# Ballancing Armatures:How to



## afxgns (Jul 6, 2006)

The following is a tutorial on getting those arms to run better. I don't know everthing, but what I do know, I'll share.

Step #1
Find a slave chassis.
Get a good straight chassis, with a decent set of pickup shoes mounted. Find a set of old green/white mags and install with a little tape on the backside to keep them from pulling out easily.
Also find three decent gearplates(bare) and a loose fitting gearclamp. Mark them and set aside
find a decent set of stock brushes and clean them up. polishing with a piece of paper on the top and bottom, install in your chassis.

Step #2
Make/find a poising tool. This is a tool that finds the heavy side of your arm. usually using two parrell sufaces, ground to a sharp edge. you can find a "how to" on the H.O. World magazine website.

Step #3
Find the right armature:
Look at the commutator, make shure there are no imperfections or pitting. make shure it fits tight on the stacks. Also make shure that the shaft is tight on the stacks. do this by holding the shaft with a pair of pliers and trying to turn the stacks with your fingers. GENTLY try to turn the stacks. if they move at all, set that arm aside and move on to the next arm.
next check the shaft for smoothness and imperfections. ANY scars will effect the performance of the arm, especially on the bottom side.
Then look at the windings and be shure you see even wire and no loose loops or tags.
Finally ohm the arm to make shure it has no dead poles and to be shure it meets your club's rules criteria.

Sep #4
ballancing the arm
Place the arm on the poising tool, and wait for the "lope". As the arm rotates, it will gain speed as it reaches the heavy side toward the bottom. let it settle and mark the heavy side with a sharpy.
At this point you entering the realm of the "Black arts". You will now find your dremel and install a cuttoff wheel and comence to ruin your first arm. (just kidding) Seriously, you need to pay attetion from now on though.
If the heavy side is on a stack, you have it made. Simply find the little clefts in middle and grind a little out of ONE of them.
install the arm in the slave,with a gearplate and spool it up. Feel the vibration?-good, now go a little further with the clft and reinstall. It should a little better. Got The idea?

More to come
I need to go to bed
Tim Leppert


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## Bill Hall (Jan 6, 2007)

Tim,

Great read and good intel. I know Marty B. does his in similar fashion.

I got a big pile of those shakers (75+) I've been threatening to sort out. 

I'm sure there's a coupla plums in the box! Probably a good winter project.

Looking forward to more.


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## martybauer31 (Jan 27, 2004)

Tim, I don't know how I missed this thread, but it's a good one. Got any more good tips?


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