[Illogical and faulty automatic support placement - workaround?]

Hi guys,

For my current model the automatic support is badly placed by the algorithm since it misses a few layers and then believes it can just print more support onto thin air.

1st support layers are put down correctly.

Support is no longer added.

Support is laid down onto thin air - nothing was printed underneath.

Support keeps being added. The gap in support is visible.

What's going on here? How can I work around this?

All the best

[How to control whether multiple objects are printed all at once or one by one?]

Thanks for the pointer, Skinny. Should have spotted that myself. I'm posting a screenshot for those other newbies who don't find that right away.

[Has anyone tried Ninjaflex filament in UM or UM2 yet?]

hmmmm - I print flexible filaments with a small mod.. (.. a strip of plastic..)

Hi James, could you post a picture of your modification?

[How to control whether multiple objects are printed all at once or one by one?]

When I multiply models they are printed sequentially or together seemingly randomly but I cannot find where to define this. It causes me a lot of trouble, since sequential printing is a must for flexible filaments.

I saw gr5's suggestion of setting the gantry height to 0 but this is a tip intended to force all copies to be printed at once.

I have 2 small spheres (see gcode) that I want to print sequentially. Where do you to set this.

[1.75mm Filament on Ultimaker 2]

Which feeder are you using ?

 

Still on the standard UM2 feeder. No mods there yet, although I have been considering them for flexible filaments which occasionally get stuck.

[Has anyone tried Ninjaflex filament in UM or UM2 yet?]

I'm still trying to determine the best settings.

I ran a gradient test from 210, 220, to 230°C nozzle temperature (left to right).

I noticed the following:

 

• At the bottom and the top, the Ninjaflex doesn't cool down fast enough and is still liquid when the next layer is applied. This leads to the bigger molten blob at the top of the 230 getting smaller via 220 to 210. It also leads to bulges of material being pushed around by the nozzle at 230° but not at 220°.
  
• I won't use 210°C because the material is too crumbly at this low temperature. You can see this in that the 210 print is much less transparent and more milky white. Also, the fill walls inside are very irregular.
  
• The fill walls are thinnest at 230°. This is hard to see in the photo. They nevertheless are still quite irregular.
  

 

So, I'm between 220 and 230°, leaning towards 220 or maybe 225°C. 230° is what the filament producer recommends but I can occasionally already see browning at these temperatures.

I had huge problems switching from printing one sphere to several at a time. Most prints failed towards the top because of a build up of irregularities. This may be a retraction problem, since if you print many, the travel distances are larger requiring more retraction. So, a no retraction that worked fine for one atom caused errors when printing several copies at the same time. I'm testing a longer no retraction distance of 5mm now (1.5 was the default).

I'm using no oil. Retraction was on default for the single prints. Also, printing at normal speed worked. I test with this filament.

What are you printing with?

[Welche Filamenteinstellung bei NinjaFlex]

Hi Sebastian,

Stelle ein neues Material ein unter Material / Advanced / Customize. Oder Export to SD, dann kannst du einfach der Textdatei eine neue Einstellung hinzufügen.

Mein Tipp 220°C, 40° Bett und langsam drucken.

Hier findest du mehr: https://ultimaker.com/en/community/4630-has-anyone-tried-ninjaflex-filament-in-um-or-um2-yet.

Viel Erfolg

[1.75mm Filament on Ultimaker 2]

After studying the excellent contributions in this thread, I ran a little test of my own. First, I thought I'd try the no frills version adjusting just the material type in Material / Settings / Customize on the Ultimaker. As for gurby, who suggested this on page 2 above, it worked for me without any problems. All I did is set the filament diameter to 1.75mm w/o adjusting anything else not even flow. If you can tell the difference between 3 and 1.7mm below, I'd be impressed. What does seem to happen is that some PLA accumulates in the wider nozzle as gr5 suspected. That lead to a minor retraction problem in one case where a 2-3mm wide blob didn't travel back properly during retraction but ended up halfway down the filament tube. I also ordered a 2mm PTFE tube and will test that once I have it. .

[Cura file export.. why is .stl gone?!?]

Renaming the file to .stl after you've exported it as .amf cannot work!

You should overwrite the given .amf extension in the save(as) dialog to save it as .stl

 

My bad. This trick is so counterintuitive that I didn't get it at first. It's weird that you can actually change the file format just by changing the file name. Thanks for clearing that up. It worked now.[/media]

[Cura file export.. why is .stl gone?!?]

Just checked it out with Cura 15.04.4 on a MacBook:

if you overwrite the extension .amf with .stl ist saves a valid STL-File

 

Hi Berndjm,

Thanks for the tip. I just tested renaming a Cura-exported AMF to STL and importing it into Simplify3D to test compatibility. Simplify3D imports .stl and .obj files. Loading a renamed AMF file crashed the program and didn't open any model. I guess the difference between the formats is too big.

I see why Ultimaker may want to change away from STL to AMF. The Additive Manufacturing Files are not based on a single company (3D Systems) but instead determined by a group of makers. It is an open standard and has native support for colors and materials unlike STL. Several other technical reasons have been discussed on 3Daddfab.

Nevertheless, STL is much more established. Nearly every 3D modeling software can read the format. As tested here, this is not the case for AMF. I'd much prefer an STL export option on the already buggy Cura port for OS X (15.04.3).

[1.75mm Filament on Ultimaker 2]

Hi Rusty,

You description sounds very promising but could you provide a little more detail?

 

Hi, I have had a LOT more success with the UM2 using 1.75 mm than the 3 mm. I inserted a small 2mm ptfe tube bought on e-bay within the existing 3mm all the way and tighly to the hot head and at the extruder I put a small washer which prevents the smaller tube going back into the extruder...

Minor changes to UM2 was changing it to use Custom filament 1.75mm under settings and use 95% flow..

 

What type of washer did you use where? Could you provide a photo or a more detailed description?

It sounds like you made no modifications to the filament motor, didn't you?

Would love to replicate what you pulled off but that would be much easier with a few more details. Hope to hear from you.

[Cura file export.. why is .stl gone?!?]

On the latest Mac version of Cura (15.04 as of early 2016) there's no STL export. If you go to the Save Model the only option you have is .AMF.

Is there a way to export .STL from Cura on a Mac?