Air Operated / Pneumatic Switches

Quick links to major topics on this page:

Why use air power to power turnouts?

This is another part of my quest for low maintainance and reliability:

  • I want to operate my layout, i.e. not just run dedicated strings of cars around and around.
  • I have switched to Kadees to allow remote uncoupling.
  • My layout is on the ground.
  • I have an environment that seems to corrode electrical connections quickly.
  • I have a lot of switches.
Therefore, I need remote control of the switches, and from the same controller as my trains.

This leaves you with the traditional electric switch motors or some alternative.

So, here's the disadvantages of electric switch motors as I see them (and as I and others have experienced):
  • Electrical contacts and bits inside corrode, stop working.
  • Very sensitive to dirt, grit, interferes with operation or accelerated wear.
  • Don't have a lot of torque (any manufacturer) so often do not throw all the way.
  • Have little or no "holding power" (some of this is by design so you can run "against" the turnout and not derail).
  • Need electrical wires, so you have corrosion at the terminals, wire is bulky, doesn't handle UV well.


So, I thought, why not use a simple air powered mechanism, a small air hose for supply, and no electrics.

The air motor is a stainless and brass piston assembly with an internal return spring, so a single air line controls it.

 

Who makes these products:

  • Originally there was a company called Del-Aire in Allentown PA,  who made air operated products. They went out of business in early 2003.
  • E-Z Air, later renamed EA-ZE Air. The "manufacturer" selling these products was the California and Oregon Coast Railway (the website, now defunct was www.cocry.com. (The product line was renamed "EA-ZE Air" because apparently Bachmann owns  "E-Z". It was owned and distributed by Stretch Manley at California and Oregon Coast Railway. was started about the time Del-Aire went out of business. Unfortunately they too went of business around June 2010. It appears that a lot of the E-Z Air stuff was from Clippard, but not the air motors themselves.
  • In late 2010, Llagas Creek seems to be selling the "simple" air motor kit, but as of 2016, I cannot find any listing of components on their web sitre.
  • In 2011, Ozark Miniatures started selling some components: http://www.ozarkminiatures.com/scripts/prodList.asp?idCategory=1303 The products are fittings and a "bare" air cylinder, made from stainless (good) and aluminum (huh?) for $20.
  • Sunset valley seems to be the only place you can buy the motors set up to attach to a switch: http://www.sunsetvalleyrailroad.com/pneumatics.html
  • Components are available from Clippard http://www.clippard.com

 


Here are some pictures of the original DelAire products

 


The picture below shows the original E-Z Air switch motor:

Below, you see one installed on an Aristo wide radius switch:

Image

The motor took 5 minutes to put it on, and this was my first one!

Remove the screws to the throwbar, then the 2 screws holding the original turnout motor.

Now place the motor in position by hand, and put a bend in the brass wire such that the plunger is pulled out by about 1/8". Don't worry about being precise, the motor has about 1" of travel, and the spring and air pressure make it self adjusting.

Now I put a second bend in the wire, and then bent the very end so I could thread the wire in without disturbing the turnout. I should clip the excess wire off some time! Works great!

 

New style parallel air motor with micro switch:

Here is a a second style of  air motor that is parallel to the track and can be ordered with a (real) waterproof microswitch inside.

I have them on all of my Aristo-Craft #6 switches since the electrics in the Aristo-Craft switches rot out quickly or the Aristo-Craft microswitch jams or both!

The EZ580 & EZ581 are for the normal LGB/Aristo-Craft/U.S.A. Trains (except #6) turnouts. The EZ582 & EZ583 are for the U.S.A. Trains #6 only. The EZ584 & EZ585 are for the PECO 45mm turnouts.

Image

 

 


 

 

In 2011, Sunset Valley Railroad started selling a line of air operated components, all apparently made by Clippard, a recognized name in the industry.

I don't think the switch motor housing is as nice looking, but all the hardware looks good:  https://www.sunsetvalleyrailroad.com/pneumatics.html

 

 

 

 

 

 

 

Standard / original type air motor:

 

 

Here's the insides of the original design:

The picture above shows the original brass operating rod, which did not work too well for me.

Since then the operating rod has been changed to this:

This new design solves three previous issues:

  • The wider and thicker "rod" puts less localized stress on the fragile Aristo-Craft throwbar, so they last longer.
  • The reduction in slop (because the new design is thicker than the previous wire) makes full use of the somewhat limited travel of the air motor.
  • The soldered joint between the plate and the wire could be a bit fragile and break.

Tips on installation:

You need to realize that the microswitch "toggles" only at nearly full travel. This, combined with the fact that the motor throw is just about the same as the throw needed on the switch, means you need to take a bit more care on installation to optimize the throw and make sure that the microswitch toggles, i.e. you get to full travel.

  1. decide which side of the switch to place the switch motor. Notice if you put the motor on the diverging side of the switch, there is only one direction it will mount that does not require cutting a tie. This is means that most installations will have the end with the air nipple furthest from the frog.
  2. I normally set the switches so that applying pressure selects the diverging route, and no pressure selects the straight through route. (this means if your air supply is off, or there is a problem, you should be able to run the mainline.)
  3. Put the actuating rod in the switch motor, and make sure that the rod moves in the direction you want it to under air pressure. Don't try to figure it out before hand, put the rod in, apply and release pressure, and if it moves the wrong way, open the air motor and flip it over. I've done tons of these and still get wrong the first time many times.
  4. Now you can get ready to bend the rod to engage the throw bar. MAKE SURE it's moving the right way, because if you bend the rod and then have things backwards, you might break the rod if you have to reverse it.
  5. Apply pressure so the throw rod is at full travel.  CAREFULLY bend the rod a bit at a time, to make it so that the switch will just hit the opposing rail. Hold the motor over the switch, lining up the mounting holes and sight downwards to see where the bend needs to be. Don't start trimming the rod just yet. Bend a little, check, bend a little more.
  6. Make sure you don't bend the rod between where you need it and the part that goes into the body of the air motor. If you do, you can cause binding in the mechanism.
  7. Once you have it close, trim the extra part of the rod, so you have about 3/8" past the bend.
  8. Test fit the air motor, apply pressure so the rod is fully extended. Then move the throwbar as close to the mounting side as possible, rotate the air motor so you can feed the rod into the throwbar, this will have the air motor at about a 45 degree angle to horizontal.
  9. Fit the motor the rest of the way into the ties. If anything is not right stop, the throwbar is fragile.
  10. Test the operation. Make sure the metal rod is centered in the throwbar slot, otherwise you will have binding.
  11. Sight along the switch and make sure the metal rod is horizontal and has no bends where it moves in and out of the air motor.
  12. Check that the microswitch is indeed switching at full travel of the air motor.
  13. Once you have confirmed this, connect the black wire to the frog, and the red and blue wires to the stock rails.
  14. TEST with an ohmmeter to make sure you set the red and blue wires on the right rails, check the frog has continuity with the stock rail that the point rail is against.

If you follow this tips, these air motors will work reliably and smoothly with no maintenance for years.

(show installed picture here)

 

What is available now:

clippard ssr-08-1/2

3PS-1/2

 

http://www.clippard.com/part/3PS-1%2F2

 

 

 

Clippard

 

 

 

DCC operation

EA-ZE Air has solenoids available in 3 DC voltage ranges.

I picked the 24 volt (nominal) ones, in anticipation that my 20v RMS DCC power supply would probably be a good match. The solenoid needs constant voltage to keep the solenoid open. Turns out the solenoid takes about 125 millamps when on, and they will pull in at about 15 volts.


Most DCC accessory decoders for turnouts are for momentary operation. Well, that won't work. The ones that work with the "Tortise" motors DO provide constant voltage output, but usually no more than 40 millamps.

The new Digitrax quad accessory decoder, DS64, has a higher current rating and can be programmed to run "stall type" switch motors, i.e. sending constant voltage forever to the switch motor.

Wiring the decoder

First, you must be careful in how you power the the solenoids, ANY time you use a device that can produce Back EMF you must be careful that the controlling device can handle this. (Back EMF from a solenoid can short out the output transistors in a controller).

Virtually all the DCC decoder manufacturers told me that their accessory decoders would NOT work with a solenoid.

A simple explanation: When you turn "off" a device that makes a magnetic field, as the magnetic field collapses, it induces a voltage and current spike that can be a lot higher than the current originally used to power the device. Most of you have seen a spark when disconnecting a circuit. That's the Back EMF.

This spike is great at destroying solid state electronics because it is so much greater in power than what you were switching in the first place... it's of shorter duration, but that's immaterial to a transistor.

So, rather than having an accessory decoder that can handle 8 amps per output, we find an inexpensive way to not let this spike into the electronics.

The solution is a diode.

Since these decoders are designed for "stall type" motors, they provide positive voltage for "thrown", and negative for "straight through".

Well, a DC solenoid will operate no matter what the polarity, so (forgetting BEMF for the moment), if we connected the solenoid to the outputs, it would always be energized.

So we use another diode such that voltage only flows to the solenoid when the voltage is positive, and the diode blocks current flow when the decoder switches polarity to negative.

I use two inexpensive 3 amp diodes from Radio Shack. Don't go lower on the amps, it's not worth it. (higher is ok)

Image

Each set of 3 terminals (from the left) are the outputs to the turnout motor (the two with the blue and red wires are power from the track).

We only use the first 2 terminals in each group. The first screw terminal is the positive, and the second common.

You can see the 2 black wires to the solenoid. The diode on the left makes it so that current flows only when the left terminal is positive. The second diode is basically across the solenoid's leads in "reverse" fashion. This diode absorbes the Back EMF when the solenoid power is switched off.

If you did not use the first diode, the solenoid would always be getting power, since it engages no matter what the polarity.

More importantly, the second diode protects the decoder from being destroyed by the Back EMF.

Do NOT eliminate either diode, the unit will not work, and you will destroy the decoder output.

An inexpensive air accumulator:

Image

Since my air supply is about 150 feet away, I made an inexpensive air tank to supply air pressure. I fed the system with the thin tubing since it was easier to run the thin tubing all that distance.

3" ABS tubing and caps from Home Despot and there you are, simple and inexpensive.

If you don't want to run a long line back to a compressor, consider an inexpensive air tank, that you can take and fill yourself, and leave out by the layout. Here's a 5 gallon one I got from Pep Boys:


Helpful accessories

Tubing clamps

When you have lots of air lines everywhere, it helps to be able to isolate sections, or have a "stub" that you can check pressure by a gauge.

The little tubing "plugs" are a real pain, so I found these; just place on a line and roll to one end to clamp off the air:

I bought mine srom Us Plastic  www.usplastic.com I used the item 16004 (4.5mm) Maximum KECK Red Tubing Clamp. Even though this is for a larger piece of tubing, it works best with the 1/8" tubing, because it can be "rolled open" to not put any pressure on the line, i.e. not restrict it at all.

 http://www.usplastic.com/catalog/item.aspx?itemid=23246&partnumber=16004#16004

 

Outdoor / weather proof enclosures:

Here's the box that holds the decoders and the solenoids:

My switchyard has a lot of switches, and unlike the box above, which is under shelter, I need 16 solenoids, 4 DCC controllers, and to be weatherproof.

So, I bought another outdoor drainage cistern. This one is about 9 inches wide by 1 foot tall, a smaller version of the one I used to put my DCC electronics in.

I had to close up the 2 holes in the sides, using the stock adapters, cut down with a rubber "plug" in the center hole where the pipe would go. Here is one of the 2 completed covers to seal up the unit:

The next thing I needed was to put some "feet" on the unit, and cover the large slots that would be the drainage grate with screen to keep out critters.

I used window screen and some pvc fittings to make the feet, PVC elbows with caps glued inside as plugs as you can see in the picture below:

The picture below shows the base as it will sit on the ground and be covered with the drainage housing. I used some grey PVC nipples to screw into the "feet" and then glued a fitting on top, so I could tighten the feet in place. I trimmed the white PVC fitting for clearance inside.

Now on to the housing itself. I needed to house 16 solenoids, 4 Digitrax DCC decoders, and a mainifold for the air distribution. I bought 4 sheets of lexan that were very close to the right size and trimmed them to fit in the housing:

Each piece has the corners notched to clear the PVC foot hardware on the base:

These 4 "backplanes" will be used to hold a decoder and 4 solenoids:

Now all it takes is two wires from the track for the decoder, and to hook up the air lines.

EA-ZE Air part numbers:

EZ663 - 24v solenoid (they have other voltages)
EZ570 - "original" air motor for Aristo-Craft & LGB
EZ580 - "parallel" air motor with microswitch for LGB/Aristo/USAT
EZ581 - "parallel" air motor without microswitch for LGB/Aristo/USAT
EZ582 - air motor with microswitch for USAT #6 only

Notes from Mike Reilley: (with corrections from Paul Frießem)

The Clippard parts one needs are:

  • Actuator - 3PS-1/2 -       http://www.clippard.com/store/displ...ku=3PS-1/2
  • Manual air toggle -  TV-3S -      http://www.clippard.com/store/display_details.asp?sku=TV-3S
  • Barb fitting - CT2-PKG -       http://www.clippard.com/store/display_details.asp?sku=CT2-PKG
  • Solenoid for electric operation -  EV-3M-12 -   http://clippard.com/store/display_details.asp?sku=EV-3M-12
  • Manifold - 15482-12 -             http://www.clippard.com/store/display_details.asp?sku=15482-12
  • Hose - URH1-0402-BKS-050 -        http://www.clippard.com/store/byo_tubing/?strSize=URH1-0402&strColor=BKS&strLength=50&sku=URH1-0402-BKS-050

 

 Old EZ air price list and part numbers

                   E-Z Air Motion Control
          Manufactures Suggested Retail Price List
                    Updated 03/05/2006
                 
Product Code         Description               US$ Each
------------         ------------              --------
EZ050           1/8"NPTM to barb (1)               1.50
EZ052           1/4"NPTM to barb (1)               2.50
EZ054           1/8"NPTM to 10-32F bushing         1.50
EZ056           1/8"NPTM flush plug                1.50
EZ070           10-32M to 10-32M fitting           1.50
EZ072           10-32F to 10-32F fitting           1.50
EZ074           1/8"NPTM to 1/8"NPTM fitting       1.50
EZ101K          10-32 to barb, black nylon (5)     2.00
EZ101L          10-32 to barb, blue nylon (5)      2.00
EZ101W          10-32 to barb, white nylon (5)     2.00
EZ102K          10-32 to L barb, blk. nylon(5)     2.00
EZ105           10-32 to L barb, adjust. brass(1)  3.75 
EZ120K          10-32 plug, black nylon (5)        2.25
EZ190           10-32 nylon washer (5)             1.00
EZ210K          Barb plug, black nylon (5)         2.00
EZ220K          Barb connector, blk. nylon (5)     3.00
EZ225K          Barb L conn., blk. nylon (5)       4.25
EZ230K          Barb T conn., black nylon (5)      3.00
EZ240W          Barb Quick Disconnects, set        3.00
EZ245K          Barb quick disc. caps, set         2.50
EZ251-04        4 Line Quick Disconnect set       43.00
EZ251-07        7 Line Quick Disconnect set       47.00
EZ251-DCP       1" dia, Plug Dust Cap              7.00
EZ251-DCS       1" dia, Socket Dust Cap            7.00
EZ252-08        8 Line Quick Disconnect set       97.00
EZ252-12        12 Line Quick Disconnect set      99.00
EZ252-16        16 Line Quick Disconnect set     118.00
EZ252-19        19 Line Quick Disconnect set     119.00
EZ252-DCP       2" dia, Plug Dust Cap              9.00
EZ252-DCS       2" dia, Socket Dust Cap            9.00
EZ252.5-22      22 Line Quick Disconnect set     138.00
EZ252.5-DCP     2.5" dia, Plug Dust Cap           13.00
EZ252.5-DCS     2.5" dia, Socket Dust Cap         13.00
EZ260           6 barb manifold                   14.00
EZ262           12 barb manifold                  25.00
EZ264           12 sta. 10-32 blank manifold      14.00
EZ270           6 station Rotary Manifold         15.00
EZ400K          50' tube, black                    9.95
EZ400N          50' tube, brown                    9.95
EZ400W          50' tube, white                    9.95
EZ401K          100' tube, black                  17.95
EZ401N          100' tube, brown                  17.95
EZ401W          100' tube, white                  17.95
EZ402K          200' tube, black                  34.95
EZ402N          200' tube, brown                  34.95
EZ402W          200' tube, white                  34.95
EZ405K          500' tube, black                  84.95
EZ405N          500' tube, brown                  84.95
EZ405W          500' tube, white                  84.95
EZ500           Actuator, wire rod, no mount      10.95
EZ500-12        12 pack #500 Actuators           124.75
EZ510           Actuator, wire rod, mounting      12.50
EZ510-12        12 pack #510 actuators           142.50
EZ511           500 & 510 wires Only (8)           2.50
EZ512           500 & 510 linkage Only             2.00
EZ519           510,520,530 Bracket & screws       2.25
EZ520           Under Table Actuator & bkt.       12.95
EZ520-12        12 pack #520 actuators           147.50
EZ521           Under Table Spring Wires (8)       2.00
EZ522           #520 Linkage parts only            2.00
EZ530           Z & N & Non-derailing Actuator    12.95
EZ530-12        12 pack #530 Actuators           147.50
EZ531           #530 spring Wires (8)              2.00
EZ532           #530 Linkage parts only            2.00
EZ560           Llagas/Parker/Sunset actuator     16.95
EZ560-12        12 pack #560 actuators           193.25
EZ561           Llagas/Parker/Sunset housing       6.95
EZ570           LGB/Aristo/USA/Bachmann Act.      17.95
EZ570-12        12 pack #570 actuators           204.50
EZ571           LGB/Aristo/USA housing only        7.95
EZ595           Bare cylinder, straight barb       9.95
EZ596           Bare cylinder, elbow barb          9.95
EZ600           35 micron air filter              12.00
EZ601           Air Pressure Regulator            17.00
EZ602           Air Pressure Gauge 1.5"dia.       12.50
EZ603           Regulator & Gauge combination     29.50
EZ604           Filter, Regulator & Gauge combo   42.50
EZ610           Toggle Valve                      11.00
EZ610-12        12 pack #610 Toggle valves       125.75
EZ615K          Push Button Valve, Blk.Button     11.00
EZ615K-12       12 pack #615K Push Button Valve  125.75
EZ615R          Push Button Valve, Red Button     11.00
EZ615K-12       12 pack #615R Push Button Valve  125.75
EZ620           Selector valve                    13.75
EZ625K          Pushbutton Selector Valve, Black  13.75
EZ630           Diverter valve                    18.15
EZ635K          Pushbutton Diverter Valve, Black  18.15
EZ640           Shuttle valve                      8.75
EZ645           Three Way Toggle Valve            45.00
EZ650           Throttle valve for toggle         11.00
EZ651           Mount #650 to panel kit            1.95
EZ655           Throttle Valve for Panel Mount    11.00
EZ661           Solenoid valve, 5.4 - 9 vdc       37.95
EZ662           Solenoid valve, 10.8 - 18 vdc     37.95
EZ663           Solenoid valve, 21.6 - 36 vdc     37.95
EZ664-01        Bracket for 1 solenoid valve       3.00
EZ664-02        Bracket for 2 solenoid valve       5.00
EZ664-04        Bracket for 4 solenoid valves      9.00
EZ664-08        Bracket for 8 solenoid valves     17.00
EZ664-12        Bracket for 12 solenoid valves    25.00
EZ670           10-32F - 10-32F check valve        7.50
EZ680           Air operated Selector valve       15.40
EZ690G          Green Air Indicator               10.75
EZ690G-12       12 pack Green Air Indicators     122.75
EZ690R          Red Air Indicator                 10.75
EZ690R-12       12 pack Red Air Indicators       122.75
EZ698           Flat Toggle Mounting Bracket       2.00
EZ699           Angle Toggle Mounting Bracket      2.00
EZ710-2         Kit with 2 510s and fittings      52.25
EZ710-4         Kit with 4 510s and fittings     115.25
EZ710-8         Kit with 8 510s and fittings     226.50
EZ720-2         Kit with 2 520s and fittings      52.50
EZ720-4         Kit with 4 520s and fittings     115.50
EZ720-8         Kit with 8 520s and fittings     227.00
EZ730-2         Kit with 2 530s and fittings      52.50
EZ730-4         Kit with 4 530s and fittings     115.50
EZ730-8         Kit with 8 530s and fittings     227.00
EZ760-2         Kit with 2 560s and fittings      61.00
EZ760-4         Kit with 4 560s and fittings     132.50
EZ760-8         Kit with 8 560s and fittings     261.00
EZ770-2         Kit with 2 570s and fittings      63.00
EZ770-4         Kit with 4 570s and fittings     136.75
EZ770-8         Kit with 8 570s and fittings     269.25
EZ810           Allen hex driver 0.050"            3.95
EZ820           Allen hex L key 0.050"             1.75
EZ830           Rectorseal Tru-Blu Thread Sealant  4.25
EZ840           1/4" hex fitting driver           13.75
EZ900           Air operated switch DPDT 15A      25.00
EZ900-3         Triple switch DPDT 15A            60.00
EZ901           6 terminals for EZ900 switches     1.50
EZ902           2 SPDT 15A micro switches & hdw.   9.25
EZ905           Air operated switch 4PDT 15A      33.25

We apologize for any errors in this list.

E-Z Air Motion Control is a trademark of California &
Oregon Coast Railway, P.O. Box 57, Rogue River, OR 
97537-0057 U.S.A. Phone/Fax 1-800-866-8635 in the U.S. and 
Canada, 541-582-4104 worldwide. Visit our web site at 
www.cocry.com or e-mail us at .

Old Del-Aire info
Apparently they were in business for over 50 years. They used clear plastic tubing (not sure it was UV resistant), but claimed to be good for 5 years in southern california weather. The air motors had a very fine wire coming out of them. There is a circlip on the end of the motor to allow dissassembly to replace the internal o ring. My guess is that this steel circlip would rust over time outside. One advantage was that the company allowed you to open the unit, and limit the travel of the piston with plastruct. working pressure was specified as 20 pounds minimum and 40 pounds max. typical pressure exerted was 2.5 poundsm and the return spring is 3 pounds
Del-Aire Products
321 N. 40th St., Dept. S
Allentown, PA 18104
Phone/Fax: (610) 391-0412, 24 hours/7 days
The initial design was developed and marketed by “RAYMARK” in the early 1950's. The second generation came under the name “CARNEL” and marketed as “HIGH POWER” until sold in ‘67. This begins the third generation under the current name of “DEL-AIRE PRODUCTS”.






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