Marx engine forward/reverse

[trainsartist]

Hi. I'm brand new here and I have a rather simple request for you experts. I've got an old model marx engine (#666) that shifts into reverse when power is shut off then applied again. I want the engine to always go forward. Is there a way to modify the wiring to stop any reverse function? There is no lever/switch on this engine to accomplish this. Thanks for the help. Jeff

[lionelsoni]

If you can locate a wire to the coil of the reversing unit, just disconnect it.  Or put a switch in series with it if you want.

[trainsartist]

That sounds like a great idea. What's the reversing unit? Can you help me identify it? Thanks ever so much.

[lionelsoni]

I don't have a 666, nor any documentation.  But I'm sure one of the Marx aficionados on the forum will be able to tell you.

[Railroader_Sailor_SSN-760]

The Marx 666 is one of my favourite engines, I have a half dozen of them that are in active service, and 2 that are apart for restoration.

 The reverse unit is located on the front upper end of the motor.

 Thortrains.net has some photos of a diassembled Marx 666 that points out the location of the reverse unit on the motor assembly.

 About 2/3 down on the main page there is a section called "The Informed Railfan" that has a link to a page called"Running Original Marx Trains".

Why do you want to disconnect the reverse unit? 

Obtaining a Marx locomotive that does not have a reverse unit is not all that hard, about 1/4 of my Marx fleet (about 60) do not have reverse units, so when I feel like having a train just go round and round, I select one of them.

I hope that I have been of some help.

 

[trainsartist]

Great responses and all was a great help. Bob, you put me on the right track when you mentioned a reversing unit. Railroader Sailor, your help is very much appreciated. Before checking the forum this time, I did get the reversing unit disabled by disconnecting a wire. But to be sure, I'll check into that website for the Marx breakdown. I want the engine to go only forward because it's actually going to be installed into a sculpture. A reverse situation cannot be tolerated for functional and aesthetic reasons. Thanks everyone for your help. Jeff

[baberuth73]

Please send a photo of your finished project- sounds interesting!

[Dave45213]

Very useful and interesting thread--thanks for the info all. I'm new to the forum but have been enjoying my old Marx trains with my kids now 5 and 2 --they love it and the trains are sturdy enough to handle their (supervised) fun.

with the reverser unit, I have a Marx Rock Island no. 99 diesel that when it gets warmed up after 15-20 minutes of use, starts reversing/forwarding constantly not making any progress up or down the track. I don't know if its the reverser, (which buzzed really loudly until I put a small piece of weatherstripping between the coil and frame avoiding the wire), switches or current/transformer. any thoughts?

Dave

[gunrunnerjohn]

If the train is changing directions, my guess is you have a loose connection to the coil of the reversing unit which is triggering it.  The other cause is a momentary interruption of the track power, perhaps a spot of dirty track, that will also cause the two speed e-unit to reverse.

 

[Dave45213]

Thanks John, will check. you brought up the power too, this engine has been running on a line with an old old Marx transformer, I should test it on the line with the newer z-750. I recall last time I had it on there though there was a terrible buzzing, and the engine seemed to run smoother/quieter with the original transformer, but I wonder if its days are numbered... 

[gunrunnerjohn]

The "terrible buzzing" is because the electronic transformer doesn't provide a pure sine wave, it's chopped by the speed control.

The classic way to quiet an E-unit is to run it on DC.  A small bridge rectifier and an electrolytic cap powering just the E-unit coil will make them quiet as a church-mouse.