X-Factory slipper shaft brass flywheel

X-Factory have announced the release of this brass flywheel for the slipper shaft of most 1/10 off-road cars, especially mid-motor cars. With the development of brushless motors, then the introduction of sintered rotors, and now high-discharge LiPo batteries, the torque effects can actually be too much in some spots on some tracks, usually in the infield. Sometimes the car can pitch too violently under power and particularly on brakes with weight transfer between throttle and brakes at times can exceed the rear tires’ grip. The flywheel bolts right on the slipper shaft, therefore rotates opposite to the motor and wheels, smoothing everything out. On high traction surfaces where the tires have excellent grip, the part is not needed so much, and sometimes a lighter flywheel will provide just the right effect. Which is why they have center-punched a dozen holes in the periphery of the weight and supplied the proper drill bit so you can lighten the part to fit your track. Drilling three holes takes out about 1/2 gram from the 15-gram part.

Source: X-Factory [xfactoryrc.com]

Categories - Accessories, Products, X-Factory

Usage

If you republish any elements from this page on another website, including text, original pictures or formatted results please be sure to add a link back to this page as the source.

Comments

1. YoKoMo-MX4 - September 16th, 2010 at 15:36

Gotta applaud Paul and the X-Factory team … always fresh and sucessful ideas.

Now, how about taking that one step further and add a one-way bearing so there is no (or much less) rotating mass penalty on acceleration.

2. floodo1 - September 19th, 2010 at 20:58

you can’t use a one-way bearing. the idea is that the flywheel is rotating at a slow speed when the car is at a slow speed (or stopped). because it takes power/torque to accelerate the flywheel the motor torque is effectively reduced when the car tries to accelerate.

now once the car is moving at high speed the flywheel is also moving at high speed, now the driver lets off to enter a corner and the flywheel begins releasing it’s energy, keeping the car going faster than it would if it didn’t have the flywheel.
now the motor has to work harder to slow the car down.

now in the corner the car slows, the flywheel slows.

go back to the beginning with car slow and flywheel slow and then another acceleration.

—

if you ad a one-way then either the flywheel never slows down, in which case it can’t absorb motor torque because the flywheel is spinning too fast…….or the flywheel never speeds up because the one-way bearing is backwards.

the ENTIRE idea is to purposefully HAVE “rotating mass penalty” upon acceleration in order to dampen the motor torque.

—-

what it really needs is a clutch on it. this way when both the motor and the flywheel rpm are low the flywheel is connected to the motor via the clutch (clutch is clamped by default).
then the motor starts to accelerate and is forced to accelerate the heavy flywheel.
But, here comes the good part….once the clutch reaches a certain RPM (idk say 10,000rpm) then it disengages the flywheel.
the clutch would then need to be able to wait for the motor rpm to fall to another point (say 5000 rpm). once the motor had reached this slow speed the clutch would re-clamp and enable the flywheel.

if you had such a setup then the flywheel would only be in operation at low rpm’s, and at high rpm’s and going into corners and such, the flywheel would never hamper acceleration or deceleration.

—-

unfortunately such a clutch setup would be excessively heavy :(

So, in the meantime direct mounting is the only viable option.
props to x-factory for going with the lightest setup :)