.

If you are talking about two completely separate cylinders on different solenoids that only go one way without switching tubing then i would double check your hose locations with the schematic on the solenoid valve. Try actuating them manually first just by flipping the little blue tab on the festo solenoid valve to make sure they do what you want before incorperating electrical and programming control.

Originally Posted by reilly

How can we control the output of two cylinders in opposite directions continously?

Re-reading your question again it makes me think you mean controlling two cylinders together, only opposite to eachother while having full position control (multi-positioning). This can be done with two festo solenoid valves - just a T setup off the first to each actuator as mike has described then using the other to regulate on/off of the release of air from the exhaust of the first festo valve.

Hope some of this helps - Please explain more if I have completely misunderstood what you are asking.

Jeff

[reilly]

I was taking about "controlling two cylinders together, only opposite to each other using 2 solenoids" therefore both of you answered my question[T-connector].

Although,we have been doing this manually. Our team needs to know if there is already solenoid control in the FRC_default.hex. As is- what will the code do?

I noticed a header file online called "Pneumatics.h" and we would like to know if we need to download this header and basically what other headers, if any, do we need for cylinder control.

Thanks!

mmreilly@gmail.com

[Mark McLeod]

Originally Posted by reilly

Our team needs to know if there is already solenoid control in the FRC_default.hex. As is- what will the code do?

The FRC_default.hex and the default code v2.2 are both setup to do the following with the pneumatic solenoids.

relay1_fwd = p1_sw_trig & rc_dig_in01; /* FWD only if switch1 is not closed. */
relay1_rev = p1_sw_top & rc_dig_in02; /* REV only if switch2 is not closed. */
relay2_fwd = p2_sw_trig & rc_dig_in03; /* FWD only if switch3 is not closed. */
relay2_rev = p2_sw_top & rc_dig_in04; /* REV only if switch4 is not closed. */
relay3_fwd = p3_sw_trig;
relay3_rev = p3_sw_top;
relay4_fwd = p4_sw_trig;
relay4_rev = p4_sw_top;
relay5_fwd = p1_sw_aux1;
relay5_rev = p1_sw_aux2;
relay6_fwd = p3_sw_aux1;
relay6_rev = p3_sw_aux2;
relay7_fwd = p4_sw_aux1;
relay7_rev = p4_sw_aux2;

For instance, pulling the trigger button on a joystick plugged into the OI Port 4 will trigger a solenoid connected to the spike connected to the RC relay4 output.
The "aux" buttons are the ones to either side of the large "hat" button at the top of the joystick. the "top" button is the thumb button on the joystick.

You don't need any additional header files.