Obxidian nozzle configuration
Hi,
I just bought my first Obxidian 0.6 nozzle, and I want to replace the default 0.4 brass one on the MK4.
I've never replaced a nozzle before, so I have a a few questions. I know this has been asked before, but I'm finding contradicting answers.
1. Do I need to run any calibration after swapping the nozzle, other than changing the nozzle diameter in firmware? I've seen instructions for changing Live Z, but I assume that is not needed for the MK4 and it does it automatically? I've seen some posts recommending to run offset calibration, but honestly, I can't really figure out a reason for it. Ok, the Z could possibly change, but it should calibrate that automatically before every print? But why would I need to run X and Y offset calibration after I change the nozzle?
2. Do I need to adjust print profiles after changing the nozzle? Basically, do I need to increase the nozzle temperature for each print? I'm finding a lot of contradictions about this. I've seen posts from multiple people claiming that nothing needs to change, but I've also seen posts that say the temperature needs to be increased by 5C. I even found posts that claim that temperature needs to be increased 15-20C, which seems too much for me.
RE: Obxidian nozzle configuration
I run Obxidian nozzles on all my Mk4 and XL printers now. I didn't have to calibrate, or adjust print profiles. With hardened steel nozzles it is usually necessary to raise temperatures but I never found a need to do that with Obxidian (or tungsten carbide, for what it's worth, which I use on my Mk3S and Minis).
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Obxidian nozzle configuration
I've had the same experience running Obxidian nozzles on my MK4 and XL. I did not have to rerun any calibrations or change any print profiles.
RE: Obxidian nozzle configuration
Recalibrating x and y offset after nozzle change (or any other disassembly) is not mandatory. But you should at least check with the quick nonius print (vernier scale print) on the prusa usb-stick whether the nozzle position of the involved head has not moved (compared to the first head). I put an obxidian nozzle into my 5c-XL last weekend and did exactly that. I was lucky that the nonius print was still spot on. That speaks for the quality of the Prusa nozzles. In general, even if you just loose and retighten the grub screw (set screw) that clamps the nozzle, its position might have changed a little. That in turn can degrade the quality of the color to color accuracy. You can look up the current offsets in the menu. Note these down before and after a recalibration and you can see how the values have changed. Please be aware that a dirty or bent nozzle can have an influence on accuracy. A few days ago, I saw a video on youtube where somebody suggested using optical calibration. Quite interesting. I am thinking about giving it a try with my cheap usb-microscope when I find the time.
RE: Obxidian nozzle configuration
When I first fitted an Obxidian nozzle to my Mk4 I was quite happy with the results using the default temperature settings. But when I increased the nozzle temperature by 5° I noticed a slight improvement to the shine on a PETG test print. At 10° extra there was a further improvement, and surprisingly, there was a further improvement at 15°, by which time the shine was as good as I was used to with a brass nozzle on my MK3S+. I guess the extra IS speed, and the steel core of the Obxidian, combined to reduce the actual extruded filament temperature a little bit.
Since that test I've created my own 'generic ABS', 'generic PETG' and 'generic PLA' profiles that have the nozzle temperatures set 15° higher than Prusa's generic profiles, and what I can say is that those materials all print well at those temperatures. Whether the increase was actually needed for all brands of PETG (my test was only with one brand), and whether it was also needed for PLA and ABS, I can't say, because I haven't specifically tested them, but certainly the extra temperature hasn't caused me any problems.
Is PETG 'shine' a definitive test for the correct nozzle temperature? Probably not, but maybe the extra temperature is helping with layer adhesion. And I haven't had a single first layer adhesion issue since increasing the temperatures.
RE: Obxidian nozzle configuration
It's been said plenty elsewhere, but it's worth repeating: you can certainly get away with not doing a tool offset calibration between nozzle changes. But just because you CAN get away with it, does not mean you SHOULD not do it. Remember that we are talking about variances of a fraction of a millimeter, and the chance that the tightening of the grub screw will have some tiny effect is non-zero.
Just invest the 10 minutes to run the tool offset after each nozzle change and you have far less problems to worry about when troubleshooting inevitably is required later.
Brand new to 3D printing and my 5-tool XL is my first 3D Printer!Check out my Multi-Tool fork of PrusaSlicer to mix and match nozzle sizes.
RE: Obxidian nozzle configuration
OP was mentioning Mk4, which has only one tool head.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...