should have dropped by sooner. I've not had any complaints of the phase wires letting go like this, they are actually pretty tough considering the amount of current that can be dumped through them. At the sort of power and current levels you were running, they are a bit on the small side though. To be honest, the 12 fet running on 48V or more definitely has the potential to fry the Mac if used hard. I now set the 12 fet a bit tamer, some of those EB2 controllers went out a bit too strong really. Some care should be taken if running a 12 fet and if it's a hot day, that will not help matters.
I will have some modded axles in the not too distant future so that I can fit doubled up phase wires in there. So basically 6pcs of the standard 2mm^2 phase wire that is used as standard, 4mm^2 is equivalent to about 11AWG I believe. You can squeeze more copper through the axle with 6 smaller wires, versus 3 larger wires, I've tried. The extra copper definitely solves the hot phase wire issue IME, so you shouldn't have the same issue recurring, it will not keep the motor cooler though. I run a 6T and that can get the standard phase wires pretty hot when pushed hard, they are barely warm with the upgraded phase wires. I had a few axles made up previously and have a few 8 and 6T motors in stock with them fitted, but no spare axles. Axles have been changed over time and the keyway is now a tight fit in the axle. Upgraded phase wires made a measurable improvement of the Dyno performance and should make even more difference at slow speed, high load where phase current is higher. Unfortunately I haven't been able to test this as the dyno has insufficient torque, my butt dyno says there is a definitely improvement at take off with the upgraded phase wires.
The new EB3 controllers are definitely much nicer with the Mac than the EB2. The EB2 also tended to dump a whole lot more current than you would expect. With the EB3 it definitely keeps the peak current in better check, is much smoother and more controllable. Not the all or nothing that you tend to get with the EB2 and Mac combination. The 3 speed further improves matters when you aren't going flat out. It's a pretty simple process to program the controllers so you can always dial it up or down as required. Personally I've set my bike with a fairly high battery current level of 50A, but the phase to only twice the battery current, so 100A phase current. This keeps things swift but smooth when you pull away but pulls harder with more power as you get moving. By playing with the phase and battery current ratio you can limit the power at lower speeds where phase currents are high and the motor is not operating at best efficiency and supply more power at the higher rpms where it is operating more efficiently, less stress on the gears too. I'll try to find out what is likely damaged on your controller, at least then you can have a backup or use it on a DD motor where they seem to work just fine.
Just for info, I do have a very few of the double width stators that have been mentioned, unfortunately that is the easy bit, the rest of the motors needs to be built around these oversized stators, not easy, but doable. Also have a few special, standard sized 500W stators arriving soon. This is a higher grade stator, should improve performance. Looking forward to trying these out and see what they produce. Should be able to offer these soon in built motors and possibly even as a bare stator for a few of my best customers to try out in their existing Mac motor
You'll have to remove the stator to do the hall sensors I'm afraid, take care. The yoke is secured to the stator support by a large circlip located under the aluminium shaft support in the centre of the stator. You need to remove the other circlips fitted on the axle too, it's all fairly obvious once you've removed the shaft support. What I have done in the past is fit the shaft support back onto the stator support and then knocked the shaft down onto a hard surface, knocking the stator out of the yoke. Use proper working gloves when messing with a motor, they snap back together very strong and you could easily get a nasty pinch or a lot worse.... If you use this method, you should use longer bolts in the shaft support (6pcs of M4 if I remember correctly). The standard bolts securing the shaft support to the stator support are a bit short and the thread in the aluminium stator support can be stripped. Another option is to rig something that will hook under the stator so you aren't relying on the stator support.
Don't worry, I'll get you fixed up ASAP and will sort something out for you so you aren't too much out of pocket. She'll be better than ever