Built my MK3S - My Thoughts (good and bad)  

Built my MK3S - My Thoughts (good and bad)

Build Process

Upon receiving my printer kit I opened up the very nicely package parts. I was happy to see there was a printed construction manual, I hate reading from a screen while building. The instructions were, for the most part, easy to read with clear pictures. All the instructions are well illustrated with colour coding to match the written comment. I would say there are a few images that are a little too small, especially when looking at black parts. The electronics were especially tricky to see with some pages have large white space and tiny near thumbnail images. Thankfully there is the online version; so while less convenient areas I couldn't quite make out could be brought up on screen and enlarged. I discovered that when I was building the X-axis I was missing the cable(zip) ties. Still not had a response on that but I have plenty so no trouble. 

Overall it took me two solid afternoons and a little of the first evening to finish the build.

First Time Setup

While the build process wasn't too difficult for me, this is where I started to hit some issues. As recommended in the manual I followed the instructional video to guide me through the setup wizard. First thing I noticed is that the video is from 2017 and some of the layout on the LCD screen isn't the same, not a big issue but something to be aware of. I started the wizard on my printer and all came to life! YAY! I haven't broken it (yet)! I went through the test with the fans spinning up. Now this is where it is different from the video and initially caused me some confusion because it span the hotend fan, went ok, then span up the cooling fan and then asked if the "left" fan was spinning. At first I wasn't sure what it meant, thinking 'what left fan?'. What it means is the hotend fan. Not sure why it was asking as both fans have the speed sensor on them. I got past that and moved on to the next tests. All was going well and  I go the bed calibrating (where you have the paper under the nozzle). Again I wasn't entirely sure what I was looking for hereat first, but figured out I was checking to see if the nozzle impacted the bed. I followed the video and found on the second point it was catching the paper. So 'helpfully' the video said I should try readjusting the PINDA probe. Okaaaaay, how? Do I need it to go up or down? How close should I have it? I mean I set it up exactly as told in the manual. Obviously I had to move it down a little (not that easy and I had to open the clip with a flat screwdriver to allow the probe to move), but for someone who might not have much experience, that isn't all that helpful. Once adjusted down a smidge the calibration when through fine. After that everything else went off without a hitch.

The wizard is really useful in setting up the printer and making sure it will be able to work. Some of the instructions could be a little clearer but it wasn't a hard process and a little thought got me around the problems I encountered.

PRINTING!!

One thing I really liked is the inclusion of the SD card with some test prints. This means I could print without having to setup any software on my PC to begin with. Like most I started with the PRUSA badge/label and I was stunned at the print quality over my DIY self built printer! I mean I could get mine to that point but the work getting it up and running was a nightmare! So I printed the badge, then the Batman logo and finally the whistle (my cats love you now!!) then I went to bed, happy that all was working.

The next morning I got up and wanted to play so I printed Marvin(?) which came out really well. So next I went on to print "buddy" and hit a failure. The printed kept having a crash alarm, even though it wasn't hitting anything. I tried to home the axis' and the X-axis would only move a little and say "Yup, here is home, middle of the axis!" (an issue with using the drivers to detect the home is that if there is resistance BEFORE it gets home, it will assume that position is it, which wouldn't happen with mechanical sensors). I tried several things to identify the problem, slacking off the belt in case it as too tight - nope. I turned off the printer and moved the axis manually and noticed there were really stiff spots in it's movement. I slackened the belt all the way (actually I removed the stepper as I REALLY didn't want to have to put the belt back in to the carriage) and found it was just stiff. Okay, linear bearings? A quick websearch and I found a Reddit article mentioning the exact same issue. It comes from the lower bearing on the x-axis seemingly being crushed with the back cover. This deforms the bearing and causes it, in my case, to totally fail. Some reported slackening the lower and middle bolt on the back cover was enough. But mine was dead, the rubber seal had actually broken off. Thankfully (again) I have some spare linear bearings from my old build (I over ordered), so with much hassle I remove the x-axis, took off one end and slid the lower linear bearing off and replaced it with my new one. This time I done the bolts up just enough to apply a little pressure on to the cover and carriage, enough to hold but no more. After some hassle getting the x-axis back on the z-axis it was back together and as of right now Buddy is printing happily.

Final Thoughts

Given the complexity of the what was being built I am impressed with how few problems I actually hit. Some of the issues just needed to have a little thought applied on my side - maybe some clearer instruction could be useful in places. However the x-axis. I am fully open to it was me and I done something wrong, but I followed the instructions to the letter, routed the cables as shown. Maybe they weren't sitting where they should have been but I would suggest you only do the lower and middle bolts up enough to hold it all, don't do it tight.

Overall it was a really fun experience (even the problem solving, although I might have been more annoyed if I didn't have my own spares - maybe adding a spare bearing could be an idea). I was missing the cable ties but again only a minor annoyance. And the print quality is fantastic! I look forward to using it more going onwards!!!