Retraction Issue

[Heutinck]

Hi I've got a duplicator I3 with a microswiss all metal hotend. I have been having and issue lately where even if I turn retraction settings off in S3D, after about a cm of z height printing, there is a major retraction the retracts the filament too far and it gets stuck. It was printing beautifully with about .8 mm of retraction. I have tried lowering the retraction and now have even turned it off, but is still seems to retract after about a z height of 1 cm. I'm at a loss on what I could check now.

Thanks

Tim

[brian442]

Have you checked the gcode to look for any large retraction movements? It would be easiest to spot these after you turn retraction off (then you could just search for any "G1 E" commands)

[Heutinck]

Hey Brian442,

Thanks for the info. never thought of that. I check and there is no retractions happening. I will have to take the hotend apart and see if there is something mechanically wrong with it. also may trend the temperatures somehow to see if the temp is dropping during the print.

I found out something interesting, but not relevant to my issue though. Even though retractions is turned off, when the print starts, after homing the 3 axis and before moving to the print stat, it preforms a retraction based on your current settings even though retraction is turned off.

Thanks Brian442

[wirlybird]

Could be the start script doing that.

[Heutinck]

Yes that's what I thought too, but then I checked my scripts tab. this is the only line in my starting script.

G28 ; home all axes

I have no other scripts except the ending script to turn off everything.

Just thought it was interesting.

[wirlybird]

I wonder if the home all is affecting the extruders also?

[neotko]

If you have more than one process, S3D has a bug on all current versions where it adds the toolchange retraction distance when changing from process A to B

https://ultimaker.com/en/community/3941 ... e-you-nuts

[wirlybird]

I am interested in this also because I have found an issue with S3D where after a long travel move it takes up to 20+mm to start extruding material again leaving big gaps at the start of perimeters. I have tried this with all retraction shut off and it still does it. It acts like the extruder lock if off and on the long move (move across most of the platform on a FFCP) the filament is pulled back up. Since I can reproduce the issue on three different printers it is most likely a software issue.

[Jeff_Birt]

I am interested in this also because I have found an issue with S3D where after a long travel move it takes up to 20+mm to start extruding material again leaving big gaps at the start of perimeters. I have tried this with all retraction shut off and it still does it. It acts like the extruder lock if off and on the long move (move across most of the platform on a FFCP) the filament is pulled back up. Since I can reproduce the issue on three different printers it is most likely a software issue.

I have seen Makerbot Print do the same thing. Looking at the GCode that S2D produces it looks like it starts to move and then starts to feed filament. Since the brim is printed so damn fast (why not first layer speed?) you see more distance covered before the filament starts extruding.

[brian442]

The brim does use the first layer speed. If you set the first layer speed to 50%, the brim is most definitely printed at half the speed vs setting the first layer speed to 100%.

Also, again I would recommend looking through the gcode files to confirm if there is actually a problem with the commands. Otherwise, you're really just guessing that it's the software when it could very easily be the firmware (I have used several firmware versions before that had retraction bugs that did exactly what you are describing). So let us know if you find a specific line in your gcode file that is incorrect.