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Posts posted by rcfocus

  1. I have the same issue for years. The Wi-Fi connection is just lost sometimes. The Wi-Fi module of UM3 seems very unstable. I don't know it is a firmware or hardware issue. But it is really troublesome to me, I can't use network to send print or check the printing status.


    A long time ago, I sent the UM3 to Ultimaker reseller to fix the issue. They said Ultimaker will fix this issue in future firmware release. But it is still not fixed yet.


  2. Mm... I can no long find official links. Ultimaker team might think it is unnecessary to adjust axes after testing a lot of UM2/UM3 for years. But I think it is still useful to ensure the axes of my UM3 are perfectly aligned.


    I ever sent my UM3 to reseller for ER18. After the machine is repaired, I used it for several weeks but feel the prints are not as good as before. Until, someday, I found the 6mm shafts are not well assembled to the 8mm shafts.


    To repair ER18, reseller has to disassemble the printhead to replace one cable. The two 6mm shafts must be removed from the 4 U-shape slots. After repaired, the 6mm shafts must be pushed into the 4 U-shape slots to fix them. But, the shafts were only pushed to 1 of the 4 U-slots. So, all the shafts will "bend" when the printhead is moved to edge of bed.


    Yes, we just can NOT fully trust reseller for maintenance. In fact, I don't blame the reseller. It takes a pretty long time to learn all the knowledges for 3DP. Experienced employees might leave company and new (unexperienced) employees will make mistakes.


  3. 7 hours ago, nighthowlers said:

    "ground level shifting". That is a term I've never come across and unfortunately unable to interpret. GND is simply a label reference for measurement purposes. In such a floating circuit what matters is the net potential difference, which should be 24V. Maybe what I interpret by ground level shifting is that when the power budget is exceeded, the power supply becomes current limited and is compensated by a reduction in voltage (i.e. 24V drooping).


    I might not express it well.


    We know that when current flows through a wire, it creates voltage drop. Large current creates large drop. The situation is the same in a PCB. The power supply is feed in one end of PCB then flows to each regulator (5V, 3.3V...) then to ICs (e.g. ADC). If you look at the positive rail (+24V --> +5V...) then it seems okay. The 5V regulator should still work even for 6V drop. But if you look at the GND rail (return path) then it might not okay if the current is huge.


    If the return path of heater is not closed to 24V power supply, e.g. it goes through PCB, then a large return current will "shift" the ground level in the GND rail. You might think all GND plane/wires should have the same voltage level. But in fact it is not true because all conductors have resistance. The GND level (voltage) are different in each location/point of GND plane and ground wires. If the heater is controlled by PWM then the situation gets worse. This is because PWM signal is "pulsed" waveform. The power output to heater will also be pulsed. This create a pulsed noise not only in 24V rail but also in ground rail. This also means you can NOT use multimeter to measure voltage. You have to use an oscilloscope to capture the pulsed noise.


    This kind of noise will create bulk of problems. For example, the ground level might be different at the locations of ADC and INA826 and it creates measurement error. I don't look into UM2 circuit yet. But it will be better if you can ensure the return path of heater is well planned.


    Since you bought a used machine, all electric components are aged. Aged components might be weaker to resist noise (from power supply, ground or EMI). You have to check them one by one and step by step. First of all, you have to ensure 24V and all the outputs of regulators (5V, 3.3V) are stable with heater enabled. For this, you have to use an oscilloscope (instead of multimeter) to capture pulsed noise.

  4. The extruder temperature you measured is based on the serial output of Marlin. But the firmware doesn't know that the grounding level is dynamically shifted. So, the firmware (PID or other) will still try to make the temperature reading stable while the actual temperature is drifting.


    I mean, you can NOT depend on the serial output. You have to use an external device to measure the nozzle temperature.

  5. The queue is only used when you print over wireless. If you use USB stick to transfer the print file then it won't use the queue. So, you can try to print over USB. For the queue, how about remove Cura connection in S5 and then reestablish connection.


    PS: I don't have UM S5, but UM3. I guess the mechanism should be the same.

  6. It is sure you can replace it by yourself. But it might break warranty. If warranty is not a concern then you can print the part by another 3D printer. (My UM3 refuses to work if printcore#2 is not well installed. No idea about UMS5). As I can see, you also need support material to print this part. That means you need another 3D printer with two extruders.


    The part's file name is "2116-H.STEP". You can download all UM3 STEP files from https://github.com/Ultimaker.


    I don't know if UM3 and UMS5 have the same printcore design or not. I guess they are the same. But you had better to make sure this issue before disassembling your machine.

    Screen Shot 2020-04-14 at 23.40.45.png

  7. What you said "I am seeing 'fat' layer vs thin layers that extend in all directions." This could be caused by a dirty Z lead-screw. When a machine is used for a very long time. The Z lead-screw will be very dirty. Please fully clean the lead-screw and then lubricate it again.


    But from the picture you posted, the lead-screw seems not dirty. Anyway, just try it and see if any difference.


    Btw, a used hot-end will be very dirty too. You should either use a new nozzle or clean it up at first. I remember there is an article showing how to clean the nozzle (hot-pull & cold-pull).

  8. Well...

    You said "all belts are tight, the axes are aligned and bed is leveled".... please ensure the belts are not too tight. Please also ensure the short belts connected to X/Y motors are not too tight, not too feeble.


    Lubricate all axes: the Z lead-screw, two Z rods, two X rods, two Y rods.


    According to my experiences, you can also try to calibrate the X/Y pulleys. To move printhead in X direction, the two X belts are rotated at the same time by four pulleys. It is possible that the pulleys loosen over time. To ensure the two X belts are synced, we have to ensure the four pulleys are aligned (don't know how to express this!). For X axis, there are two rods and the two belts. You can loose the two screws on one X rod (rod#1). Please also ensure the the screws of pulleys on the other rod (rod#2) are well screwed. Then, tighten the two screws of the pulleys on rod#1. Now the four pulleys are aligned.


    For Y axis, the structure is the same. So, do it again for Y axis.


    Please also check the screws of X/Y motor pulleys. You have to ensure all pulleys are tightened.


  9. Z lead-screw wobble is fine. It won't affect X/Y precision. In fact, it is almost impossible to make a perfect lead-screw. So, additional axis rods must be used. The two big rods (at the left and right sides) parallel to the Z lead-screw is used for this purpose. They ensure the precision of X/Y direction.


    There must be other problem. Since your UM2+ is pretty new, how about sending it back to distributor for service?

  10. Active bed leveling will push the heated nozzle into build surface with a little bit large force. Due to various PEI thickness and hardness, it might not work well. But you can disable Active Bed Leveling and use Manual Bed Leveling. Manual bed leveling is still the very basic and important calibration technique.

  11. 21 hours ago, Smithy said:

    Have you tried to go to preferences in Cura, (printer-> Connect via Network) and click on connect there? It happens not often to me, that Cura cannot connect to the printer, but if it happens I just click on connect and that's it.


    Yes, every time when UM3 can't be connect I will go to "Connect via Network". For situation (3), no printer is listed so I will click on "Refresh" several times. But UM3 is still not listed. After power-cycle UM3, it will be listed in Cura automatically.


    For situation (2), UM3 is already listed there. The button "Print over network" is still available. But Cura will fail to send out the model when I click on the button.


  12. There seems having rule for the Wi-Fi issue. Here is the observed behavior.

    (1) Power on Mac --> Power on UM3 --> Keep Mac active during printing --> Print is done --> Cura can send the next model to UM3 without problem.

    (2) Power on Mac --> Power on UM3 --> Mac go to sleep during printing --> Print is done --> Wakeup Mac --> Cura can NOT send the next model to UM3. UM3 is still shown as connected in Cura.

    (3) Power on Mac --> Power on UM3 --> Power off Mac during printing --> Print is done --> Power on Mac --> Cura can NOT detect UM3.


    For situations (2) and (3), I have to power-cycle UM3 so that Cura can connect to it again. Hope that the observation is helpful for Ultimaker team to find the root cause.

  13. On 5/16/2019 at 9:00 PM, Link said:


    you need to update you z offset plugin, there is anothter thread on this, basically the UM firmware does not support the G92 command now, so the new plugin takes account of that and calculates the offset in a different way. Once you change the plugin to the new version it will work as expected 

    Thanks a lot! I will update it.

  14. I updated FW 5.2.11 when it is available. The auto-leveling function is working very well. But the Wi-Fi issue is still there. I still have to power-cycle UM3 so that it can be detected. Or, do I have to call customer service to replace the WI-Fi board? At least, my UM3 is usable now.


    I have noticed one issue with FW 5.2.8. If z-offset is used (say 0.05mm) then the nozzle will print in the air. There will be a big gap between nozzle and glass. But I don't test it on FW 5.2.11 yet. Could any one confirm this issue get fixed or not? There are too many models need to be printed ASAP... no much time to test/verify all issues.

  15. 12 hours ago, Patronus said:

    @SandervG @kfsone ...Both machines literally want to print .6mm deep into the glass. I know this because after the 3rd .2mm later it's still scraping the glass, only after the 4th later does it print above the glass by which time the nozzle is clogged. I replaced the printcores to see if it helps with the bed levelling but it made no difference. I now have to do manual levelling and I'm not sure if I've lost my touch but even that is a struggle now. If the print head as much as touches the levelling card then it scrapes the glass when printing. I now actually need to see some daylight between the nozzle and the glass, when doing a manual levelling, before it prints the first layer at the desirable height.

    I experience the same kind of issue. Honestly speaking, it has been a disaster to me since v5.2 is updated. Here is a list of encountered problems.


    (1) The first thing I noticed is Wi-Fi get disconnected automatically. Then in Cura, UM3 is no longer discoverable. Now I have to power-cycle UM3 to get Wi-Fi connection work again.

    (2) Auto-leveling is unusable. In fact, it causes the prints to fail again and again. I also noticed the auto-leveling procedure will push the nozzle to the print-bed so.... hard. I am so afraid of the build-glass might get broken. So, I decided to turn auto-leveling off.

    (3) Then I thought manual-leveling might work. Yes and no. It does work... but I noticed two issues.

       (a) The print has a shorter height. I usually print a cube (10x10x10mm) to verify the accuracy. The height is around 9.82mm with 0.1mm layer height. But in the past (with the old firmware), it was always between 9.9 ~ 10.1mm.

       (b) The print is pretty difficult to be removed from the build-glass. Sometimes, I have to break the print to remove it.

    (4) For XY calibration... I don't want to test it any more. I use Ultimaker breakaway material for support. But the material is so expensive. I don't want to waste my money.


    Even I am an engineer, I don't want to open the machine and recovery it to old firmware because I know all those issues are caused by new firmware, not hardware. They all can be solved by hot-fixes. A fix is called "hot" because it is so critical for users to get it fixed ASAP. Now, I know the QA team have some for hot-fixes but JUST don't want to release. They want to release a new version and hope the new version will solve all the issues.


    If users complain lots of critical issues after Apple release new iPhone software and one of the issues will cause your iPhone failed to dial up then what will Apple do? I guess Apple will release a hot-fix for users ASAP. Apple won't  say "Hey, please wait for us to fix all the issues. We don't want to release a hot-fix only for your iPhone able to dial up."


    We spend "a lot' of money to buy Ultimaker 3 not because it is for fun but because we believe it is a reliable machine for professional work. Some of the issues are so critical that it make me feel UM3 is no longer a reliable machine. It just does't work. But I know the root cause is the QA team behind it. They didn't fully test the firmware before release it and now they don't care about users' feeling. Ask yourself, what will Apple do? The QA team is wasting my (and other users) time, and time is money for me.


    I don't want to complain... if I want, I will post a lot of complains long time ago. I just want to tell the QA team "We don't need total solution at this moment. It will let me (and other users) feel much better if you can release hot-fixes one by one."

  16. I have the same issue recently. For a new bed (glass), there is no issue. But after the glass is used for months, I start to get the issue. So, I think the characteristic of the glass surface must be different. There might be very small particles... or something... that can not be fully cleaned. I use 75% ethanol solution to clean the glass after each print. I may have to try other methods.


    You can try to take off the glass and clean it very carefully, or you can start to use glue, or change the glass with a new one.

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