I am for sure interested in one of these and watching closley your progress. Hoping for success here.
As others have suggested it is acceptable to put the ESC on the thrust tube for cooling....that has worked for years on other EDF projects. The best possible options is to have the esc inside the tail cone if one is availalbe. Down the road you may wish to look at Tams website to see if he sells one to fit your motor diameter.
On the new big twin EDF I am wrenching on....(Actually its on Burley Bench at the moment for some custom work)....I am experimenting with putting the ESC in the inlet ducting as shown. This is the Skymaster F4 running twin TJ100 fans....12S. In the end may shift the ESC back to the tail cone location inside the rear ducting...but looking at options.
I got two more TJ100's PNP waiting for a new home...when you get frustrated with those fans
