'Bent on a Budget pt 2: Servo Assisted Brakes

Building an electrically assisted recumbent quad from items found around the house PETER TREMLETT shows us how he rigged up servo assisted disc brakes. Though someone isn't going to be happy when they realise the steering wheel to their X-box has gone missing....

Because I am using this to steer my F-RQ, (Fast Recumbent Quad)



(how i got it)
I have the problem with how am I going to operate the disc brakes at all 4 wheels if I use the paddles on the console as my brake levers.

First I found a pair of TT bar end brake levers, and measured the amount of throw the lever had, 2".




and measured how tight the rotor calipers would lock the disc brake when the lever was fully depressed




I now know that the TT bar end brake levers will totally lock the calipers when fully compressed, so the next challenge was to find a way to electronically throw the lever the full 2' when I pressed the paddle switches on the console.

Enter the humble but torquey servo motor,




I could find servo motors readily but couldn't find any way to drive the servo motor on a momentary basis, till I found this simple schematic of a servo motor controller




which looks like this in the physical realm




By using the lids of small milk flavouring tins, I have the perfect sized cam required to pull the TT bar end brake lever the required 2" to lock the brake rotor caliper




So now when I squeeze the levers here, behind the steering wheel, my brakes are electronically operating a servo motor that operates my mechanical disc brakes!