A technique for superior prints

How these tests were performed:
All tests on DaVinci 1.0 running 1.1.J firmware using XYZ natural filament with a bed temp of 80 and extruder temp of 220.

T1 series: XYZware 1.1.1
    default configuration except for .2 mm resolution

T2 series: Simplify 3D
    default DaVinci 1.0 configuration except for .2mm resolution

T3 series: Simplify 3D
    default DaVinci 1.0 configuration except for .2mm resolution
    turning off extruder slowdown on short layer times
    addition of layer change gcode to send the extruder for a walk and a clean

In spite of all the claims of superior performance using Simplify3D, I just don't see that much of a difference. HOWEVER, S3D's ability to add layer change code allows one to add gCode... that of course is something XYZware doesn't and never will allow you to do.

The most dramatic difference is in the printing of the cone. As many of you have experienced, pointy ends result in existing layers not having enough time to cool before the next layer is extruded leaving a gob at the top of your print where a small point should be. The solution? Send your extruder for a walk. Originally I just added gCode to walk around the perimeter of the bed, but oozing led to some pretty rough edges, so I then elected to move the printer to the cleaning blades and run it through a cleaning cycle. This provided superior results for the cube and the dovetail joint, but left a lot of artifacts on the cone. Granted these threads are easily removed with the scrape of a utility blade, but in an attempt to reduce these artifacts as much as possible I replaced the DaVinci wiper blades with the wire brush head from a welder's brush. While it did not completely remove the artifacts (the ones that remain are the product of the extruder leaving the print, not from returning from the extruder wipe). If I understood retraction better I might have more success in reducing the exit artifacts.

Although it is not as apparent in the pictures, my technique removes the bowing in the first 5 or 10 mm of a print. And for me personally, the flat top of the dovetail joint is great news indeed as my parts now fit together off the bed and reveal impressive accuracy and tolerances.

This technique does slow things down of course, but with S3D's ability to chain processes I can select to only send the extruder for a layer walk for the bottom and the top 10 mm. This seems to provide consistent superior results.

I suspect my results are what would be available if one has a print cooling fan, but I haven't seen a practical solution for adding one to the DaVinci yet. In the meantime, I'm happy with the results I'm getting and I'd far rather have prints with a few artifacts that can be easily scraped off then failed print after failed print.

S3D's attempt to control this problem is to give you the option of slowing down the extruder for layers with short print times, but for prints like the cone, this only makes matters worse as it just keeps the hot extruder pressed against the print and actually getting the existing layers hotter and hotter. If you include my extruder walk code for any portion of your print, make sure you turn off the "slow down extruder for small layers" option.

Finally, the lack of a fan, or more innovative approaches to this problem is a very solvable problem, the physics and the math are well understood. Here's a great link to a description of the whole phenomenon that a slicer could incorporate into its layer calculations.

http://cdn.intechopen.com/pdfs-wm/21961.pdf

Here is the gcode I add to S3D's script for layer change code: (If you are using the DaVinci's wiper blades, then uncomment the left to right wipe lines. Personally I feel the replacement of the wiper blades with the wire brush is a great improvement and I don't use the wiper blades at all anymore.

G1 X-45 Y10 F4000 ; move to a safe place, set speed as desired
G1 Y200  move head to front for manual cleaning if desired
G1 Y10
G1 Y200
G1 Y10 ; move back and forth to scrape
G1 Y-15
G1 Y10
G1 Y-15
G1 Y10
G1 Y-15
G1 Y10
G1 Y-15
G1 Y10
; G1 X-25 F1800  left and right to scrape
; G1 X-45
; G1 X-25
; G1 X-45
; G1 X-25
; G1 X-45
; G1 X-45 Y100 F4000 ; move head to safe position