I have sourced a number of can motors, many with flywheels. Upon closer inspection, some will fit only in wide bodies (for me PAs, F/FP-45s, F7s), while I have some GP-60s and an SD40-2 to contend with. I bought NWSL .010" "shim" washers some years ago, I guess it's time to install them to minimize end-to-end play in the motor shaft. I always put a stud in the frame and hardwire the motor; except once I hardwired to the trucks themselves, which I think might be my new standard.
The only deposits you could get in a DC motor is carbon dust from the brushes, which is conductive. This dust would fill in the slots between the commutator segments causing arching and a possible flashover, where an arc under one brush is dragged to the next brush around the commutator. Very detrimental to the DC motor.
The brushes polish the commutator giving it a shiny chocolate/copper color. This 'film' enhances commutation ( the passage of current between the brushes and commutator ) reducing arcing and increasing the efficiency of the motor.
sandusky Polished with 2000 grit, clean paper towel, eraser, paper towel, (motor spinning under it's own power) applied deoxit D5; yeah, some arcing, more than I'd like to see.
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SouthPennI run-in can motors using the same procedure as the open frame motors. After the run-in, the stall current usually drops 30-50 milliamps.
Interesting note on this, the stall current drops slightly because deposits building up on the commutator create a small amount of electrical resistance. The stall current is highest when the commutator and brushes are completely clean since electrical resistance is at its lowest, so this is also when the maximum possible torque is at its highest.
I run-in can motors using the same procedure as the open frame motors. After the run-in, the stall current usually drops 30-50 milliamps.
Of course, the drive train is being run-in too.
Sandusky,
Keep this link in Your favorites......explains just about everything there is to know about Atheran BB engines, including Motor Tuning and clean-up by the NMRA:
http://www.mcor-nmra.org/Publications/Articles/Athearn_TuneUp.php
Take Care!
Frank
My Athearn PA-1s are both black on the commutators, and they run justy fine.
.
Are you having operational problems?
-Kevin
Living the dream.
Honestly, can motors have gotten so cheap I can think of no good reason not to convert; they make a HUGE difference even in the old reliable Athearns. I've never regretted a penny I spent on can motors.
Disclaimer: This post may contain humor, sarcasm, and/or flatulence.
Michael Mornard
Bringing the North Woods to South Dakota!
The final polish of the commutator is done by the brushes. This is when the brushes become fully seated. No lubricant should ever be applied to the commutator or brushes. Lubricants can collect the brush dust and deposit it in the commutator slots or prevent the brushes from moving in their brush holder.
Something like CRC electronics cleaner can be used to clean up after your manual polishing. Then run the engine for 20 minutes in both directions, varying the speed. Then attach a weighted car ( I use a hopper about half full of lead shot ) and repeat the 20-minute run in.
I'm presuming that you are working with Athearn BB motors. They are not the easiest motors to tune up. When I converted to DCC, most of my BB engines became shelf queens. I often wondered if the brush arcing could introduce spikes and noise on the DCC feeders.
You could install can motors.
Ahh, I use CRC 2-26, for just about everything with electrical parts, or that could be in contact with electrical parts.
I've just learned about Deoxit D5.
Thanks!
Mike.
My You Tube
I need new brushes....
Deoxit D5 is designed to clean corrosion from electrical components (think Stereo, etc.)
From my experience with Athearn motors, or any motor with brushes, it's shape and condition of the brushes that create the black streaks.
Maybe I'm wrong, and I'm not sure if over lubricating the tiny brass bearing, or maybe bushing would be a better term, would cause this.
When I do a DCC conversion on BB Athearns, I usually polish the commutor with a pencil eraser, and all is good. When I'm done, I blow off the commutor with a blast from a can of aresol stuff, and I clean out the notches/grooves in the commutor with a #11 blade, and then blast again with the can.
I've never heard of Deoxit D5.
[quote user="RR_Mel"]
Brushes are made of graphite / carbon - it's only natural the black discoloration will occur.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
SouthPenn Did you lubricate the commutator?
Did you lubricate the commutator?
No, I lubed the motor bearing at that end, from the outside.
I've cleaned and polished the commutator(s), but when I fire up the motors, they almost instantly get black(ish) again. Maybe I over-oiled?