skeinforge retraction stuff...

Why would your restart distance be negative.  The point of restart is to get material back in the nozzle before it's called for so you're not missing anything.  You're more or less telling it to not print anything for the first .2 that's it's calling for.  If the setting is even reading a negative.

I don't know if it were me I would increase retraction and leave restart alone.  I know this has been covered already here give a search for retraction and you should see some posts and users settings.  Might all be for repetier host though

Ya your restart should not be negative. I wonder if that value is just being ignored and assumed 0.

First mess with retraction so that when the extruder moves from tower 1 to Tower 2, no filament is left at the exit point. I would do this with restart length set to 0. Once you feel that value is dialed in, move to your restart value. Fiddling with both at once can lead to misdiagnosing a situation and waste more time and plastic.

I found by making your printer travel faster between non printing bits seems to fix that problem. I set mine to about 80mm/s in slicer/repitier.

OK, thanks for the info. I've now set "Retraction distance" to 2.0 and "Restart extra distance" back to 0.05. I'm testing this right now.

Now... back to RH/slic3r. I've installed the package and done some tests... it makes a real mess! I'm using the 0.3mm solidoodle setting, and it just doesn't work. There's no raft so nothing is sticking. The first loop of the first layer just unsticks as soon as the nozzle comes back with the second loop of the first layer... even sometimes it doesn't even manage to do a square (first loop first layer of my tower), it just doesn't stick.

I've never had this issue with proterface..... how do you make a raft in slic3r, and what's the funny "outer boundary" slic3r does before starting the print? At first I though is was the raft, but it only does an outer boundary...

Thanks, the brim concept helps understand. I might have got a little carried away on my critics on my first few slic3r tests.

Since I've reduced first layer speed to 0.25 (so the first layer doesn't get pulled away) and set retract length to 2mm (to avoid drips) it seems to be working better.

I've got a print going right now of a part I've been having a few difficulties with (nothing spectacular... but I'm begining!) and for now it's looking pretty good, no blobs nor drips and it is stuck to the plate without the raft. Hopefully this version will give me a nice finish (and no raft to remove... which is a pain).

Thanks all for the help.

I repeat, Solidoodle is a miracle. Does anyone have this symptom of looking at anything and just wondering "could I do this easily with SD?"

Well the print is finished and looking quite nice (best version I've done). The way slic3r starts from inside is a good idea.

The one thing I've noticed is that it looks like nozzle "scratches" the surfaces while moving around, as if the layer was in fact a little to thick. Also, I noticed the wire diameter is set to 1.7mm, should it be 1.75 (and could this explain this impression of overthickness)?

First layer should look a little squished.  Think of the point of contact on the cylindrical filament coming out.  If it's just touching you get a single thin point of contact like a ball touching the floor.  If you push it into the bed a little you get a significantly wider point of contact and grip.  I set my first layer flow rate down to .9 to combat the scraping.