# Help needed for pneumatic shopping list.



## Brandon (Jul 6, 2011)

I'm going grocery shopping for pneumatic parts and since I'm completely new to pneumatics and have very little knowledge so far, it would be helpful if someone could double check my list before I find out I bought the wrong parts, not enough, or missed a part that I'll need.

My List:

a. 24x Actuator (3PS-1/2) - http://www.clippard.com/store/displ...ku=3PS-1/2
b. ? Barb fitting - CT2-PKG - http://www.clippard.com/store/displ...ku=CT2-PKG
c. 5 1/16” ID Hose “T” Fitting - http://www.clippard.com/part/T22-2-PKG
d. 20x Solenoid for electric operation EV-3M-12 - http://clippard.com/store/display_d...u=EV-3M-12
e. 2x Manifold - 15482-12 - http://www.clippard.com/store/displ...u=15482-12
f. 1x Hose - URH1-0402-BKS-050 - http://www.clippard.com/store/byo_t...02-BKS-050

My questions are:

1) Is 1/16" enough for 90' tube lengths or would 1/8" be better?
2) Is it better to daisy chain or home run each switch when you have two switches that need to move together?
3) Are accumulators near switch points a good plan or should I not plan on these for now?
4) How many "grouped" switches can be run off of one solenoid?
5) Is f. the right hose? The link to the hose listed in past threads is bad and this hose is BKS rather than BRS so I'm not sure it's the right type, diameter or material for UV.
6) Are the c. 1/16" Hose "T" Fittings the correct ones?
7) How many barb fittings do I need? Do I need one at the solenoid as well as the actuator? (so 2 per switch point)
8) Anything special needed to connect solenoids to the manafolds?
9) Anything special needed to connect both manafolds together?
10) Should a larger diameter hose feed the manafolds and should they be in parrallel in the case several (2-6) get switched at once? 
12) What is the right part to connect an air tanks female 1/4" fitting to the manafolds?
13) Am I missing any parts?

EDIT!!! Don't get the ev-2m solenoids that are talked about in several places on this board, you need the ev-3m. The 2 does not have an exhaust and will not release pressure from the cylinder/actuator.

Also, you can find the cylinders and actuators for often less than half price and still new on eBay and other stores.


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## Paul Burch (Jan 2, 2008)

Brandon,
Have you checked the Sunset Valley pneumatics? Even if you don't buy from him the photos might help.
http://www.sunsetvalleyrailroad.com/pneumatics.html


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## Treeman (Jan 6, 2008)

Jim Cary provided one of those pictures of his installation. He is one of our customers and is very happy with Air Wire products and Sun Set Valley controlling his locomotives and turn outs. He does a very professional looking job.


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## Greg Elmassian (Jan 3, 2008)

Some answers

1) Is 1/16" enough for 90' tube lengths or would 1/8" be better?
>>> using accumulators, I have 200' runs on 1/16" no problem
2) Is it better to daisy chain or home run each switch when you have two switches that need to move together?
>>>> no problems on 2 switches on same line
3) Are accumulators near switch points a good plan or should I not plan on these for now?
>>>> I have 3 accumulators, farthest switch is 60 feet, that one moves a little slowly, but ok.
4) How many "grouped" switches can be run off of one solenoid?
>>> it's more of a matter of response time, I would think 3-4
5) Is f. the right hose? The link to the hose listed in past threads is bad and this hose is BKS rather than BRS so I'm not sure it's the right type, diameter or material for UV.
>>>> 
6) Are the c. 1/16" Hose "T" Fittings the correct ones?
7) How many barb fittings do I need? Do I need one at the solenoid as well as the actuator? (so 2 per switch point)
>>> my solenoids were purchased with the barbs installed, and my switch motors came with them mounted too
8) Anything special needed to connect solenoids to the manafolds?
>>> nope, but use teflon tape
9) Anything special needed to connect both manafolds together?
>>> teflon tape
10) Should a larger diameter hose feed the manafolds and should they be in parrallel in the case several (2-6) get switched at once? 
>>>> if the manifold is close to the accumulator, don't worry, in theory yes
12) What is the right part to connect an air tanks female 1/4" fitting to the manafolds?
>>>>
13) Am I missing any parts?
>>>>


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## Brandon (Jul 6, 2011)

One more question, based on Gregs comment that it's a good idea to have the switch direction default to the desired path if the air is off.

Some of my switches have the push/pull lever on the wrong side to default to the ideal path. So do get it to default to the ideal path I can solve it one of two ways. One is buy a 3ps-12-ar actuator but it's longer and has a buldge in it (and 50% more, but not an issue on cost) or I can reverse the actuator and run a U wire back to the push/pull lever on the switch or use a servo arm to swap the push/pull.

Opinions on either? I'm guessing the -ar actuator since it's more foolproof but it will be harder to hide since it's half again as long and 1/2" larger in diameter where the buldge is..


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## John J (Dec 29, 2007)

Brandon said:


> One more question, based on Gregs comment that it's a good idea to have the switch direction default to the desired path if the air is off.
> 
> Some of my switches have the push/pull lever on the wrong side to default to the ideal path. So do get it to default to the ideal path I can solve it one of two ways. One is buy a 3ps-12-ar actuator but it's longer and has a buldge in it (and 50% more, but not an issue on cost) or I can reverse the actuator and run a U wire back to the push/pull lever on the switch or use a servo arm to swap the push/pull.
> 
> Opinions on either? I'm guessing the -ar actuator since it's more foolproof but it will be harder to hide since it's half again as long and 1/2" larger in diameter where the buldge is..




Build a Battery box over it. Have you ever noticed by crossing gates and signals there is large silver cabinet. That contains batteries to operate the signals when there is a power failure. 

I see a lot of Switches are run by solar power. You could put a large box over the air cylinder and put some fake solar panels on top. That would hide the cylinder and look like it belongs. 

JJ


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## Brandon (Jul 6, 2011)

As I'm learning about pneumatics, I'm wondering why people are using 2-way actuators and solenoids instead of 3-way. 

I'm actually having a hard time finding good information on how a 2-way solenoid and actuators work but from what I can tell, it doesn't look like they have exhaust ports. So I'm wondering how long it takes actuator springs to go back to their resting state after pressure is stopped from the line, since there isn't an exhaust port in a 2-way solenoid and 2-way actuator circuit?

If 2-way solenoids do have an exhaust port (which I haven't been able to verify with images of the 3ps-1/2 clippard solenoids) then I still wonder why people aren't using 3-way actuators and solenoids.

My first though is that the 3ps-1/2 has 30oz of force when under pressure and 12 oz of spring force to the resting position when not under pressure, both of these seem low to me so I'm wondering if this is really enough to avoid switch points not holding their positions and cause derailings. Also, a 3-way would let you apply the same pressure to both paths and you could theoretically adjust it to whatever works best for switches (5psi, 20 psi, 40 psi, etc). The downsides I see are actuators might cost more (solenoids appear to be the same price), having to run double the tubing to switches, and not having a spring putting pressure to keep the switch in a "resting/off" position in case you just want to run a mainline loop without the pneumatic system running.

What am I missing for why people don't use 3-way solenoids and actuators?


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## Greg Elmassian (Jan 3, 2008)

The 2 way solenoid has an exhaust port, and the actuator has an internal return spring. The return springs are pretty fast, certainly faster than the prototype.

3 way actuators and solenoids cost more, last time I checked. More complex thus less reliable.

40 psi works great, my units will operate down to about 10 or a bit less psi.

I don't know the spring force of my units, mine are the original ones from C&OCRY, which apparently were custom made.

Hope this helps.

Greg


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## Paul Burch (Jan 2, 2008)

Here is a handy hint as yet untried by me but I'm told that it works. If you want to slow down how fast an actuator works to make it look more prototypical put a small clamp like a rail clamp on the 1/8 hose. Clamp it down enough so that it restricts the airflow just enough to slow down the actuator. Who wants to try it and report back?


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## Brandon (Jul 6, 2011)

The clamp idea sounds great.

Greg, 3 way solenoids are the same price as two, go figure... 

I guess the question is how much force is needed to hold a switch. The 3ps that other have used are just 12oz and 30oz. Anyone know what a good force range is desirable? Any chance those with pneumatics could measure and report back?


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## SD90WLMT (Feb 16, 2010)

Good idea....
How about trying different tubing sizes ( thinking brass tubing ) to create a restrictor...
Then a given diameter would provide a given time delay....

Not advertising..I don't use air systems....

D


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## Michael W (Oct 10, 2012)

You can actually buy restrictors ready to go as 1/8 and 1/16 is used on trucks as signal lines for air assisted transmissions and brake systems
Kind regards michael


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## CliffyJ (Apr 29, 2009)

Another method of making an accumulator is to run a large-ish hose (say, 1/2" id) to the distribution manifold / solenoid group, using the internal volume of the hose as the accumulator. Think of it as a long cheap flexible tank. I used that method recently (different application), with an extra coil to get the volume I needed, and it saved me a bunch.


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## Greg Elmassian (Jan 3, 2008)

3" abs pipe accumulator, cheap and easy










Try this link:

http://www.elmassian.com/trains/track-aamp-switches/air-operated-switches


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## SD90WLMT (Feb 16, 2010)

Lol...why does that ..black pipe...look like ABS pipe..?

costs more than PVC pipe does..tho may be larger in diam. than typical PVC is.....


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## Greg Elmassian (Jan 3, 2008)

fixed... it's the black stuff in home depot..

Greg


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## Brandon (Jul 6, 2011)

Greg, I sent you an email the other day since you have pm disabled.


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## CliffyJ (Apr 29, 2009)

Nice solution Greg.

Some folks might think an actual accumulator / tank / pony bottle is necessary, that's what I was wanting to suggest an alternative for. And yours does as well, as long as the pressure stays low and it doesn't get stepped on or otherwise cracked. 

Speaking of pressure, what are we talking about? Just curious.

C


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## SD90WLMT (Feb 16, 2010)

Those pvc & abs pipes can handle more air pressure than your compressor can make....

The pressure rating is marked on each pipe.....

D


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## Greg Elmassian (Jan 3, 2008)

40 psi seems to be a good working *pressure *for the 3 types of air cylinders I have tried.


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## Dan Pierce (Jan 2, 2008)

Wow, 40 psi is now a working voltage????? Can it light a led???? What value is the crimp used to lower the flow to the led.

Just for fun.....


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## Dick413 (Jan 7, 2008)

Dan LOL


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## CliffyJ (Apr 29, 2009)

SD90WLMT said:


> Those pvc & abs pipes can handle more air pressure than your compressor can make....
> 
> The pressure rating is marked on each pipe.....
> 
> D


That's for water, which doesn't compress. If the pipe cracks, the water spills out. Air, which compresses like a spring, is different. Like, a bomb. So you have to be careful not merely about rating, but protecting / shielding the thing -- which I'm sure Greg is doing. 

The advantage of a hose is that it's made for air pressure, doesn't need serious protection, and doesn't fragment when cut (say, by a shovel). 

CJ


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## SD90WLMT (Feb 16, 2010)

Well ya got Me there Cliff...

I have without issue or failure...used 3/4" and 1" pvc pipe as an air line in shop settings..running 90 - 100 psi ...filled by a 60 gallon / 5 hp shop air compressor....

Go figure....

D


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## JerryB (Jan 2, 2008)

SD90WLMT said:


> Well ya got Me there Cliff...
> 
> I have without issue or failure...used 3/4" and 1" pvc pipe as an air line in shop settings..running 90 - 100 psi ...filled by a 60 gallon / 5 hp shop air compressor....
> 
> ...


Running pressurized air in PVC lines is really bad shop practice. As to your statement that you are ". . . without issue or failure . . ." it only takes one catastrophic failure to do serious damage to a person. And if something in your building catches fire, the first thing that will happen is failure of the PVC lines, causing rapid spread of the fire.

Of course it is your shop, but recommending that as acceptable practice to the unwary and not warning visitors that you have a potentially dangerous situation is really negligent behavior.

And yes, I know all about the folks who will defend this practice. That doesn't make it safe nor acceptable!


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## Greg Elmassian (Jan 3, 2008)

40 psi is pretty much nothing.

That ABS is pretty thick.

Greg


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## Brandon (Jul 6, 2011)

Ps, according to someone at clippard, their dual action cylinders will not work with a three way valve but need a four. They also said a 2 way will not work for a single action with spring return as there is no exhaust for the output line, and a three way is needed for single action cylinders with spring return. This conflicts various comments on this forum that a ev-2m and 3ps would work. Maybe people here using two way valves have air leak that allows cylinders to lose pressure over minute or two?


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## Greg Elmassian (Jan 3, 2008)

Sounds like a terminology problem.

The solenoids I use are either energized or not. When energized they put air out the output port. When not energized that output port vents to the atmosphere.

So, that must be a 3 way to use the proper terminology.

so 2 way is simple connect or not... 3 way must come from the understanding that there are actually THREE ports, input, output, and exhaust, and the THREE way is from the output is either connected to the input or the exhaust... like a "three way" electrical switch in a house is SPDT...

I learn something every day.

Greg


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## Brandon (Jul 6, 2011)

Wish we could update all those old threads that reference the ev-2 solenoid as anyone who only reads those 3-4 threads will order a part that won't work, like I nearly did.


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## CliffyJ (Apr 29, 2009)

Greg Elmassian said:


> ...so 2 way is simple connect or not... 3 way must come from the understanding that there are actually THREE ports, input, output, and exhaust, and the THREE way is from the output is either connected to the input or the exhaust... like a "three way" electrical switch in a house is SPDT...


Right, the 2-way is just like a SPST. Either open or closed. The 3-way, as you say, has 3 ports. There is the common port, usually piped to the cylinder. The other ports allow the cylinder to connect to either the air supply or to exhaust. And just like a relay (both are solenoid-operated, spring-return), you have an NC and an NO port, i.e., Normal (non-energized) = Closed or Open.

"4-ways" can have various internal drillings. But a valve sold to operate a double-acting cylinder will most likely be set up to permit air to one end of the cylinder, while the other end is open to exhaust. When energized, it's vice-versa. 

CJ


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## fyrekop (Sep 20, 2011)

Thanks Brandon for starting this thread and to all that have provided so much good information. I was planning on using electric switch motors activated with DCC. Re thinking that and may go pneumatic. Decisions, decisions


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## jbooker (Jan 15, 2008)

Hi Brandon,
Curious how you made out with your air switch shopping list. 
I can confirm that the 3 PS 1/2 is the cylinder sunset valley uses. 40-60 psi is good. Your info is correct that clippard 2-way valves do not have exhaust ( they have only input & output) so the spring return cylinder will not work. The 3-way valves have input, output and exhaust. So, when closed, the air between valve and cylinder releases through exhaust causing the actuator to return via spring.
There are 2 exhaust options for 3-way valves: 1 that exhausts into atmosphere and another with a threaded exhaust port (called 'fully-ported') This is not necessary, but could be used to restrict exhaust flow for a slower more prototypical return. 
Let us know how you make out!


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## Totalwrecker (Feb 26, 2009)

If you are waiting for word from Brandon .... try coming back this spring when he might. I think he' a seasonal.
John


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## Michael Glavin (Jan 2, 2009)

Some how I duplicated my post, see my comments below.


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## Michael Glavin (Jan 2, 2009)

Quote:
Originally Posted by *SD90WLMT* http://forums.mylargescale.com/16-t...atic-shopping-list-post580394.html#post580394
_Those pvc & abs pipes can handle more air pressure than your compressor can make....

The pressure rating is marked on each pipe.....

D_





CliffyJ said:


> That's for water, which doesn't compress. If the pipe cracks, the water spills out. Air, which compresses like a spring, is different. Like, a bomb. So you have to be careful not merely about rating, but protecting / shielding the thing -- which I'm sure Greg is doing.





CliffyJ said:


> The advantage of a hose is that it's made for air pressure, doesn't need serious protection, and doesn't fragment when cut (say, by a shovel).
> CJ




Pressure is a scalar quantity. Pressure is pressure, matters not what the medium is... Water, gas/air and oil it’s all the same with regard to Force(s) acting upon an object. 

As alluded to, the consideration here is explosive decompression, water is very dense and carries all most no compressive energy while the density of compressed gases (air in this example) is quite low, the potential of compressive energy is very high. The compressed spring example draws a great parallel IMO.

So the potential of explosive decompression realized of/with compressed air is a notable concern. Shards of plastic flying about would be dangerous. OSHA rules and or regulations specifically state that PVC is not to be used with compressed gases... 

And there is this, PVC air piping inherently becomes brittle; and is easily fractured compared to a water pipe of PVC. Compressed air byproducts; acids, oils and UV rays play a big part in degrading the integrity of PVC pipe. 

Fire damage as mentioned is another quagmire of plastic piping not generally considered IMO.

Michael


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## Greg Elmassian (Jan 3, 2008)

3 inch schedule 40 pvc has a maximum working pressure of 260 psi.

I'm running 40 psi. That is almost 7 times less.

I'm not the least worried about explosive fragments.

Your water pressure is higher than 40 psi, enough said. Yes I understand that since water is incompressible, if it bursts a pipe it does it differently than compressed air. The pressure here is so much below the capability of the pipe that there should be no worries.

I also used black pipe, which resists UV, and my accumulators are not in direct sunlight.

As to the pipe becoming brittle, if you dig a bit deeper, the assumption where this is stated is that the air compressor oil gets in the pipes and makes the plastic brittle.

I have filters that ensure no oil gets in the air line. In addition, so little air is used, there's not enough new air to cause a problem. All of the reading about warning against pvc is for people using it for commercial compressed air at over 100 psi.

The data is true, but not directly applicable to make my accumulators a source of concern.





Greg Elmassian said:


> 3" abs pipe accumulator, cheap and easy
> 
> 
> 
> ...


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## Michael Glavin (Jan 2, 2009)

Greg,

While I tend to agree with your assessment, its paramount that we understand failure modes and make informed decisions thereof... 

Working in the commercial/industrial environment for decades, I have seen PVC air piping more times than I can specifically recall, to that end I have yet to hear of an issue with same. Does that make it ok, NOT IMHO. However I have read about failures that ultimately lead OSHA to ban PVC's use for air piping. That said most facilities operate with system pressures at 150PSIG or less. As a conscientious Contractor I advise responsible parties of their shortcomings and leave it at that.

Michael


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## Greg Elmassian (Jan 3, 2008)

I agree, it is wrong to use pvc for compressed air supplies. I did read about 10 screens worth of information last night from OSHA and various states on the recommendation, and in many states, the banning of pvc for compressed air supplies.

Since my system does not meet the criteria of over 100 psi, and certainly not 150 psi, oil in the lines, uv exposure, significant temperature swings, vibration, I do not consider my use equivalent to the use that it is not recommended for.

I was not arguing with you, and I do agree that it's important to understand the failure modes (which is actually what we do a lot here on the forum for many things).

Regards, Greg


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## jbooker (Jan 15, 2008)

My List:

a. 24x Actuator (3PS-1/2) - http://www.clippard.com/store/displ...ku=3PS-1/2
>>>>that's the part we use. Another supplier at surplus prices:
http://www.plccenter.com

b. ? Barb fitting - CT2-PKG - http://www.clippard.com/store/displ...ku=CT2-PKG

c. 5 1/16” ID Hose “T” Fitting - http://www.clippard.com/part/T22-2-PKG
d. 20x Solenoid for electric operation EV-3M-12 - http://clippard.com/store/display_d...u=EV-3M-12
e. 2x Manifold - 15482-12 - http://www.clippard.com/store/displ...u=15482-12
f. 1x Hose - URH1-0402-BKS-050 - http://www.clippard.com/store/byo_t...02-BKS-050
Some more answers

1) Is 1/16" enough for 90' tube lengths or would 1/8" be better?
>>> using accumulators, I have 200' runs on 1/16" no problem
2) Is it better to daisy chain or home run each switch when you have two switches that need to move together?
>>>> daisy chain is fine, but if you're planning on DCC routes or computer control, then home run might be better since you can setup routes 

5) Is f. the right hose? The link to the hose listed in past threads is bad and this hose is BKS rather than BRS so I'm not sure it's the right type, diameter or material for UV.
>>>> BKS is black and BRS is brown in Clippard product. They say only the brown hose is UV resistant.

6) Are the c. 1/16" Hose "T" Fittings the correct ones?

7) How many barb fittings do I need? Do I need one at the solenoid as well as the actuator? (so 2 per switch point)
>>> You need one barb on the manifold output and one barb on the actuator. Both have 10-32 threaded holes so same 1/16 barb X 10-32 thread will work on both ends.

8) Anything special needed to connect solenoids to the manafolds?
>>> you could buy Clippard EMC card and them they'll be installed and wored from factory.

9) Anything special needed to connect both manafolds together?
>>> teflon tape and an 1/8" NPT Male-Male connector. The manifolds have 1/8" NPT thread on both ends. You need to connect one end to your compressor and also get a plug for the unused end.

10) Should a larger diameter hose feed the manafolds and should they be in parrallel in the case several (2-6) get switched at once? 
>>>> 1/4" ID Input would be good for 12 X 1/16" Output manifold. We use 3/8" IN cuz that's the push connectors we have and it's a long run to the compressor so the 3/8 is my 'accumulator'.

12) What is the right part to connect an air tanks female 1/4" fitting to the manafolds?
>>>>Manifold has 1/8"NPT thread input. 

13) Am I missing any parts?
>>>> 
1/8" NPT connector for Manifold input, 
1/8" NPT Male-Male coupler to connect 2 manifolds together. 
1/8" NPT plug to close open end of second manifold.
Teflon tape
Piping from compressor to manifold

Also: how are you going to connect the actuator to your track? Notice sunset valley sells theirs with a metal piece with two holes to attach to the track ties. This metal piece also has a third hole which connects to the cylinder. The Clippard PS3 1/2 has a second port on the side which has 10-32 thread. You will need 10-32 bolts to connect the cylinder to whatever piece you come up with for mounting. 

Notice the stainless screw in the pic below. In this case, we found some Aristo switches (not all - they must have changed design) include this pices of plastic which worked well for connecting cylinder to track. I would consider SVRRs metal piece much better solution than this though.

Also the cylinder has to grab the turnout throw bar somehow. SSVR has tiny 1-72 X 1/2" treaded screws tapped through the actuator pin. If you want to do that then you'd need drills and taps and prolly a mini drill press from somewhere like micromark.com

Here is a pic of my pneumatic project: 12 turnouts, DCC ready using Clippard EMC-12-24-30 electronic manifold card. Just hook to track power and air and go.



















These EMC cards are expensive, but they come with manifold & values installed plus the lights, manual switches, and db25 connector make them very efficient to work with from setup to troubleshooting to programing decoder. 

They retail about $250 more than cost of manifold and valves alone. Unless you find them on ebay for cheap like I did.

Let us know how you make out.

HTH,
Josh


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## CliffyJ (Apr 29, 2009)

Josh, 

Those are beautiful pneumo panels. At first, $655 retail looks crazy expensive. But with 12 valves and the fittings and electrical connections baked in, $55 / valve doesn't seem bad at all.

Can you describe your controller board? Sure looks nice, is that a custom job? I assume it's got all the decoders on it?

===>Cliffy


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## jbooker (Jan 15, 2008)

Hi Cliffy,

The controller board is the AUX-BOX HC from TrainTekLLC.com. I chose it because one board can do 12 switches and therefore it paired well with the 12 valve clippard boards. Here's a closer shot:










Yes, I would think twice about the Clippard boards if I had to buy them for retail, but in this case I grabbed them used on ebay for under $100 a piece. I can afford to replace a valve here and there for that price. ;-) Even at full price though I think a reasonable case can be made for these boards. Each valve costs $28 plus Manifold is $20 so your in the $400 neighborhood already. Basically the board adds about $20 per valve. Personally I put a lot of value in the fact that it's compact and comes with manual switches, indicator lights, polarity and who knows what other protection, plus the ease of use with db25 connector, external power connection. All that adds up in my view. Just get some ribbon cable, and plug and screw terminal - done. We're installing 4 of these inside and prolly 6 more outdoors so the pneumatic system alone could get pretty messy without the clippard board.

PS...I took your idea from your most excellent remote switch project and used the copper tape method for the common wiring. The method proved extra useful in this project since, having boards on both sides of the lexan, I was cramped for space.

Keep up the great work!
Josh


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## jbooker (Jan 15, 2008)

Another comment for the original poster....

You might consider the 24v valves instead of 12v. That way if you find the need to run off track power your can do that.

Josh


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## CliffyJ (Apr 29, 2009)

Thanks for the further info Josh, and you as well, great work!


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## Brandon (Jul 6, 2011)

jbooker said:


> Hi Brandon,
> Curious how you made out with your air switch shopping list.
> I can confirm that the 3 PS 1/2 is the cylinder sunset valley uses. 40-60 psi is good. Your info is correct that clippard 2-way valves do not have exhaust ( they have only input & output) so the spring return cylinder will not work. The 3-way valves have input, output and exhaust. So, when closed, the air between valve and cylinder releases through exhaust causing the actuator to return via spring.
> There are 2 exhaust options for 3-way valves: 1 that exhausts into atmosphere and another with a threaded exhaust port (called 'fully-ported') This is not necessary, but could be used to restrict exhaust flow for a slower more prototypical return.
> Let us know how you make out!


Hate to dig up this thread but not as much as I'd hate leaving someone hanging, especially if others are wondering the same thing. I must have missed this thread update but I did put a post on my railroad thread showing my setup.

http://forums.mylargescale.com/29-b...named-railway-build-thread-26.html#post587842

My setup has changed a little though, I removed the manifolds from the PCB boards and mounted them directly to a piece of MDF board so they were more compact and for the raspberry-pi and all 8 manifolds would fit nicely. 

In short, my shopping list was SDR-05-1/2" cylinders and eto-3m-12 solenoids, though most any -3m- would work and I went with -12 (12volt) solenoids because I'm controlling them via the raspberry-pi and some 12v relays. I'll try to get a photo up of the setup in the next few weeks, but I'll post it to my build-thread rather than here so just bounce over there if anyone is looking in the future.

I guess I'm a little seasonal and I miss threads, apparently. send me a PM anytime you have a question though, I usually don't go more than a few months without logging in here.


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## Greg Elmassian (Jan 3, 2008)




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