Motor replacement for Lionel 752

The 752 uses a similar motor as the 616 and 636 (But the ball mount stud is different - at minimum you'd have to transplant that). Just like the 752, they are not exactly inexpensive or extremely readily available and for the effort and money, you end up with something that isn't "right".

With that said, you will sink a lot of time and money in trying to cobble something together from other parts and so I generally find the best route is to fix the motor you have. These units are generally well designed and with a little love, can be made operational again.

If you could elaborate on the condition and symptoms of your motor (and include some pictures!), we will be able to direct you in any very cost effective repairs to get it going.

Here is some documentation on your motor:

http://www.olsenstoy.com/searchcd31.htm?itm=786

Included is a schematic to ensure you have everything wired up right.

Here it is. The motor turns freely. I removed the e unit because I plan to run forward only. One brush to power, the other to coil. One brush spring is shot. I have put power to it and the hot wire collects ok from the middle rail. There is no short, but it looks like there is an open somewhere. 

I have cleaned the armature with contact cleaner and eraser. It appears that no one has been messing with the motor before. Lots of corrosion but no physical damage.

any tips on how to test the armature and coil?

thanks

The armature has 3 plates. With the armature out of the motor, use a multi-meter to measure the resistance across all permutations (plate A-B, A-C, B-C). They should all read very close in value (About 1 to 2 ohms if I recall). Then read the resistance values from each plate to the shaft (A-SHAFT, B-SHAFT, C-SHAFT). Each one of those readings should be infinite resistance.

For testing the field, simply measure the resistance between each end of the field (One end should be grounded to the chassis, the other a brush well). This should be a rather low value to represent continuity.

Brushes and brush springs are very inexpensive and available from the standard parts places (Olsen's Toy Train Parts, Jeff Kane at the Train Tender, Smitty's Toy Train Parts etc etc) and would be a wise investment.

In addition, a wiring schematic is included in the documents referenced above - couldn't hurt to verify your setup!

Even though the armature and field coil may seem to check good resistance, without a coil "ringer" there is no way to tell if there is even one shorted turn.

With the corrosion, it is very possible the insulation on the windings may be compromised.

Wire up the motor like this:

One transformer lead to one brush. Jump the other brush to one field winding. The other field winding is grounded. The other transformer lead goes to ground. Power it up, and the motor should run. Reverse the 2 brush connections and the motor will run in reverse.

If the motor does not run, it is probably bad.

Larry

Armature and coil tested ok. While I had it all apart, I used intact cleaner on the brush plate, armature, and brushes. Replaced as much of the wiring as I could. Had to touch the brush ends with sandpaper. I did the bypass wiring you suggested and........it runs.

you guys are great.

THANK YOU!

Glad you got it going!

They are a great train.

Spider82 posted:

I have a 752 streamlined that is ready for rehab. The motor is corroded and will not run after serious cleaning and testing. Of course, I have the top motor mount that connects it to the body. I would like to repaint it and run it on the layout. This will never be a collectors prize, it is a runner.

Professionally Repairing the motor is not in the budget.

Of course, I have the motor mount that connects it to the body. Has anyone it in a different motor? Any ideas on what can be done to make this a fun runner?

thanks

 

Is this the same motor? I have  the derelict, and if you need it for parts, I'd be happy to send.