3devos

Success! It turns out that the issue was likely not caused by the Atomic pull but rather may ham-handedness. Once the fan shroud was off I noticed that the nozzle seemed to be pushing against the opening through the housing and the heat sensor and heater cartridge cables were very taught... as soon as I gave those cables some slack, the spring around the coupler snapped everything back into place. Thanks again for the help!

Here another view - I will give it another shake... It didn't budge after my first attempt.

[/media-thumb] Here are a couple pics of the parts. I haven't measured the actual gap yet.

I can in a few hours - I'm at work at the moment and my estimate was made from my memory which is suspect at best

I ran up against a clogged nozzle last night while printing with standard PLA. Did 2 Atomic method pulls to clean out any crud. This seemed to work well and I didn't think there was any excess resistance while doing the pulls. When I looked at the nozzle afterwards, I noticed it had moved upwards into the housing about a half centimeter or so. As well, the isolator and teflon coupler have also moved upwards by the same amount. Is there an easy way to get this components seated back to their correct position, or am I going to need to take the printer head apart in order to fix things? Thanks in advance for any input!

Hi gr5 - just wanted to touch base regarding pronterface. Life has kept me from my printer the last couple of weeks, but I have it installed and read through what little documentation I could find. I am guessing that I can use it to manually move the printer head up and down to see if it steps correctly? If that's the case I'm not entirely sure how to gauge whether the steps are even or not, given how small the actually vertical movement is for each layer.

Hi joatrash, That grinding "sand" sound you mentioned was the type of noise I started hearing one day as the bed/printhead moved into position immediately following the initial release of filament just prior to beginning to print the object. It was very noticeable and was not something that I'd heard before. On my machine it seems to still be present but has become less obvious. UM's support team has just gotten in contact with me and want me to take a look at cleaning and re-greasing the Z-screw as well as making sure the Z shafts are still lubed up. They've mentioned that if that doesn't work they will send me a new Z-screw and Z-motor.

I will install pronterface asap and give it a whirl - thanks for the heads up! I did use the green grease shipped with the printer and applied some to the Z screw, which did seem a little bare on the last couple of inches towards the top. When the printer is off I can move the bed up and down by hand (by the back corners). The bed will almost move downwards without pressure along the threads, except at the top couple of inches where it still needs a little downward force to move it.

I don't have the prints in front of me right now but I am pretty sure they are accurately laid down in both X and Y with no noticeable variance in either of those axes. I don't think there is any actual lateral movement in X or Y occurring. I will double check later this evening to confirm. I noticed when I switched to Cura 14.03 that the cylinder had a slight hourglass curvature inwards for the first half a centimetre but this corrected itself. On all of my prints with Cura 14.12.1 the cylinder is perfect straight in the vertical, minus the banding issue. Since using 14.03 didn't have any real positive effect on my test prints I'm just going to disregard that issue as something not worth pursuing.

The initial layer height on all of the test prints was .3mm

Hi gr5 - all of the prints in these posts were printed at a layer height of .1mm. I'm not sure if it is making a band on every layer... I'm guessing not as it looks like there are roughly 5 bands per mm in the alternating over/under-extruded pattern. My guess is that it's not precisely .2mm per band, but I'm not sure how to accurately measure that. I guess if it's over extruding one layer then under extruding the next, the layer height would be alternately compressed then stretched if the Z step is off?

Ok so I started another test print of the banding column, this time on Cura 14.03. I could see the same results so aborted the print mid-way. When I looked at the print more closely I could see the banding was very regular... I'm guessing it may be over extrusion due to some error in the Z-step? Below is a pic of the bands, which show what may be over extrusion when looking at the profile edges? https://www.dropbox.com/s/8u97hu6f7wqr90x/IMG_1722.JPG?dl=0

Hi there, I ran a test print with the latest Cura where I used the heated bed at 55 C for the first 1 cm of the print and then turned the bed off after that. The print ultimately broke loose from the bed, however it printed long enough to run through the section that should have had the bed heat turned off. The horizontal banding appears as usual and is exactly the same through both sections, when the bed is on and when the bed is off. Below is a link to a pic of the test results: https://www.dropbox.com/s/871jjwkf6eryo80/IMG_1721.JPG?dl=0 I'm currently running a test with Cura 14.03 (firmware installed on printer as well) to see if there is any difference when printing with PID enabled...

Hi PM! Thanks for the suggestions. I'm away from the printer until this evening but will implement your ideas when I get a chance tonight. In response to your questions: >> When you say you have tried with other Cura versions did you install the firmware as well? - No I did not... seems obvious but didn't cross my mind at the time. I will give this a go following the test you mentioned in your other suggestion. (see below) In regards to installing the firmware, do I just run the older version of Cura and install it from there? >> Can you try printing a section of the banding test with the heated bed off? Start your print at your normal bed temp and then stop it for a cm or two. - I will run this test first before trying to revert to the version of Cura that uses PID and post the results Thanks again for the quick response. I have a ticket submitted as well with Support but I get the sense from various comments on the forum that they may be a little overwhelmed.