New UM3: First observations and woes

[lvl2contact 3]

So I've had a few days to play with my new UM3 thanks to the very helpful people at MatterHackers who handled my expedited shipping beautifully.  Migrating from a FFCP, which had a few nuances but is a very dependable machine. Thus far my upgrade has been less dreamy than anticipated, with a solid shot of reality.

So here's a list of my observations at time of writing..

 

• Loading material, it does not mention to adjust the feeder tension. It defaults to half way, which ground a lot of filament and leaves gnarly bite marks. -- Edit I did have grinding issues, but further reading shows middle feeder position is correct. Will fix and re-test soon
  
• Running out of filament sucks, getting stuck between the feeder and extruder. Had to remove the tube and manually remove the remaining filament.
  
• Many menu items dont have a cancel operation, causing me to turn on/off the machine in certain situations.
  
• The UM3 Android app is out dated and has only worked once.
  
• My bed adhesion sucks, even after manual leveling. My Amazon ordered glass plate for the flashforge sticks like a dream - I can print and walk away and it sticks every time.
  
• Prime blob is helpful but spits out too much, often getting dragged into or brings stringing into the start of the print causing it to fail. Majority of my initial prints fail for either this or the bed adhesion reason. (Used uhu, elmers, hair spray..)
  
• Any time filament gets stuck and ground, I have to break off a few feet of (then wasted) filament. Ouch.
  
• Lack of full S3D support is disappointing, though not UM's fault.
  
• The plastic block the printer core assembly slides into to raise/lower printer core 2 is slightly too low, so sometimes it makes a pop noise when the fan gets forced under it to switch cores.
  
• The HBP assembly makes an odd popcorn/knocking noise.
  
• Cura sometimes gets stuck reporting the printer is busy printing when indeed it is in 'idle' state, confirmed through an API call
  

 

For reference, a majority of my testing has been done using the default Cura 2.6.2 profiles on the included UM Silver PLA, and some MH Pro PLA. Still testing, so hopefully Ill have some more positive feedback soon.

I see people posting such beautiful prints! In search of that UM dream.

Edited August 9, 2017 by Guest

[lvl2contact 3]

After re-re-leveling the bed per the ultimaker.com statement that there should be 14mm between the aluminum plate and the bottom of the glass bed, washing the glass very well, and correcting filament tension I am now able to get prints out more reliably. Also performed a firmware update, and Cura now 9/10 times reports the printer as 'busy' after a print forcing a restart. Ugh.

Ive attached some images of them. Most of the prints are done slowly, the rook at maybe 10-20mm/s .1 or .06, dont remember. The owl came out okay, but suffers from blobs and/or other filament color being deposited in the wrong area. The bear came out pretty well considering he is half an inch tall (printed at .06). Even at low speeds, low temps, and 0.2mm (the phone stand) overhangs are still an issue and it has some artifacts. In areas it looks like temp was too low causing under extrusion, on the corners I have warping.

Happy it is working. Not super impressed yet, looks like the settings still need a lot of work. The rook was the best I could get it after a handful of attempts. I did purchase the 3d Solex nozzle, and may retry with the 0.25 nozzle when I have time.

Purple prints are using MH Pro PLA. Any silver is the UM.

[Nicolinux 288]

Hi,

not sure about the other issues, but I can comment on some.

The popcorn noise of the print bed when it moves is caused by the big linear bearings. They have tiny metal balls which move along predefined paths inside the bearing. Sometimes they move faster while the bed slides down and they bump into other balls. It is nothing to worry about. I have these sounds too and at first I thought some plastic wrapping got caught in the z-screw

The printcore hitting the fan is a rather serious issue. Could you post a picture of if?

[lvl2contact 3]

I have tried playing with retraction but still get a bit of the blobs/stringing. Dual extrusion prints also require the prime tower or else there are literally strings of filament hanging off layer change points.

Also, I am having issues with my first layers. All of them have partial adhesion issues, like bubbles, which cause issues if the extruder catches them or at minimum leaves a crappy bottom layer.

Using ultimaker brand PLA. 60c bed, ~200 temp. Ive played with temps with little success. My attempts at printing ABS have also been failures as the warping without an enclosure is pretty significant, my FFCP prints ABS without issue. Awaiting arrival of my advanced printing kit.

[lvl2contact 3]

Pic of my rather bad stringing, currently at 200c. Default retraction setting and speed.

Ill set aside some time to test zhop, retraction distance/speed, and try to lower temps but this still seems worse than it should be. Hmm.

[SandervG 1,521]

Hi @lvl2contact, thank you for sharing your findings! I'm sorry to hear your first experiences are not perfectly smooth yet, but this is a good step in allowing us to help improve it

Like you already stated in your initial post, I think the feeder tension set to the middle is the best way to go for most materials.

Do you use default Cura profiles or did you go ahead and already tried tweaking them?

Could you share some photos of what your first layer looks like generally? Perhaps we can try to focus on 1 specific print, to get it done perfectly and you can take that knowledge to your next print.

Do you use any adhesive? For PLA you generally only need the heat from the heated bed and perhaps a thin layer of glue.

Filament getting stuck and ground can hopefully be prevented completely, with the correct feeder tension.

About the fans hitting the switch bay, that shouldn't happen. I just tested it quickly here, and even when the rod is out of its sliderblock, it still shouldn't touch. Do you have a photo that shows how close it is? Perhaps this also could be a lead to what part is out of spec (if any).

Looking forward hearing from you, thanks!

Edited August 16, 2017 by Guest

[Nicolinux 288]

Here is another idea. Please test if the glass plate is completely flat. Take it out, put it on a flat surface and push down on all four corners to see if it wobbles.

[lvl2contact 3]

SandervG-

I posted a few images of my first layer above your post. Here is an additional picture of a few failed first layers, where either the first layer was scarred or the prime tower did not adhere and got dragged into the print.

Using both default and custom cura profiles, testing different temperatures, retraction settings and so forth. Regarding first layer, it seems the auto leveling is not doing me much good here.

Adhesive I typically print PLA bare glass without issue. I have tried glue, no improvement.

I havnt had the popping noise recently, so hoping it is gone or I just have not been around to experience it. Tried a switching test but could not manually reproduce it.

Nicolinux-

You are correct, I was afraid of this. My bed is indeed warped. I laid the glass out on both a granite counter top and a table, and on consistent sides I can slide the leveling card under the bed with varying levels of ease. The warping is also not a consistent curve either as it is more severe on certain corners/sides of the glass.

Ill try inquiring with support about a bed replacement I guess. Still trying to solve my stringing issues as well.

[lvl2contact 3]

I received my advanced printing kit. The front enclosure.. leaves much to be desired. Anyhow..

Further frustrations have set in. The adhesion sheets literally glue the part in an inseparable fashion to the bed, and theres no way to get the bubbles out. I removed the sheet and had to soak it in goo-gone for an hour.

Back to square one, I was trying to make progress. I disabled auto-leveling, and manually leveled the bed again. Definite improvement. Wanted more still - logged in to the printer via SSH and manually ran G30's to check sensor results around the bed.

 

20x20 -0.85887200x20 -0.8362720x180 -0.84943200x180 -1.07979

 

You may notice there's a large dip in the corner. After rotating the bed and retesting, and testing the old glass bed, the dip persists. I've determined the aluminum support bed is the culprit. For fun if anyone cares, I observed a ~20 micron deviation in measurement results. I believe the UM docs or comments stated a target of under 30, which checks out.

I wanted to write an app to automatically evaluate the bed leveling sensor info and graph it to depict the bed level state and possible warping. Half the APIs (per /docs/api) return message not found, and the send print job via gcode file simply returns 400 bad request.

 

On top of the bed leveling and severe warping issues, there exists stringing and other rough print items that Ive been unable to tackle thus far.

At this point, I am considering returning the machine. Aside from all the rave reviews and as much as the UM3 should be a great machine - maybe I just got a lemon. But my chinese Flashforge has been a far less problematic machine.

[SandervG 1,521]

Hi @lvl2contact, has the printhead been bumping into your docking station again lately? Regarding the adhesion sheet and your print, did you print with PLA on the adhesion sheet? That is not necessary. Usually, glue and heat will do the trick.

After the improvements of disabling active leveling, was the need for more necessary? I can not deduct the information from your post, but if it is level and the adhesion is good, it is good right? At least it could be a good basis to start printing on, improve your print quality and then once this is all up and running you could see if you can fine tune the bed into perfection.

You said you had Ultimaker Silver PLA, and another brand. Have you tried default profile in Cura (should follow these guidelines) with your improved bed leveling?

Is the stringing within your single color print, or is it between in a dual color print? Do you use a prime tower or any of those helping elements?

Thank you for your time and patience, I'm sure we can get to the bottom of this.

[lvl2contact 3]

SandervG -

I have experience at least another instance of the popping noise. Unfortunately I wasnt watching the printer at the time (it sits behind me).

Adhesion sheet - This was printing with ABS. Which so far has been a big challenge, a mixture of bed adhesion and severe part warping even using the front enclosure, and adding my own majority-top enclosure. My FFCP does not experience this. Using MH Pro ABS, tested temps 230-260c bed 80-100c with no, or little cooling.

Leveling - Well, yes I still get some adhesion issues and/or peeling off the plate, though the quality of my first layers is significantly improved after foregoing the autoleveling. I wanted to figure out further why, and at least found the big droop in the bed corner ( > 200 microns!).

Filament - Ive used UM oifficial brand Silver, and white PLA. Also used MH Pro PLA, and MH Pro ABS. I have indeed tested defaulted profiles.

Stringing - Single and dual print. My dual prints exhibited a lot of stringing/z blob. But individual prints experience lots of stringing at retraction points. Ive again tested default profiles, increasing and decreasing both retraction distance and speed. An above picture shows some of the 'hairs' on a layer. My ABS prints have come out very rough on small details.

Dual printing - I had a dual UM robot that came out pretty good, short of some spots and warping. Most of the times attempts have failed so I gave up after repeat frustrations (10+ attempts), see the cube for example (PLA). I tried prime tower, but it kept getting knocked off and pulled into the print. That is, if the print already wasnt very bad (the rough silver spots/slight overhangs, etc).

The gotcha here is I printed the Minical that comes on the flash drive, mixing the MH Purple PLA and UM Silver PLA, and I would say that came out great. It had slight warping, and small artifacts near retraction points, but very good overall. The test minical print shipped with the machine is still the best it has produced though.

So far, the experience has just been very frustrating. I printed a Raspberry Pi case for a game console, and after the (ABS) print kept failing and warping I used my other printer which came out great first try.

Printing a marvin in the silver PLA as I type this. Half done, hes looking good so far. I worry still about the myriad of issues though that plagues me:

 

• Bent bed plate - requires physical replacement or.. bending
  
• The bed adhesion issues - which require a new bed or surface (build tak?), but the glass on the flashforge (same material?) is just fine as-is
  
• The print warping - Unsure what else can be done to solve, unless I received a very bad roll for example of MH PLA
  
• The stringing issues - The default, and adjusted retraction+temp settings arent solving. My bowden tubes are tight.
  

 

These remain my topics of concern.

As a last note, it feels like the cooling fan air is pushed out in a diagonal fashion from back towards the front left of the printer. Wondering if this is correct.

Edited August 23, 2017 by Guest