Hi Everyone !

I'm coming to you in the hope you would help me with some questions :

I have BF46 milling machine ( from OPTIMUM ) which is not CNC but that have a big brushless motor driven by a control board.

Brushless and board : that's why i try to post here hopefully.

FACTS :

On a hard work, at low speed, with a large tool, the machine stopped suddenly .
I looked at the board and found 2 blown fuses ( close to power 220v entry point )
I changed them and they blew again almost instantaneously.
Hand turning free the nose of the milling is not as usual : there seems to be a slightly hard point during hand rotation.
Looks like the motor has passed away...


-1- if the load on these type on motor overpasses the torque capacity, there is no other protection than fusing the engine together with the fuses ( and may be the board as well )?

-2- the controller board is not able to stop the work and let the engine cool down ?

-3- there were a little bit of oil into the motor : is that bad for the motor ( does it crunch the varnish on copper wires ? or dissolves the glue fixing the magnets ? ) - oil was left in gear box -located below motor- during machine transportation to another workshop and milling was tilted down to horizontal for the trip.

-4- the motor ( fit vertically ) has 2 end caps, top one with some circuitry : i could not separate the rotor neither the top, only the bottom cap came apart from end shaft bearing : is there anything of some interest to visually check out the rotor ? ( should it be a smooth solid uniform part or are there some magnets that can be split out from that bit ? )

-5- do you think, in case the motor ( rotor ? ) is damaged, that the board could be damage as well ?

-6- i changed the board not so far ago, and it cost me 1000e.... is there a mean to repare those board rather than changing as a whole at customer cost ? ( i'm not a businessman, i'm working by my own... ) That is to say : manufacturer is not very helpful except at heavy cost.

Sorry for my mistakes in English language, and many thanks for reading and helping if you have any idea !