Pausing print for longer period, unload, load filament.  

Pausing print for longer period, unload, load filament.

This is a kind of a continuation of the "Can you pause a print for a day?" thread, located at https://shop.prusa3d.com/forum/prusa-i3-kit-building-calibrating-first-print-main-f6/can-you-pause-a-print-for-a-day--t2326.html , but I am making a new thread due to some observed... peculiarities, which I'd like to get some comments on from people familiar with the firmware, and from people with more experience.

Basically, due to a long print that wouldn't finish before night time, I searched for a way to pause it over night... The information in the above thread was quite useful(since MrMik successfully resumed the print), but it lacked some details... Namely, since I wanted to also remove the filament, and I'm new to this printing business, I didn't know what would happen if I did unload filament, leave it over night, and then reload filament in the morning. As in, would that cancel the print entirely?

So, steps taken (Printing from SD card btw.):
1. Pause print
2. Move extruder on x axis to the rightmost position(had room there, and extra filament flows past the bed anyways 🙂 )
3. Unload filament
4. Preheat - Cooldown
5. Set bed temp manually to 50°C
6. Next morning, Preheat - Flex
7. Load filament - after it finishes, remove any remains from the extruder
8. Resume print

So far it worked, above steps went without a hitch, the job didn't get cancelled, and it resumed fine... but this is also where things got interesting... Upon resuming, the speed was slow... as in, real slow, at least until, I assume, the next command was read from the SD card. Also, I am printing the job at 220°C, and had to manually reduce the temp from preheat 230°C to 220°C. So, questions:

Question 1: Is this slowdown a feature, or a bug? It worked great, since it easily powered through the excess filament, resulting from the pause and load filament, that was deposited on the print(oozing while moving the extruder). If it's a feature, does slower speed also help with initial layer adhesion after the pause? Or could one speed up manually (if that is possible) without detrimental effects? (I did search for this, but all I found was someone asking if it was a bug somewhere on github... Then again, my Google-fu, or Duck-fu, or whatever, is not exactly up to standard 😐 )

Question 2: What happens if the printer is powered off(Manually, power failure, etc.) while the print is paused? Does it remember the state it was in(as in, paused)? Can it continue the print if axes were not moved during the failure? Will it try to rehome x and y, and what happens to z?

Question 3: If one wanted to also cool down the bed, or turn off the printer entirely, has anyone played with how long does it take for the heat from the heatbed to fully propagate through the print after restart? Depending on material, what are the chances of the print popping off the plate as it cools down( Flex as opposed to PLA, ABS?)? MrMik did have some success with cooling the bed in the linked thread, but had problems with the initial layer after restart. Will fully reheating the printed part reduce any warping resulting from cooldown? And finally, does the heat from the heatbed make any difference regarding the interlayer adhesion?

Question 4: Do the temperature and other settings get read/changed only at the start of the job, and if a specific gcode is sent, or at every layer? This is with regards to manually setting 220°C.

These are my noob questions, and also firstpost.

ROFR

P.S. - If this should be in the linked thread, feel free to merge.

P.P.S. - Sorry if these are totally noob questions.

P.P.P.S. - Loving the i3 mk2 kit so far, easy to assemble, easy to calibrate, Slic3r presets seem to mostly work... All in all, a breeze...