Lionel 1121 switch using accessory power?

[lionelsoni]

But see the warnings about coil burnout in the old topics, as well as my method of drilling and tapping the frog.

[jkerklo]

I have modified 1121 switches to operate from separate power for use on an automatic layout. It isn't easy.

Remove the switch cover. If you look inside, the common wire from the solenoids goes through a hole in the base plate right under the coil. No room to snag it and make another connection.

The metal bottom-plate has to be removed by drilling out the rivets.

Then disconnect the soleniod wire from the track center-rail, attach a separate wire, punch a small hole in the switch top plate, and bring it out. I also ran a wire from center rail common, both to a 2-pin .062 molex connector. This way, I could also provide a more reliable center-rail power connection or use a jumper plug to operate the switch from track power.

The bottom plate is re-attached with flat head machine screws with the flat screw head on the bottom. Careful of the nut; in one place it can interfere with wheel flanges and may need to be ground down. I chose nuts (over rivets) so the bottom plate could be removed again easily.

The light will be connected to the accessory voltage. Other arrangements can be made.

Connect an accessory transformer (I used 14 volts) to track common (outside rail) and the soleniod wire brought out of the switch. An electrical switch connection from the center post on the switch (track common) and either outside post will operate the switch.

The switches operate much better on a constant 14 volts. The trains also run better after this is done. A 1121 switch uses about as much current as a small engine, so, with the change, there isn't any loading on train power.

John Kerklo
TCA 94-38455
www.Three-Rail.com

[lionelsoni]

The short answer is, yes, it can be done. But there are some subtleties to it. I have looked up a couple of old topics that cover your question. Have a look at them and see if you have any more questions:
http://www.trains.com/community/forum/topic.asp?TOPIC_ID=7853
http://www.trains.com/community/forum/topic.asp?page=1&TOPIC_ID=11825

[Dave Farquhar]

I've seen instructions for how to do the modification at least a couple of different places. I'm pretty sure one of those places was in Peter H. Riddle's Tips and Tricks for Toy Train Operators (the title was something like that--search on the author name). It's published by Kalmbach. I just did a search and it seems to be in your public library in Pittsburgh, as are several of his other books. I definitely recommend him.

[Anonymous]

Hello you busy forum people :)

Has anyone ever modified a Lionel 1121 switch to run off of accessory power instead of track power? When running the train slow, the action is not crisp and sharp as I would like it. Heh, the light bulb basically acts like a voltage level indicator...
Is this easy to do, if anyone ever has?
Should I just be happy with track power, (Id be ok with it, just trying to make it better).

Thanks!

hgable

ps, just figured out in the beginning of the week that the train convention is in Pittsburgh, just a mile from my house. Is that open to the public? Should I bother to stop in and see?