# Lms 4211 Mini Mill Power Axis Drive Board Info



## Wireaddict (Apr 24, 2015)

I recently had to replace the XMT 1115J drive  board on my mini mill & had questions about the functions of the 2 onboard LEDs & 3 adjustment potentiometers [pots, for short].   LMS didn't have any info on this so I did some research & this is what I learned: R3 is max. speed [CW=increase]; R29 is overload adj. [CCW=increase]; R33 is min. speed or speed regulation [CCW=increase].  The numbers for these pots are printed on the board next to them. [Many PC board mfgrs. identify pots as resistors, using the letter "R" instead of of a P as I would.]  And as for the green LEDs on the board: LED2 lights when power's on & the overtravel limit switch [& any other safety device] contacts are closed; LED3 only lights momentarily when LED2 first lights, without a schematic I don't know if it's really necessary.  [The connector for LED1 is for the yellow 'fault' LED on the drive unit front panel.]  I got this info from John Gerling who services these drive boards [http://www.repaircontrol.com/ or email at jgerlingrvm@charter.net].  I sent this drive board info with LMS so they may share it in the future, too.

Another thing, the drive unit containing this board is mounted on the end of the mill table & gets a lot of vibration.  That might've caused the original drive board to fail; one of the leads on a  5-watt resistor had broken [& resoldering it didn't fix the drive, incidentally] so I made braces for some of the taller components on the new board with toothpicks & contact cement between them & the board surface.  Time will tell if makes it more rugged.


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