Dim3nsioneer

Try setting the tension of the feeder so that the indicator is in the middle. This is the recommended position for UM2s since March this year. IIRC indicator on top means maximum tension (I replaced the feeder with Robert's design on my UM2).

The printer is supposed to be new, right? Otherwise a look at the PTFE piece might reveal the problem... btw: what's the setting of the white pressure indicator on the feeder?

I had this effect once. It was caused by the minimum extrusion amount between two retracts. The situation was that a short travel, a very short printing distance and a longer travel followed each other. Retraction was performed on the first short travel due to the minimum travel length. Then the print distance was performed but as it was very short it was not really visible. After that the longer travel was performed but as the minimum printing amount between two retracts was not reached the longer travel was performed without retraction. All together it looked like it would retract, prime and then travel.

I would heat up the nozzle and push the filament through manually. Like this you may find the spot where the resistance begins. This will give you an idea what might be wrong. Which E current values did you try?

Your start.gcode is missing a 'G92 E0' for resetting the extruder position before the first line with a print command (but after the G90). It's also recommended to do some priming before print as it is done in the default start.gcode.

It's hb under 3.2mm thickness... :sad:

Excellent paint job! It looks as if it would move the next second...I would be scared to have it at home... :eek:

Maybe I missed the point. Why exactly do you want to change from three point levelling to four point levelling? It only brings disadvantages imho.

:rolleyes: (just to not disappoint you Ian... ) If such a video exists, I would also be interested to see it...

Today, I tried the 0.6mm profile for a fairphone case. I stopped the print after the first cutout. The lines were sagging so much that half the lower cutout was closed by a curtain. So I stay with my own Cura settings...

Afaik PET+ is only V-2. And you need at least 3.2mm thickness.

Freecad has a remarkable set of tools. However, it's not very stable and rather slow (v0.13). And I read about issues people were having with Cura when Freecad 0.14 was installed.

Yes, you're right. Cura plugins are postprocessing scripts. And it may be indeed very difficult to write such a plugin. I also had planned something similar in the past. However, after having had a look at the Curaengine source code I think it should be possible to implement height dependent layer width. But not too soon.

Yes, gcode settings always override machine settings. The gradual increase of the fan speed is also written into the gcode by Cura and realized with one command on each height until it has reached its final value. Then you can tune it on the machine and it will stay the same.

Thanks for the image. Indeed not bad quality. I have to think about the dual extrusion on my UMO again... :ph34r:

Did they have a special fan for cooling down? I think Marlin supports such a fan. I tried something similar with my dual extrusion UMO. It worked, but it took extremely long to cool down the nozzle. You maybe recall my Ultimaker robot with the Swiss cross. It took 6 hours to print it with this strategy. I think it's not the solution.

Yes, if you apply 100% for layer 31, then it will be 100% from that height on. There is no reset on UM2s running with UltiGCode. On an UMO or an UM2 with RepRap flavor, there is a reset to previous values if more than one object is printed and the tweak height is underrun. This is the rule; here comes the exception: speed is reset to 100% after a print on an UM2 with UltiGCode with http://wiki.ultimaker.com/CuraPlugin:_TweaktAtZ. It's planned to provide a reset also for UltiGCode in future. But this requires a few additional commands in the UM2 firmware which do not yet exist.

Most probably an issue with the sdcard.

Afaik any mcode used in a Ultigcode file will override the UM2 setting. This means it will print with 110% flow from that layer on (and will stay on that value for the layers following the tweak height). Which version of the plugin are you using? 3.1.2?

I would call printrun a remote control for the printer: http://koti.kapsi.fi/~kliment/printrun/ It will not solve your problem but you will see if you can get a stable connection to the UM2 at all.

If you haven't tried it yet, I would switch to a different USB port, to one that is driven by a different USB host in your computer (or try a different computer). If this doesn't help, you may try to remove the Arduino board from the rest of the UM2 electronics and flash the Arduino board only (on the UMO, this helps in certain cases). Do you get a stable connection to the machine with e.g. printrun/pronterface?

Yep! And no more amplifier board on the print head: https://d274pdkuk9fmjq.cloudfront.net/spree/products/224/carousel/SDB7880.jpg?1411184632 btw: It still has only one fan. I call this a missed chance... :sad:

Sounds a bit like choosing options for a new car: "You cannot have the sports model with air-conditioning but you can select the base model and then add the stronger motor and air-conditioning." Not ideal, isn't it? But I'm sure, UM will find a way...

Yes, the closest realization might be a four wheel solution where one wheel nearly touches 80° of the filament (concave wheel surface). It would be a bulky setup but with a clever spring mechanism it should be possible to even allow for different filament diameters.

I doubt they will communicate such details right now for several reasons. I guess the solution is at a quite early stage. And the competitors are not sleeping. The dual extrusion will be a strong USP for Ultimaker. I wouldn't take any risks.