<p>I have a <a href="https://www.alunar.net/m508-self-assembly-3d-printer.html" rel="nofollow noreferrer">Alunar M508 machine</a> that I am trying to get new firmware on. The firmware that was loaded on the machine wasn't very good. The x axis was mirrored and the home point was way off. I was looking into Marlin to put on the machine, but don't have any experience on what to edit in the code to make it work for this machine. </p>

<p>Does anyone have any experience with this machine? Uploading new firmware that works or editing the code to make it work for this machine. I appreciate any help!</p>

<p>Here is a link to <a href="https://github.com/camalot/alunar-prusa-i3-marlin-i3-firmware" rel="nofollow noreferrer">the firmware I am currently using</a>. I'm on MacOS Sierra 10.12.5 using the 1.6.8 Arduino IDE.</p>

disclaimer
: I am the maintainer of the firmware that
you linked
.
The firmware will not improve your print quality. well, it may to some extent, but for the most part, it wont.
There is fine tuning involved that may be set for MY printer, but the values may need to be changed for you. Not to mention the physical tuning that I have done with my printer. Software is not the place to initially look for print quality improvements.
Some examples:
I printed anti-wobble caps for the Z-axis rods. Which improved the print drastically for me. As the print got higher, the quality got worse.
I printed Z-stop improvements, so I could fine tune the Z-stop.
I printed X & Y belt tensioners. Loose belts cause skipped steps which causes poor quality prints.