I have been working on remixing Eric’s BMG carriage a bit-
I stretched in the X & Y directions to make room for LM8UU bearings to clear each other vertically. After getting some crappy bearings. I took a gamble on the EASE ones from Triangle Lab. Honestly, I am really impressed by the quality. They appear to be fully ground for squareness and length on their ends, the cylinder also look like they are This is the 4th iteration of the carriage. I am literally going to print my first prints with it this weekend.
I had some layer registration issues with the last versions that I hope will be cured with the better bearings.
I ended up opening the bearing housings because no matter what, I could NOT get them to size just right for slip fits without increasing the preloads on the bearings. I also relieved the tops of the bores so that any sag that might occur if you print without supports would not interfere with the bearings.
There is a touch of misalignement on one pair of bearings on my last print- I chased the bores with a 15mm drill bit, but did not get too agressive with it. I really want a 15mm chucking reamer for Christmas (a full set really, but I’d settle for a 15 & a 16mm). The bearings on that axis bid ever so slightly- I think that with time the PETG will relax enough that it might settle in on its own. You can feel the rod slide nicely with one or the other bearing, but with both, you can just feel a tough of binding. Half-a-blonde one as some might say.
I also modified the V6 part coller to be 8.5mm lower than the original in order to use a Volcano hot end. I also built in support blocks 0.2mm seperated from the part faces. I got some sag in the original prints.
I also modded in a 3rd screw to support the fan. The combined weight and moment arm would tweak the fan a bit on the rear screws and sag.
So far, my only dislike is that the cartridge heater wires are too stiff to route nicely.
I am hoping for the best - I will post up proof prints when I can.
Dennis