Transparant filament grinded

[phantom 17]

Hi guys,

does anyone know why my ultimaker transparant blue filament is getting grinded by the extruder, but the regular blue that comes with the printer works fine without this issue ??

i print at 50mm speed 0.2 mm height for both. Temp i use for the regular blue is 195-200 and the transparant at 210-220 degrees.

greetz Phantom

[gr5 2,170]

That's 4mm^3/sec which is pretty darn fast. Most UM2's can print that fast with the filament at 220 but not at 200. The plastic is much more fiscous at 190 than 240 (think toothpaste versus honey).

Here is a table of what the absolute limits are that my printer can do (dark blue line in graph):

http://umforum.ultimaker.com/index.php?/topic/4127-um2-extrusion-rates-revisited/

You went over the blue line by just a bit but it sounds like our printers are similar.

Also different colors have different softness and react differently to the "grinding" gear in the feeder.

At any rate, slow down the speed or raise the nozzle temperature.

 

[phantom 17]

Hi gr5,

i used to print at 210-215 degrees but had stringing issues. I fiddled around and found it works pretty well with this speed at 195c and then raise it a little to 200-205c when it prints at height. ( standard blue ultimaker PLA ) The prints come out great, or i just have low standards :-p

So you suggest that the transparant pla is softer then the standard blue, do I need to tighten the extruder when I use the transparant PLA, and then loosen again when switching PLA ?

[gr5 2,170]

So you suggest that the transparant pla is softer then the standard blue

Well I first suggest to slow down to 25mm/sec at .2 layers as at this temp the filament is thick like toothpaste.

I'm not sure if you need it tighter or looser for this filament. You might want to try a mk8 drive gear (C in this picture):

http://airtripper.com/1676/3d-printer-extruder-filament-drive-gear-review-benchmark/

You can buy these in many countries and in many locations but try ebay first.

 

[gr5 2,170]

Well in your original post you stated that you use different temperatures for the different filaments but re-reading it you printed lower temp on the one that prints fine. Which is impressive. I can not print UM light blue that fast on my printer. I can get close but I can't quite get to that speed.

My printer never chews filament. Instead the extruder slips backwards. This is by design. The current limited to the extruder motor is lowered such that it should come very close to chewing it up but not quite. But for different types of filaments this changes. Some filaments are softer or harder and some extruder motors deliver more torque than others.

You may be impatient but the only way to print faster is to either raise the temperature or lower the speed. Look at the graph more carefully please that I linked to. The graph is even designed for .2mm layer height which is what you are printing at. It makes it easier to read.

When I don't care about quality of surface I print much faster than you and at 240C. When I want it to look very nice I print cooler and slower.

 

[phantom 17]

Yes i print the transparent hotter but how hot depends on how big the model is. The larger prints hotter then the small with the temp range as per my first post. I think cura's factory setting is 45 my and just added 5 after my first prints which looked great. I also tried 60mm with raising the temp to 225 for the regular blue but prints where messy.

my extruder goes backwards as well so I know that that works.

You have a point there with difference in torq, that might be the answer.

I'll take your advice and print slower with the transparent blue at same temps and see if that improves, as it will stop the extruder from going backward so much which probably grinds the filament I guess.

Thanks for that chart link and the advice. I hope it won't happen that often so I don't have to throw so much away in the bin ;-)