How to Print Raftless / Discussion

This is the discussion related to the wiki page How to Print Raftless.

Outline vs Wipe

Justin Marrese 21 Jan 2011 19:47

I tried printing raftless on my TOM last weekend by following the similar instructions for the cupcake- the problem I came across was that Skeinforge seems to perform the Outline step before the Wipe step. I usually get a little bit of ooze in the second or two between the wipe and the printing and that little curl of plastic keeps the extrusion from sticking immediately.

My (hackish) solution was to change the start.gcode to not stop the extruder (or more correctly, reverse it for a short time then resuming forward, hoping to introduce a small delay before more plastic comes out); the plastic will start sticking while the extruder moves along the build platform from the wiper to the start position. (Though if travel speed is too high the plastic will be stretched tight and will actually pull up the first part of the outline.) I think use outline after wiping would be much better of course, but I haven't figured out how to re-arrange plug-ins in skeinforge.

Re: Outline vs Wipe

relet 24 Jan 2011 10:18

Same problem here. I had some success with just leaving the outline away, but really what I would like to achieve is to just have a short straight "primer" line somewhere outside the model, and then start with the perimeter lines.

"Gaps" in pre-formed ABP belt

Justin Marrese 21 Jan 2011 19:57

The pre-formed ABP belt has a ~1/8" wide spiral on it in between the windings of plastic that form it. (Mine actually has one spiral where there is top-later material but no bottom-layer, and one with bottom but no top.)

I had trouble with raftless prints not sticking to that part of the belt. The problem was worst on the spiral with no top layer, though still a small problem on the spiral with no bottom layer. If the first outline of the print started on that spiral the build would usually fail.

My solution was to fill this gap with the 3mm wide kapton tape (on the top side of the belt for both.)

(I had tried an incredibly low z-height while troubleshooting the problem, so my first print scraped up the kapton where it overlapped the edge of the gap. Raising it to a more reasonable height had no problem with hitting the kapton and no more problems with the plastic not sticking.)

Adjusting Z in repG 0029_r2

meetar 17 Mar 2012 13:55

In my gcode, the G92 line looks like this:

G92 Z10.2 (set Z to 0)

Adjusting the 10.2 number doesn't seem to do anything. I even set it to 0 to see whether it would try to print 10mm off of the build platform, but the build height doesn't change. Are these outdated instructions?