Model Railroading > 3D Printer (Part 16) – Twist and Shout

This is Part 16 of a series on my recent experience with an Anycubic “Photon S” 3D printer.  (Parts 1 thru 15 were posted earlier.)
 
Scallops Anyone?
By twisting the part 30 degrees along its long axis, different parts of the LCD screen would be used to create the surface of the walls.  Each edge would still be ragged, but the pattern would be different for each edge.  Also the edges would be side-by-side, instead of stacked.  For the wall facing upward, this worked well.  The lines were significantly reduced, which was a step in the right direction.  However, for the wall facing downward, the lower edges became scalloped. 
 
45?
For the next print, the rate of upward travel of the Build Plate was reduced from 3mm per second to 1mm per second.  This would give fragile areas of the new resin layer (such as the leading edge of a corner) a better chance to stay attached.  The well car body was rotated at 45 (vs. 30) degrees, to see if that will remove the scallops on the downward-facing wall.  These changes lengthened the print time to over 9 hours.  The scallops did disappear from the downhill side, but mysteriously appeared on the uphill side. 
 
Whoo-Hoo! We Have A Winner!
The next print split the difference (between 30 and 45 degrees) and the part was rotated 38 degrees.  The exposure time per layer had been reduced to 8 seconds (vs. 12) to reduce print time.  However, it was now increased to 12 again.  This required a print time of over 14 hours!  :-O  But, in spite of the ridiculously long print time, that did the trick.  Neither the uphill nor downhill faces exhibited any scalloping.  The uphill side printed cleanly, completely line-free.  The downhill side did have some faint lines.  However, this was the most successful print to date.
 
The Ol’ Switcheroo
As a side-bar, the Slicer software does not allow the part to be moved or relocated with the Supports attached, so they are automatically deleted each time the part is rotated.  It is easy to focus on the need to rebuild the Supports, and assume the parameters (such as exposure time per layer, and Anti-Aliasing) are kept as is.  However, the Slicer software has a habit of changing some of the parameters each time the software is restarted, or the part is moved.  I am now mindful of this, and double-check ALL parameters to ensure they are the desired values PRIOR to pressing the Slice Button.
 
Squeaky Wheel
A binding sound started to occur when the Build Plate lowered at the start of a print.  This is the sound of components in need of lubrication.  If the parts wear, they become more loose fitting, and less accurate.  The stepper motor needs to work harder, and will eventually fail.  Appling some thick (85 weight) Nano Lube to the lead screw should quiet things down. 
 



Edited 1 time(s). Last edit at 02/19/20 12:25 by tmotor.

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If you hear the plate grinding or hitting when it hits the vat, then its out of adjustment.   Everyones solution was always "Add shims" but that does not solve the issue.  There is an allen key on the back that you adjust to reset the little aluminum piece that the sensor catches.