I'm already working on a controller, Luke! I've been doing a lot of work recently on building a small, high current, controller. One thing I discovered, when looking through dozens of FET spec sheets, is that there are some surprises, as a big package isn't necessarily the best. Some may have spotted that getting heat out of the FET junction is the big issue that limits the current a single FET can handle. There's nothing much that can be done about the internal thermal resistance, and this tends to be similar for pretty much any package. The big packages offer the means to get heat out of the package more easily, but this can be done another way, I think.liveforphysics wrote:You're not going to find a sensorless controller to do it any justice.
There isn't a sensorless controller available that can even do the 1/3rd the size HXT motor any justice.
Get one of those motors to Jeremy or Burtie, and they can figure out a sensor position/solution for it, and then it can be used properly.
RC controllers are for toy motors in 10lbs toys. This is not a toy motor.
As far as the people asking about bigger phase leads, that would just require doing a higher KV wind. They just pair the phase wires up in delta and run them out of the case on RC motors, so the wire size is determined by the winding dimensions, which are of course determined by the number of winds.
I've found this FET: Yes, it's a small, surface mount package. BUT, look at the ratings and then think about this as a mounting option:
What if the power rails and the phase connections were solid copper bars, connected to internal finned heatsinks?
What if the FETs were soldered directly to the copper bars, providing not only a good electrical connection, but also a near-zero thermal resistance (no insulators needed)?
What if the controller had a small internal fan to keep the "live" heatsinks cool?
I'm thinking of a 12 FET power "board" using these FETs, driven by a 6 FET controller board. I reckon such a controller would comfortably handle well over 200 amps. In fact, in might well do around 150 amps on just 6 FETs. The downside would be the 75V FET Vds limit, but as the motor is rated at 60V max this shouldn't be too big and issue.