Calibration of Dual Printing

Like I promised a while ago, will I start now with my session with printing 3D Dual Prints.
For a goal I set myself to print a good looking "Pet Monster Valentine - Heartless" from thingiverse.com (Link: http://www.thingiverse.com/thing:17309)

But before printing something "out of the blue" and I'm not statisfied with the print itself in the end, I first try to calibrate and tweak it my printers settings as good as I can. Therefore I continued looking on thingiverse.com and found this Dual Extrusion Calibration Model:

As you can see on the picture, the uploader need to have a good calibrated printer to get such a nice clean result of this print. This or something close to this, is something I would like to achieve before actually printing the Pet Monster Valentine - Heartless.

All in all I made three test runs todays with the Calibration Model. These are my results:
#1 Test:

Regarding the settings, I didn't changed anything and let the printer software Simplify3D choose the prefered seetings for the Wanhao Duplicator 4. The temperatur for the extruders were 230°C and for the heated bed 110°C. Additional to that I choose to print it with a raft and not directly on the heated bed.



The results are accaptable in my point of view but I thought better results needs to be possible.

Some points that didn't went that well in this print were:
- There were a bit oozing on the side
- In the end of the printing of the blue part, it extruded to much filament and it goes into/over the black part
- The edges are not that well either, to much filament was extruded in the corners and it bends out.


A so called "purge/wipe wall" would be the suitable be solution. With this technique the non-used extruder is building a "wall" where it wipes of the overproduced filament.
I was looking for this option in the entire Simplify3D Printing Suite, but i couldn't find an option to add something like this. A solutions for this problem would be the change of the printing software for e.g. to "Cura" (where i actually need to change the currently running firmware of my printer) or "Makerbot", which has definitly the "wipe wall" option. After a little while i found the workaround to build a wall out of the "skirt" that are as high as the printed model and i gave it a second try:

 As you can see it build a "wall" out of the skirt. The downside of this is, that you can only wipe off one extruder - the one who making the skirt.

Some points that didn't went that well in this print were:
- The oozing got better on way better on the black part (which is probably because this was the color who was building the "skirt wall")
- The "ending" of the blue part is still there
- The blue corners went actually worse














Trying to solve the new upcoming and old problems i changed the temperature of the extruders from 230°C to 220°C and did a Noozle Calbration with the programm of the printer. After this I started the 3rd and last print, again with a "skirt wall".

 The results of this print were that:
- The oozing got better in the blue part aswell

- The Corners were still bad
- The same is for the "Ending" of the blue part which goes into/over the black part

To solve the last two points even more tweaking is needed, especially with noozles.

The Comparison with every test print:

I continued looking for additional information to the workaround with the "skirt-wall" and found out that it used to work to make to skirts, one from each extruder, to wipe the material off. But actually Simplify3D itself removed that option in an later update.

After a little while and more research on the internet i found another option or "dirty hack" would be more precise, where you print to extra coloums or models in the same height of my actual print to wipe of the overproduced filament.

I found this solutions here: http://www.forum.simplify3d.com/viewtopic.php?f=23&t=2075#p8128

It's a smart idea and workaround, but what i really don't understand why Simplify3D doesn't have a "purge wall" like many other printing software has...

Anyhow my next tasks for the Dual printing is giving a try to the MakerBot Software and maybe to try the "Dirty Hack". Also I'm planning to tweak the extrutision of the noozles better.