irregular layers at 0.2mm

[francfalco 37]

hi all,

just recently bought my UM2 and whilst i'm impressed with default 01/.06 profiles, the 0.2 profiles doesn't give me the finish i'd expect - very irregular layering, especially around cylinder and curves?

 

Any settings in expert to help get those layers more even and regular?

 

I'm sure its an easy fix?

 

 

any pointers much appreciated

 

cheers

 

[pm_dude 27]

Seems like a loose belt thing to me.

Check this guide:

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#circles

Follow the procedure circles not touching.

 

[gr5 2,171]

I think it's going clockwise around the cylindrical part some times and counter clockwise other times. Combine that with high print speed changes where the nozzle pressures vary greatly and you get this pattern.

You might be able to reduce this if you reduce the polygon count around the cylinder. Marlin can only look 20 or so line segments ahead and if you have 20 line segments in that cylindrical portion it has to slow down a lot (be ready to stop because it doesn't know what's coming up and there might be a sharp corner coming up and not just this smooth curve).

You can almost surely fix this by printing at the jerk value which is 20mm/sec. That way the printer will not speed up or slow down at these spots. Or you can get it close enough at 35mm/sec to greatly reduce this.

1) What speed where you printing at?

2) How many line segments are in each of those curved areas? (try to keep it under 10 line segments) In other words, for a given slice, how many polygons does the printer head pass across? What CAD software did you use? Some of these have settings when you save the STL (e.g. solidworks or DSM), other's have settings when you create the Curve (e.g. sketchup).

 

[francfalco 37]

Yep, i thought loose belts too - still need to check those.

If they are all tight, i'll look at model geometry and software settings.

I use CinemaC4D to model and i'll try reducing the poly count around the curves.

i'll also test various reduced speeds

cheers