I have spent days trying different configs.

Calibration cubes print great(see attached picture) but when printing anything else I just can't get the same quality.
I use Slic3r for slicing and have tried so many changes.

Can some help ??? I'm pulling my hair out

Assuming you have a heated bed, are you running PID to control the temperature?

If not this could be the issue.. In the first few seconds after the bed is switched on or off, the bed moves a bit up or down due to the sudden heat change. Those prints look exactly like mine did, before I enabled PID.

post your slicer settings, or picture snapshots of speed and infill settings as well as extruder settings.also tell us what printer type you are using.

my guess is you are pushing your machine fast, yet just getting started. several factors limit speed, outside temp, type of nozzle, type of feedstock, vendor, and many others. if you push the flow rate really fast it will work sometimes and not at others. corners and circles require 0.6 the flow rate to go down properly, and this may be part of the issue. my guess is that you have over compensated flow rate because it can not put down the calibration cube normal without higher flow rate, but it may be causing skipping of feedstock, or motor stalling which limits flow rate, and then when a corner or circle is made, and the flow rate decreases to compensate, the feed stock no longer skips and more goes thru.

I would also guess you are running feedstock at too high of a temp. it seems counter intuitive to lower temp, but if heat creep is involved and there is no cooling, the feedstock heats further up, and this causes swelling to be longer, and to form a longer plug, and makes feedstock eventually harder to push.

Hi, yes the beds heated and up to temp. before printing starts.
Also the PID is all setup

Hi James,
Thanks for your suggestions.
I'll try reducing the flow rate and see what happens. May also lower the hotend temp.

My machine:
Loosely based on a Prusa Air but my own design.
Ramps1.4
Budaschozzle hotend
Wades extruder

Software:
Marlin
Slic3r
Pronterface

Calibration cubes are great for dimensional accuracy, but reveal very little about how real objects will look. They are about the easiest thing for your printer to print (single axis motions, minimal z-lift, minimal retractions, no bridging, etc).

It could be z-leadscrew-wobble that you're seeing. If your leadscrews aren't perfectly aligned, you'll get banding that occurs as a result of your print head shifting slightly with height... or bed depending on the geometry of your printer.

But since your calibration cubes are ok.. it's probably more like a belt isn't tight somewhere.

Edited 1 time(s). Last edit at 02/23/2014 06:14PM by iquizzle.