optidrive
 

is the optidrive that comes on the revo necesary? i was thinking of getting rid of it and going forward only. not to mention, i think it is cause some electrical grimilin in my revo. it makes it act like the battery pack is dead but in actuallity its almost full.

With an FOC, you can get rid of the optidrive, I believe.

thats what i thought but im not sure if it also controls the transmission shifting

Nope, shifting is not related to electronics. Purely mechanical. Lots of racers get rid of the FOC.

they get rid of the optidrive? and get an forward only conversion? so what does the lead coming from the tranny that goes to the optidrive do?

As far as I understood, there's an optical sensor which dedects if the tranny gears are moving. The Optidrive simply allows or forbids shifting into reverse. It's not needed when you have a FOC.

I hope I am right. Would be great if a nitro smoker could confirm or correct this information.

That's what i know about the optidrive as well, when the gears move above a certain speed, it won't go in reverse..

With the FOC you can loose it..

can i also just unplug the reverse servo until i have a forward only kit so i can get rid of the optidrive? also, where would i plug the lead coming from the tranny? the third channel?

i took the optip drive out of my revo but i still got reverse

From what I have read the opti drive was used to reduce rotational mass in the transmission. It does as was posted sense if the gears in the transmission are moving. The other thing that the revo was supposed to do was limit the speed in reverse, or rather limit the throttle. This opti drive system was also supposed to reduce or eliminate the jerking that the t maxx tranny was prone to when taking off after switching from forward/reverse.
"the best part of wakeing up, is NITRO in your cup!!

There was a clutch in a Tmaxx tranny, that they elimated from the Revo, that was supposed to protect the tranny from damage. The Optidrive does that job now.

Mine wouldn't work right so i removed it

yeah, i know a guy that removed his optidrive, kept reverse, and loves it. all you gotta do is make sure you don't switch into reverse while moving - there's no safety catch to prevent damage at that point, but shifting into and out of reverse becomes instantaneous without the opti-drive.

i remember reading in some Traxxas literature that they alluded to the opti-drive having something to do with shifting, but that's not the case so far as I can tell... it just prevents reverse shifting while moving. like Dafni said, the shifting is all mechanical with springs and tension inside the tranny.

Like others have said: All the optidrive does is sense forward or reverse motion via the transmission optical sensor (hence the name "Opti") and locks out the shifting servo. That's it. Purely for safety of the tranny. Removing the unit will still allow you to shift; you will just lose the safety.

Even so, I have heard of instances where the OptiDrive allowed the servo to shift while the tranny was still in motion - probably a programming issue.

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?

nope. the optidrive has NOTHING to do with the 2 speed. its all mechanical. thats why you remove it when you go with a FOC. i personally hated the damn thing and had nothing but grief from it...

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.