AF 3rail ogauge remote switches.

[George Thill]

Can AF 3 rail ogauge switches be wired for non-derailing function? if so, how? Thanks!

[ADCX Rob]

Well, it depends.  There's always a work-around.  With the flyer switches, which have their solenoid coils' common leads connected to the base/outside rails, the switches need the hot side switched to the red and green Fahnestock clips - which will require a relay activated by a regular Lionel-style trigger section(a section of track with an insulated outside rail).

This will require a power supply / transformer set at a suitable level to throw the switches, a separate(non-track power) power supply for the relays(will power many switches) and two relays per switch(1 for each switch direction/trigger section). 

You will have to be careful not to park trains on the trigger sections to keep the solenoids from overheating.

[servoguy]

Here is a thread about making 1121 Lionel switches non-derailing.  Very simple and easy.

http://www.modeltrainforum.com/showthread.php?t=20377&page=6

It might be advisable to rewire the solenoids so that they are normally connected to center rail power, and it takes a ground to operate them.  This is the way Lionel does it.

[George Thill]

Thanks, guys. it looks like the only way to avoid having to use external relays is to rewire the solenoid coils,. Does that mean drilling out the rivets that hold the switch cover in place to access the soleinoids, or is there another way to get to the common wire? Where is it soldered to the base?

[ADCX Rob]

servoguy

It might be advisable to rewire the solenoids so that they are normally connected to center rail power, and it takes a ground to operate them...

"Might" is putting it mildly - must is the right word if you're going the 1121 route.

[servoguy]

If the solenoids are re-wired like a Lionel switch, then the need for relays disappears, and everything is simple.  The only problem I see is getting the AF switches open to make the changes.  AF must have owned a rivet factory considering the number of rivets that hold the bottom cover on the switch.  Taking the bottom cover off is a good idea for another reason:  The switch probably needs lubed after 70+ years.

[George Thill]

I can always drill out the rivets, a tedious job, but I think I'll try to punch them out first using a nail set punch and backup block with  holes positioned and sized to clear the rivet heads. I can reattach the cover with #4 bolts and nuts ( I have a lot of from a previous project.), which will facilitate any future maintenance needs.

[George Thill]

Hey guys, punching out the rivets was easy! I didn't need to make a back-up block; I was able to use a small bench vise that just happened to support the switch upside down in the proper way to knock out the rivets with a pointed punch and small hammer.

The common solenoid wires are soldered to the base near the bracket that holds the light sockets, and easily accessible with the cover off.

 It may take a while for me to make the modifications and install the switches, but I'll let you know how it turns out.

Thanks again for your help!

[lionelsoni]

Lionel powered their 1152 and later O27 turnouts from the track to reduce the chance that a train parked on the turnout would burn out a solenoid.  This was desirable because these turnouts, unlike the O31 022,  lacked the switches to disconnect the solenoids after throwing.  It was not a foolproof solution, since it is still possible to stop a train on the turnout with the track voltage turned up.  So it is a good idea to use something like a capacitive-discharge circuit with these turnouts, and any other turnouts not designed for automatic operation, especially as an alternative to an always on accessory supply.

It is possible to operate these turnouts automatically from control rails without rewiring or using relays, using the following capacitive-discharge circuit:  Connect the negative terminal of an electrolytic capacitor (about 5 millifarads) to one of the solenoid terminals.  Connect the capacitor's positive terminal to one terminal of a number 53 lamp.  Connect the other lamp terminal to a positive DC supply returned to the outside rails.  To operate the turnout, connect the positive capacitor terminal to the outside rails, either with a momentary switch or by connecting it to a control rail.

Duplicate this circuit for the other solenoid.  If you want, use a single lamp for both solenoids by connecting each positive capacitor terminal to the lamp through one of two diodes (1N4001s, for example), with the cathode to the capacitor and the anode to the lamp.

When a train wheel first touches the control rail, the lamp will light and the capacitor will deliver its charge to the solenoid.  After the train passes, the lamp will recharge the capacitor as the lamp dims out.  You can use the lamp in a bumper or other accessory for this purpose if you want.

 

[George Thill]

I should try this before modifying more switches!

Bob, because I've seen on these and other posts that  you  know so much about electronics and mechanics, I looked at your profile; I too have had a career in opera (semi-professional) first as a dramatic tenor (hence my forum name of George Thill) and now as a bass-baritone.

[ADCX Rob]

I completely forgot about the DC solution.

If you are careful not to park on the trigger sections, you don't even need the capacitor components.

[lionelsoni]

How would that work, Rob?

[ADCX Rob]

It wouldn't.  You would still need the relays.  Never mind!