peetersm

I'm noticing the price on the UMO+ kit has dropped a lot! I may have missed a news article highlighting a price drop, OR maybe it's a "limited time only" sale. @sandervg which one is it? Dynamism could not answer that for me. If it's a limited time thing I would like to know. thanks

@gr5 I'll triple check my temps and PIDs. What I really find interesting is that even at the same temperature I only see these patterns when printing in the 18mm/s to 25mm/s range. What would cause these temp cycles only at slow speed? Does the slow speed allow heat to creep up the filament too much and cause some weird pressure resonance in the hot zone?

OK I did a bunch of printing this weekend. Makeing different files to try to measure what was happening. I got pretty close to thinking that this comb pattern could help me identify the period of the zwave. I did get a working UMO+ and tried swapping the extrusion assembles and the zwave did not follow the extruder, so I eliminated that as a source! Progress. I did see some under extrusion. So I ran some temperature tests and discovered the temperature where under extrusion starts on the home machine was about 200C but on the work machine I printed at 180C with no issues. THEN I printed everything hotter on my home machine and things started to look a lot better. So Apparently the z banding is due to some extrusion issues at low speeds??? Possible causes.... 1. Nozzle is not reaching reported temp, and actual temp is probably lower then reported. 2. Something in the print head is causing more friction at lower speeds (old Teflon coupler maybe). I have watched the temp while it prints and is not drifting a lot, or jumping around. Maybe I need a new PT100.

thanks everyone and @neotko for the great ideas to check. here's where i am today. 1. The print head bearings are fine and snug, no tack tack there. 2. The slight Y block movements in my video is in the "normal range" when compared to the UMO+s I have at work that do not exhibit the issue. So I think today I'm going to try to focus on my extruder assembly. I think I'm going to try to see if there is a relationship between the slow speeds and teeth marks on the filament and maybe see if I can correlate rotations on the hobbed bolt or wood gear to extrusion differences. I suppose I could try swapping the entire extruder assemblies with a functioning machine, but that seem like a bunch-o-work so I'll start with more test prints and measurements before resorting to that.

thanks for the ideas. Here's me checking my rods. 1st you'll see the block on the Y axis wiggle a tiny amount when moving in the X direction. Next I move the head a round fast since I'm not sure what "tack tack" sound I'm looking for. Also I think I see similar but maybe less wiggle on the X blocks when moving in the Y direction. I wonder if this is in the "normal" range, I 'll look at the printers at work to see if they look the same. If this was causing my issue would I still see the apparent correlation to printing speed and my z-waves?

ok, I finally got back to do some testing and I'm still lost. :( Not all is lost, I think I have decided printing the 1st layer is not a good way to test my "slow-speed-extrusion-problem" theory, BECAUSE I think my bed is not flat. here's the most dramatic image, printed at 20mm/sec showing what I think is bed waves. Since the thin to thick sections do not appear periodic with the distance the path travels BUT periodic along the x direction in bands. Here's some more test prints I ran at different speeds, thinking I might get no bands at higher speeds but I think was my bed was going down a little every print so each print was a little thicker and I stopped seeing the bed waves.

I think that would be the one that is too short for the UMO+, I would get the longer one before you start putting that kit together. I just got one of my spares out and measured it at 153cm. I think we're high jacking this wonderful thread. :-( Should we start a "UM2 upgrade kit on the UMO+" or something?

not a fan of the UM emoji, I think leaving them as text would almost be better. :-p

Well all I know is we had 3 different UMO+ kits with 42inch PT100 cables, and support's explanation was that these were UM2 parts and that's why they were too short. maybe they were from the UM2Go. If the "normal" UM2 has a 51inch PT100 that might be workable if you move the extruder to the left side from the right.

Good point, I'm just worried if all the cables are similarly shorten for the UM2 you will have more work to make it fit. Notice the new placement of the extruder motor is also closer to the board. So some hole drilling and mounting would be needed. BUT if all it takes is soldering an extension on the PT100 this would be the way to go since supposedly the upgrade has a "new PT100" which is much more accurate then the previous one. Actually if @sandervG is looking for UMO+ testers, I bet he could find some without looking very far. :-)

I think I can guarantee this will not work. Based on the that fact the the UMO+ PT100 needs a 64inch cable while the UM2 PT100 only has a 42inch cable. I know because I've seen 3 different UMO+ kits that had the UM2 pt100 stocked accidentally. Sadly on the 1st two we did not realize this until everything was put together and we were routing the cables to the circuit board and came up WAY short! We had to take the PT100 cable out of the spiral wrap and run it straight across the top of the machine and down to get the machine working. On the 3rd kit I measured the pt100 before assembling, saw the issue and got the right one shipped before this mistake happened again.

I think if the gun is thinner at the top (barrel) then it would make sense that when laid flat on the print bed you would see these layer-steps, since the pommel is thicker than the barrel and the tip of the barrel is probably thinner that the back end.

MORE fun give always I printed for sessions I'm doing at this years MACUL. My co-presenter always insists on raffling off cool stuff at the end of the talk. :-) this way more people stay to the end LOL, she is a very smart 4th grade teacher.

Some fun give always I printed for sessions I'm doing at this years MACUL. My co-presenter always insists on raffling off cool stuff at the end of the talk. :-) this way more people stay to the end LOL, she is a very smart 4th grade teacher.

Thanks for all the great suggestions, it's much appreciated! Here's my results. (FYI - I had to stop doing test prints tonight and start printing handouts for the sessions I'm presenting at at MACUL Thursday and Friday. It will be Saturday when I can do more test prints) 1. I re-greased. 2. moved the bed up and down electrically and did not see skipping like in the video. 3. While the steppers were still energized I tried moving the bed up and down by hand and I think I do detect some small wiggle. 4. added a 40oz (2.5lb) weight to the back and ran two test prints, the 1st one slightly better but the 2nd one was back to it's old tricks. (two separate print runs back to back) @gr5 the banding seems to be related to the distance printed, see the images above where the period of the banding changes for different diameters. Also see the large diameter print where at the z scar the banding does not "match up". I feel like at a low speeds I end up with periodic under-over extruding where the period has to do with amount extruded. I have measured my filament (colorfabb) and I'm pretty satisfied that it's not varying more than +-0.04mm. I'm worried it might be my extruder. here's the photos of the 2 prints I did with the weight on the bed. Ok i hesitate to show this photo since I'm not convinced in what I am seeing and have not tested this more...but......here''s another thing I have noticed (which may or may not actually support my suspicion about the extruder) This is a picture of bed leveling print that I run from time to time to check my level and adjust it on the fly. (anyway) what you see is periodic patterns of thin and thick lines. this was done at 20mm/s and may be due to the extruder, or maybe my bed has wavy lines. I have not tried rotating the test pattern by 90 degrees to see if the bed is the cause or if I am really seeing extruder periodic over-under extrusions.

I would say "adsorbs". It's on an old wooden table on foam cubes (to make it quieter). the fact that this z-wave seems to be linked to printing speed really has me stumped. Of course I may be latching on to that. So I appreciate other perspectives to help me see other possible correlations and causes.

I have not tried moving the printers to different spaces, but out of desperation I can try that. and #4!! I know what the heck? it's a confounding outlier.

ok this is still driving me crazy. This weekend I asked folks at my local maker's space for ideas why this is happening only on my machine, the UMO+s I have at work do not do this. They suggested it might be a power supply issues. So I brought home one of the power supplies from work to try on my printer. here's my test prints. I included a print done at work to show how nice those look. the 7 prints I did at home were all done back to back, from the same gcode file. Anyone have any ideas for me , this is making me insane! also FYI - I'm convinced this is happening only when printing around 20mm/s

LOL, yes I agree, it certainly is better that I documented 9 months ago in this post and video here. Apparently getting the most basic features of a search (key words actually appear in the results) is harder that we would guess, since this is not something you've been able to accomplish yet. Possibly Google has spoiled us all? Thanks for the kind and level headed reply as always! :-)

Similar confusing experience, seriously wondering why you think there's been an improvement worthy of asking for feedback on. 1. Searching on my username. "peetersm" the top 6 hits do not contain the string "peetersm" at all and 13255 hits are returned, I stopped checking after the top 6 did not contain that text. 2. I posted several topics with "bug" in the title, so I seached on "bug peetersm" gives me 13254 hits, (i have a funny feeling that there are 13254 posts or that is the limit on results returned) anyway, in the top 3 pages (75hits) nothing. 3. Search on "retraction blobs" 13254 hits (hey there's the number again). a little better since I'm now seeing my key words in some of the hits. 1st hit = 1 instance of "retraction blobs" in the body of the opening post. 2nd hit = ZERO instance of "retraction blobs" in entire thread 2 pages. 3nd hit = ZERO instance of "retraction blobs". 4th hit = 2 instance of "retraction blobs" in the body of the opening post. 5th hit = 4 instance of "retraction blobs" , 1 in the TITLE, 2 in the body of the opening post, 1 more in a response. do you really need us to tell you these things? can't your developers realize that having the key words appear AT ALL or next to each other OR in the title is kinda a clue that that thread might be what the person is looking for?

You would want all the features of github for sure. I feel like this is a dumb question since everyone seems very stoked about this idea but ...What's wrong with github anyway, other than it already exist, is bug free, and it's not owned by UM?

Good questions, I just joined 3d hubs so I could take part in the UM contest, I'll have to read up on what their policy is on printing non-commercial licensed models.

This is a nice summary of an ongoing hullabaloo around legal issues of 3D prints, artist, CC license etc. This would apply to items posted on youmagine.com as well. http://3dprint.com/120727/ebay-licensing-3d-models/ I know UM had a small attempt at starting a conversation about a licensing structure.