Rack and Pinion

The rack and pinion is used to convert between rotary and linear motion. The rack is the flat, toothed part, the pinion is the gear. Rack and pinion can convert from rotary to linear of from linear to rotary.

The diameter of the gear determines the speed that the rack moves as the pinion turns. Rack and pinions are commonly used in the steering system of cars to convert the rotary motion of the steering wheel to the side to side motion in the wheels. 
Rack and pinion gears give a positive motion especially compared to the friction drive of a wheel in tarmac. In the rack and pinion railway a central rack between the two rails engages with a pinion on the engine allowing the train to be pulled up very steep slopes.
Download and make your own Rack and Pinion model in the shop


Sunday 19th Jun 2011 14:37

Just wanted to say that this site is fantastic!

Thursday 23rd Jun 2011 02:23

Linear motion transfered to rotary motion does turn me on.

Saturday 5th Nov 2011 19:07

i love this website, great work 

Friday 25th Nov 2011 16:39

what is the use of it can you tell.

Sunday 27th Nov 2011 10:05


robives's picture

Rack and pinion drives are used in car steering. The turning action of the steering wheel is converted into a side to side action on the wheels being steered

Tuesday 17th Jan 2012 14:41

nice website

Wednesday 25th Jan 2012 15:07


michael42er's picture

For the model "Rack & Pinion" there is little scope for applying a different model. The slider model from the "Mechanical Gentleman" is suitable.
There are some small adjustments necessary:
The pinion to reduce the diameter from 10 to 8 teeth.
The underside of the slider is turned up, so that the cam is slightly lower.
The rack of the slider extended.
The lower body is usually glued directly to the base. In the video for demonstration only placed separately.
About sense or nonsense is debatable known. It gave me just a joy to vary with the models.

A short video clip on Youtube: http://www.youtube.com/watch?v=9ctCOp8Z5vY


Wednesday 25th Jan 2012 15:34


m.hengsbach's picture

Here are some photos of the model. After a tip from "Chuck" I've given him back his left arm.



Wednesday 28th Mar 2012 18:21

Awesome helped me so much with gcse systems project at BASSALEG!!!!

Thursday 30th Apr 2015 10:12