RE: VFA Artifacts on X+Y Straight Edges
I suspect that VFAs and noise (at least on my machine) are due to the gantry being out of square, turning it into a sort of bistable mechanism: both of the gantry brackets on my Core One are slightly more than 90°. I think I'm going to disconnect the gantry and bend the brackets while referencing them to the linear rods using a machinists square. I did measure the alignment of the rods, which was pretty good at +50 microns at the back over 200 mm.
The distance between front/back stops on the left and right were not good, though, with the right side being 0.5 mm longer than the left. When manually homing just the Y-axis to the front, it's enough that it causes print head to jump to the right (on the X-axis). Similarly, running the gantry to the back stops causes the print head to jump to the left when it makes contact. Hopefully it won't be too difficult to realign everything.
Kinda peeved about the quality control on such an expensive printer, to be honest. Also it's crazy that they haven't released a hot fix for the firmware bugs reported a month ago, or even given a release date for that matter. Quite frustrating.
RE: VFA Artifacts on X+Y Straight Edges
They have posted some murmurs on Github which suggest that the kit release, or the release of the fan/filtration option, might be accompanied by a new firmware. But there is no 6.3.1 alpha or release candidate in sight yet...
6.3.1 is coming, don't you worry. I can't disclose the details about the particular date. We have learned to not promise too much in order to not disappoint. That being said, there are some cues already in the wild. Think about chamber filtration, kit version and so on 😉
I personally would love to have a shorter release cycle. I would also love to have the same firmware version being released for all the printers based on xbuddy platform. Lastly, I would love to have more transparent process towards the github community here. Let's hope we will get there eventually 🤞
https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/4505#issuecomment-2744230569
RE: VFA Artifacts on X+Y Straight Edges
Let's hope it will fix more than the nozzle cleaning routine...
RE: VFA Artifacts on X+Y Straight Edges
I suspect that VFAs and noise (at least on my machine) are due to the gantry being out of square, turning it into a sort of bistable mechanism: both of the gantry brackets on my Core One are slightly more than 90°. I think I'm going to disconnect the gantry and bend the brackets while referencing them to the linear rods using a machinists square. I did measure the alignment of the rods, which was pretty good at +50 microns at the back over 200 mm.
The distance between front/back stops on the left and right were not good, though, with the right side being 0.5 mm longer than the left. When manually homing just the Y-axis to the front, it's enough that it causes print head to jump to the right (on the X-axis). Similarly, running the gantry to the back stops causes the print head to jump to the left when it makes contact. Hopefully it won't be too difficult to realign everything.
Kinda peeved about the quality control on such an expensive printer, to be honest. Also it's crazy that they haven't released a hot fix for the firmware bugs reported a month ago, or even given a release date for that matter. Quite frustrating.
Wouldn't it be ironic if eventually it turns out that all the "lemon" Core Ones were assembled by Marek, the one technician who did not pay attention during the build training session where belt and gantry alignment were explained? 😉
It might well be a combination of multiple factors, I think. Mechanical tension or friction in the gantry assembly; belts and idlers not exactly in the same plane; some motors having uneven microsteps and hence exciting more belt vibrations, ...? I would be really curious how much Prusa already knows about the issue, and just does not publish (yet) since they to not yet have a solution. Let's see where we land eventually.
RE: VFA Artifacts on X+Y Straight Edges
Ahahahah, really it would be a BIG relief to me and would be even more important to get a kit rather than a preassembled version.
I always got kits for all my Prusa printer before, this time I chose to buy it already assembled to be sure everything will be fine...
If it was just a matter of the person who built them, that would be a very good point.
RE: VFA Artifacts on X+Y Straight Edges
I can't wait for Prusa to release the assembly manual. Once it is online, I'll probably reassemble the CORE One myself. I have multiple problems that could come from the assembly and/or the delivery. I'm hoping the belt ripple will disappear, but it is very unlikely.
RE: VFA Artifacts on X+Y Straight Edges
I suspect that VFAs and noise (at least on my machine) are due to the gantry being out of square, turning it into a sort of bistable mechanism: both of the gantry brackets on my Core One are slightly more than 90°. I think I'm going to disconnect the gantry and bend the brackets while referencing them to the linear rods using a machinists square. I did measure the alignment of the rods, which was pretty good at +50 microns at the back over 200 mm.
The distance between front/back stops on the left and right were not good, though, with the right side being 0.5 mm longer than the left. When manually homing just the Y-axis to the front, it's enough that it causes print head to jump to the right (on the X-axis). Similarly, running the gantry to the back stops causes the print head to jump to the left when it makes contact. Hopefully it won't be too difficult to realign everything.
Kinda peeved about the quality control on such an expensive printer, to be honest. Also it's crazy that they haven't released a hot fix for the firmware bugs reported a month ago, or even given a release date for that matter. Quite frustrating.
Wouldn't it be ironic if eventually it turns out that all the "lemon" Core Ones were assembled by Marek, the one technician who did not pay attention during the build training session where belt and gantry alignment were explained? 😉
It might well be a combination of multiple factors, I think. Mechanical tension or friction in the gantry assembly; belts and idlers not exactly in the same plane; some motors having uneven microsteps and hence exciting more belt vibrations, ...? I would be really curious how much Prusa already knows about the issue, and just does not publish (yet) since they to not yet have a solution. Let's see where we land eventually.
Marek must have built mine because on the X linear rail I only had 2 fasteners installed. I thought maybe Prusa decided they only needed 1 on each end, but after looking at pictures I realized, no, there should be one in every other hole (similar to a voron). I installed them from spares I had around. Funny enough, it really didn't seem to make a measurable difference.
RE: VFA Artifacts on X+Y Straight Edges
What’s the thing with Marek? Some running joke or a real thing. 🙂
RE: VFA Artifacts on X+Y Straight Edges
What’s the thing with Marek? Some running joke or a real thing. 🙂
It's just a name I picked out of thin air, to illustrate the idea that one specific guy might be responsible for building all the Core One units which don't perform quite right. Just kidding though; I don't think that is the most likely scenario. It's probably a combination of hasty assembly (occasionally, and by more than one individual) and parts tolerances.
But I like "Marek-built" as a shorthand for "a bad Core One unit". Hope that none of the actual assembly technicians goes by that name! 😉
RE: VFA Artifacts on X+Y Straight Edges
Looks like homing has also been redone, the parking location is now in the back, and the MMU has gotten some love as well. And that awful Z-height bug has been fixed. Looking at previous releases, the official build will probably be released tomorrow. Very exciting!
I see a new tag on the firmware for GitHub in the source code...
I also see commits that enable phase stepping and configuration for the MK4 and the Core One!!
RE: VFA Artifacts on X+Y Straight Edges
I hope the phase stepping reduced the VFAs mostly. I know from my DIY printers that some more tuning of input shaper and motor current as well as print speeds can counteract and nearly completely remove the VFAs.
I tried the part with the different speeds and it shows less VFAs on higher speeds.
So let's see...
RE: VFA Artifacts on X+Y Straight Edges
Nice, can you post the link please? 😀
I see a new tag on the firmware for GitHub in the source code...
I also see commits that enable phase stepping and configuration for the MK4 and the Core One!!
RE: VFA Artifacts on X+Y Straight Edges
Nice, can you post the link please? 😀
https://github.com/prusa3d/Prusa-Firmware-Buddy/releases/tag/v6.3.1
RE: VFA Artifacts on X+Y Straight Edges
Here is a link that compare tags to 6.3.0 https://github.com/prusa3d/Prusa-Firmware-Buddy/compare/v6.3.0...v6.3.1
/Anders
RE: VFA Artifacts on X+Y Straight Edges
Looking at the 6.3.1 tag, I also see that phase stepping looks reverted for core one: https://github.com/prusa3d/Prusa-Firmware-Buddy/commit/4de21731b0562ef47f580f40cd52d53de240b445
RE: VFA Artifacts on X+Y Straight Edges
The menu is hidden, but the phase stepping itself (with default values) is not reverted? I need the check the code.
BTW, what is the purpose of this menu? Self-calibration using the optional accelerometer like for Input Shaper I guess?
RE:
The menu is hidden, but the phase stepping itself (with default values) is not reverted?
That is the current status in 6.3.0: Motors are driven in phase-stepping mode (whatever that means), but it cannot be calibrated and hence cannot correct for deviations/imperfections in individual motors.
The fact that they tried to activate the menu entry for calibration in 6.3.1, but now had to take that back due to out-of-memory problems, is a huge disappointment. There goes the hope for reduced belt ripple (or VFAs) and reduced acoustic noise...
Edit: Yes, the calibration would need the accelerometer. It tweaks parameters, optimizing for smoother tool head motion. Well, it would do that if it were enabled...
RE:
The fact that they tried to activate the menu entry for calibration in 6.3.1, but now had to take that back due to out-of-memory problems, is a huge disappointment.
WHAT? You mean that it's not going to be released anytime soon? I mean, they tried to add it on 6.3.1 but they remove it? Or are you talking about phase stepping missing at release?
RE: VFA Artifacts on X+Y Straight Edges
Guys, phase stepping wouldn't have fixed the belt ripple issue anyway.
Read my comment on page 10. The XL has the same belt ripple even though it has active phase stepping calibration.
As far as I am aware all FDM printers on the market right now have belt ripple if printed at a specific speed. This is especially noticeable with glossy filament.