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

[ngreen]

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

[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.

[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

[Ryan Cumings]

Well I was trying to think of a way to limit the amount of air we lose when you lift ourselves onto the bar. We would still need the 60 psi (actually would it be better to have the retract only exert 130 lbs of force??) to lift, but do we really need 75 cu In at 60 psi to be lost just to extend the piston?

[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.

[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]

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.

[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.

[NoRemorse]

Well, this is the info I can give you.

1) The piston has the most force when extended (you probably knew this though)

2) In this situation I don't know what you are trying to do makes sence. Are you regulating down the pressure it uses one way to below 60, or do you want it to be more on one side. I believe that you may only use 60psi on the cylenders.

3)If you want one side at 60psi, and the other at a lower, you may need 2 seperate solenoids to accomplish this.......

[tanks]=====['T']===[reg at 60psi]===[solenoid]===[r]
....................||............................ .....................||
.....................\====[reg at 30psi]===[solenoid]===[e]

DISREGAURD the dots!


r and e are 'extened' and 'retract'

I don't know if ths what your shooting for though