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Retail Price: $34.95
Part #: 4722
Dimensions (overall): 1.25"x1.25"x1/20"
Weight: 1.5 ounces
Applications: For any electric motor spring, both lay-down and
stand-up to a desired tension angle.
Who's It For: Racers looking to tune their electric motors using
various spring tensions.
Good News:
Small sizeis easy to fit in any toolbox.
Quick and easy to adjust spring tension angles.
Results are professional.
Well-made, high-quality feel.
Bad News:
Please be sure to read the Conclusion to this article.
A motor dyno is almost necessary to see accurate results.
High price for a seemingly simple tool.
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There are various methods for breaking in, maintaining, and setting
up and electric motor. Although there is no one correct method for
getting the most out of an electric motor, adjusting your motor springs
(i.e. tension) is a good place to start. Most racers use a pair of
pliers to bend or re-bend their motor springs to a desired shape. But,
now they can use Niftech's new Motor Spring Bending Tool to make the
job even easier.
The Product
Niftech's Motor Spring Bending Tool consists of two solid aluminum
"wheels" which assemble together on a common shaft. The main wheel has
reference markings in 10-degree increments and metal roll pins to hold
the spring in place. The thumb wheel sits above the spring and is used
to change the angle of the spring by twisting the wheel left of right,
depending on how you want to alter the spring itself. By changing the
angle, or tension angle, you can change the amount of pressure the spring
will exhibit on the motor brush.
The reference markings on the tool are set 10 degrees apart. Niftech says
that you could use this tool to accurately increase or decrease spring
tension by 5-100 grams of variance. The only way to accurately measure
this is to use their Spring Tension Measuring Tool (#4725). The markings
on the tool are used to compare and match springs when bending.
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What Does Spring Tension Do?
Spring tension affects the way a motor performs. For example,
hard-tension springs are good for off-road or touring car motors because
the motor is subject to heavy loads and/or physical jolts. A hard spring
will keep the brush in contact with the comm, reducing arcing and brush
bounce while at the same time providing more torque power. On the other
hand, light springs place less of a load on the comm. Less load means
less resistance, and less motor resistance equals higher rpm and top
speeds. For lightweight cars where rpm is more important than bottom end
torque (pan cars, Formula 1) light springs can make the difference. In
applications such as oval racing where cars are travelling around the
course at an almost constant speed with little, if any, braking, high rpm
lighter springs are better. However, if the springs are too light the
brush will bounce off the comm surface and arc - or worse, burn up - and
performance will be lost.
Another use for the tool is to compensate for lost brush length. As a
motor brush wears it shrinks in length. That means a brush that's shorter
will not have as much tension placed on it as a longer brush would. The
spring bending tool will allow you to increase the tension angle to
compensate for the lost brush length. This could save you money by
allowing you to continue using the same pair of springs by bending them to
match from time to time.
To The Testing Room
With a pair of motor springs and the Niftech tool in hand I headed for the
work bench. I tested the tool with standard tension, stand up style springs.
I installed the first spring on the tool's post and the roll pins that hold
the spring in place on the bottom. The top portion of the spring, the part
that clips above the motor brush hood when installed, pointed at the -4.5
mark on the tool. I put the thumb wheel into place and proceeded to add
tension to the spring by turning the thumb wheel counterclockwise. I bent
the spring so that the top portion was set to the -2 mark on the tool. I
took the spring off then placed the other spring on the tool. Using the
same amount of pressure on the top piece of the tool I was easily able to
get the top portion of the spring set to the -2 mark on the tool. I removed
the spring and compared it side-by-side with the other spring I had already
bent. Perfect. Both springs were bent to exactly the same angle. The bend
was neat and professionl looking.
To test things further I put both springs back on the tool one at a time
and bent them to the 0 mark and compared the two. I then decreased spring
tension down to the -9 mark by rotating the thumb wheel clockwise. Each and
every time I compared the springs they were both perfect in their tension
angle and looked very professional. [Note: Niftech sells springs in three
different thicknesses for different spring rates. Each spring will fit onto
the tool and measure at zero degrees on the tool. Along with a chart soon to
be available from Niftech you will be able to see how much pressure in grams
a spring will exhibit by it's wire thickness and the degree reading on the tool.]
Conclusion
All in all, the Niftech motor spring bending tool is a valuable tool in the
art of motor tuning. It's easy to use and it does the job very well. With
the reference markings, it's easy to get two individual springs to have
the same tension angle in them. Someone who owns or has access to a motor
dyno will be able to see results more accurately. I think with a dyno you
will easily and immediately be able to see the results that spring tuning
makes. With just track testing it will be harder to see the most accurate
results from making spring adjustments. The $34.95 price may seem high to
many, but I think one you use the tool and see measurable results you'll
forget about the price. If you do purchase this tool I would also suggest
picking up Niftech's Spring Tension Measuring Tool (#4725), which will give
you exact spring tension figures to keep track of when experimenting.
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