RE: Beltrouting is causing VFA ?
Hang on, it does say Gates(R) Powergrip! On the upper belt directly to the left of the Nextruder, i.e. in a section where the back has never touched an idler. Does the print wear off quickly when the belt runs over the idlers maybe?
I don't think that's it - on mine the printing is visible on the two belts at the back between the motors. I'm pretty sure those bits regularly run over the idlers.
No print is visible anywhere else on my belts -- neither on the long runs in the back nor at the sides. Mysterious... I don't have that many printing hours on my Core One. And if one were to assume that e.g. one of the idlers is stuck or otherwise causes excessive friction on the belt, it should not wear off the print from the whole belt length?
Maybe fake Gates belts vs. originals -- Prusa unknowingly buying a batch of fakes on the grey market, which was marked with sub-par printing? Or a new batch of environmentally friendly but functionally lacking ink used by Gates themselves? When my Core One finishes its current print job, I will try to rub off the remaining print near the Nextruder...
RE: Beltrouting is causing VFA ?
Could it simply be that the printing repeat pattern is long enough that there's only one repeat on each of these belts? On yours it's on the section near the extruder, on mine it's on the bit at the back? When my current print job finishes I'll try to check the entire length.
RE: Beltrouting is causing VFA ?
There seems to be only one repeat on each of my belts.
RE: Beltrouting is causing VFA ?
Definitely are Gates belts - clearly marked on the back.
I'm wondering if it's the actual belts themselves, the stretch on mine in just a few weeks of light use makes me think these are not Gates belts, rather a cheap no name brand from Ali
RE: Beltrouting is causing VFA ?
There seems to be only one repeat on each of my belts.
That seems like a straightforward answer to the "hard-to-find belt marking" mystery. Thank you for checking!
By some strange coincidence, both belts on my Core One have their print just to the left of the Nextruder -- the last place I looked, and not visible without twisting the belt. But I guess the most likely scenario by far is that Prusa does use genuine Gates belts, and Gates just marks them sparingly.
RE: Beltrouting is causing VFA ?
That's good news. Unfortunately, it seems that they do not use Gates pulleys. People that replace the pulleys have to allow for 1 mm of extra width on the Gates version. I have ordered some high resolution pulleys to fit on the Core One but it is difficult to find genuine Gates pulleys where I'm at.
RE: Beltrouting is causing VFA ?
@ SgtCaffran where did you find the gates pulleys ? (or do you mean the idlers ? because those are 1mm wider than the prusa ones)
RE: Beltrouting is causing VFA ?
Sorry, you are correct. The idlers are 1mm wider. I bought some toothed idlers and pulleys to try if that improves the VFA when I get my upgrade Core One. They're not sold as Gates, though. I have seen some good reviews of the Mellow branded idlers/pulleys that are sold via AliExpress.
RE: Beltrouting is causing VFA ?
As i mentioned before, the toothed idlers did not help at all.
Another thing i read is that non-toothed idlers have better bearings, which last longer. That's why i moved back to smooth ones, but i kept the modified parts, i did not want to redo the belts again.
RE: Beltrouting is causing VFA ?
It's an interesting example. For sure the idlers are not the main cause of the VFA's on the Core One. However, there have been cases where toothed idlers did make a difference. For example, on the MK4 there is some anecdotal evidence that it helped reduce some VFA.
Also, it does seem pretty clear that the 2 mm pitched VFA's are directly related to the belt system. I still feel a better supported belt on the idlers is a good thing.
RE: Beltrouting is causing VFA ?
Interesting reading here. It's cool that so many are invested in trying to sort this. Have Prusa announced anything in relation to this?
Scott
RE: Beltrouting is causing VFA ?
As i mentioned before, the toothed idlers did not help at all.
Another thing i read is that non-toothed idlers have better bearings, which last longer. That's why i moved back to smooth ones, but i kept the modified parts, i did not want to redo the belts again.
This is just false about the bearings. More Internet experts. I say show me the data.
RE: Beltrouting is causing VFA ?
I'm wondering if it's the actual belts themselves, the stretch on mine in just a few weeks of light use makes me think these are not Gates belts, rather a cheap no name brand from Ali
Hmm -- they don't have any print on the back, which I think the original Gates belts have?
Seeing that Prusa have moved to cheaper motors and Y bearings, and make their own idler wheels (which can apparently be improved upon by buying brand-name replacements), it would not come as a surprise that they try to save money on the belts as well. They must be in a tough position: Prusa's use of brand-name parts used to be one of their differentiators over the cheap Chinese competition. But with the competitors having caught up in terms of innvovation, performance and print quality, apparently the price pressure is so high that Prusa now switch to no-name parts as well.
The THK-made X rail is the only branded component I have found in my Core One kit, electronics parts aside.
Any source for the claims of moving to cheaper motors, bearings, etc.? Like a two years ago they switched from Misumi bearings to better ones. They may not be branded (because they do bulk orders directly from manufacturer), but that does not mean it's some cheap Chinese production. AFAIK Prusa is moving to local European suppliers if possible. Like when they stopped using Chinese LDO motors. Or if possible, they produce components in house, like circuit boards.
Prusa printers costs much more than Chinese competition. But a significant part of price difference is in better, more precise and reliable components. If Prusa would drop in print precision and printer reliability to the level of competition, they would loose.
RE: Beltrouting is causing VFA ?
Any source for the claims of moving to cheaper motors, bearings, etc.? Like a two years ago they switched from Misumi bearings to better ones. They may not be branded (because they do bulk orders directly from manufacturer), but that does not mean it's some cheap Chinese production. AFAIK Prusa is moving to local European suppliers if possible. Like when they stopped using Chinese LDO motors. Or if possible, they produce components in house, like circuit boards.
Well, I am not sure we should take Jo Prusa's explanation for supplier changes at face value. Of course he won't say "we did it because the new stuff is cheaper." But he also told us that they have never seen problematic VFAs in their in-house printers, and that the Core One is the quietest Prusa printer ever. We need to accept the fact that, among other roles, he is Prusa's lead marketing person.
I do note that my Core One's Y bearings are distinctly noisy, the right one more than the left one, but both sides louder than I think they should be. I read that users have found much-reduced belt ripple after replacing Prusa's XY pulleys with other brands. I read an ex-Prusa employee's pretty damning opinion on the new stepper motors which replaced LDO. (Yes, he is starting his own boutique printer shop and has probably exaggerated.) And if I am not mistaken, Prusa saw the need to introduce phase stepping as a way to compensate for motor tolerances after they moved away from LDO, which may or may not be correlated.
It would be great if they were moving to European suppliers, e.g. for the stepper motors or bearings. How about giving us the supplier names to advertise their commendable actions? The fact that they don't makes me doubt this story.
Prusa printers costs much more than Chinese competition. But a significant part of price difference is in better, more precise and reliable components. If Prusa would drop in print precision and printer reliability to the level of competition, they would loose.
Yes, that's how it should be. But is it still? They are not even advertising "better quality" any more; the sales pitch is "assembled in Europe" and "upgradable".
RE:
———- prev post ———
Prusa printers costs much more than Chinese competition. But a significant part of price difference is in better, more precise and reliable components. If Prusa would drop in print precision and printer reliability to the level of competition, they would loose.
——————-
Jeez.. 1) that cheap wifi module that formed the basis of their brand-new communication platform for their current and future models. So bad, they had to invent binary GCODE just to get the data to the printer. 2) anyone like their camera? 3) read about all the electronic design issues with their MMU2 4) for my MK3S+ build a few years ago, the instructions had you leaving the packing oil in the Misumi bearings and never cleaning it out and installing grease.. greasing the rails consistently has prevented any issues.. but Prusa certainly doesn’t get design right all the time. I’m not sure you should add any country adjective to the comparison. .. just sayin’. 🙂
RE:
———- prev post ———
Prusa printers costs much more than Chinese competition. But a significant part of price difference is in better, more precise and reliable components. If Prusa would drop in print precision and printer reliability to the level of competition, they would loose.
——————-
Jeez.. 1) that cheap wifi module that formed the basis of their brand-new communication platform for their current and future models. So bad, they had to invent binary GCODE just to get the data to the printer. 2) anyone like their camera? 3) read about all the electronic design issues with their MMU2 4) for my MK3S+ build a few years ago, the instructions had you leaving the packing oil in the Misumi bearings and never cleaning it out and installing grease.. greasing the rails consistently has prevented any issues.. but Prusa certainly doesn’t get design right all the time. I’m not sure you should add any country adjective to the comparison. .. just sayin’. 🙂
Actually, the primary concern for me was more a matter of chinese computer security as it relates for IOT devices. Prusa is made in a member state of the EU, which is actually concerned with personal privacy, etc. Not a guarantee but a potential plus...
Also, regardless of any potential recent changes, the Core One is built like a tank (Panzer). I'm seeing a lot of people / build shops in the US using Bambu printers until they die, and throwing them away due to a lack of ease of repair. I literally had that conversation at a supplier yesterday with someone who made that exact point.
For me, one of the issues is that Bambu appears to block the printing of certain types of items, and requires a connection to their cloud - at least in some capacity.
In so far as the VFA subject is concerned:
I had a similar issue with my core one and it turned out that the issue was the belt had loosened since the printer was originally put in service. I pulled up the app on my phone and tighten the belts according to the instructions from Prusa. Based on a prior blog post that I had seen I adjusted the belt to be 95 Hz. Squeaking sound went away as did the VFA issues (mostly).
I got the idea to tighten the belt above 85Hz because a video blogger was reviewing the Core One and Prusa support told him to tighten the belt to 100/105Hz. As such, I split the difference. (Manual states 85Hz) This tells me that Prusa is aware of the issue, and has a basic VFA solution.
RE: Beltrouting is causing VFA ?
I was a bit glib.. and for that I apologize.. I fear that linking to a "cloud" is unavoidable in today's ecosystem of devices. I was disappointed at Bambulab's stance on restricting their services, but it is not unlike Apple's design philosophy that makes it difficult for 3rd party integration. In the end, Bambu just needs to have one instance of customer hacking that causes damage and they are out of business. There are always "lies, damn lies, and statistics" as far as disposable Bambu printers. I wonder if those printers are in the hands of people who are less capable of repair (as that is more of their target audience). Prusa owners even build their entire printer and much more capable of repair. YGK3D on YTube had 2 broken Bambu's (X1C's I think) that sat for quite a while and was considering disposal , but when he took at it.. was not as complex as he thought, and was successful without too much work. But I would agree that the repairability of Bambu devices has not been a design goal for their printers and that Prusa is likely better in that regard. And I think that comes from Prusa's emphasis on designing printers that their customers can build as kits.. A really great philosophy (I truly loved building my MK3S+). The VFA problem with Prusa doesn't really concern me as much as their release of printers without enough of a testing system that starts in-house and then goes thru a limited beta pool and finally release. And I'm still disappointed with aspects of Prusa's design expertise. The firmware updates for my MK3S+ were so faulty that I left my machine frozen at an old release just because I lost faith that I wouldn't have to replace parts to work with the newer releases. The whole data communication system they used on all their new printers is just inexcusable. It works, but has no longevity. Really wish they'd gone with a reasonable level of Pi that could do them for 5 years plus of growth.
I also would have liked them to build a CoreXY from scratch, instead of capable of upgrading bed slingers. It is like Microsoft's goal of making all their software compatible back too many years. I'm sure there are efficiencies that could have been gained by narrowing the design goal.
I think Prusa could go a longer way with customers to admit they might have a VFA issue and partner with some highly technical customers in finding a solution. Perhaps form an external testing group and supply them with parts for potential solutions, but I fear they then worry more about being liable for future repair costs.
RE: Beltrouting is causing VFA ?
All good points.
I do think that Bambu has done a good job of making their printers more of a commodity item. That has the effect of making them replicable as opposed to readily repaired by folks just as you mentioned. I also think you're correct about the whole Prusa is "more about serious builders" concept...
The belt thing was really interesting, and if I can find that review and the segment where the reviewer talks about Prusa telling him to tighten the belts to cope with VFA, if will!
GB
RE: Beltrouting is causing VFA ?
[...] readily repaired by folks just as you mentioned. I also think you're correct about the whole Prusa is "more about serious builders" concept...
Maybe Prusa are deliberately designing a few flaws into their printers. So new users can readily appreciate how repairable the printers are. Try your hand at repairing a few factory flaws even in the first weeks of use!
RE: Beltrouting is causing VFA ?
That reminds me of the concept of the bamboo strategy and making a commodity so that you might just buy a new printer rather than try to fix it!