Should I be calibrating my new MK4?
for the past couple of years I've had an any cubic kobra, great little printer and my introduction to 3d printing. One of the reasons for upgrading to the MK4 was to reduce the amount of time spent faffing with settings and calibration etc. However, should I expect to do a full calibration of a new MK4 (built from a kit) doing things like estep extruder calibration etc?
My first print was the scraper that came on the usb stick using the included purse PLA and it came out really well and printed crazy fast, I'm guessing it was done with input shaping. However, I then tried to print some pieces in Prusa PETG which came out with rough surfaces and stringing, using the stock non-IS petg profile. I'm now wondering if I should go through all the calibration steps with my new printer or just start trying to tweak the PETG settings.
Before you change any settings make sure the filament is in top condition; dry it thoroughly - at least 3 hours, and try printing again.
Cheerio,
RE: Should I be calibrating my new MK4?
It was straight from a brand new, freshly opened pack from Prusa that I ordered with the printer.
RE: Should I be calibrating my new MK4?
Brand new, freshly opened does not automatically mean that it is dry enough, especially for PETG. Before changing anything on your printer, dry the filament first.
RE: Should I be calibrating my new MK4?
what would you suggest as the best way. I have a food dehydrator or can put the reel in the oven
RE: Should I be calibrating my new MK4?
I had a reel of Prusament PLA delivered with my printer that gave me major problems that originally looked like a printer problem, it had been manufactured about 3 weeks before, so "just opened" <> ok. It was fine once it had spent a night in my esun drier.
RE: Should I be calibrating my new MK4?
I have no experience with ovens. I guess it depends on what the lowest temperature is that can be reliably held with it. 50 °C for 3-4 hours should be okay for a start. Some filament dryers say that they reach 70 °C but only on paper mostly. I would check this with a thermometer first. Too high a temperature would deform the plastic of the spool and bake the filament together. The food dehydrator is perhaps better suited for this, less danger of overheating and baking the filament together, also depending on the temperature that it can sustain.
RE: Should I be calibrating my new MK4?
The thermostats on most ovens are too coarse for filament drying
RE: Should I be calibrating my new MK4?
that's very interesting, looks like I'll be drying everything from now on.
RE: Should I be calibrating my new MK4?
Thanks very much for the info, that gives me temps and times to work on, I'll dig the old dehydrator out and make a cardboard shroud around the reel and see how that works.
I use a food dehydrator with a printed centreless collar that drops over a standard tray and holds two spools. Now I have the XL it's working overtime.
Cheerio,
RE: Should I be calibrating my new MK4?
It's not pretty, but it works 🙂
RE: Should I be calibrating my new MK4?
Cut the centres out of the old racks which is neater. Can just squeeze 4 reels in there if needed but probably only run with 1 or 2 for better airflow. 
RE: Should I be calibrating my new MK4?
OK, first print off the dried roll and what a difference, it's not perfect but it's 99.9% better than before. Thank you @Diem for the suggestion, it would never have occurred to me that I'd need to dry a brand new reel of filament. I'll now be drying all my petg before use each time.
Question still stands though, how many people do a full calibration on a Prusa printer and should I still be doing that for best accuracy going forward?
RE: Should I be calibrating my new MK4?
RE: Should I be calibrating my new MK4?
Second print still had a little bit of stringing but much better and smoother than the first version I made with the un-dried filament.
it would never have occurred to me that I'd need to dry a brand new reel of filament. I'll now be drying all my petg before use each time.
PETG is not the worst, but perfectly dry PETG and TPU can be showing damp deterioration by the end of a long print. In really humid weather half a day is enough.
Question still stands though, how many people do a full calibration on a Prusa printer and should I still be doing that for best accuracy going forward?
You shouldn't need to calibrate for 'standard' filaments, Prusa has aleady done so and created the presets. Having said that you will sooner or later encounter a reel that needs special treatement, +5° perhaps or slower first layer. You will generally get a better return for your effort if you attend to lubrication, bed cleanliness and general maintenance. My guess is that most of the people on the forums trying recalibration, modifications and black magic are missing simple remedies, like drying, and wasting their effort.
The whole point of buying Prusa is that, uness you have extreme requirements, you don't need to rework the settings.
Cheerio,
RE: Should I be calibrating my new MK4?
Thanks, that's great advice. I printed the 'print in place' gear mechanism for the umikot coffee distributor in PETG overnight and it came straight off the bed and all the gears rotated beautifully so yeah, seems to be well set up so far 🙂