What's new
What's new

Now Ive done it. Mycenter 2 !!

Call Kitamura at 847-520-7755, ask for service, and have your serial #. They are there from 7 am to 5:30 pm central time and are your best source for technical questions regarding your machine. They will have a PDF they can email you regarding tips on removing the ball screw or replacing the thrust bearings. For parts you can buy direct, like the Lube pump and other odds and ends, I have found their prices are about 10% more than the best I can find so I would say buy your parts from them, through your distributor as they don't sell direct. This way you know they are correct and it helps support their FREE tech help for anyone who owns a Kitamura.

Before pulling things apart you should figure out if it is your screw or thrust bearings, it is much easier to do while in the machine. There is a vast difference in quality between a rebuilt vs new screw assembly, and a fair amount of work to install it right, so if it were my $$$$ I would go new. This way you can have the parts on hand to install after you pull them and don't have to wait weeks to get your rebuilt screw that will hopefully work and last.

Mine has .0002" lost motion in the Y axis thrust bearings.
 
To other mycenter2x owners a couple of questions.

3) If this turns out to be thrust bearings where is a good source for replacements?

From a local reputable Bearing Dealer. All the uncannily low price stuff on ebay is going to to be counterfeit. Counterfeit Super Precision bearings are as common as sliced bread.

There was some talk way back when in this post about red oil. Certainly could be tranny fluid, but I think some tricked out Japanese oils are red too.
 
Call Kitamura at 847-520-7755, ask for service, and have your serial #. They are there from 7 am to 5:30 pm central time and are your best source for technical questions regarding your machine. They will have a PDF they can email you regarding tips on removing the ball screw or replacing the thrust bearings. For parts you can buy direct, like the Lube pump and other odds and ends, I have found their prices are about 10% more than the best I can find so I would say buy your parts from them, through your distributor as they don't sell direct. This way you know they are correct and it helps support their FREE tech help for anyone who owns a Kitamura.

Before pulling things apart you should figure out if it is your screw or thrust bearings, it is much easier to do while in the machine. There is a vast difference in quality between a rebuilt vs new screw assembly, and a fair amount of work to install it right, so if it were my $$$$ I would go new. This way you can have the parts on hand to install after you pull them and don't have to wait weeks to get your rebuilt screw that will hopefully work and last.

Mine has .0002" lost motion in the Y axis thrust bearings.
Support Kitamura yes!
What your technique for distinguishing thrust from nut movement?
The Y on this one seems very good. I suspect it was replaced at some point.
A quick swing across the 14" table with indicator shows about 8um difference max.
That seems pretty good considering its clearly been run hard for years.
Definite nod to its quality.
 
Anyone know the procedure to swap out tool pots n i80 control?
One is cracked and needs replacing and all could use a clea up.
 
With the air off you can pull out or put back the one that is in the down position. No idea how to get them out of the turret. This is for my 2001 Mycenter 1.
 
I gave Kitamura a call but service tech was not super helpful. I was hoping to get a pdf describing ball screw removal procedure but he said no such thing existed however if the thrust block is not removed from the screw the table has to be lifted to get screw out.

Now that covers are off and motor pulled I can indicate it tomorrow and see if the play can be isolated. I will say turning screw with allen wrench it feels stiff and notchy. That does not seem to change across the length of screw.
 
Put the indicator on your screw and then on the nut. I used a 4' long 2x4 to push and pull on the table to make sure I was using enough force. If you are using a magnetic holder keep in mind it magnetizes every surface you stick it to.
 
I cannot detect movement between the nut and thrust housing. There is a few 10ths movement table to nut before the screw rotates. But something is clearly degrading as rotation is rough and notchy although still tight. I notice to remove X screw either the screw has to be removed from thrust block or table has to come off. Removing thrust nut would at least clearly identify where roughness is.
 
Seems like the ball nut is a problem. Putting indicator on side of ball screw thread and turning it I see indicator moving several 10ths in sync with notchy points. I suspect its been reworked once before and likely ruined.
Do I call Kitamura and ask for ballscrew partnumber or just contact a distributor?
 
Update for the record. While waiting for the proper hook spanner I unbolted the nut so I can check thrust and nut independently.
The ball nut is very tight and makes the rough noise BUT the thrust bearing is producing the notchy action.
 
Update: removed thrust assembly from screw. The nut was absurdly tight. One thrust bearing is in really bad shape. From what I can gather the bearings may have been replaced without properly setting the spacer. Or maybe someone tightened the heck out of nut trying to extend the life a bit.
Sending entire unit out for inspection.
 
Received ballscrew back from Roberts yesterday. The screw itself was still in great shape with just some seal degradation. The thrusts were in bad shape.
Now comes install and alignment time. From what I can tell, the thrust end is the control and nut position controls alignment.
Access to the exposed screw is tight but my plan is, with table as close to thrust as possible, zero out yaw/pitch relative to the X-way.
Suggestions and comments welcomed.
 
Screw installed. Nice to move a .001mm and see .001 on the indicator. What ever comp value is there must be when
screw was new as this thing already has backlash dialed right in.
I used a couple of 123 blocks to make a little truck to slide along the way and with table close to thrust block indicated along screw.
Got it nearly dead on fore-aft at about .003mm. Vertical was more at .008mm.

We will see how it holds up over time but its got a good start.
 








 
Back
Top