squarefrog

Now that the print has cooled, I see the source of the problem - the circular standoffs aren't even connected at the back! I'm going to try dropping the speed and increasing the temperature, but I'd welcome any other suggestions.

I'm struggling to get decent small round shapes with the ultimaker 2. I'm pretty happy with any straight lined extrusions I get, but I can't seem to get any smaller rounded shapes to come out well. I am using the latest Cura, using the 'Normal' profile, with 1.75mm PLA, at 210ºC. Here is what the model looks like in Cura: And the following are the current results: How can I rectify this and get cleaner extrusions?

I would definitely agree with that. It took us a while to find good settings for use with the White. Thankfully now though we have a couple of nice Acura profiles setup for our machine. One is high resolution slow prints, one is lower resolution quick prints. It also didn't help getting cheaper filament, but it's worked out OK in the end!

I think generally, we're happy with a slower print, but because this part was so large I wanted to ensure it would finish printing during work hours. We have previously had a couple of failed prints that we didn't discover until the next day. I think res arching the Olsson block and an 8mm nozzle will be the next step. I'm impressed at how easy it is to sand or file the plastic after which helps to smooth out the appearance.

Great links, thank you! Unfortunately I had to severely deform the coupler to remove it. I'll chalk that up to an important lesson. I think in future after I do a long print, I'll extrude a little material, just to ensure there isn't any left over filament in the coupler as it cools down.

How long do the PTFE couplers last? I think this printer has done a maximum of about 70 hours. I replaced it and I now see what the problem was. The filament and melted nicely, but from pushing new filament in to do atomic cleaning it must have forced melted filament back up the PTFE coupler. Once the unit cooled down it solidified in the coupler, so no amount of pushing would push the hardened filament back into the hot head.

I presume this means complete disassembly of the print head, so the nozzle is on its own? Then hold with pliers? Not sure I trust myself banging a super heated metal object down on my desk

After yesterdays long print, the nozzle didn't seem to be extruding at all. No problem I thought, I'll do the atomic method and clear it. However, this seems to have compounded the problem by completely compacting the nozzle. When I attempted to atomic clean again, the extra filament I added to the top didn't even melt to the solid mass of filament inside the nozzle. Is there anything I can do to unclog it quickly so I can get up and running again quickly? I thought about heating the nozzle and pushing a guitar string up it to clear enough so that the atomic method would be successful. The material inside the nozzle is PLA. I've heated all the way up to 230ºC, which is as far as I dare.

Good advice. I have had some good results printing with a brim, but for some reason I didn't use it this time. With regard to the underextrusion, do you suppose knocking the temp up from 228ºC to perhaps 232ºC would sort it? If anything that large print stuck on the bed TOO well! But it was just a matter of waiting for the bed to cool completely then it popped right off.

Just a quick update. Printed a larger part with some 'quicker' speeds. Excellent results. Not as refined as the previous slower prints, but definitely impressive. Had a few spots of underextrusion, nothing major. Had to let the bed completely cool before it'd let me pop it off. So this time I used 0.25mm layer height, at a temperature of 228ºC, all other settings stayed the same. Thanks for the suggestions - particular the chart of related heat/speed relationships.

Wow thanks for the detailed replies! I'll have to wait until my boss gets back to try find the larger nozzle. I did try printing a raspberry pi frame at 1.6mm height and 210°c, but I got some underextrusion. Bumped the temp up to 212°C and it was a little better, however I did see the corners warping off the build plate. I'll try the frame again tomorrow at 214°C, with more careful glueing and see how I get on. I don't recall setting the temperature as high as 240°C yet, so think we'll be OK. It surprised me how minor the increase in print speed affected the large robot chassis print. Layer height definitely seems the place to get the pure speed gains.

Thanks for the reply. And thank you as well for including suggestions for different temperature settings and layers. Is there a formula that provides a good starting point for the relationship between layer height, filament temperature and build speed? It took us a while of trial and error to arrive at the 205ºC/40mm/0.1mm value!

I've been trying a bunch of prints on the Ultimaker 2, and I've got some really fine quality prints. Firstly, I've aligned the bed using a piece of paper, and while this sticks the print to bed very well, do I need to be concerned that the print head seems to 'knock' the infill pattern within the object? You can hear it as it is zipping back and forth. Note this doesn't happen when it slows down to print the visible edges of the object. Secondly, although I'm happy with the slow, good quality prints, I'd like to see if I can get a print thats a bit quicker, even if this means I lose a little resolution. I found a robot enclosure on thingiverse, and with my current settings it will take nearly 22 hours to print! I've read through a few threads here, but I'm not sure where to start with speeding up the print. Here are my current settings: - PrimaValue 3mm filament (measured at just under 3mm), cheap white PLA from Amazon UK - Print temperateure: 205ºC - Printbed: 60ºC - 3 stripes of glue stick, then smoothed out with a wet rag Basic - Layer height: 0.1mm- Shell thickness: 0.8mm- Enable retraction: YES * Minimum travel: 1.5mm * Enable combing: All * Minimal extrusion before retracting: 0.02mm * Z hop when retracting: 0.0mm- Bottom/Top thickness: 0.6mm- Fill density: 20mm * Solid infill top: YES * Solid infill bottom: YES * Infill overlap: 15% * Infill prints after perimeters: NO- Print speed: 40mm- Support type: None- Platform adhesion: Brim * Line count: 1 * Start distance: 3.0mm * Minimal length: 150mm- Nozzle size: 0.4 Advanced - Initial layer thickness: 0.3- Initial layer line width: 100%- Cut off object bottom: 0- Dual extrusion overlap: 0.15- Travel speed: 150mm/s- Bottom layer speed: 20mm/s- Infil speed: 80mm/s- Top/bottom speed: 15mm/s- Outer shell speed: 30mm/s- Inner shell speed: 60mm/s- Minimal layer time: 5s- Enable cooling fan: YES * Fan full on at height: 0.5mm * Fan speed min: 100% * Fan speed max: 100% * Minimum speed: 10mm/s * Cool head lift: NO