I have a 326 with a large motor but it is slow forward and reverse. A quick run down I have ultrasonic cleaned the rolling chassis it rolls effortlessly,new brushes,springs,rebuilt the e-unit, reheated all solder joints, removed the tender wheels and buffed clean, cleaned the commtater face and slots but it runs real slow. I'm starting to suspect a bad field or armature windings , how do I check the parts to comfirm they are good and what is the OHM value range for good parts.......

This message has been edited. Last edited by: newhavenrailroad,

Ted,

These values are taken from Robert Hannon's A.C Gilbert Postwar American Flyer S-gauge Reference Manual.

The Field resitance should be .8 to 1.0 ohms

The Armature resitance should be .8 to 1.0 ohms measured between any two bars of the commutator and all should balance .1 ohms and not vary .2 ohms from the specs.

Both the field and commutator windings should read an open to the shaft and cores. This would check for broken down insulation between the windings and the cores.

Look at a know good commutator as a reference to be sure it has not is twisted on the shaft. (The pitch) This will change the performance too.

Can you substitute a common motor for a test?

What is the Current draw in amps?

Carl

Thanks Carl, for the info I bought the book tonight. Apon closer inspection i found the comutator faces are badly cupped at the segments best measurement I got was about .020 deep. Is this beyond repair? Or should I send it out somewhere for repair............

Ted,

The commutator could be replaced if it is beyond being resurfaced.

There are people who do it. Perhaps someone has some suggestions...

Carl

Ted:
I would contact Mr. Hannon and get his advice. He does an excellent job of repair and rewinding. I have used him before.

I sent off email to Bob Hannon hopfully he can resolve my problem with it......

Bob Hannon got back to me, and he can rewind the field and armature and replace the damaged commutor. So today for the heck of it I could not do any more damage to the commutor I chucked the armature in to the drill press and drilled a .350 hole in a piece of wood to fit. I started with 220 and removed all the cupping then proceeded to polish with emery down to 1500 diamond grit to a mirror finish. During reassembly I added .020 thrustwasher to the front end of the armature to make up for materal removal. When it was finished I had a 16 car train sitting I hooked it up and it will pull them 1/2 throttle at a good clip, it runs like it should now ,Thanks everybody for the help...................