gixxer

Quick update. Been using the new IPM for some time now and haven't noticed any improvement. But I wasn't experiencing any real problems before. The new IPM is still in my machine being used every day.

Yes get the emails working again PLEASE. I haven't been back to this forum in a while for the same reason as Swordriff. I bet you've seen a huge decline in activity since the change to the new forum!

Been printing with polyflex all day today and an 18h print running now. There's reasonable retractions. So far it's working great. I'm using the first Teflon replacement. This polyflex has to be one of the best most printable flexible filaments I've used.

We use large quantities of liquid nitrogen at work now that would be a crazy idea! Access to compressed air is easy for me at work. If the regulator was outside and set to 0.5 bar it should be reasonably quiet. Question is, is it worth the effort?

Update on the ColorFabb XT-CF20 Had another go with the XT-CF20 only to see under extrusion once again. However this time I sat and watched in fail. The print was solid so very little retraction. I did manage to recover it by increasing the temp to 260C! (yes I know!) and reducing the fans down to 50%. The temp change didn't have any noticeable effect on the print though. The actual nozzle temp was at set point (250C) prior to under extrusion. Material - ColorFabb XT-CF20 Total Print time - 4h Max print per model - 7h Nozzle type - 0.5mm (E3D) Temp - 250C Speed - 50mm/s Retraction/No retraction - Yes Time to fail - 2.5h FIX for fail - Increase temp and lower fan speed.

Hi John, I sometimes get small inclusions of dark char like deposits within a white print. Whenever I've watched this happening it's source has been the outside of the nozzle and not from within. Check the nozzle surface is clean before starting a print. Any small pieces of filament that are stuck to the outside can release after its gone through a few heating and cooling cycles which then get embedded in the print. This is far more noticeable on a white print due to the contrast.

It might be worth mentioning that I print with a lot of ninja flex which I always oil pre feeder. Consequently there is almost always a small pool of oil around the Teflon isolator even when not using ninjaflex. Now I don't know the implications of this on clogs but I don't really get them. Could it be worth someone else trying to print with a material that that know they will have issues with and run a small amount of oil along the filament pre feeder?

I had a fail with ColorFabb XT-CF20 to but there was no retractions at the failure point at all. The print was a 10" tablet case layer flat that failed just before it got to the walls. I'm going to give the ColorFabb XT-CF20 another go soon on a more challenging print.

OK not an original idea. It's been discussed here https://ultimaker.com/en/community/view/4536-compressed-air-cooling-as-alternative-to-fans?page=2 But not concluded 8)

Crazy idea alert!! Just wondering, has anyone tried running a compressed air line to the head? It could be run next to the bowden and into almost any shaped duct without having to worry about flow. It could be controlled using a regulator and valve. The air would be much cooler than the hot air above the heated bed that the fans currently circulates. I would think you'd also have a significant weight reduction on the head.

Labern- You are absolutely right. The fans on the um2 are not designed to be restricted. If you look at the fan curves for this kind of fan you'll see than when restricted the air flow plummets. You need compressor/blower fans if you plan on restricting the flow.

Just found a gcode analyser http://gcode.ws/ I'll have to wait until tomorrow to try it out though.

Lol! Perhaps I'll tell the boss it's for his kids that normally works:P I'm using Roberts feeder also. The ninja flex semi flex is very good by the way.

Ive not ptinted anything as retraction heavy as http://www.thingiverse.com/thing:287891 as yet. If anything, in the past when attempting prints like the Elephant - Voronoi Style I would have problems with grinding the filament. Id like to add that I change filament materials several times a day and never do an atomic pull. I just use the move material option to clear out the last filament from the nozzle and thats only if I'm not using a skirt/brim. Is there any way of easily counting the retractions in the gcode? If so I'll happily let you know. Printing Elephants at work can only be done when the boss is off It might also be a good idea to state the retraction distance used. All my tests where done at 4.5mm @ 25mm/s. Perhaps a longer retraction would cause more problems.

Material - Ninjaflex Semiflex Total Print time - 8h Max print per model - 8h Nozzle type - 0.6mm (E3D) Temp - 255C Speed - 50mm/s Retraction/No retraction - Yes Time to fail - n/a FIX for fail - n/a Material - Taulman T-Glase Total Print time - 5h Max print per model - 5h Nozzle type - 0.5mm (E3D) Temp - 250C Speed - 40mm/s Retraction/No retraction - Yes Time to fail - n/a FIX for fail - n/a

You can add Colorfabb XT to the list. Material - ColorFabb XT-CF20 Total Print time - 6h Max print per model - 2h Nozzle type - 0.6mm (E3D) Temp - 255C Speed - 50mm/s Retraction/No retraction - Yes Time to fail - n/a FIX for fail - n/a

No not really. The issue only seems to occur after using simplify3d. Pause doesn't work and the fans have a mind of there own. The only thing I've found to resolve the issue temporary is to complete a print that was sliced with cura then some times the machine recovers. When printing with S3D the pause works every time so now I just use that slicer. I suspect it may have something to do with the start and end code in both slicers that may be causing the problem. Haven't bothered to look to much into it as S3D just works. Have you been using a slicer other than cura? Note: I found this post again by pure chance as it's gone from my profile. Are u listening UM!

It's a 750

Could you check the ID of the original tube for restrictions? This could go a long way to clearing up some under extrusion issues for others.

An easy test would be to drop a 3.1mm drill bit down the tube. If it passes straight through there should not be a problem with the original tubing.

I see that the ID of the new tubing you have fitted is 4.7mm compared to the 3.2mm (I think) standard Ultimaker tube. The larger ID Would provide less friction than the original as the point of contact would be less. However the reason for the original being just slightly larder than the filament size is to constrict movement of the during retractions. Have you noticed any degradation in the quality of prints after changing the tube? I does also beg the question as to whether the original tube maintains its ID thorough its length. I wonder what the tolerance on the Id of the original tube is? This could go some way to explaining why some people have issues with under extrusion while others do not. I haven't had any real issues other than using the UM supplied blue filament myself. Perhaps others with under extrusion problems could test this theory???

Update with details. Material - Polymax Total Print time - 40h Max print per model - 8h Nozzle type - 0.6mm and 0.8mm (E3D) Temp - 240C Speed - 50-80mm/s Retraction/No retraction - Yes Time to fail - N/A FIX for fail - N/A Material - ninja flex Total Print time - 20h Max print per model - 3h Nozzle type - 0.6mm (E3d) Temp - 260C Speed - 50mm/s Retraction/No retraction - No Time to fail - N/A FIX for fail - N/A Material - colour changing abs Total Print time - 14.5h Max print per model - 14.5h Nozzle type - 0.4mm (E3D) Temp - 260C Speed - 50mm/s Retraction/No retraction - Yes Time to fail - N/A FIX for fail - N/A Material - ColorFabb XT-CF20 Total Print time - 3h Max print per model - 3h Nozzle type - 0.6mm (E3D) Temp - 240C Speed - 50mm/s Retraction/No retraction - Yes Time to fail - 3h FIX for fail - None as yet will retest

OK I've clocked about 30h with polymax now and no issues at all. About 10h with ninja flex no issues. 14.5h single print with a colour changing abs with no issues. First fail was on colour fab XT-CF20. Went fine for about 3h or so then started underextruding badly for no apparent reason. Switched back to polymax again with no atomic pull and no problem. I'll give the XT-CF20 another go though to see if I can repeat the failure. But from the marks on the filament it looked like the feeder losing traction on the filament. Not experienced this with XT-CF20 before but it is a very ridged filament any way. All prints done with my custom block and E3D nozzles 0.4, 0.6 and 0.8 but mainly the 0.6. The ultimaker standard Teflon was cooked when I took it out by the way, had done about 600h I think. Diameter at exit was down to about 3mm and showed ware on the inner surface at the contact point. I'll hopefully have time to post the full details of each material tomorrow in work.

I've been on my own quest to find the best bed adhesive. I've tried many different materials, tapes, print stickers, hair sprays, 4mm pei sheet, abs slurries, and glue sticks. I've experienced all sorts of adhesions from next to nothing all the way to welded to the glass bed. I've now settled on two techniques. My original glass print bed has two sides. One side is sandblasted lightly the other in untouched. I use the sandblasted side for pla unless I'm planing a very large long print that I can't risk loosing adhesion. (after 30+ hours and a kilo of filament you really don't want to fail at the last 30min) For everything else (ABS, HIPS, Nylons etc) I use UTU glue stick. http://www.uhu.com/en/products/paper-glues.html This gives very good adhesion and reasonable release. This is the best glue stick around better than the Elmers purple stick. Between each print I spray IPA onto the glued bed and smear the remaining glue around. You can use water but the IPA works better, don't know why. I have on rare occasions used print stickers if I have very little touching the bed as the adhesion is very strong. That are a one time use in my experience though.

Ah... Just looked at this again without the wine. Theoretical the system works as planed however to correct filament variations on a range of diameter from 2.60mm through to 3.1mm the drive wheels would need to taper from a diameter of 1.7mm to 1.2mm! This would correct for any filament variation withing the stated range. However this would not work in practice with such small drive wheels :angry:. Bummer! Still... nothing ventured nothing gained.