This is the final entry in the 4-Part blog posts re. my Prusa i3 MK3S printer. The previous posts can be found here: Part-1, Part-2, Part-3.

Once I completed assembly of my printer, I followed the instructions to do a self-test and calibration. The self-test failed while performing the “Loose belt pulley test” on the X-axis. The manual said to be sure the motor pulleys are not loose, and to be sure the screws are tightened against the flat part of the pulley shaft.

First, I checked all the pulleys and they were not loose. This was puzzling to me, because I could not get rid of the error. I finally decided to re-tighten the X-Y belts. This fixed the problem. I was quite surprised how tight the belts had to be in order to pass the self-test. If you run in to this same situation, check your belt tension.

The next challenge I had was getting the print head depth calibrated correctly. I followed the instructions using the ‘sheet of paper’ method, but the hard part for me was getting the “first layer” calibration correct. This involves getting the perfect Z-axis height at the beginning of the print. The instructions really did not provide a lot of help – they simply describe, in general, what the thickness of the print layer should be.

After much trial and error, I was able to get this right. As with all things 3D, patience and trial-n-error are the keys. Once I was able to print the tree-frog flawlessly, I knew my printer was up and running.

As I review the entire build test, and calibrate experience, I have a few thoughts:

1. This was a very fun kit to put together. Beware though – it is not for beginners. I have a lot of technical chops and have built a lot of things from kits. This one was a challenge, and it took a lot longer to assemble then I thought it would. There are a lot of parts and assembly procedures.
2. The quality and capabilities of this printer are top-shelf. It is also very quiet. I would definitely buy another Prusa printer.
3. I am not a big fan of the Prusa filament that came in the kit. Some people swear by it. I found the other popular brands to make better prints.
4. 3D printing is a slow process and you will learn how to be patient if you are lacking this skill. Printing large objects take a very long time.
5. You will constantly be fiddling with your printer. That is the nature of the business.
6. Once you learn the basics, you will use your printer in ways you never thought possible. I was not sure I would use it a lot. Turns our I use it all the time.