# Pendulum Reverse Pictorial



## rkenney (Aug 10, 2013)




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## rkenney (Aug 10, 2013)




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## rkenney (Aug 10, 2013)




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## rkenney (Aug 10, 2013)




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## rkenney (Aug 10, 2013)

The conclusions are fairly obvious. The reverse unit adds much needed weight to this locomotive. The solenoid grounding lever needs a soldered pigtail to ground for reliable operation.

The End


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## Big Ed (Jun 16, 2009)

Great Bob, if I ever have one this is good reference.
Where did those diagrams in post #1 come from?

What locomotive did this the motor come out of?
Is this from the Bild a Motor ?


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## rkenney (Aug 10, 2013)

Big Ed said:


> Great Bob, if I ever have one this is good reference.
> Where did those diagrams in post #1 come from?


Dr. Tinker



> What locomotive did this the motor come out of?
> Is this from the Bild a Motor ?


Yes, This is from the Bild-A-Loco motor.


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## T-Man (May 16, 2008)

I haven't seen anything like this. Thanks for posting.


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## tjcruiser (Jan 10, 2010)

Bob,

BRAVO, once again. This is a wonderful info thread, and I believe the first time we've had such a detailed discussion of an old pendulum style reverse unit here on the forum. Your descriptions are incredibly clear, and most helpful to future tinkerers. Thank you for investing the time here!

A couple of questions:

So, it appears you've wired the e-unit with simple (conventional) wiring, rather than a re-do (or a repro) of the "printed circuit" wires. Are repro circuits available, by chance? What's inside one of those? Is it just wire and terminal ends laminated into pieces of cloth? Could one make something like that? (Cloth, varnish, etc.?)

In regards to ground lever ... perhaps adding a bit of weight to the "teeter totter" lever and/or tweaking its pivot fulcrum would yield a better and more reliable ground? Your thoughts here?

Again, many thanks!!!

TJ


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## rkenney (Aug 10, 2013)

tjcruiser said:


> Bob,
> A couple of questions:
> 
> So, it appears you've wired the e-unit with simple (conventional) wiring, rather than a re-do (or a repro) of the "printed circuit" wires. Are repro circuits available, by chance? What's inside one of those? Is it just wire and terminal ends laminated into pieces of cloth? Could one make something like that? (Cloth, varnish, etc.?)


The original connections are flat brass strips that follow the contours of my drawing (fourth picture - first post). You can see one of the strips poking up in the third picture where the cloth has frayed. Being flat they maintain their position relative to one another and of course they're sandwiched between two pieces of cloth for insulation.

I was thinking if they needed replacement that telephone wire might do run over the top so as not to interfere with the wheels. I just wired it temporarily to test the total operation.



> In regards to ground lever ... perhaps adding a bit of weight to the "teeter totter" lever and/or tweaking its pivot fulcrum would yield a better and more reliable ground? Your thoughts here?


As received the lower contact was popped out of place,









Don't know how this occurred but it wouldn't work that way.
It has to swing freely though, and when the motor field is energized it swings to the disconnected position. That prevents the constant buzzing everyone is familiar with on the Ives type e-unit. Cleaning the pivots might help, it probably worked better when it was new. But testing shows it is 100% reliable when a jumper wire connects it directly to ground. A short piece of flexible wire can be soldered to the piece and the other end with an eye to the screw that holds it to the motor.

I'll post a picture when I mod it.


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## tjcruiser (Jan 10, 2010)

rkenney said:


> But testing shows it is 100% reliable when a jumper wire connects it directly to ground.


Yeah, but doesn't that mean that the e-unit is always operational, i.e., you won't be able to disengage the e-unit and run always-forward?

Or am I misunderstanding the function here?

Just curious. This pendulum setup is most definitely new to me (and likely many others here), and I'm just trying to get my head around how it all works.

Thanks!

TJ


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## rkenney (Aug 10, 2013)

The solenoid grounding contacts are shown below in both the closed and open position. Note that it is the silver arm on the bottom that actually moves. Normally it is held closed by gravity and completes the solenoid circuit. When the field winding of the motor is energized, its magnetism pulls that contact end down opening the solenoid circuit (no more buzzing).









The lower of the two pictures shows the lower contact held open by the curved brass arm below it. This is the manual disconnect to allow the motor to continue in one direction only.

That lower arm is the piece that makes a poor ground. it only contacts the frame at its two pivot points. All I propose to do is solder a wire to that lower arm and attach it to the screw that assembles the reverse unit to the motor. It will still hang closed by gravity and open when the motor field is energized or it is propped open by the manual lever, but it will make a solid ground connection through the wire and not rely on the pivot point contacts.

Hop this helps.


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## tjcruiser (Jan 10, 2010)

Ahhh!!!! Now I get it!!! Clever!

Thanks for the follow-through here, Bob.

I am learning TONS from this thread and your posted info!

Thank you!!!

Just a thought: When you solder a wire to the pivoting arm, use a relatively thin wire, and wrap it several turns in a coil ... between end attachment points. That will yield a very unstiff "spring", which, in turn, will impose little-to-no restraint to the natural pivot of the contact arm.

TJ


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## rkenney (Aug 10, 2013)

*Pendulum Reverse II*


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## rkenney (Aug 10, 2013)




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## rkenney (Aug 10, 2013)




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## wvgca (Jan 21, 2013)

even though i don't have any of these units, i did enjoy your description of the modifications that you made ...


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## Millstonemike (Aug 9, 2018)

I like the chimp (the post is pretty Ok too  )


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## rkenney (Aug 10, 2013)

Just a little note by way of followup. I was unhappy with my modification, not because it didn't work (it worked great), but because it was not a very elegant (cumbersome) solution and it involved replacing an original screw with a Philips head screw.

Phillips head screws were first used in automobiles during the early 1930s as a screw that could withstand the higher torque of automated assembly practices and would self center on the bit.

Just something to consider for any early 20th century restoration.


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## tjcruiser (Jan 10, 2010)

Hey Bob,

I love the final solution. But, in thinking it through, do you think the pivoting pendulum bar SHOULD have rested on the frame cross-bar to begin with? I.e., perhaps Lionel intended that to happen, and somehow yours (as found) just got bent out of whack somewhere in its life?

Perhaps???

Great story ending!

TJ


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## rkenney (Aug 10, 2013)

tjcruiser said:


> Hey Bob,
> 
> I love the final solution. But, in thinking it through, do you think the pivoting pendulum bar SHOULD have rested on the frame cross-bar to begin with? I.e., perhaps Lionel intended that to happen, and somehow yours (as found) just got bent out of whack somewhere in its life?
> 
> ...


I guess its possible. The difficulty with that is that it is a healthy little piece of metal, probably a little more than 1/8 inch. bending it the small amount I did was no easy task so if that was its original shape how did it get bent?

Just as a point of clarification, the manual lever to hold it open also prevented it from hanging down further (towards the brass rod). The manual lever was also at the limits of its travel and solidly riveted to the frame (so I couldn't easily have modified it to allow more travel).

Its also possible that when the pivots were less worn they made a better ground. :dunno:


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## tjcruiser (Jan 10, 2010)

Hi Bob,

Good observations / questions above. In the realm of possibilities, if I had to place a bet: I'd speculate that the pendulum was as you originally found it, but that the pivot had a bit more "meat" so as to give a better ground there.

My two-cent bet!

Cheers,

TJ


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## rkenney (Aug 10, 2013)

I really liked the way it turned out. Particularly that I didn't have to add any hardware. Bending the switch pendulum did solve the ground problem and makes for consistent operation. 

Of course you are sort of stuck with a Marx type 2 position only E-unit, but its authentic and original. Hope the posts help somebody tame a sporadic pendulum reverse unit,

On to the sheetmetal!!:smokin:


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## tjcruiser (Jan 10, 2010)

Bob, this two-part, old-school pendulum e-unit tutorial has been a GREAT addition and resource to anyone rolling up their sleeves into one of these. Your detailed photos and descriptions are the poster-child for how to "share the knowledge" here on MTF.

Thank you!!!

TJ


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## tjcruiser (Jan 10, 2010)

A question, though, Bob...

For continuity (and future member search and find reference), should we merge your two pendulum threads into one? Is there a reason why you split them into two?

I'm thinking it would be nice to have all of the photos / dialog under one location.

Your thoughts? (As a Mod, I think I have the magic decoder ring that lets me merge threads, if needed.)

TJ


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## rkenney (Aug 10, 2013)

Merge away TJ. Use your magic de-coder ring for the good of MTF!:smokin:


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## tjcruiser (Jan 10, 2010)

Hocus. Pocus. Done!



TJ


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## rkenney (Aug 10, 2013)

A little Hocus-Pocus of my own:


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