Air Operated / Pneumatic Turnouts/Switches

 


Quick links to major topics on this page:

Why use air power to "throw" turnouts/switches?

This is another part of my quest for ultra low maintenance and reliability, so first, I needed to consider what I needed for my switches:

  • I want to operate my layout, i.e. not just run dedicated strings of cars around and around.
  • I have converted to Kadee couplers 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 turnouts/switches.
Therefore, I need remote control of the switches, and from the same controller as my trains.

Now, add in my requirements for low maintenance, weather resistance, etc, and you realize that electrically powered switches are problematic at best.

If you do some research, you will see that very few electric switch "motors" last outside, have a positive throw (powerful), and the best outside are generally LGB, which still normally require yearly maintenance, are are big and ugly.

So, when I heard about pneumatic switch control, it sounded like a great idea, and since electric solenoids for controlling air pressure was available, sounded like I could interface to DCC easily.

Basically, the air "motor" is a small piston with a return spring, so pressure moves one direction, remove the pressure and the spring gives the other direction. You can use small diameter hose, and about 40 psi.


 

Who makes these products / history:

  • 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
 

Sunset Valley:

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

Below is the basic motor in the mount, and showing a mechanical toggle for the air pressure:

Below is a more closeup picture of the cylinder with the air fitting on one end and the "business end" on the right.

Below is a closeup of the electric solenoid to control the air pressure:

The picture below shows several solenoids attached to a supply manifold:

 

 

Clippard:

Here's where you can go to get the air motors and solenoids

I'm trying to compile a list of Clippard components, this still needs some work:

clippard ssr-08-1/2

3PS-1/2

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

Thanks to Mike Reilley on tracking down some of these part numbers.

Right now working on 3d printing some units using the Clippard cylinders

 

Information on products no longer available:

(you may come across some of these on the used market)

DelAire:

Here are some pictures of the original DelAire products

 
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 pounds 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”. until sold in ‘67. This begins the third generation under the current name of “DEL-AIRE PRODUCTS”. 

Ez-Aire:

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

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

 

 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 .

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)

 


  
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.

Weather Underground PWS KCACARLS78