From 1:50 onwards...



Nice explanation    And it is damn old too !

Amazing, simple and precise. Would be great if you an make it a sticky in the car section.

Made sticky 

This is one of the best technical videos I have watched... ever !

This is awesome i will never forget the working of a diff. Wish they taught us like this in school. Does anyone have anything on servo saver. Wanted to know what is its purpose?

Anything even remotely similar on "limited slip" differentials?

http://www.youtube.com/watch?v=MVxezPgFUL4&feature=related
some thing similar i guess

Nice video to understand how differential gear works. If the outer wheel rotates at (n+1) rpm
then inner wheel rotate at (n-1) rpm.
(1)   But where can we get small differential gears for RC scratch build?
(2)   Is there any alternative electronic device (like V tail mixture), so that it can be fitted into a 4 Ch. remote.

Here I came up with an idea to make a manual speed control + differential unit to scratch build a rc car.

Req. of material:
(1) 2 nos. of gear motor with variable pulley ( dia. of pulley increase/decrease varying Length L1)
(2) 2 nos. of pulley (fix dia)
(3) 2 nos. of Servo

Mounting Bed (B,C) are movable by respective Servos ( 1&2)
Overall speed can be controlled by Servo 2

Differential effect : Servo 1
Speed Control : Servo 2

Thanks for the excellent video Anwar.. Excellent way of explaining..

This is probably my favorite Youtube video !

It gives us a very good explanation.

ankur's explanation was superb too.

Maharana...this was the great problem when i started to make rc cars seriously...at present i collected ample of toy, but good quality gear boxes and differentials...still i trust on one configuration...a simple power transistor assisted traction control+ differential control...its a simple combination of electronic circuits and some mechanical parts...yes we need two or four identical gear boxes for final drive..works nicely...or fully independent control also can be done..the traction variation will be controlled by a simple potentiometer connected to the steering link...the potentio meter must be twin and sliding, so it will control the speed variation while cornering..a simple pcb preset fixed in between the pot and circuit gives us a final fine tuning...and, if this is intended to do by a 4 channel professional radio..its even more easy....

to do it with  a proff radio, connect two identical servo, to the same channel of the RX, and fix one on the steering mechanism, and one to control the pot.we know a twin pot will be independent, so we can alter the direction of control.
when first servo controls the steering the second one control the traction variation...and in extreme,we can even reverse the motor in same given direction...yes we must consider the rotational direction of the second servo,and if its not in to the desired direction, we can alter the circuit in reverse, or can be done by reversing the pole of the servo motor...i have done some crafts even with 6 independently direct driven gear mode,while first sets steers, worked without a trouble...in such setup all used wheels also can be steered simultaneously...a 360 degree turn from stand still...or up to any degree as we increases the arm length of the steering control gear box...

I am thinking of making a differential gearbox for rc car...thinking of what material to use for the housing... though I had managed to  make a model using just meccano parts for showing its working to school students...

try brass gears inside alu casing...!! i will be the first one to pickup one...!

Brass wouldn't work very well. Hardened steel would be my choice.

For the housing, a good nylon-carbon composite would be good.

machining them  will be  a prob...! u  may have to cast  it...but for  small quantity it  wont  be economical..!

will surely come up with a solution as I need it for my shocker car!

this would work cheap and nice...! may be u have to mod  for  fitting....!

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=16086&buddycode=75F28901-4304-4E0D-ADBA-2A9D1353C03F

a diff. at a good price... will need a driveshaft pinion too...any inexpensive method of shipping offered by hobbyking?? I paid 2k for an order worth 4.5k!

Great explanation. Funnily enough, my brother was watching the same video while I was downloading it.

Dont miss this video..  Awesome.. 

Each time you pass power from one gear wheel to another, you can do one of three things: Increase speed: If you connect two gears together and the first one has more teeth than the second one (generally that means it's a bigger-sized wheel), the second one has to turn round much faster to keep up