big-ted wrote: ↑
Fri Nov 08, 2019 12:27 pm
If you look closely you can still see that the curvature of the tank isn't quite smooth. Rather than being a cylinder the tank is almost slightly polygon shaped. I don't know if one of the stepper motors was sticking to cause this or if it's sone kind of resolution limit.
I don't know what drawing software you use but I've had that problem with Sketchup, and recently found the answer.
Sketchup by definition doesn't draw true curves, it uses a series of straight lines joined together to approximate a curve.
I recently discovered that by default it draws a circle with 24 straight line segments. With a very small radius this isn't really noticeable but the bigger the circle the more obvious it becomes.It is possible to increase the number of segments to pretty much as many as you want, but only when a circle is first drawn on a new drawing and that new number then becomes the default FOR THAT DRAWING ONLY, it isn't possible to set it as a universal default, for some weird reason.
My Qidi printer then quite faithfully reproduces all the straight lines segments, not a curve!
This picture shows part of something I'm working on at the mo. The one on the right is the standard 24 segment circle ( part of) and on the left is increased to 64.
The angles are still visible but a lot less obvious (the O/A span of the arch is 140mm, for reference). I might try it again with say 120 or so segs, but this object takes about 6 hours 40min to print so I'm not too keen, it might be quicker to get the wet n' dry out!
I don't know, but it is quite possible that other software does something similar.