Anyone tried PBC Linear FJ08 or FJC08 bearings? These are Frelon lined aluminum bearings that are a drop in replacement for standard LM8UU bearings.
I’ve just ordered some to give them a try. Unlike the often discussed Igus bearings these are the correct 15mm diameter and given the aluminum shell they shouldn’t require being press fit into a housing to achieve the correct tolerances.
http://www.pbclinear.com/FJ-JIS-Closed-Linear-Bearing
How much are they? Haven’t tied them but look interesting.
I’m curious as to if these really are a drop in replacement.
While I have not tried these specifically I have tried the similar Igus bearings on just open rods. This type of bearing seems to ride a lot smoother on the rails. A very light coating of plastic safe silicon lubricant makes them glide effortlessly. Turned out that for my bearing mounts the Igus bearings where just slightly too big so I can’t actually install them.
Please let us know the results of your experiment.
@Jeff_Parish , the dimensions are exactly the same as a standard LM8UU (8mm ID, 15mm OD, 24mm long). The Igus bearing you are thinking of (with the aluminum shell) has a 16mm diameter rather than 15mm.
@Jeremiah_Coley , they are available directly from the manufacturer on eBay for $45 shipped for a set of 6 FJ08 bearings.
@Matthew_Kelch Yep. Just double checking on reality. Thank you. These look like a very good alternative.
The sample Igus bearings I have are physically 15.5mm diameter and 24.8mm long. Just enough oversized that they are in fact not a direct replacement in spite of information otherwise. 
@Jeff_Parish the tolerances listed for these are as follows " 8.013 - 8.035 ID 14.961 - 15 OD 23.619 - 24 L" , so I would say they will probably work as a drop in replacement… But we all know reality and “advertised as” are two separate things.
I believe that price ($45) is for 4 bearings not 6, unless I am misreading something.
Important not to deform them by pressing or pinching… there is the rub.
@Jeremiah_Coley Looks like they are no longer on sale. I guess they cleared out the excess inventory with me linking to them.
@Brook_Drumm , do you think it will be an issue given the aluminum housing? I know it’s an issue with the entirely plastic Igus bearings, but these appear to be mostly aluminum with a thin layer of Frelon on the contact surface. Seems like it would be relatively difficult to substantially deform the shell in this application.
@Matthew_Kelch that was my thoughts also.
@PrintinAddiction the quantity changed at some point today, looks like they are no longer on sale.