Let's Make Robots!

A guide to H-bridge design and motor interfacing?

I'm going to need a pair of H-bridges for The Heavy soon.

Each needs to control a 180Watt motor at 12v, but (ideally) be able to run 24v to the same motors at a later point in development. So looking at 15Amps per controller. 20 for safety?

I want to run them with PWM, and be able to change direction quickly, as well as lock the motor and set it to freewheel.

Anyone with a CNC mill taking paying/exchange jobs?

I'm looking around to see if anyone's got a 3-axis CNC mill they'd concider doing a job on? I'm trying to address the lack of parts for making the current RepRap "Mendel".

 I've been using silicone moulds and PU fast-casts for a couple of years, so if I can get someone to make a single version of each part on a mill (without undercuts/crossways holes) I can make multi-part moulds to cast replicas.