Two pressures?

[Ryan Cumings]

Is it possible to use different pressures for the extend and retract on the pistons? For example, use 60 psi for the retract and regulate the 60 psi down to 30 psi for the extend?

[dez250]

why would you want more pressure on the retract then the extend. In pneumatics like we have there is no real "speed control" or "stroke distance control" that we have by limiting pressure input on different sides.

[NoRemorse]

you could use the 2ndary regulator on one of the pneumatic lines downstream from the solenoid valve.

NOTE: im not entirly sure how this would work thoug, i dont know how air reacts passing backwards through the reg. I am under the impression it gets vented, but it might restrict flow then. try it!

[Tom Bottiglieri]

in te kit of parts *not sure what they are called* there are little pressure regulators that attach to either end of the piston. The are whit and orange and have a little turny knob on the top for adjusdments. Put those on and tweak around with that.

[dez250]

Originally Posted by ToMMan b182

in te kit of parts *not sure what they are called* there are little pressure regulators that attach to either end of the piston. The are whit and orange and have a little turny knob on the top for adjusdments. Put those on and tweak around with that.

please spell check all posts before posting

[NoRemorse]

those are not pressure regulators, those things are called "Flow Controls". They allow the flow of the air passing OUT of the piston to be controlled. They can be used as 1 way valves to, because air in is unefected, and air out can be cut off when the valvr is all the way closed.

[jimfortytwo]

EDIT: So my guess at your intent was wrong. And four other people replied while I was typing this. However, maybe this post with have intrinsic value to someone else. Consider it a recap.

I'm going to sort of ignore your question, because I've got a feeling you're asking how to dodge the 10ft/sec rule with a piston bar hanger. I assume that what you're trying to do is actually control piston extension and retraction *speed*. If thats the case, using a regulator to restrict pressure for the extension is only indirectly going to solve your problem. NoRemorse's flow controls screw directly onto the pistons, and will allow you to adjust stroke speed without effecting force.

If you really want to restrict *pressure* for whatever reason, and you fully realize that this will have only indirect impact on piston speed, you'll need that second full blown regulator.

[Ryan Cumings]

Not exactly trying to dodge the 10 ft/sec rule. It was more of a way to reduce the amount of air we exhaust when we extend the piston so we don't need to wait 30 seconds for the system to gain enough pressure to fully retract the piston.

[jimfortytwo]

I understand your intent now... your clarification got sandwiched in between my read and my write. I don't know what your mechanism actually looks like, but would it be possible to leave one side of your pneumatic vented and just use a bit of surgical tubing for the extension?
I'm not sure what the technical term is, but I know I've played with cylinders that had a spring loaded extension and a pneumatic retraction. I couldn't tell you if those components are FIRST-legal, but you might be able to cobble a reasonable facimile together. Then again it might not be worth the added complexity.

[ngreen]

I think using the single solenoid off a secondary regulator would work best. Just shorten all your tubing so it will regenerate pressure quicker. You don't need to worry about flow controls all that will do will slow down your cyclinder and not reduce amount of air used.

I think he wants to extend and then retract Ken.

edit: But I imagine it would work the other way too

[Kevin Sevcik]

As an answer to the original question, if a secondary regulator downstream of the double solenoid doesn't work because of the directionality of the regulator, you could always use two single solenoids and have one supplied by the secondary regulator.

Also note: I recall accidentally hooking a regulator up backwards once, and it completely failed to regulate pressure, so I think the regulator after the double solenoid should work. If you want to have more than one cylinder set up like this, single solenoids would be the way to go since I think you're limited to just the regulators in the kit.

Also, to everyone else, I can think of one good reason to set up a cylinder like this. If you know for certain that you don't need 60psi on the retract and only need 30psi, setting the system up like this could potentially save you a lot of stored air and battery power, depending on how often you cycle the cylinder. It works out to about a 25% savings for every extend-retract cycle. That could potentially be very important.

Edit:
I'm a slow typist, but I swear I thought of that before he posted his intentions. Honest.

[Ryan Cumings]

Originally Posted by Kevin Sevcik

As an answer to the original question, if a secondary regulator downstream of the double solenoid doesn't work because of the directionality of the regulator, you could always use two single solenoids and have one supplied by the secondary regulator.

Also note: I recall accidentally hooking a regulator up backwards once, and it completely failed to regulate pressure, so I think the regulator after the double solenoid should work. If you want to have more than one cylinder set up like this, single solenoids would be the way to go since I think you're limited to just the regulators in the kit.

Also, to everyone else, I can think of one good reason to set up a cylinder like this. If you know for certain that you don't need 60psi on the retract and only need 30psi, setting the system up like this could potentially save you a lot of stored air and battery power, depending on how often you cycle the cylinder. It works out to about a 25% savings for every extend-retract cycle. That could potentially be very important.

Edit:
I'm a slow typist, but I swear I thought of that before he posted his intentions. Honest.

Ahh much thanks.. We are all forum hawks tonight.

[ngreen]

THe second regulator would be your best choice. It should work but just test it.

[Sachiel7]

why would you want more pressure on the retract then the extend. In pneumatics like we have there is no real "speed control" or "stroke distance control" that we have by limiting pressure input on different sides

Well, you're 1/2 right. True, you can not regulate stroke distance with pressure. You CAN regulate the speed at which the piston moves (and it can be different extending and retracting) with the small fittings that have the white knobs.
You also CAN create a very simple multi-positioning setup with parts from the kit. This will allow you to extend a piston part of the way and stop.
You typically do this by using 2 selenoids. One double, and one Single.
We did this last year, I can't entirely remember the setup.
But It's not difficult, or space consuming or anything

please spell check all posts before posting

The spell check feature has not been readded into the forums yet.

[Tom Bottiglieri]

ahh oh well im not too worried about my spelling... i know i can type right but im usually just to lazy to go back and fix my lazy online talk