5AX-120YA Tilting Rotary (4th and 5th axis) Table

Nikken 5AX-120YA with tilting and rotary Z3BF controllers and junction box.

I saw this on eBay for not a bad price so I made a deal with the seller and headed out on a road-trip from Oakville, Canada to Norwich, Connecticut. I left at 2am, arrived at 12pm, stayed for an hour while I reconnected the table and its controllers to the guy's milling machine to test it, then plopped it into the van and drove back. I think I got home around 10:20pm. As you can see, the system is complete with Table, Two Controllers, Junction Box, and Cables. Lucky for me, it was used to machine plastic so was in great condition despite the loss of paint and being covered in a yellow, oily, stringy plastic residue.

Almost all the information required to interface directly with the table can be found in two manuals - the general instruction 5AX-120 Manual, and the Alpha 8 Controller manual. The Alpha 8 manual contains most of the cable signal specifications, but is not the correct manual for the tilting/rotary table - the connectors are slightly different, citing JV04-type connectors rather than the MS3102-type. This table also requires a Junction Box to join the two controllers and to provide power to the table's tilting axis through a different cable.

The Alpha 8 Controller manual describes three of the four cable pinouts in table 5-1, on page 93, namely the feedback cables which are the same for both axes - I believe these to be correct for the 5AX-120YA, and the power cable signal for the rotary axis (probably the correct signals, but the pins may be different because of the different cable types JV04 vs MS3102). Then, according to the 5AX-120 manual, on page 33, note #4, the tilting power connector uses a different military connector, one of type MS3102A20-27F. The electrical signals for this tilting power interface is not documented in either of the two manuals. This tilting axis power cable specification should likely be found in a third Junction Box manual , or in the electrical schematic for the table itself.

I found a reasonable estimation of the tilting power cable's pinout in the 5AX-170 Ver 4 manual which describes one extra pair of pins used to detect overtravel (both ends of the travel, two dog switches, are tied in series.)

I took two approaches - the first was to get in there with the multimeter and trace the signals and voltages. I came up with a pinout based on physical wiring, measuring voltages during jog, clamping, and unclamping, and took off the table's end caps to watch the dogs trigger the limit (tilting) and deceleration (index) switches. The second approach was to beg and plead the technical engineering support at Nikken for info, who in turn had to defer all questions to Japan. I finally received a copy of the original 1993 documentation very nicely overlaid with an English translation. My pinout exactly matched the newly received documentation with exception to the DC power cables being reversed. At least then I could confidently apply 100AC to the brake solenoid without fear of blowing something up.

Wiring Diagrams

I ordered MS3102A military circular connections from Mouser and Arrow electronics and installed them in the side of my controller cabinet. I also needed a 120V to 100VAC transformer to power the air-brake solenoids and tried to unsuccessfully wind my own step-down transformer using an undersized core I ripped out of a 12VDC wall adapter - not enough windings == not enough reactance == too much current draw == smoke. I tried picking up a larger core from A1 Surplus nearby, but couldn't find the perfect one so, onto ebay again and found a very nice but hard-to-find 30watt AC transformer that did the trick.

My controller box is getting crowded. Perhaps it's time to finally trim all those wires I kept long in case I wanted to move things around? Admittedly, I was too cheap when I bought my original controller box - I should have super-sized the box to give me more room inside. This will all be much cleaner when I nip and tuck and close it all up.

I could have placed the table any of four different ways, but this orientation gives the greatest clearance of the rear column, lots of C-axis lateral movement, and though the wires hang from the front, I tucked them off to the left where they won't be a bother.


The table uses two controllers have snappy little 75V 3000rpm Sanyo Denki brushed servos that, according to Nikken's drawings for the 5AX-120FA (note the "FA", not "YA" like mine) operate the axes at 11.1 rpm for the tilting, and 22.2 rpm for the rotary axes. After considerable tuning and trying to squeeze every last bit of performance out of them, I reluctantly settled at roughly half: 1500 deg/s for the tilting, and 3400 deg/sec for the rotary. Perhaps the FA was a faster table. My system uses an 82VDC Keling supply, so I dialed down the PWM to 0.91 output to keep the table motors at 75V. All in all, it's not like I need super-fast movement anyway.

Tuning complete

And finally after a full day of tuning, a video of this major accomplishment (yeah, yeah... I know it's not bang on... it was a quick test:

I took care of a few other things while I had all my tools and wiring out:

  • Installed an encoder on the spindle to enable rigid tapping, replacing the previous (defective) one I installed but could never get working
  • Finally fixed the fan on my VFD that had shorted a while back (fried my controller motherboard too) because of the excessive use of mist coolant - vent coolant outside with garage door open!
  • Finally installed a braking resistor in the VFD as well - but it's alarming on overvoltage every time I stop my motor abruptly.. Did I fry the resistor already?
  • Finally drilled holes for the industrial buttons and LEDs and mounted the door on the cabinet
  • Finally installed the monitor/keyboard arm to bring the monitor and keyboard closer to me as I work, freeing up the top of the Ikea television stand I use as a tool holder storage area :-)

And now finally, I can clean up my garage.

I wonder what I'd like to machine first. Obviously, something complicated like a turbine impeller :-)

By the way, the two Alpha controllers, junction box and pendants are for sale since I no longer need them. Make me an offer.