Ztrains: Cleaning Your Motors And Brushes

Regular oiling and cleaning
Marklin suggests oiling your Z scale locomotives approximately every 20 hours of running time. I'd suggest adding this simple motor and brush cleaning routine to your regularly scheduled oilings. After just a couple of cleanings, you'll be an old hand at motor and brush maintenance, with this entire procedure taking 5 to 10 minutes to complete. In this article I focus on a steam locomotive, specifically Marklin's 4-6-2 Pacific model. This procedure is similar for the motor and brushes on a 2 truck electric or a diesel locomotive, except on those locomotives you'll have to remove the motor from the chassis.

Removing the brushes
After removing the shell from your steam locomotive, you'll need to remove the brushes to have full access to the brushes and the commutator (see here for a full description of motor parts). The brush is usually made up of either carbon or graphite, and as a locomotive is broken in these small blocks of carbon are shaped to perfectly fit the commutator by the spinning action of the motor. Each brush will have a slightly different physical profile after the loco is broken in, so it's vital to replace the brushes on the same side of the motor they originally came from.

I use a standard round toothpick to remove my brushes. You could use a small jeweler's screwdriver or similar, but in case your hand slips during this procedure, the toothpick will minimize the possibility of causing any damage. With the point of the toothpick, gently push against the copper wire / spring that holds the brush in place (see photo above left). In one smooth motion you can push this copper wire forward and up slightly, this will clear the copper wire from the brush, and the brush will then simply fall out of the motor. Remove both brushes, and place these brushes in two small plastic cups with your cleaning fluid. Mark the outside of these cups so you can tell which side of the locomotive the brushes came from.

Regarding which cleaning fluid to use, there are many ways to go on this... 99.9% pure isopropyl alcohol, Goo-Gone, etc. Recently I thought I'd try a new cleaning fluid designed for the electric motors in RC racing cars. It's called Buggy Blast and it's made by a company called Trinity. I called the Trinity company and they confirmed that Buggy Blast is safe for use on most electric motors containing plastic. Buggy Blast is sold in a 17 ounce aerosol can (approximately $4.99) and comes with a 4 inch applicator tube that fits into the aerosol nozzle. I simply point this tube into the plastic cup containing the brushes and spray until there is enough fluid to cover the brushes.

Brushes for your brushes
I found a remarkably handy item in the oral hygiene section of my drugstore recently that seems custom made for Z scale... the Butler© Proxabrush (see photo above center). These brushes are made up of blue mono-filament nylon bristles wrapped around a thin metal core. They are ideal for getting into hard to reach areas of your motor (they are also great for cleaning out trucks on electric locomotives as well as gears in general). After I let my brushes soak in the Buggy Blast cleaning fluid for a moment, I lightly ran a Proxabrush over the loco's brushes. You can see (photo above right) how effective this cleaning method is. After an additional brush and rinse, I then lightly dabbed the brushes dry on a foam make-up pad to remove any remaining oil and grime sediment. These are the same inexpensive pads I used in my locomotive wheel cleaner project.

Cleaning the commutator

With the brushes cleaned, you can focus on cleaning the commutator. Take one of the Proxabrushes, dip it into your cleaning fluid and then work it in and out, on both the top and the bottom of the commutator (photo right top). You'll need to keep dipping the brush in the cleaning fluid (if you use the Buggy Blast) as it does evaporate very quickly. The in and out action of the Proxabrush should spin the commutator enough so that all sides of it get brushed. You may want to keep a separate small cup of the cleaning fluid available to rinse out your Proxabrush as it will get black with oil in a hurry. You want the brush to remain wet during this operation, primarily so that the cleaning fluid can run into the gaps on the commutator and flush out any oil and grime particles.

The next step is to tear off a very small piece of a foam make-up pad and soak that with cleaning fluid. You then take that small bit of foam and "spear" it onto the end of a toothpick (photo right center). Very gently then, wipe down the commutator to remove the loosened grime and to give it a nice shine. You can actually spin the toothpick around in your fingers for an even more thorough cleaning. You will have to use several of these small pieces of foam as they are very absorbent and pick up oil like a magnet (photo right bottom).

As long as you have both the Proxabrush and the foam in hand, you can also wipe down the copper wire / spring that holds the brushes in place. One thing to watch out for however is getting any of the cleaning fluid on paint as most cleaning fluids can remove paint if left on long enough, just something to be aware of. Since the shell of the loco has been removed, the main painted areas to be aware of are the side driving, or connecting rods. If you do get little of the cleaning fluid on them, wipe the fluid off immediately to prevent any possible paint loss. I actually wiped some of the Buggy Blast directly on the driving rods to see what the reaction would be, and suffered absolutely no paint loss as a result. As with any cleaning product, it's always advisable to test in an inconspicuous and non-critical area first.

Reassemble, oil and run those trains!

Your motor and brushes should now be shining (photo right), and you'll probably be surprised at how much grime was hiding in there. Now all you need do is to reinstall the brushes on the correct sides of the locomotive. Again make sure the brushes are put back on the side they were removed from.

Putting the brushes back in on a steam locomotive is probably the trickiest part of this whole process, essentially it's just the reverse of removing them. Set the brush into place in the motor and with a clean toothpick manipulate the copper wire / spring into it's correct position on the brush. A little practice goes a long way here, it just requires a little patience. After the brushes are in place, don't forget to oil your loco in accordance with the manufacturers guidelines.

May 4, 2008

TimeCast, Historic Miniatures

TimeCast of Shrewsbury, England produces a series of dedicated Z scale, as well as many 6mm, historically accurate European and North American structures that are reasonably priced... and very good.

The thumbnail photo above is actually one of their 6mm scenes with a Marklin box car in the photo for reference. Looks good from here!.

From the Napoleonic era to the fields of Gettysburg to WWII era Germany... TimeCast covers quite a lot of ground.

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