I'm working on a design for a machine that will make a number of different
yet similar products. There will be 2 servos and a stepper to do the bull
work yet there is one air cylinder that will provide pressure on material.
The amount of pressure will vary from one product to another and from one
kind of material to another. I'd like to automatically change the air
pressure within the program for each product/material. Such a thing? No,
I'm not going to build one. If it ain't off the shelf, it won't happen.

On Mon, 12 Jul 2010 01:58:11 -0400, the renowned "Buerste"
wrote:

I'm working on a design for a machine that will make a number of different
yet similar products. There will be 2 servos and a stepper to do the bull
work yet there is one air cylinder that will provide pressure on material.
The amount of pressure will vary from one product to another and from one
kind of material to another. I'd like to automatically change the air
pressure within the program for each product/material. Such a thing? No,
I'm not going to build one. If it ain't off the shelf, it won't happen.

Two possibilities come to mind right off:-

1) You could get a proportional regulator.

Eg.
http://www.wattsfluidair.com/catalog...Electronic.pdf


2) A number of solenoid valves and manually set regulators.




Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

1) You could get a proportional regulator.

Eg.
http://www.wattsfluidair.com/catalog...Electronic.pdf

One nice unit. i could use that if it hasn't got a gold plated price tag.
Have you ever got a quote on one?

Karl

"Buerste" wrote in message
...
I'm working on a design for a machine that will make a number of different
yet similar products. There will be 2 servos and a stepper to do the bull
work yet there is one air cylinder that will provide pressure on material.
The amount of pressure will vary from one product to another and from one
kind of material to another. I'd like to automatically change the air
pressure within the program for each product/material. Such a thing? No,
I'm not going to build one. If it ain't off the shelf, it won't happen.

There are electrically controlled regulators, they can take an analog output
from a PLC or similar and control air pressure. We have them at work on our
tire uniformity optimizers and balancers, I'll see if I can get some info on
them. We have different inflate pressures depending on the tire being
tested and the machines automatically adjusts. Of course there are also
proportional valves and pressure transducers but you have to close the loop
in the controller.

RogerN

On Mon, 12 Jul 2010 05:08:08 -0500, the renowned "Karl Townsend"
wrote:


1) You could get a proportional regulator.

Eg.
http://www.wattsfluidair.com/catalog...Electronic.pdf

One nice unit. i could use that if it hasn't got a gold plated price tag.
Have you ever got a quote on one?

Karl

Around $500 +/-. Not too bad, IMHO.



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Spehro Pefhany wrote:

On Mon, 12 Jul 2010 05:08:08 -0500, the renowned "Karl Townsend"
wrote:


1) You could get a proportional regulator.

Eg.
http://www.wattsfluidair.com/catalog...Electronic.pdf

One nice unit. i could use that if it hasn't got a gold plated price tag.
Have you ever got a quote on one?

Karl

Around $500 +/-. Not too bad, IMHO.

Sounds well within reason for use in a production machine that probably
only needs one or two.

On Mon, 12 Jul 2010 02:15:34 -0400, Spehro Pefhany
wrote:

On Mon, 12 Jul 2010 01:58:11 -0400, the renowned "Buerste"
wrote:

I'm working on a design for a machine that will make a number of different
yet similar products. There will be 2 servos and a stepper to do the bull
work yet there is one air cylinder that will provide pressure on material.
The amount of pressure will vary from one product to another and from one
kind of material to another. I'd like to automatically change the air
pressure within the program for each product/material. Such a thing? No,
I'm not going to build one. If it ain't off the shelf, it won't happen.

Two possibilities come to mind right off:-

1) You could get a proportional regulator.

Eg.
http://www.wattsfluidair.com/catalog...Electronic.pdf



Also Bellofram
http://www.pressure-controls.com/ipeptransducer.php

and Festo and probably SMC.

--
Ned Simmons

"Ned Simmons" wrote in message
...
On Mon, 12 Jul 2010 02:15:34 -0400, Spehro Pefhany
wrote:

On Mon, 12 Jul 2010 01:58:11 -0400, the renowned "Buerste"
wrote:

I'm working on a design for a machine that will make a number of
different
yet similar products. There will be 2 servos and a stepper to do the
bull
work yet there is one air cylinder that will provide pressure on
material.
The amount of pressure will vary from one product to another and from one
kind of material to another. I'd like to automatically change the air
pressure within the program for each product/material. Such a thing?
No,
I'm not going to build one. If it ain't off the shelf, it won't happen.

Two possibilities come to mind right off:-

1) You could get a proportional regulator.

Eg.
http://www.wattsfluidair.com/catalog...Electronic.pdf



Also Bellofram
http://www.pressure-controls.com/ipeptransducer.php

and Festo and probably SMC.

--
Ned Simmons

And MAC, which is what I've used in the past. The Parker unit is very nice
for the price though.

http://www.macvalves.com/products/PPC.htm

On 07/12/2010 07:26 AM, Pete C. wrote:

Spehro Pefhany wrote:

On Mon, 12 Jul 2010 05:08:08 -0500, the renowned "Karl Townsend"
wrote:


1) You could get a proportional regulator.

Eg.
http://www.wattsfluidair.com/catalog...Electronic.pdf

One nice unit. i could use that if it hasn't got a gold plated price tag.
Have you ever got a quote on one?

Karl

Around $500 +/-. Not too bad, IMHO.

Sounds well within reason for use in a production machine that probably
only needs one or two.

If it just falls in there and works, and saves you the day or two of
dinking around that a 'free' one would, most certainly.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On 07/11/2010 10:58 PM, Buerste wrote:
I'm working on a design for a machine that will make a number of different
yet similar products. There will be 2 servos and a stepper to do the bull
work yet there is one air cylinder that will provide pressure on material.
The amount of pressure will vary from one product to another and from one
kind of material to another. I'd like to automatically change the air
pressure within the program for each product/material. Such a thing? No,
I'm not going to build one. If it ain't off the shelf, it won't happen.


Aw, c'mon. You just need a solenoid valve, a fancy PLC with high-speed
PID, an accumulator and pressure feedback. Oh, and several days of
dinking around, but it'll be fun so that won't matter.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

"Tim Wescott" wrote in message
...
On 07/11/2010 10:58 PM, Buerste wrote:
I'm working on a design for a machine that will make a number of
different
yet similar products. There will be 2 servos and a stepper to do the
bull
work yet there is one air cylinder that will provide pressure on
material.
The amount of pressure will vary from one product to another and from one
kind of material to another. I'd like to automatically change the air
pressure within the program for each product/material. Such a thing?
No,
I'm not going to build one. If it ain't off the shelf, it won't happen.


Aw, c'mon. You just need a solenoid valve, a fancy PLC with high-speed
PID, an accumulator and pressure feedback. Oh, and several days of
dinking around, but it'll be fun so that won't matter.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

Well, if there were only a few pressures you could set each pressure with
manual regulators and select with valves.

A person might be able to do a pretty good job with a small air tank, a
pressure transducer, and a valve or two. Inflate tank to pressure, shut off
valve, when tank gets low, turn on valve automatically. Maybe an op amp
with some hysteresis to compare setpoint and transducer?

RogerN

"Buerste" wrote:

I'm working on a design for a machine that will make a number of different
yet similar products. There will be 2 servos and a stepper to do the bull
work yet there is one air cylinder that will provide pressure on material.
The amount of pressure will vary from one product to another and from one
kind of material to another. I'd like to automatically change the air
pressure within the program for each product/material. Such a thing? No,
I'm not going to build one. If it ain't off the shelf, it won't happen.


There are pressure regulators that accept 4-20MA and 0-10v signals. One of the lines I
maintain has a bunch of them. I just can't tell you the model number from home atm.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

Ned Simmons wrote:

Also Bellofram
http://www.pressure-controls.com/ipeptransducer.php


I'm thinking SMC for sure, maybe a ITV1000 or something in that series. Motion's web site
isn't working for me at the moment. I was going to look up pricing.

http://content.smcetech.com/pdf/ITV_4017.pdf

Wes

On 07/12/2010 02:27 PM, RogerN wrote:
"Tim wrote in message
...
On 07/11/2010 10:58 PM, Buerste wrote:
I'm working on a design for a machine that will make a number of
different
yet similar products. There will be 2 servos and a stepper to do the
bull
work yet there is one air cylinder that will provide pressure on
material.
The amount of pressure will vary from one product to another and from one
kind of material to another. I'd like to automatically change the air
pressure within the program for each product/material. Such a thing?
No,
I'm not going to build one. If it ain't off the shelf, it won't happen.


Aw, c'mon. You just need a solenoid valve, a fancy PLC with high-speed
PID, an accumulator and pressure feedback. Oh, and several days of
dinking around, but it'll be fun so that won't matter.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

Well, if there were only a few pressures you could set each pressure with
manual regulators and select with valves.

A person might be able to do a pretty good job with a small air tank, a
pressure transducer, and a valve or two. Inflate tank to pressure, shut off
valve, when tank gets low, turn on valve automatically. Maybe an op amp
with some hysteresis to compare setpoint and transducer?

That would be one way. It's basically what a mechanical regulator does,
except that the mechanical regulator does it -- well -- mechanically,
and powered by the pressurized gas:
http://en.wikipedia.org/wiki/Pressure_regulator.

I have no clue if anyone actually does this, mind, or if there's any
sane reason to do so when mechanical regulators work so well.

But it'd be fun...

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

"Wes" wrote in message
...
"Buerste" wrote:

I'm working on a design for a machine that will make a number of different
yet similar products. There will be 2 servos and a stepper to do the bull
work yet there is one air cylinder that will provide pressure on material.
The amount of pressure will vary from one product to another and from one
kind of material to another. I'd like to automatically change the air
pressure within the program for each product/material. Such a thing? No,
I'm not going to build one. If it ain't off the shelf, it won't happen.


There are pressure regulators that accept 4-20MA and 0-10v signals. One
of the lines I
maintain has a bunch of them. I just can't tell you the model number from
home atm.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

I've been seeing a few on ebay, I bid $8 on one this morning and it went for
$16.XX. I found them listed under proportional regulator and I/P or E/P.

Here's one
http://cgi.ebay.com/FAIRCHILD-TDFI78...item3f0169738c

There are some Buy it now not too bad of price.
http://cgi.ebay.com/KOMPLETT-E5N-STD...item413eae3172

http://cgi.ebay.com/Fairchild-TAEI78...item3ef5056095

There's a bunch he

http://cgi.ebay.com/Y68621-SMC-E-P-R...item5adabd3c64

http://cgi.ebay.com/SMC-E-P-Regulato...item3357a7a882

http://cgi.ebay.com/SMC-E-P-Regulato...item1e5cf1ef8f

http://cgi.ebay.com/SMC-E-P-REGULATO...item1e5ac27e5b

http://cgi.ebay.com/SMC-E-P-Regulato...item53e25c2fb9

http://cgi.ebay.com/SMC-E-P-REGULATO...item43a0090113

RogerN