Friday, Jan 11 2019
The other day I moved the bed on my CR-10S back out of the way and felt some notching. By notching I mean a place where if felt like one or more of the bed rollers/bearings fell into a divot in the Y axis rail. Extra force was required to move the bed once if found the notch. Exploring with fingers and a flashlight showed no issues with the rail. I discovered the notch can be felt every tine the wheels rotate one full revolution. One or more of the rollers has a flat spot, I think. Or maybe bad bearings. In any case I ordered replacement rollers with bearings. They arrived today.
Removing existing rollers
New rollers installed
These pictures are taken facing the bottom of the printer. The printer is laying on the side with the extruder. I removed the mirror, heated bed, and four of the original wheels. I left the two center weels in place to support the bed frame. I removed and replaced the two center wheels after installing new wheels in the outer four spots.
Heated bed installed
I installed the heated bed then adjusted the wheels. It is possible that I had the wheels over tight, leading to a flat spot. With that in mind I adjusted the eccentrics such that there is no wiggle of the bed and there is equal tension on the sets of wheels. I can just move the wheels when holding the bed in place. I don’t think they are too tight.
The bed now moves freely. Time to re-connect the printer to the control unit.
Some wire ends need tinning
Bed level check
When I installed the bed leveling sensor I added some wires to connect the Z end switch connector to the bed leveling sensor control board. I did it that way because I did not want to cut the connector off the stock wiring harness. However I did not tin the end of the wires I added. I should have. I’m fixing that now.
I put my mirror/build plate on the bed and adjusted the corners to get it more or less flat. Recently I discovered the Octoprint Bed Visualizer plug it. I ran it to see how level the bed is according to the sensor.
My flat mirror isn’t as flat as I’d like. The second picture shows that the corners – the only part I can adjust, are at the same height. The center sags. I’m going to try adding a very thin shim under the mirror in the center of the heated bed. Aluminum foil is about .02mm thick. I’ll start with about 3 layers in the middle of the bed and see what it looks like.
But first a test print. I’m printing a benchy in PLA at .2 mm layer height using my fast printer configuration. Fast is a relative term. It will take about 90 minutes for the benchy to print. That’s faster than my slow configuration.
Saturday, Jan 12 2019
The Benchy came out fine, better than the last two I printed. Now I’ll play with shimming the build plate.