<p>What are the "magic numbers" people refer to regarding print resolution on the Monoprice Select Mini?</p>

[{'answer_id': 3905, 'author': 'Mark Harrison', 'author_id': 6851, 'author_profile': 'https://3dprinting.stackexchange.com/users/6851', 'pm_score': 4, 'selected': True, 'text': '<p>The "magic numbers" are optimal values that work particularly well for the layer height.  Michael O\'Brien derived these numbers by reverse engineering the <a href="https://hackaday.io/project/12696-monoprice-select-mini-electro-mechanical-upgrades/log/44772-x-y-z-a-motors-stepper-driver-investigation" rel="noreferrer">mechanics of the Z-axis stepper motor</a>.</p>\n\n<p>Using these values as your layer height will generally improve your print quality over using round layer heights such as 0.15, 0.2, or 0.25 by eliminating quantization errors.</p>\n\n<p>To see an example of this, print a copy of <a href="http://www.thingiverse.com/thing:763622" rel="noreferrer">3DBenchy</a> at 0.15 and 0.175.  On the 0.15, you will see some wavy patterns on the curved bow portion compared to the 0.175.  This is the result of inexact rounding.</p>\n\n<pre><code>Layer Height (mm)\n0.04375 (results may vary)*\n0.0875\n0.13125\n0.175\n0.21875\n0.2625\n0.30625\n</code></pre>\n'}, {'answer_id': 11637, 'author': 'Lt72884', 'author_id': 19604, 'author_profile': 'https://3dprinting.stackexchange.com/users/19604', 'pm_score': 0, 'selected': False, 'text': '<p>Though this approach is logical on paper, in the real world it doesnt work as well. Even if you do choose a magic number for the layer height, you cant gurentee that your print head, once homed at the beginning of a print, is using a full step of the motor. Its more common to be on a half step than a full step with a motor</p>\n'}, {'answer_id': 14925, 'author': 'Jimb', 'author_id': 25544, 'author_profile': 'https://3dprinting.stackexchange.com/users/25544', 'pm_score': 0, 'selected': False, 'text': "<p>This is an issue with homing. It is not synced to the stepper motor so it may occur on something other than a full or half or even quarter step. That said, it always does this so moving up from there, the first little bit may be off but I would expect once the motor runs freely, the error will go away. Also keep in mind with microstepping, you can have 1/16 or 1/32 steps as well. Using the magic number ensures the new position you request is within the limits of the stepper/controller to reach. Its like rounding numbers. if you don't, as you increment, the numbers will always be consistant. If you round, the numbers will dither around.\nAt least thats my $45 (inflation) and stickin to it.\nGood luck everyone and have fun.</p>\n"}]
['https://3dprinting.stackexchange.com/questions/3904', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/6851/']