Mostly great, with a few hiccups
Hello, I've tried to share this with support as well, more informationally than anything. I'm hoping to just share my experience for others.
Know that I am VERY happy with my MK3S, but have encountered some small issues. Before the MK3S I bought an Ender 3 Pro which I've also been very happy with, but the quality and integration of the MK3S is readily apparent.
Here's my experience so far!
I just purchased a MK3S Kit, with the MMU2 on Sept 4th. I got it assembled about a week and a half ago with no issues, and have been printing the Ikea LACK enclosure w/ MMU2 support ( https://www.prusaprinters.org/prints/3673).
It's been *mostly* problem free with 8d : 7h : 13m of print time, but I have had some minor struggles that I wanted to share.
First, my heated bed thermistor cable developed a break, and I got MINTEMP errors after about 5d of printing. I actually managed to isolate the break in the wire, cut it out, and solder it back together with heatshrink tubing and it has been solid since. I've ordered replacement thermistor(s) in case my repair does not hold up.
The thermistor issue was really my fault, I believe I crimped the cable in the cover for the heatbed connector.
Secondly, and more vexing, is my X axis bearings seem to be failing in an odd way. In my print time, I have had SEVERAL X axis crashes. 56 in total according to the machine.
When this first began happening, I tested moving the X axis by hand and it was very rough/catchy. I added machine oil to the smooth rods on either side of the extruder/bearings, and moved the extruder over the oil several times, and this seemed to significantly improve the issue.
My X belt status went from 255 to 273 after adding the oil, tho the 255 was from initial calibration. When I had to oil the axis, I suspect things were MUCH worse, and I could barely move the axis by hand.
Now, another 2-3 days of printing later, and my X axis is almost totally frozen in place. I can move the X axis to the right, but almost not at all to the left.
I've cleaned the smooth rods, and added more lubricant, just to get things moving again. I intend to disassemble the X axis and inspect the bearings. I've already ordered replacement bearings from Amazon (I'm in the US, so ordering directly from Prusa would be cost prohibitive w/ shipping), and I'm not likely to run the machine again until I replace the bearings.
I'm pretty confident that I'll get this resolved, but I wanted to share my experience as a new Prusa owner, and see if anyone else has encountered similar issues with the X axis bearings?
RE: Mostly great, with a few hiccups
Loosen the 5 screws on the back of your extruder that clamp the bearings.
You are crushing them...
RE: Mostly great, with a few hiccups
Loosen the 5 screws on the back of your extruder that clamp the bearings.
You are crushing them...
Thanks, but no. I disassembled the extruder, and pulled the bearings, they all measure 14.94mm nominal around the entire circumference.
However, the seals on the end seem to have degraded and fallen apart. They almost seem melted. I had been noticing pieces of black "stuff" falling on the print for a while. It seems to be plastic from these.
I've got new bearings arriving tomorrow.
RE: Mostly great, with a few hiccups
Bearings should be cleaned then packed with grease before installation. White Lithium #2 (Lithease) or Superlube Synthetic 21030.
RE: Mostly great, with a few hiccups
Bearings should be cleaned then packed with grease before installation. White Lithium #2 (Lithease) or Superlube Synthetic 21030.
Yes, totally agree. Tho, the instructions did not advise this, and I was following them exactly. I properly packed the new bearings, and I've got ~30hr on them with no issues. I'm sure it'll be fine now that they're properly lubricated 🙂
RE: Mostly great, with a few hiccups
Even your new bearings will wear out. Honestly, I am surprised about how fast they wear even when greased properly. About 2000 print hours and even good bearings on Y start making too much noise.