Pictured above is a homemade timing tool and a Parma 500 series armature. You can see that the timing tool is made from a motor can bushing and some piano wire. Note that a small section of piano wire extends from the can bushing and slides into one of the slots on the commutator. A second section of piano wire is placed perpendicular to the small section of piano wire. This longer section will be used to read the timing on the protractor (see picture three below).
Here, the timing tool is inserted on the armature shaft with the small section of piano wire (described above) lined up in a slot on the commutator.
Here the armature and timing tool are inserted in a protractor. The armature is placed flat on the table with two of the lobes touching the table. Straight up from the armature will be 0 degrees (This will read 90 degrees on protractor). Then you calculate your degrees from there. The armature in the picture would be timed at 30 degrees.
Motor Timing Tips
[1] I recommend that you purchase your arms already timed by the manufacturer. With the wide variety of pre-timed arms available, self timing is seldom necessary.
[2] Timing adjustments can be easily made without adjusting the commutator, by using the new Parma Rotor set-up or the Trinity Twister set-up. These set-ups have adjustable endbells that can be twisted in the can to advance or retard timing. Make sure these set-ups are legal in your area.
[3] If you are going to time the armature yourself, there are several considerations to keep in mind.
[A] There are simple, inexpensive armature timing kits available for sale through you local raceway.
[B] It will probably be necessary to place the armature in an oven for a short period of time to loosen the epoxy enough to turn the commutator. Use gloves to handle the armature. Do not use pliers or other clamping device on the Commutator, these may damage the commutator.
[C] After you have timed the armature to the desired setting, it will be necessary to lightly re-glue the armature to prevent the commutator from moving after it is re-installed in the motor. Use a tooth pick or similar device to place epoxy around the commutator by the armarure lobes and winds. DO NOT GET GLUE ON THE METAL PORTION OF THE COMMUTATOR. The glue should be installed very lightly. Large globs of glue can effect armature balance, and may be deemed illegal in unbalanced classes.
[D] After you have timed and glued your armature, you should send it out to a motor services company to have the commutator re-trued, and the armature re-balanced if you are running it in a balanced class.
