Questions and issue after first hours of use.  

RE:

1 - The axis measurement failure is not correct. Likely an assembly issue, contact Prusa Customer Service. Welcome to Prusa quality.

2- Yup, see it often, the thermal runaway when swapping prints quickly while the printer is hot. More Prusa quality. Might as well bring this to CS at the same time. The firmware has more bugs than windows 95, I've brought them all to CS, not a single solution or firmware correction to date.

3 - Most filaments are set to 170, you can change this in the start G code. Though I wouldn't recommend it unless you want oozing.

4 - In the Settings -> chamber filtration menu, there is no Auto, you have None, Adv Filt.., DIY. Select "Adv Filtrat".. You can also change start g code to have the adv filt running at the start, while heating, not just during printing.

5- Print slower, defaults are way too fast, even for the structual. Though back to #1, you may have something loose from assembly which is making this worse.

6 - Rubber feet are know to have adhesive issues since the Core one, Prusa continues to use it anyway. I recommend the https://www.printables.com/model/1479562-prusa-core-one-l-squash-ball-feet , helps with vibrations. If you want a front power switch, https://www.printables.com/model/1521586-prusa-core-onel-front-switch-squash-ball-feet

RE:

Posted by: @simmania

I received my Core One L a few days ago and started printing stuff. I must say that I'm pleasantly surprised by the ASA print quality. But after the first hours of use I have some questions/issues:

1
When it needs to do the homing for the X and Y axis, it bounces into end stops (alternating the X and Y direction) about 20 times. This feels very unprofessional and I wonder if this is how it is mend to be. Sometimes it says that there is a axis measurement failure and it does it all again.

2
When changing the build-plate for a new one after a print (without waiting for it to cool down), it gives a red screen with thermal runway failure and I have to reset the printer.

3
It does the nozzle cleaning always with 170 degrees nozzle temp. Independent of the filament type. It that ok? Also for higher temp filaments like ASA?

4
I have the optional filtration unit. It is set to 'auto' in the settings. But I can not feel the fan blowing during a ASA print. Is it off during ASA prints? Will it be turned on after a ASA print to get rid of the toxic gases inside the printer?

5
The printer is shaking like hell when moving fast (I already mentioned this in some other thread). Even at moderate printer speeds. I'm afraid it will skip some motor steps some time.

6
The rubber feet coming of very easily. The double side tape doesn't hold them very well.

Any comments on these points?

 

1. Yes, that's called fine homing and can happen occasionally. If it is happening before every print then possibly your belts are too loose or the gantry is slightly bent. First check the belt tension, first read this guide: Adjusting Belt Tension
2. Normal behavior. Wait for the plate to cool to at least 40-50° before removing it. 
3. This is the nozzle preheat temperature. It only need to be hot enough to soften the filament, not melt it. The point is to flatten it against the tip. You can change it be going into Filament -> Management Filaments -> Edit Filaments -> ASA -> Nozzle Preheat Temperature
4. Yes, that is by design. You need enough negative pressure to for volatiles to flow through the filter. If you create too much of a draft, parts will warp. 
5. It's fine, just print better feet. Make sure it's on a stable surface. 
6. Well known issue. Can remove existing tape and replace with 3M double sided tape or adhesive. Or print your own feet. 

RE: Questions and issue after first hours of use.

4:
But when it is off during ASA, there will be no negative pressure. It needs to turn slowly I guess. And will it run at higher speed after the print to filter the toxic gasses?

2:
Because I keep the door closed (toxic gasses) this takes a very long time. So I prefer to quickly open the door, exchange the plate and close the door again.
Can I prevent this error?

RE:

4.  Filtration menu, enable post print filtration, set the duration and speed. You can also adjust the minimum speed it runs during the print. I added this g-code so I have filtration soon as I start the print.  

In the beginning of the start g-code

M106 S102 P4 ; Advanced Filtration 40%

Very end of start g-code

M106 R P4 ; Advanced Filtration Auto

2. I was dealing with the same issue for the same reason, printing ABS. Nothing you can do to prevent this from occuring.  Report the issue to CS. You'll see this error occur also when the printer randomly restarts itself after sending a new print file over, while it is too hot, then it will give the error after the restart. So restart it again and you'll be back to printing.

RE:

Posted by: @simmania

4:
But when it is off during ASA, there will be no negative pressure. It needs to turn slowly I guess. And will it run at higher speed after the print to filter the toxic gasses?

2:
Because I keep the door closed (toxic gasses) this takes a very long time. So I prefer to quickly open the door, exchange the plate and close the door again.
Can I prevent this error?

You want to keep the gasses and other particles flowing through the filter and not through the case or the door frame. It only runs at a higher speed at the end of the print. 

On the Core One, the temperature sensor (thermistor) is embedded in the heated aluminum bed carriage, not in the removable sheet sitting on top of it. When you yank off a hot plate and slap on a cold one, you're introducing a large thermal mass that's significantly cooler than the carriage and heat immediately begins conducting from the carriage into the cold sheet. This is what triggers a run-away. If the the temperature drops faster than expected, the firmware thinks that the thermistor is damaged, the heater has failed or something else bad happened.

So simply, putting on a cold plate acts a heatsink, the temperature drops suddenly, the firmware panics. 

RE: Questions and issue after first hours of use.

1. Is normal - after few days of print the belts stretch and reach the final form, and then they need to be readjusted by belt tuning as suggested by the others.

2. Preheat the new sheet before swapping, xan use drybox for that.

5. And 6. Doing all calibrations helps to make things a bit less shaky but yeah it can be moving. Personally I do not have issue with the rubber leg adhesion, and placing it on really sturdy table helps to decrease movement, vibrations and noise.