<p>I've done calibration test with "Concentric circle test" (<a href="https://www.thingiverse.com/thing:11895" rel="nofollow noreferrer">https://www.thingiverse.com/thing:11895</a>) and at specific points there are little bumped points on the print. Also Thingiverse page of the test mentions about these.</p>

<p>How can I solve this problem?</p>

<p>My printer is Creality Ender 3 Pro, I use Esun PLA+ with 210 celcius extruder and 60 celcius bed temperature.</p>

<p>Here is the printed object, both are same print, just took photo on different base.</p>

<p><a href="https://i.stack.imgur.com/53vd2.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/53vd2.jpg" alt="enter image description here"></a></p>

<p><a href="https://i.stack.imgur.com/eqnA7.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eqnA7.jpg" alt="enter image description here"></a></p>

[{'answer_id': 10385, 'author': 'Trish', 'author_id': 8884, 'author_profile': 'https://3dprinting.stackexchange.com/users/8884', 'pm_score': 2, 'selected': False, 'text': '<p>5\xa0V and 3.3\xa0V are both <a href="https://learn.sparkfun.com/tutorials/logic-levels/33-v-cmos-logic-levels" rel="nofollow noreferrer">logic "highs"</a> in computing and measured against GND. If the fan simply has to know the on stance and nothing more, then you could run a fan with the logic 5\xa0V (and probably 3.3\xa0V for about 50% spin speed).</p>\n'}, {'answer_id': 10386, 'author': 'Tom van der Zanden', 'author_id': 26, 'author_profile': 'https://3dprinting.stackexchange.com/users/26', 'pm_score': 3, 'selected': False, 'text': '<p>The 5V is derived from the 12V supply by a linear regulator (L7805CD, DPAK package with 100 C/W thermal resistance). The maximum you can draw from it (without overheating the regulator) is around 200mA. Considering the electronics on the board are already using some power, the maximum would be around a 150mA fan but this would have the regulator running near its maximum limits.</p>\n'}, {'answer_id': 10404, 'author': 'cmm', 'author_id': 2082, 'author_profile': 'https://3dprinting.stackexchange.com/users/2082', 'pm_score': 3, 'selected': True, 'text': '<p>You would be better to use a 12V fan.  </p>\n\n<p>The 5V is for powering logic.  It should not have motor loads, even fan motor loads, applied to it.  You will not be saving power over using a 12V fan.  According to @Tom \'s answer, the 5V is derived through a linear regulator.  </p>\n\n<p>A linear regulator has the property that the current drawn from the regulator at 5V will equal the current drawn by the regulator at 12V.  <span class="math-container">$7/12$</span>\'ths of the power will be lost in the regulator chip as heat, which may cause the chip to overheat if there is not enough cooling margin in the thermal design.</p>\n\n<p>If you use a 12V fan the current consumption of the fan for the same cooling capacity will be lower, and you won\'t waste more energy dropping the voltage.</p>\n\n<p>May I ask how hot the steppers are?  Too hot to comfortably hold for more than a few seconds may still be completely acceptable for motors.  So hot that the plastic holding them melts is too hot for the mounting, but may still be ok for the motor.  So hot that they cause burns with 5 second contact is probably too hot.</p>\n\n<p>If the motors are too hot, it might be better to check the current the motor drivers are programmed to deliver (either through software configuration or a potentiometer -- I don\'t know the printer).  Getting the current right is a better fix that managing the excess heat.  It may also improve the linearity of microstepping and improve print quality.</p>\n'}]
['https://3dprinting.stackexchange.com/questions/10390', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/16714/']