Replace bearings in BK12 & BF12 fittings

[dazp1976]

These are the AC contact bearings I plan on using when I replace the rubish deep grove bearings in my Chinese BK12's for my Z axis.

http://www.wychbearings.co.uk/7001-2RS-MAX-Enduro.html

I haven't got them yet, so I can't comment on quality.

For my X and Y axis I made my own bearing block as dazp1976 suggested using larger bearings and my mini-lathe. Although if I knew wynchbearings sold 7001 at a reasonable price way back when I made them I would have just bought cheap BK12s and replaced the bearings.

I found I had to shim my AC bearing to remove play. I used a mixture of 0.1mm shim washers and some thinner ones I cut out of some brass shim shock. They all feel rock solid now.

https://www.ebay.co.uk/itm/A2-Stainl...DHNWICz7gz71SQ

I've been using these a while.
https://www.ebay.co.uk/itm/7201-B-2r...oAAOSwBRVaWdEz
In terms of needing shimming it depends on how you make your blocks to house them. Mine need none, just have to watch how tight I do the end nut.
I've now ordered these to go on the floating end: https://www.ebay.co.uk/itm/3200-B-2R...72.m2749.l2649
I've found that if I put a bearing up tight on this end it eliminates about 0.02mm of my 0.035mm of backlash. A little bit of flex in the screw by the looks of it.