motors-drives.....etc

[grf]

hi everyone.
my BF30 mill motor refuses to start since yesterday and i started looking for alternative solutions as i cannot figure what is wrong with it.
it looks like everything is working fine apart from the fact it does not start lol.
my motor is a brushless motor (MBL-123HM-300HA-S) with some sort of encoder on top of it and i checked to see what alternative drive options are out there and got lost.so

what are the differences between a AC servo motor and a Brushless servo motors.

can you use a VFD to drive any of the above?

thanks

[Al_The_Man]

VFD won't work, Hitachi claim they have one but do not release details.
AC and BLDC are practically identical, the main difference is in the commutation.
If it is BLDC then there are quite a few drive options depending on the nature of the controller itself.
Al.

[grf]

thank you for the reply. i was researching online about it.
if i understand correct the main difference is that the bldc has permanent magnets and the ac does not.

what drive options are out there for a BLDC motor. my main restriction is 1 phase power.
thanks

[Al_The_Man]

You mentioned AC SERVO motor in your O.P., these are identical to BLDC in that they both have P.M. rotor magnets, visually they cannot be distinguished from each other, it is the AC induction motor that does not have magnets on the rotor.
As to the drive, it depends on what controller you are using as to whether you need ±10vdc or step/dir control, also whether or not the loop is closed back to the drive or the control.
i.e. Encoder goes to drive or controller?
Al.

[grf]

my drive is the one that comes with the mill.
i do not want anything more than to replace the unit that does not work at the moment.
the video link has all the details of the setup
http://www.youtube.com/watch?v=1JBEY9PLacU]Bf30 problem - YouTube
the feedback goes on the main board. i have no control over the unit through mach3 or anything like that.
i really would like just to get a new drive that will work with the motor.
thanks again for all the info

[Al_The_Man]

OK I was assuming you were looking for a servo, but it sounds like it is the spindle motor you are having problems with?
If so, it is probably one of the Shenzhen BLDC motors.
They were either 1.5hp or 3hp most likely it is one of these, the dimensions would tell.
There are ways of subbing in a BLDC servo drive such as A-M-C or Aerotech.
Also Baldor now make a line of BLDC controllers although I have not tried one yet, I am just waiting for the opportunity to put one to the test.
There are some posts here where some have replaced the whole set up with a 3 phase motor and VFD, they may have a working drive to sell.
I have a motor here that someone donated and I am presently testing it with various drives.
Al.

[grf]

i would be very interested in a second hand set.

[Al_The_Man]

PM sent.
Al.

[grf]

thanks for that
hope me being in Australia not to be a problem.

[grf]

so while i am waiting from a couple of places to hear back about motor options i thought of investigating a bit about vector drives and 3 phase motors.
i do understand the benefits of having a vector designed motor but how important it really is for a hobby machine? also if a motor is 240v in delta does that mean it can be used with a vfd that gives 240v output?

[Al_The_Man]

I have used motors on equipment as old as 1950's motors, they sure weren't vector rated motors!
Delta motor should be fine with 240v rating.
Check out the Hitachi VFD's, many on ebay.
Al.