Brushless drive ESC

[knightrous]

I'll just post this link again. Maybe someone is interested in some.
http://vedder.se/2014/01/a-custom-bl...or-controller/

Getting a controller is not the issue, plenty of brushless controllers out there that are proven and reliable in combat robots (the Vedder controller is a big unknown). The big thing we need to do is develop software that will properly for robots and handle a variety of motors (If found some controllers don't like some pole designs in motors ie: H36 motors with a Trackstar controller). BotBitz is working towards hacking the TZ85A to work as a dual purposes controller in both it's current Brushed mode that we sell, but also a Brushless mode. The problem is we need a good amount of time to develop the code, test it with a large range of motors and conditions before we could even consider selling it. At the current moment, I find the Turnigy Trackstar 6S 150A V6 controllers to best off the shelf solution, they are fully programmable, zero delay, have a wide range of voltage (2-6S) which suits most robots and they also have sensor ports (Just need some good sensored outrunners ). So while this controller is readily available, it kind of makes the job of hacking the 85A into a dual mode controller a reinvention of the wheel and therefore a slow progressing project.

I still keep reading that sensorless outrunners won't work.

It's not a case of them not working, it's a case of the conditions they are applied to they don't always work correctly. We have plenty of videos (as posted previously) with robots driving around with outrunners with sensorless controllers, but if you put the robot in a standing start stall condition with full weight and traction, they don't work (Check my video where the weight is distributed level). If your robot gets pushed into a corner and the opponent pins you, the sensorless setups rarely startup and just sit their cogging (as seen in my video) until they can make the first commutation. This is where the sensored controllers really shine, even when stalled, they can begin commutation instantly. This is one reason why I'm trying the bigger NTM 42 series motors is to get better start up torque, not to get 500+ watts of power into the drive.

Charles Guan (e0Designs/etotheiplusone) has done some epic builds with electric scooters and go karts using big outrunner brushless motors and ended up shifting to external to get reliable standing start performance in go karts, where 300lbs of weight taking off from a stand still with wheel spin is the game...



EDIT: Forgot to comment against Nick's post.
I already have a set of those motors for testing, however this is what I dont like about them:
- Max of 4S means they are only suited to low voltage robots or you have to build split powered robots with two batteries.
- Weight, they are 300+g each, which is nearly double the weight of a comparative outrunner.
- Cooling, they are fully enclosed and rely purely on the small heat sink fins. You could add fans etc etc to them, but this is more weight, space, complexity and it's probably not as good as the cooling an outrunner provides to itself.
- Size, they are pretty long motors, much longer then the outrunners and even Dewalts.