There is problem is getting repeatable consistent slip.
In my experience, gear slip gets worse with use. Sometimes it'll loose drive all together within a lap or two, sometimes it'll go on in "controlled slip" for quite a lot longer. Sometimes the "controlled slip" phase can be made to last longer by accelerating gently and backing off the brakes - a tactic I've seen used occasional near the end of a race when the driver decides that'll waste less time than taking the car off and tightening the grub screw.
Electronic adjustments in the controller are repeatable / consistent and adjustable at the turn of a knob. The commonly used choke adjustment (or what some makers call "traction control") has a somewhat similar effect.
QUOTE (JamieG @ 5 Jan 2012, 09:18) <{POST_SNAPBACK}>... while with a mechanical friction system you increase the revs of the motor much faster and when the gear get the grip, the motor is in the point of the curve of max torque.
The result is to have a bullet car exiting the curves with the motor screaming.
Generally motors have maximum torque at stall (zero rpm) and the torque decreases as the rpm increase, so there must be an alternative explanation of the effect.
In my experience, gear slip gets worse with use. Sometimes it'll loose drive all together within a lap or two, sometimes it'll go on in "controlled slip" for quite a lot longer. Sometimes the "controlled slip" phase can be made to last longer by accelerating gently and backing off the brakes - a tactic I've seen used occasional near the end of a race when the driver decides that'll waste less time than taking the car off and tightening the grub screw.
Electronic adjustments in the controller are repeatable / consistent and adjustable at the turn of a knob. The commonly used choke adjustment (or what some makers call "traction control") has a somewhat similar effect.
QUOTE (JamieG @ 5 Jan 2012, 09:18) <{POST_SNAPBACK}>... while with a mechanical friction system you increase the revs of the motor much faster and when the gear get the grip, the motor is in the point of the curve of max torque.
The result is to have a bullet car exiting the curves with the motor screaming.
Generally motors have maximum torque at stall (zero rpm) and the torque decreases as the rpm increase, so there must be an alternative explanation of the effect.
