[slowtwitch]

Hello folks, I figured I give an update on what has been happening with my mill. A couple weeks ago, I was making parts for my linkage system when the Z axis started to act up. Very erratic motion then nothing. I could hear the stepper running, which kind of led me to believe that the coupling was shot.

Well, after removing the covers and such, I was correct in my diagnosis The coupler was split in two. Naturally, in their infinite wisdom, Mikini decided on using odd ball sized couplers I know someone posted here about this and I found this out when I changed my Y axis coupler. The only thing close (after a bunch of searches) was slightly larger in the OD and just a bit shorter in length. I replaced the Y coupler with a zeromax double disk coupler I found on eBay.

Anyway, on my machine, I had to remove the column to get to the problem. There is no access from underneath to get at the stepper. To make a long story short, I replaced the thrust bearings on the end of the ball screw (NSK-7001CTYDBCP5) that I bought on Ebay for $45.00 , machined the stepper mounting block to fit the new coupler ( 10 x 12mm Dual Diaphragm Flexible Coupling D40mm L49mm Motor Shaft Coupler on Ebay for $25.00) , these are Chinese, but, very nicely made. Lastly, I installed a new stepper motor....just to be on the safe side.

I had thoughts of moving the stepper to the top of the column, but, decided it would take a bit of time and decided against it. Anyway, after reinstalling the column and tramming it up, all is working great again........but, something has come up.....hence the title of this thread.

I was browsing around Ebay, when I came upon these....

Attachment 288392

These are brand new, never installed. the seller had them listed wrong and I was able to buy them for $250 for both pairs. The motors are 571 oz/in, nema 34. I've tested them on the bench and they seem to run really nice.

Maybe when i have some spare time, i'll throw them in the mill

If i do, i'll give a full report

[SWATH]

Awesome Pete! A couple of years ago I considered putting these in my mill so I wouldn't have to worry about lost steps. I didn't do it because I fixed the problem I was having but was always curious how these performed.

[slowtwitch]

My mill isn't losing steps , so I may just leave it...as they say , if it ain't broke , don't fix it. On the other hand, I do have a second Emco lathe that needs to be put together