[colton_m]

Hello everyone,

I need some suggestions on how to fix an issue with a Hitachi Seiki lathe. Here's some background info:

The machine is a 1992 HITEC-TURN 23SII. It sat for 3 years with no operation until last weekend, I turned it on, ran the spindle and moved the axis around. Everything worked fine. Next, I moved the machine about 100 feet on roller skates to a new location in the shop, I re-hooked the power and did a complete leveling of the machine. This is where the problem started, the X-axis began making a bad squeaking / grinding sound when moving it even 0.02". I sprayed three squeezes of WD-40 into the clutch at the top of the X-axis ball screw and the sound went away, everything buttery smooth again. I then proceeded to clean the machine for about two hours. Then I went to go home, I pressed e-stop and then power off. Then BAM, the turret fell straight down and landed on the tailstock. I was able to re-engage the clutch manually and use the lathe after that, but again, as soon as I pressed power off. BAM (this time only fell 1/8") because I left the turret low on purpose.

Any thoughts?

Thanks

[underthetire]

Ya, you hosed the X axis brake with WD40. That is not a clutch, it's a magnetic brake to hold the axis at power down.

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[shas595]

Hello,

so the "clutch" on top is a magnetic brake as he said. When its not powered it stays clamped via spring pressure to keep you x-axis from dropping down. When you hit standby youll hear the click of it disengaging after the control confirms that the X-Axis motor is energized and now holding the turret up.

There is not a lot of pressure holding it up - so any fluids or wear will allow it to start dropping once it squeezes back in place. You should probably remove it (while the turret is on block) via the 3 4mm allen screws and the 1 4mm allen on the ballscrew (a cap to keep the the gear in place). Take the unit apart vai the 3 phillips scres and clean the ceramic surfaces and dry it and get rid of any fluids. Put back and test it out - keeping the turret low with some wooden blocks incase it drops

John

[colton_m]

Hello,

so the "clutch" on top is a magnetic brake as he said. When its not powered it stays clamped via spring pressure to keep you x-axis from dropping down. When you hit standby youll hear the click of it disengaging after the control confirms that the X-Axis motor is energized and now holding the turret up.

There is not a lot of pressure holding it up - so any fluids or wear will allow it to start dropping once it squeezes back in place. You should probably remove it (while the turret is on block) via the 3 4mm allen screws and the 1 4mm allen on the ballscrew (a cap to keep the the gear in place). Take the unit apart vai the 3 phillips scres and clean the ceramic surfaces and dry it and get rid of any fluids. Put back and test it out - keeping the turret low with some wooden blocks incase it drops

John

Thanks man, I was able to get it apart and clean/dry everything really well. The brake is now working as it should. For anyone else that encounters the same problem you should note that there were three .0025" shims on top of the riser posts that the phillips screws clamp down on. They are very easy to overlook and if removed the brake can not completely release.