Hi everyone,
I am a relatively new H2C owner and have a question. I just started a dual-color print and left all calibration settings at default (Auto).
It took ~18 minutes from the printer receiving the job via Studio to the printer starting to print. Bed leveling with the left nozzle always takes much longer than with the right one. Is this normal?
Btw, this was a PETG Print, so nothing where it has to wait for the chamber to heat.
Best regards
Sebastian
In general, the pre print activities are much longer with the H2C compared to my former X1C or A1mini. Seems to be caused by the much higher complexity and size. But some of the tasks are not repeated in later prints - it seems the printer remembers the history if you leave settings on auto.
And I also think, in later firmware there might be some tuning with that to reduce the time. For example some of the tasks are performed like double times.
One way to look at it is if you consider that the first layer is by far the most important/hard part of many prints is to consider that it really started ābuildingā that by doing all the checks most are there to prepare and make sure that that layer will be as best as possible. I am sure bambu might tune it a little over time but that is really it in the end printing starts to make sure all is ready/checked/aligned to put down that first layer its just not pushing plastic yet.
Daniel.
Hi Sebastian,
I was pretty horrified at first also. But the thing is pretty smartā¦ subsequent prints with the same nozzle/filament/bed are much quicker. Not instant start by any means, but a few minutes.
Iām prototyping some little parts right now that take only ~10 minutes each to actually print (all same nozzle/etc), and the startup overhead isnāt āthat badā IMHO. Though I do try to get a few prototypes on the bed at once to reduce the overhead time ācost.ā
Anyway, maybe try it for a while and see if it gets/feels better. I do hope BL can speed the process up in the future, but I have no idea. So far every time I think āitās just sitting there doing nothing!ā it turns out it actually is doing something cleverā¦ 
Cheers,
-Max
oh, this is not one of my first prints (~ it has roughly 70 hours). I just really noticed it now since i by accindet meassured the time it took (started working after sending the print and was done when the print started). i did a black / yellow PETG Print yesterday evening which finished somewhere this morning. A couple of hours later (printer was still on) i started another one in black / yellow (same nozzles, different model kind of the same size). There i had a look at the time and it was 18 Minutes from printer downloaded the gcode to printing the first line. What i already noticed before today is that the right nozzle goes through the bed leveling as i know it from my previous P1S (kind of at least). While the left nozzle is doing it much slower and often times lowers the bed more and checks again compared to the right one.
I primarily wanted to make sure that everything is ok with my printer
Ah, I misunderstood, sorry. Hmm, granted Iām not standing over it with a timer, but it seems to only take > 10 minutes to start printing when it needs to heat the chamber. Even with a new nozzle or material, with all the purging and flow calibrationā¦ Iām pretty confident that I havenāt seen anything like 18 minutes on a regular basis. FWIW.
Interesting observation, thanksā¦ Iāll need to pay more attention to that. Iāve been doing a bunch of quick prints with the right nozzle, and now that you mention it, it does seem to start printing quicker than with the left nozzle. Anecdotal since I havenāt actually timed it with exact same scenarios.
Cheers,
-Max
My special case with the 18 minutes was a print that started with the left nozzle and then switched to the right. Maybe this also has an effect. I will start one again with the right one starting and and then again one with the left one starting and will have a look if that changes anything.
My H2c does It too, really annoying right nozzle levelling is way faster
Its worth to try and tightening the screws that hold the white heater block in place.
There are 4 on the left and 3 on the right.
And yes, the left nozzle takes a bit longer.
The nozzle sits on a rail and has no hard stop (with some light force you can lift the left nozzle a tiny bit) and this seems to cause some additional retries at times.
When printing ABS, the chamber heater is turned on at step 8 or 9 in the preprint sequence. Why donāt they do that sooner, so you donāt have to wait so long? I would think that for ABS, the bed heater would be turned on first, but maybe some of the other processes donāt work right at elevated chamber temperatures.
I was wondering the same thing about starting to heat the chamber sooner. Perhaps it wants to wait until other parts pass basic checks before starting the heat (being conservative). But 
Iāve taken to setting the chamber temperature manually from Studio before sending the print so it starts heating sooner. Saves a few minutes. The idea was from an Bambu article recommending preheating the chamber for a while first to help stabilize the environment for high temperature filamentsā¦ but of course I canāt find it now to link (I think it had something to do with preventing warping). I suppose one could preheat the bed this way also, but thatās so quick I havenāt bothered yet to preset it.
I donāt really see anything it does before chamber heating would be negatively affected, as it waits for most actual calibration steps until after heating the chamber anyway. I think the one exception is nozzle offset calibration, but if anything Iād expect having the correct ambient temperature would make that more accurate (or more likely have no effect).
Itās pretty clear where the chamber heater is first enabled in the printer definitionās āMachine startā G-code (search āset chamber temperatureā), but I havenāt been brave/foolish enough to mess with that yet. Itās just a couple lines of code.
-Max
Indeed the left nozzle leveling is considerably slowerā¦ it has to bump and re-bump the plate with the nozzle way more often than with the right one. And more retries that move the plate further away (vs. the quicker short moves), which take longer. Kinda frustrating to watch. This seems like the root cause of prints being slower to start when using the left nozzle, as others have noted. I hope this can be improved in the future.
(I did check the retention screws, and first layer/prints are fine so doesnāt seem like a mechanical issue, but thatās a good tip, thanks.)
-Max
same with me. The left nozzle keeps retrying mesh points. the right nozzle seems to be fine, it just tap tap taps, then moves along. But the left nozzle likes to tap tap tap, then lower then try again. sometimes multiple times for one location. It has NEVER outright given me a failure, but it takes a couple more minutes than the right nozzle leveling does. I have this issue with multiple nozzles, plates and filaments. Iām wondering if there is something loose or maybe its cause that nozzle is the one that moves so maybe its not as solid as the right nozzle.