optidrive

[BrianG]

Originally Posted by JThiessen

I've had nothing but problems with mine. Maybe I'm tired right now, or its just been so long since I used it, but wasnt the Revo tranny an automatic two speed, and the optidrive used the rpms for the shift point?

The two-speed works by a centrifugal clutch. Both the main gear for speed 1 and speed 2 are always engaged to the input gears, but only gear one turns the middle shaft (and therefore the output gear). When you start, the 2-speed clutch is disengaged, so gear 2 just free floats on the shaft. Once the speed gets to the shift point, there is a little spring loaded arm on the clutch that is forced out from centrifugal force and grabs one of two little pins inside gear 2. Gear 2 then becomes engaged. Gear 1 then becomes free floating on the shaft (courtesy of a OWB) because the shaft is now spinning slower than the gear. Once the speed slows down enough, the clutch arm is disengaged and gear 1 takes over again. When you turn the "shift later" screw, you are simply adjusting how much spring tension on the clutch arm, which determines the point the arm engages. Purely mechanical.

The Optidrive is just an electrical lockout that prevents shifting in reverse if the truck has not stopped or slowed down enough. Speed is determined by a little LED/sensor shining through a slotted wheel in the tranny. The faster you go, the more pulses in the sensor. The Optidrive reads this data to compute a safe speed to allow shifting. As stated before, you can wire the shifting and throttle servos directly to the Rx and it will work fine - BUT there will be nothing to stop you from shifting into reverse at WOT. If the OptiDrive acts funny, you can try re-programming it. I never had any issue with mine before I went FOC.