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Spindle rebuild on my 2001 Kitamura, a how to with some questions.

DavidScott

Diamond
Joined
Jul 11, 2012
Location
Washington
So it is time to pull the spindle and replace the bearings. This is a 2001 Mycenter 1 which has a 15k BT30 spindle with a chiller. I find this machine quite interesting so I figured I would try documenting the process, and of course, I will have some questions since I haven't pulled the spindle on this machine before. Already stumped and past 5 central so I can't call for help, that will have to wait till the morning. In the meantime perhaps someone here will know the answer to my questions. I don't know how the spindle is attached to the motor, it's a direct drive, so I am not sure how to proceed. The first photo shows the coupling and the top of the spindle looking in through a side access port. There is some movement between the big cylinder that is just above the spindle and the spindle so it is not solidly connected to the spindle. It does not move when depressing the drawbar. The second photo shows the print for my spindle assembly and the third photo just shows the top of the spindle to the bottom of the motor.

Any ideas what all I have to do to drop the spindle? Other than the air/oil lines, temp sensor wires, and prepare for a lot of oil coming out with it.



Coupling.jpgPrint-1.jpgPrint-2.jpg
 
This thread may have some use, you could even try PMing some of the participants: Looking for spindle for 1985 Kitamura MyCenter 1

One of the respondents says the spindle is belt driven, so may be a variant from what you have.

But from the schematic I can't be sure what the coupling is. Perhaps if you're daring you could undo the obvious bits, then gently try sliding the spindle out of the head, and see if it slips free, as if there's a spline coupling connecting the motor and spindle.

Do you have rigid tapping? That makes a slip fit coupling unlikely.
 
I think the coupling is keyed to the spindle. In the print it does call out keys in the correct area, I just never figured this could be the case. Yes on rigid tapping and when the spindle reverses it goes tic-toc from the slop in the coupling.

I have a few other questions for a tech but wanted to get as far as I could before calling to get some help. My gut tells me it just slides out but it is heavy and there is going to be an oil bath when it comes out so I want a better idea of what to expect.

Thanks for the link to that post. The bearing arrangement looks the same as mine but being belt drive there are differences. I wonder how their repair ended up? I will look into contacting them. I like the suggestion of draining as much cooling oil as possible before removing the spindle. It looks easy enough to separate the oil hose where it connects to the bottom of the circuit.
 
In your Print-1 picture item 32 appears to be an internally splined coupling. The items marked 45, 49, and 77 are the connection for the coupling to the spindle motor. It is a form of taper lock typically called a spanring (German design origin and spanring is an Anglicized version of the German name). Items 33 and 34 are the mating half of the splined coupler and spanring locknut.

From the drawing I can not tell if the spindle cartridge will drop out of item 32 and leave it in place on the spindle motor. I doubt that it will. I think there must be another access spot where you can loosen/remove the bolts in item 45,77 and release the spindle motor from the coupler. Then the coupler and spindle come out together. Since the spanrings are a taper lock concept they are sometimes a bit tough to get them to break free. Be prepared for that.

Muddying up the water is the tool unclamp lever and crosspin (looks like item 44,46). Some of that lever mechanism may need to be removed to get the spindle out. Can't tell that from the pics.

From the drawing it looks like a hollow shaft Yaskawa spindle motor. Do you have TSC or air through the spindle? In either case there will be a seal (Item 47?) that should be replaced particularly if TSC equipped.
 
I just remembered I got the instructions on how to install the spindle back in 2014 and had the bright idea to look at it. The coupling attaches to the motor and must be splined to the spindle as it just slides on. Unfortunately, most of the print is in Japanese so no idea what the notes say, but I remember the verbal instructions and the tolerances are there. From what I can see the spindle should just drop out cleanly without messing with the unclamping stuff. I don't see any way to get to the spanring without pulling the motor off.

Yes, it is a TSC able machine that has most everything needed but a little plumbing and a pump so all new seals will be in order. Airblast is through the center of the spindle now and quite powerful.

I don't know how the unclamp lever actuates the drawbar. It works at any spindle position and I don't see any cutouts in the coupling.
 
I'm thinking the white piece in the pic "coupling" is the unclamp lever. It must have a couple cam rollers on the top of it that depress a ring that is fitted to the unclamp crosspin.

All in all it is a uniquely built spindle. It does not look like the spindle can come out until the crosspin (looks like item 44,46) is out, or the tool retention collet is unscrewed and then the drawbar is left inside the head.

It would really nice if the spindle dropped out of the coupling that is attached to the motor. I just can't tell from the drawing if it will. It would also make the most "sense". The coupler would be assembled to the motor on the bench and it could be checked and tweaked for TIR at assembly. If one had to fit the spanring bolts with the coupler on the spindle it would be impossible to ensure that it was running true.
 
You say oil bath.

???

Shirley - nothing that spins 15K is in oil bath. :willy_nilly:

I would expect it to be oil/air lubed.
Possibly dripped.
Unlikely greased (well, maybe as a 30 taper?)
and highly unlikely bathed.

???


----------------------

Think Snow Eh!
Ox
 
And the lines, and the plate under the motor.

I am waiting for a call back from Kitamura tech but until then. Yes, the coupling is mounted to the spindle motor on the bench and has to run true within .0004" the whole length. I sure hope I don't have to remove anything to drop the spindle as there just isn't access to it. Hopefully, they have some more PDF worksheets they can email me.
 
I talked to the tech and he sent me a highlighted print showing what to remove. This is a new tech and I am not confident he knows exactly how to do this. He is figuring it out from the print, the same one that I posted above. I "think" I know how to proceed and am about to start taking things apart, please pray for me, I probably need all the help I can get! I will be taking lots of photos to document how everything is connected before disconnecting, it may be very important in a few weeks when I am trying to put it all together again, and will post all you want. I'll keep you updated and may have questions.

Edit - Shit, this is the 13th reply to this post. Hope that isn't an omen.
 
You'll no doubt keep power to the machine on while pulling the spindle, so you can wind the head up and down.
So thick MDF/ply on your table...and unplug the chiller unit (electrical connector or fuse) before undoing your pipes.
This should stop a lot of your mess...
Thank you for that, I already turned it off and was just going to manually do it but am thinking your right. It's at least worth a try to turn the chiller off and hope the machine doesn't freak out too much to move the Z-axis.

I have the cross pin pulled out of the spindle so it will drop out of the coupling without tearing more apart than was necessary so that is nice. All looks good enough so far. I did discover that the cross pin came out while the machine was running and beat things up a bit in the past. I will post more and some photos at the end of the day.
 
I can't figure out how to turn the chiller off. If it is set in auto mode the power button does not work and I can't find the auto/manual switch to set to manual to make the power button work, and if RE1 and RE2 is ON. I called Kitamura 16 minutes too late for the day so it's up to you guys. Can I disconnect the 3 power wires to the chiller to turn it off? I have access to where they connect to the chiller and it would be easy to do. There is no breaker or manual switch to disconnect the power.

I do have the manual that came with the chiller and that is what I am looking at to figure things out, as well as the access cover off on the chiller. It's a Daikin AKSN105AK Series.

I might have found the switch. Below is what I am looking at. Description in the manual, an image in the manual of what switch 1 looks like?, and the board which has switches on it and RE1 and RE2 connected to it.

The far right photo shows the wire block where the incomming wires are connected. There are 5 going out to the machine plus ground. R, S, and T are power and RE1 and RE2 are jumpered.


Chiller-1.jpgChiller-2.jpgChiller-3.jpgChiller-wire-block.jpg
 
While I am waiting for help here are some photos.
From left to right. Side view showing the only side access and chiller lines.
Front view assembled and then front view with the unclamp yoke removed.
Drawbar ring with the through pin with captive screws, one was missing a lock washer. In the far back you can see the rear section of the yoke that the unclamp cylinder is attached to that bolts to the end of the yoke.
The last photo shows the yoke and the damage done when what looks like the cross pin came out. There is very little damage to the spindle coupling.

Head-Left-Side.jpgHead-Front.jpgHead-Front-2.jpgDrawbar-Ring.jpgUnclamp-yoke.jpg
 
.....Can I disconnect the 3 power wires to the chiller to turn it off? I have access to where they connect to the chiller and it would be easy to do. There is no breaker or manual switch to disconnect the power......

That's what I do. Also, the wires connected to terminals 60 and 61 are probably the alarm signal. Look for those in the Kitamura wiring diagram to verify before doing anything to bypass an alarm.
 








 
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