Preface: 

Before installing a set of brushes it is always a good idea to check brush hood alignment. Take a Trinity brush hood
alignment bar and see if it will easily pass through both brush hoods. If it won’t, loosen the screws and try again. You can use
the bar to align each hood then lock the screws down.  The best way to install a brush is by soldering.  Clamp the brush lead
about 1/8th of an inch from the end with a good pair of hemostats.  Pre-tin the brush lead and then pre-tin a small spot beside
the brush hood.  Place the lead over the pre-tinned spot and heat until the solder puddles and flows.

Break-in Procedure:

Option One for optimum performance:  We recommend breaking in the brushes dry. Place a small plastic four blade fan on
the motor shaft and clamp motor securely into a motor stand. Use at least three volts from a power supply that is capable of
at least 15 amps. Many of the Trinity motors will pull between 11 and 15 amps during break in with our AT30 series brushes.
Put a drop of our synthetic oil on each bushing and let the brushes seat fully.  This generally takes about twenty minutes or so.
Using heavy springs will help speed up the break in process. After the entire brush face has become smooth and shiny it is
fully seated. Clean out the end bell and brush hoods using a little lacquer thinner or motor spray on a Q-Tip. True the comm
using a diamond bit and a little oil. Clean comm segments with a tooth pick and windings with a little motor spray. Reassemble
and run the motor for a few minutes to re-arc and seat the brushes.

Option Two for the weekend racer:  Use the same process as mentioned above but only run the motor for two or three minutes
until the serrations start to seat. Then install the motor in your car. If you are running (3 ) heats and a main, this may work well
for you. The key with this method is to minimize brush burning by running heavy springs and not over gearing your car or truck.
If any thing, gear down a tooth or two to reduce motor load.  The first heat the motor will not provide maximum amp draw
since it is running on the tips of the serrations. The next two heats you will feel the motor delivering more punch. By the third
heat the brushes should be fully seated. Just before the main pull the motor and true the comm. At this time you can gear up if
you like. Be sure your springs are in good condition especially on the positive brush. We generally use a new purple spring
which will help provide maximum amp draw for the most inside punch and maintain good acceleration all the way down the
straight-away. Once the brush face is fully seated and shiny from edge to edge the motor will deliver maximum performance.
They will need little maintenance at this point. I will check them occasionally for any contamination from over oiling or traction
compound. Just take a Q-Tip dipped in lacquer thinner and push through the brush hoods and clean the comm, then clean the
brush face.

Summary: 

The option one method is necessary when the motor will be used under heavy loads such as “N1 Class” boat
racing or for the “A-Main” of 4WD Sedan Class on carpet. If the brushes are not fully seated they will not be able to provide
maximum performance, and the brushes will arc and burn.  I have seen many boat and car races over the years where the
motor will fade half way through the race and then burn because the brushes were not making full contact or racers where
taking a short cut by using comm drops. Comm drops will lead to premature brush and comm wear and possible motor failure.
Clean and dry the brushes and comm to provide maximum conduction, which translates to less heat build up, less motor
maintenance and longer motor life.

Brush recommendations: 

A few years ago many speed controls were produced with current limiters. Today they are rather
hard to find. So to reduce amp draw for low traction and slippery conditions you can change your brushes and accomplish the
same thing. We also run polarized combinations to fine tune amp draw.  Examples are: using an AT30 on the positive and an
AT70 or AT40 on the negative or an AT70 on the positive and an AT40 on the negative. Try it next time when you find that
you have too much punch from using the new high voltage GP3700 batteries.

We recommend three different types of brushes to meet your driving needs.
• The AT30 series for high performance and maximum amp draw.
• The AT70 series for low traction conditions and high turn modified motors.
• The AT40 series for slippery conditions and low turn modified motors.

High performance on high traction surfaces:  For high performance needs like touring car racing on carpet tracks or “N1 Class”
boat racing our AT30XHS-LD full face brushes and purple springs work best in all the Trinity based motors. In a P2K you will
see an increase of 2K rpm or more. In a Monster Stock you will see a 3K to 4K increase in rpm. The AT33XHS-LD hollow
face brushes work best in Reedy and Orion/Peak style stock motors using stock springs. AT31XHS-LD V-Slot, AT32XHS-LD
D-Deck or AT34XHS- LD Pro Flow brushes can be used in various combinations to maintain amp draw with lighter springs.
V-Slots are great on bumpy off-road tracks because the slot helps keep the brush centered on the comm. D-Deck’s are used
by four cell carpet racers running stock or light springs. AT34XHS-LD Pro-Flows provide just enough cooling when you gearing
up on carpet tracks.

Medium traction and high turn modified motors:  Our AT75 series brushes work great for modified motors between 12 and 19 turns.
The lower silver content helps to extend brush life and reduce heat. The AT70 series are best in stock motors where reduced amp
draw is preferred.

Slippery conditions and low turn modified motors: Our AT45 series brush will minimize brush burning in low turn motors from 6 to 11
turn.  The AT40 series are great in stock class on very slippery tracks. They also work very well in Reedy and Peak/Orion motors.
These two motor companies use the same double stack drilled armature which is prone to saturation and over heating. Reducing amp
draw is critical to keeping these motors from over heating.
 

Written by Ted Schultz, owner of Aggressive R/C Technologies