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Discussion Starter #1
I want to find out why my Lionel 736 engine wheels weren't turning. I have dismantled the 736 engine and the wheels turn by hand easily now. The electric motor worm gear also turns when I grab it with a pair of pliers. I want to bench-test the electric motor but I am not sure how to do it. I have removed it from the frame and attached test wires/clips connected to a transformer but nothing happens. Any suggestions would be appreciated - my electric motor knowledge is very limited.
 

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Connect one lead from the transformer to one of the brush holders. Connect the other to the metal frame of the motor. A jumper is needed between the brush opposite the one you connected power to and that central tab above the brushes (the field coil). The motor should run for you. To change direction, swap connections to the brushes.
 

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Discussion Starter #3
Thanks.

Thank you for the procedure - I will do it first thing tomorrow morning. :thumbsup:
 

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In the photo, it looks to me like the bakelite brushplate is not fully seated. Might be a good idea to remove the brushplate and clean up the brushes and commutator. Then reinstall the brushplate making sure it is fully seated. Here’s the Olsen’s page with the 736 service manual. Take a look at the motor on page 4.

http://www.olsenstoy.com/736.htm
 

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The motor is the same one used in the 671/681/682/2020, of which I have 5 of. Connect a strap from the center post of brushplate to either right or left post. Take transformer leads and hook on to ground (metal of casting) and touch the unused post of brush plate, with other xfrmr lead. The motor will run in 1 direction. Reverse the strap, and xfrmr leads, and motor will run in opposite direction.

When was the last servicing done?? If it hasn’t been done, chances are you will need new brushes, and a thorough cleaning. The best way is to unsolder the wires from brush plate, **mark them somehow, to put them back correctly***. Take the brushplate off, clean the copper face of the armature, replace the worn brushes, and add some grease on the geared end of armature. This should get you back in business.

I think I still have photos of one of my motors, and if so, I will post them.
 

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Discussion Starter #6
Thanks for your advice - I ran into a small problem when I was connecting electrical clips to the motor one of the wires came loose and will need to be soldered. Since this is needed I will follow Teledoc's suggestion and replace the brushes - I ordered them a few minutes ago.
 

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Postwar Turbine motor maintenance

Dbmnj, I found my old photos of a turbine motor, and how to hook up test leads to test the motor. There are a few more photos of the armature face, with before and after, of what it should look like. Some brush plates have "tubes" where the brushes are installed, the later plates have a spring to fit into a slot of the brushes. The whole concept of the transformer hookup is the same, for all Postwar Turbine Motors..

strap for forward.JPG
strapping for forward

strap for reverse.JPG
strapping for reverse

681 armature before.JPG
Armature before cleaning

681 armature after.JPG
Armature after cleaning

gear side 681.jpg
Geared end of armature

681 brushplate.jpg
Turbine brush plate
 

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If the wheels were not turning at all before disaasembilly, then something was bindi g or not lined up. It should turn a bit even if the engine isnt powered. Check to see if all the washers are in around the motor. I think i remember something like that.......
 

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The 736 wheels are not geared like a 2046 but depend on the connecting rods to power three axles from one. This leads to wear on the gearing, rods and bushings and with excessive wear they can get sloppy and contribute to poor running. The wheels should turn the motor if not then it is bound up in some way or the old Lionel lube has hardened. As mentioned above a good cleaning and fresh lube is never a bad idea!
 

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Discussion Starter #11
Soldering question

I will need to solder the wires to the brush plate when I get the brushes. Is there a trick to getting these thin wires to stay in place when I start soldering?
 

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Discussion Starter #12
OK sorry for the delay getting back to this project - I cleaned the armature, installed new brushes and bench tested the motor with a poor result. The worm gear barely turns, the motor struggles and makes a noise that sounds like it is binding. Do I need to replace the motor and if so where can find one? :dunno:
 

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First things first. Take it apart again and check that you have all the parts that are listed in the previously posted exploded parts diagram. One washer or spacer missing and it will bind up. This is especially true if someone else took it apart before you and lost a part. Happended to me more then once. Also its easy to drop something and not realize its missing. Start there. And without the motor in do the wheels turn ok? Just making sure nothing is bent. ( wheel axel)
 

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Dbmnj, To answer your previous question, the motor I posted was in that condition, when I bought it. The problem I had (eBay purchase), was multiple breaks in the field coil wire. I had nothing to lose, and tore it apart, to where I could remove the old wire, and rewind it by hand. That motor runs as good, if not better than the other 4 motors I have. It took a little ingenuity to do what I did, but I did it.

Did you test the motor, by itself, outside of the frame, like I posted. You have to take a close look at the geared end of the armature. That must have the tiny ball bearings behind the washer/clip. If it is original, it should have 9 bearings, minimum. There is a replacement that can be used, but off the top of my head, I forget the part number. If you need to take that end apart, it can be done, but not for the “faint of heart”. I suggest you take the brush plate off again, and try to spin the armature by hand, to see if it feels like it is binding. If it spins freely, then something else is causing the sluggishness. The replacement thrust bearing is 681-121. There are very very thin washers that may be causing your problem.
 

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Dbmnj, Do you have a repair Manual to look at. The Olsen Toy Train Parts Website is temporarily down at the moment, but that have “Library” section, which is a searchable database, the same as the repair manual. When I mentioned the bearing near the geared end, there are 4 parts, that have to be correct. Starting from the outside, you have a retaining ring(C clip); part 671M-22. This holds the washer, bearing, & washer in place. Next should be the front thrust washer; part 671M-23 (2 required for both sides of the bearing. The original bearings were individual bearings, (minimum of 9 bearings), but replacement 681-121 is preferred. So this would be retaining ring, washer, bearing, washer, in that order. If you decide to take it apart, it will let you remove the whole armature. The cavity where the armature shaft would be, may be gunked up with lube/grease, which shouldn’t be there. If you see that may be the case, with the armature removed, pour Naptha into the cavity, let it soak a little, and put everything back together. I would put just a few drops of oil, in the top hole, and then test the motor. Old grease, and missing bearings, & washers, would cause the problem you are having. It’s up to you as how far you want to go, with doing it yourself.
 

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Discussion Starter #16
Electric motor repair

Thanks TELEDOC & sjm9911 for the suggestions - I can't get to work on the motor 'till next weekend but I want to note the following:
(1) I am the original owner and the 736 locomotive has never been dismantled before.
(2) wheels move freely without the motor connected.
(3) I will look carefully to see if I dropped any parts.
(4) I will remove the brush plate to see if the armature moves freely.
(5) Can I see the 9 bearings without removing the retaining ring clip? I would hate to drop them. :eek:
 

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Discussion Starter #17
Armature turns freely - motor not!

The motor will run in 1 direction. Reverse the strap, and xfrmr leads, and motor will run in opposite direction.
After cleaning the armature and installing new brushes I did the "Forward/Reverse" wiring test again and the motor struggles & makes noise in both directions. I removed the brush plate and turned the armature which rotates freely without any noise.
I am not capable of rebuilding the motor - what can I do? :dunno:
 

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Discussion Starter #19
Spin freely?

I was able to spin the armature manually - do you mean for me to apply oil when I have it running with the jumper wire & transformer wires attached? :confused:
 
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