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michaelkubina / SpotMicroESP32

My take on a SpotMicro with an optimized design for supportfree 3D-printing. It utilizes an ESP32-DevKitC for the low-level control of the electronics. The heavy computation will be made by external devices, which in return have the power to command the robot.
GNU General Public License v3.0
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Elephant foot leads to tight top shoulder holes - fixed. #17

Closed JonathanMortes closed 3 years ago

JonathanMortes commented 3 years ago

Hey, maybe look at this one some time. I fitted only one in the end but it was quite tricky due to there being not much leeway to ease its way (I'm still trying to fit the others but almost 30min in it's getting tedious). Maybe making it slightly wider would help with assembly speed. The bottom shoulder is fine btw. They're both quite the upgrade from previous model. Captura de pantalla 2020-12-31 a las 9 26 26g

michaelkubina commented 3 years ago

Hello Jonathan,

from memory those holes should have the same dimensions in both the top and bottom shoulder block. But memory can be wrong, so i have looked into the FreeCAD-Files and i can confirm the dimesions are exactly the same. I think the issue here is the "elephant foot" effect, when printing (e.g. https://all3dp.com/2/elephant-s-foot-3d-printing-problem-easy-fixes/).

In the bottom part the nutholes are printed later, so they are not the first layer touching the buildplate. But in the top part they are printed with the first layer and thus can be slightly smaller in the first 1-2 layers. The width in both parts is at 5,8mm, but in the top part the first 1-2 layers can be off by a margin due to this effect.

The easiest solution is to scrub the edges of the first layer in the nutholes a little bit - the other option is to get rid of this effect.

JonathanMortes commented 3 years ago

You're right. I did do those quick fixes but waited for confirmation before closing the issue just in case. And indeed, I started to suffer from elephants foot by progressive misscalibration. I guess it was time to recalibrate after almost a kilogram of PLA printed. Thanks for the suggestion and help, Michael!