This week I attempted my longest and most colourful print with disastrous results, a major layer shift after completing over 50% of the print.

I was attempting to print this.  lightning-mcqueen-kit-card-disney-pixar-cars-movie

I am running the latest firmware on both the C1 (6.5.3) and MMU3 (3.04)

I was using Tecor PLA+ from Inkstation. 

I used the "Generic PLA" profile in PrusaSlicer (2.9.4)

Could someone tell me what happened and how do I fix it?

thank you

Kind regards

Jan

I'm wondering why Sequential Printing doesn't also allow the option of printing the first layer of all objects first.

I've printed lots of sequential prints in a production environment, and I'm seeing a common issue that could be avoided. Normally, the first layer goes on perfect because it is laid down immediately after bed level sensing. However during a sequential print, that is only true for the first instance. The first layers of subsequent instances aren't guaranteed to adhere good because the bed shifts slightly over time because of heat. I see occasional failures,  and a lot of bad looking first layers because of this.

If the slicer had the option of laying down all of the first layers before starting sequential printing, this would fix the problem.

Edit: doing a quick google search, I see that this feature has been requested multiple times already by multiple people. One suggested the option of "print n layers first" and I think that's the most flexible solution. I also see that brims are already printed this way in sequential print mode, so the logic of that behavior should also apply to the object.

Mike

It lets you plot filament properties against each other in 2 or 3 dimensions, filter by property or material type, and compare things like strength, temperature resistance, price/kg, print settings, etc. Click any data-point and it takes you to the PDF data sheet. It turned out useful enough that I figured others here might be interested too.

For example, you could try plotting tensile strength vs impact strength vs deflection temperature with a price cap of $50 and you would find out PC is an interesting high performer.

Free, no account needed, no ads, and currently Prusa, Polymaker and Bambu Lab filament only.

Feedback welcome.

https://filament-plotter.vercel.app/

However, right from the first setup and calibration there were failures. The first attempt at purging filament failed, but then after 15mins started working. I got a small print done, but the next print shadow printed maybe at 1cm height. I couldn't unclog the nozzle, tried cold pulls, pushing through at 280c etc. Eventually I swapped the nozzle for a new one (I bought the advanced set) and it worked again for as short while but became blocked again after one small print. I'm using prusament Galaxy PLA. Through all of this I've been on chat with tech support. I've said I'm not particularly pleased with the it clogging all the time and not even purging on the first attempt, but keep being told, that stuck filament is a fact of life with 3D printing and I need to learn how to unclog. Fair there will be some maintenance required, but a complete clog every other print?! 

One support person in chat asked me to take the cover of the gears, but having not build the thing, I undid the three screws on the cover and pulled off the three layers, so now I have grease everywhere and a jumble of gears. He asked for a photo, which I sent, but didn't see anything odd and I asked why was I taking apart a fully assembled printer, and was told that there was not need to take it apart, they had just forgotten it was fully assembled. So I tried to follow the instructions to fit the gears back in, but don't have the alignment tool, because it doesn't come with fully assembled printers apparently. I eventually managed to put is extruder all back together. It's definitely useful to know how it all hangs together.

I was still having issues with not being able to print anything over 30mins without shadow printing, or else if I did a very quick print, the nozzle would be blocked the next time I tried a new print. I have spent so much time cold pulling and pushing acupuncture needles up the nozzle. 

Eventually I purchases an e3d ObXidian nozzle, and it seems to be better. at least the purge is reasonable straight, but sometimes needs a little help not to curl up. The original nozzles used to just make curls of filament to cover itself.

Printer is a little better now with the new nozzle, but now bed adhesion is a problem for some prints it seems.

I came here to see if people were having similar problems, and it seems I'm not completely alone. But I wondered if there was something else that I can look at with my printer to try to get consistent prints, so I can print and leave it rather than waiting for the next failure?  

Should I be looking at log files, is it a temp issue, could the motor have a fault etc. Any diagnostics I could be doing? Appreciate any help 

The above article is sorely lacking in detail, especially with regard to what steps to follow when attaching the accelerometer to the print head,
and what will happen after that when you select the calibration of Input Shaper or Phase Stepper.

Here is some of that missing detail.   I hope that Prusa will edit the help article and provide the missing steps.  START WITH THE PRINTER TURNED OFF!

1.  Install the SHORT accelerometer jumper cable between the socket on the main control board that is shown in the help article instructions circled in orange, and the hidden connector inside the WiFi module after you remove the WiFi plastic cover.    Then reinstall the WiFi module and cover, and reinstall the main control board sheet metal cover.
2. Do NOT connect the accelerometer yet.   Turn ON the printer. 
3. Perform Belt Tension check and adjustment if needed.  You do not want to perform Input Shaper and Phase Stepper calibrations until you know the belts are properly tuned.  So check them now.
4. We are now ready to move on to installing the accelerometer.   First: If the build plate and bed are not near the bottom,  go into CONTROL -> MOVE AXIS -> Z-Axis, and move the build plate bed DOWN between 175mm and 200mm, so it is far away from the print head.
5. Turn the printer back OFF!
6. Behind the rear Z-Axis worm-screw rod, there is a hole in the back panel covered by a black rubber plug.   Remove this plug and set it aside.
7. Route the LONG cable for the accelerometer from the inside of the build chamber, through that back panel hole, and connect it to the visible
   white socket on the WiFi module.   Connect the other end of that long cable to the accelerometer, and assemble the two plastic parts as shown on the help article that is linked above.
8. Remove the silicone sock from the print head heater block, being careful not to damage the small wiring above it.  Set it aside.
9. Gently push the open end of the accelerometer assembly onto the nozzle and heater block assembly.  The accelerometer 3D print is intentionally stiff for this rectangular opening, and may require some gentle but firm force.   Be very careful about twisting off axis, to avoid bending your heat block or heat break.   If you have the right tool or finger nails, you may be able to gently spread the two long sides of the accelerometer plastic to get it started sliding onto the print head heater block.   Push it up until it is firmly seated.
   NOTE:   The accelerometer cable will indeed try to rest directly against the Z-Axis vertical worm-screw rod, and when you later start the calibration, the Z-Axis may move (home), but this will not damage the cable.  It may get a small amount of grease on the cable that can be wiped clean when all done.
10. Turn the printer back ON.
11. Use the SETTINGS menu on the LCD panel to select INPUT SHAPER and then Calibration.   Follow the on screen instructions.   NOTE:  Do not panic, but the process will HOME the system and bring the build plate into contact with the bottom of the accelerometer.   This is why the accelerometer bottom is flat and plastic.  Nothing will be damaged.  When the calibration is completed, the values are automatically stored.  There is nothing else you need to do.
12. Use the SETTINGS menu on the LCD panel to select PHASE STEPPING -> Calibration.      Follow the on screen instructions, and the values will be saved automatically when the process completes.
13. When done, exit the settings menu.
14. Ensure that the build plate and bed are moved down and away from the print head,  and Turn OFF the printer.
15. Carefully and gently remove the accelerometer from the Print Head assembly.  It may take some downward force.   If you can fit a finger nail around the top edge of the accelerometer black plastic (without harming the heat block small wiring), and spread the plastic outward it may help to start sliding the accelerometer loose, downward, and off the print head.
16. Put the accelerometer, with it's long  cable still attached, in a storage bag or box.
17. Re-install the silicone sock on the print head heat block.
18. Re-install the small rubber hole plug onto the back panel behind the rear vertical Z-Axis worm-screw rod.

I hope these instructions can help other new users until Prusa can re-write that above linked help article.
As you can see, there were a fair number of questions and concerns for a first time user that were not provided
in the article.   But the Technical Support Chat option was very good, and the support team is great, so I was able
to figure it all out with very little delay.

Cheers,

Neal