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Miyano BND Part Ejector (Sub Spindle) Dissassembly Question

Pete Deal

Apr 10, 2007
Morgantown, WV
The part I'm currently making is short and has a center through hole so quite a bit of coolant gets into the sub spindle and it's coming out around the part ejector assembly. The sub spindle has a Kitagawa hydraulic chuck cylinder with a coolant sump so i think the coolant ought to be going down that pipe. I think it may be clogged up. I took the part ejector assembly off and where it was bolted to there is an aluminum ring that bolts to the back of the Kitagawa hydraulic unit (doesn't turn) and a steel ring that turns with the spindle (center black part in photo below). The part ejector assy bolts to the aluminum ring. I got the 7 of the 8 screws that hold the aluminum ring in place out. The head stripped on the 8th so I had to drill the head out. This ring is now loose but won't come off. I think it's being held in place by a flange on the steel ring. Can't figure out how the steel ring is held in place. I wonder if it's threaded to the spindle? I know there a few folks on here who have similar machines so I'm posting to see if anybody has been into this before. The Miyano assembly drawings are not very good and I can't really tell from them.

Miyano Sub Spindle Ejector Bracket.JPG
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Vancbiker - You're right good observation. It looked like it went to the coolant tank but I looked closer and it does head back to the hydraulic tank. I looked at the actuator on my Mazak and it has the same hydraulic drain behind the coolant catcher hose.

I sent an email to the guy I bought the machine from. Good guy who works on these machines and knows them pretty well (CNC Digital, Lagrange, OH- he's been good to deal with). He called me pretty quickly and said STOP! don't go any further. It's a hydraulic drain for I suppose leakage. He said it doesn't come apart this way. The whole hydraulic actuator has to come off the back of the spindle and disassembled from the other end. I also looked more carefully at the part ejector and it has a drain slot in the bottom so I guess that coolant is supposed to drain there. Which is not great either since it just sort-of drips all over the place back there. Maybe I can put a catch pan there.
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