Back on the Acra mill...

[FOMOGO]

Removed the knee lift assembly including the screw, And cleaned everything up. The double row bearing on top of the screw, which consists of 14 ball bearings, and two metal retainers felt crunchy. I removed the two retainers, and in the process of cleaning out the metal chips all of the bearings came out. A bit of a Rubics cube getting it back together, but not to bad. When I went through this process on the BP I installed a shield to keep swarf off the ring and pinion gears, and installed a grease fitting in the knee with a copper line to provide lubrication for the gears. Will be doing the same on this one. I packed the bearing with grease, and can give it a shot or two with a needle point every few years from the bottom of the knee, which is probably more than it will require. I figure any help I can give the Chinese power feed is a good thing. Have all new 6204zz bearings arriving tomorrow for X&Y axis. Went with Penguin brand (pack of 4 for $20, need six in all) as I've had good luck with them on other stuff, and I'm fairly confident they will outlast me. Mike

 

[cathead]

Nice work!! Thanks for sharing Mike.

 

[brino]

That lead-screw looks to be in great shape (little wear) .... what year is the machine?

Brian

 

[FOMOGO]

It's a 1994 model. The majority of wear is on the X axis. Will have to see how much I can adjust out at the nut. Have been considering making a form tool to match the thread at the highest wear area and turning the screw to match the full length, thereby removing most all of the backlash without having to replace the lead screw. Mike

That lead-screw looks to be in great shape (little wear) .... what year is the machine?

 

[brino]

Have been considering making a form tool to match the thread at the highest wear area and turning the screw to match the full length, thereby removing most all of the backlash without having to replace the lead screw.

Well there's an approach that had never occurred to me!
Thanks for sharing that idea Mike!

Brian