I made this motor starter for HM supporter, Bamban's Bridgeport Milling Machine
6/16/2016
the box is very simple to hook up to any motor.
you simply hook the box up to your idler motor and distribute the 3 phase circuit from the idler motor to whatever you'd like to run.
in my home shop, i have a 5 hp and a 7.5 hp RPC's wired in & ready to go at the push of a button.
i use the 5 hp most of the time,
but when i want to fire up my 300 amp POWCON 3 pahse welder- it needs a bit more juice, so i run the 7.5 for that or anytime i need to run larger capacity motors.
on your BP,
this box, as configured, only has the capacity to start the motor in one direction.
because the start capacitor in the box is starting the motor with a strong bias in one direction of rotation.
a 3 phase motor is happy running forward or reverse, they truly are bi-directional the efficiency and power output is equal, regardless of direction of rotation.
but since we are tricking the motor on start up to believe it has 3 phases( but one of the phases is a burst of 120VDC @ 200UF momentarily)
after the motor is running, it creates it's own 3rd phase, the start capacitor is no longer in the motor circuit after you let up off the green(start) button.
you'll wire the output of the box to your BP's drum switch, then the drum switch to motor.
sequence of operations:
after the box is wired in, to start the BP you'll pick a direction on your drum switch F or R- then push the green button- the mill will run in that direction.
you will push the red (stop) button on the box, power is cut to the BP's motor.
if you'd like to restart in the same rotation, simply push the green button again and then the red button to stop once again.
to reverse the motors' rotation select the other direction on the drum switch and push the green box button, the motor will run in reverse until the stop button is actuated.
one point of information, the drum switches are normally open center switches.
that is that they don't conduct electricity between poles in the center position and are isolated.
that being said, there is potential for possible motor damage if you were to mistakenly switch directions on the drum switch before the motor came to a complete stop.
get into the habit of stopping the mill with the red box button.