This is a heavy duty linear slide carriage for 4040 aluminum extrusions. I designed it to use 8 608 bearings and although I am not sure exactly what this is rated to, it is extremely sturdy and I have it in use on my prototype z axis for my printer.
READ BEFORE USE:
Although this worked for my 4040 extrusion, I highly recommend you check the fit by first printing a small cross section where you can jam the bearings onto a ~5mm thick piece and make sure it is tight but not too tight of a slide on your specific aluminum extrusion!
I hope you find this helpful!