Prusa summer update  

Re: Prusa summer update

I'm a little confused by the discussion of GT2 belts. Apparently generic sometimes performed less well than Gates. Mine are simply marked GT2, so I'm assuming generic. I'm wondering what I should look for to determine if a swap to Gates would be advisable.

Now to print those upgraded cooling parts....

Re: Prusa summer update

I'm a little confused by the discussion of GT2 belts. Apparently generic sometimes performed less well than Gates. Mine are simply marked GT2, so I'm assuming generic. I'm wondering what I should look for to determine if a swap to Gates would be advisable.

Now to print those upgraded cooling parts....

Don't waste your money on the Gates belt. I purchased, had to get 50' minimum, mainly to try to eliminate belt rub on my Y-Axis and I see no noticable difference between the supplied belt and the Gates belt...

Re: Prusa summer update

I'm a little confused by the discussion of GT2 belts. Apparently generic sometimes performed less well than Gates. Mine are simply marked GT2, so I'm assuming generic. I'm wondering what I should look for to determine if a swap to Gates would be advisable.

Now to print those upgraded cooling parts....

Don't waste your money on the Gates belt. I purchased, had to get 50' minimum, mainly to try to eliminate belt rub on my Y-Axis and I see no noticable difference between the supplied belt and the Gates belt...

Has anyone here tried a polyurethane with Kevlar belt?

Re: Prusa summer update

[...] Has anyone here tried a polyurethane with Kevlar belt?
Are you just asking in general, or specifically as a possible troubleshooting step for the extrusion issue? The blog post notes that they transplanted a Prusa extruder onto a completely different printer and the issue persisted, so my understanding is that they've pretty well got it down to the extruder.

Re: Prusa summer update

Just in general, for anti-ringing purposes. He seemed to have had some experience with belts, and no one really answered my earlier thread with respect to polyurethane belts.

Re: Prusa summer update

Just in general, for anti-ringing purposes. He seemed to have had some experience with belts, and no one really answered my earlier thread with respect to polyurethane belts.
Gotcha. Never mind!

Re: Prusa summer update

Pretty much predicted he would blame most of the issues with extrusion on the end user...

(3) previously owned MK2S and none of them had the issue. No one posted about it before the MK3. Hilarious.

Re: Prusa summer update

Pretty much predicted he would blame most of the issues with extrusion on the end user...

(3) previously owned MK2S and none of them had the issue. No one posted about it before the MK3. Hilarious.

But they tested so many independent printers and they all had the same issue! /s

Re: Prusa summer update

Pretty much predicted he would blame most of the issues with extrusion on the end user...

(3) previously owned MK2S and none of them had the issue. No one posted about it before the MK3. Hilarious.
So that means you can print up a comparable print on the Mk2S and post pics with comparable lighting for comparison? Would love to see the finish we're supposed to be targeting. Thanks!

Re: Prusa summer update

But they tested so many independent printers and they all had the same issue! /s
Not "the same", but certainly "not without issues" when compared using objective criteria:

Re: Prusa summer update

Pretty much predicted he would blame most of the issues with extrusion on the end user...

(3) previously owned MK2S and none of them had the issue. No one posted about it before the MK3. Hilarious.

But they tested so many independent printers and they all had the same issue! /s

They also say that there is no problem with their printer yet there is..... 👍🏻

Re: Prusa summer update

Pretty much predicted he would blame most of the issues with extrusion on the end user...

(3) previously owned MK2S and none of them had the issue. No one posted about it before the MK3. Hilarious.
So that means you can print up a comparable print on the Mk2S and post pics with comparable lighting for comparison? Would love to see the finish we're supposed to be targeting. Thanks!

Maybe you didn’t see the “Previously owned” part? However, I ask that you find any post or article written about widespread extruder issues on the previous model. You won’t be able to because they don’t exists.

Re: Prusa summer update

[...] Maybe you didn’t see the “Previously owned” part? However, I ask that you find any post or article written about widespread extruder issues on the previous model. You won’t be able to because they don’t exists.
Then when we see examples printed and subjected to the same criteria, there shouldn't be any obvious flaws. However, until we've seen that, all we have to go by are examples that typically aren't subject to the worst-case lighting. Prusa put up 7 samples from a variety of printers. Each has imperfections. If the Mk2s truly has none, that's good news, but all your statement shows is that nobody specifically looked for it, confirmed there are no flaws and posted results. Except perhaps Prusa who seems to think it has the same issue:

The true inconsistent extrusion is omnipresent on all 3D printers we have here in the office – from cheap to expensive ones. If you position a light source in parallel to the object wall you can see it as a light noise in the object texture. Good material hides it, but some materials, like the light blue we used in our tests, make it more visible.

I'm assming they've got some Mk2s about. What I have started doing is watching the YouTube reviews of other printers. A lot are described as having fantastic finish, and yet you can see obvious flaws if you pause at the right moment. From the MakeAnything YouTube channel comparing the Alphawise U20 and CR-10:

Again, I'm reminded of Megan Fox's thumb. Nobody noticed it until one day someone made a big thing about it. Then it was in headlines. She was still the same person she was the day before, but everybody obsessed about her toe-thumb.

I'm not saying the Mk3 has no flaws, that it isn't subjectively worse than the Mk2s, or that this isn't an issue of concern. Prusa seems to think the same and is still working on it. It will be very interesting to subject other printers to comparison of the same model printed in the same filament held under the same lighting for comparison. Thus far, most of the benchmarks don't seem to focus on "surface finish". Now that low-end printers are printing at 0.05mm and lower layer heights, perhaps it's time that benchmark suites be modified to include such a comparison.

Re: Prusa summer update

[...] Maybe you didn’t see the “Previously owned” part? However, I ask that you find any post or article written about widespread extruder issues on the previous model. You won’t be able to because they don’t exists.
Then when we see examples printed and subjected to the same criteria, there shouldn't be any obvious flaws. However, until we've seen that, all we have to go by are examples that typically aren't subject to the worst-case lighting. Prusa put up 7 samples from a variety of printers. Each has imperfections. If the Mk2s truly has none, that's good news, but all your statement shows is that nobody specifically looked for it, confirmed there are no flaws and posted results. Except perhaps Prusa who seems to think it has the same issue:

The true inconsistent extrusion is omnipresent on all 3D printers we have here in the office – from cheap to expensive ones. If you position a light source in parallel to the object wall you can see it as a light noise in the object texture. Good material hides it, but some materials, like the light blue we used in our tests, make it more visible.

I'm assming they've got some Mk2s about. What I have started doing is watching the YouTube reviews of other printers. A lot are described as having fantastic finish, and yet you can see obvious flaws if you pause at the right moment. From the MakeAnything YouTube channel comparing the Alphawise U20 and CR-10:

Again, I'm reminded of Megan Fox's thumb. Nobody noticed it until one day someone made a big thing about it. Then it was in headlines. She was still the same person she was the day before, but everybody obsessed about her toe-thumb.

I'm not saying the Mk3 has no flaws, that it isn't subjectively worse than the Mk2s, or that this isn't an issue of concern. Prusa seems to think the same and is still working on it. It will be very interesting to subject other printers to comparison of the same model printed in the same filament held under the same lighting for comparison. Thus far, most of the benchmarks don't seem to focus on "surface finish". Now that low-end printers are printing at 0.05mm and lower layer heights, perhaps it's time that benchmark suites be modified to include such a comparison.

Try however you might to disprove my point, but again I ask that you find the widespread extrusion errors that the MK3 is having in the previous model. You won't. Not because no one was looking for it, but because it didn't exist. You can't tell me no one was looking for extrusion issues. I'm willing to bet nearly everyone who uses a 3d printer looks at the outside surface finish and passes judgment on whether is was a success or not based on how the surface looks.

The MK3 was and still is problematic compared to the MK2S simply because it was pushed out too early and the bugs with all the "Smart" features seem to be the problem. Do I want the MK3 to be a success? Of course. I am eagerly waiting for them to iron out all the BS they won't admit to so that I can purchase one or more of them to add to my collection. It's not a matter of if, more of when they will figure everything out. Josef himself said it right after all of the problems were popping up at early release. He would make sure to do a release to a test group BEFORE releasing the next model they come up with. I feel like they rushed into the MK3 but can certainly make it better.

If someone can live with having the same quality prints as a CR10 or some of the other garbage printers, that's all on them. Id expect slightly better results from a $700+ dollar machine claiming to be better than everyone else on the market at that price point.

Re: Prusa summer update

[...] Try however you might to disprove my point, but again I ask that you find the widespread extrusion errors that the MK3 is having in the previous model. You won't. Not because no one was looking for it, but because it didn't exist. I'm not trying to disprove anything! I simply want to see for myself. That will require someone with access to the other printers printing the same model with the same filament and photographing it in the same light.

You can't tell me no one was looking for extrusion issues. I'm willing to bet nearly everyone who uses a 3d printer looks at the outside surface finish and passes judgment on whether is was a success or not based on how the surface looks. Interestingly, someone has mentioned that one of the 7 blue examples Prusa posted was done on their older printer. Details will be interesting.

I do think expectations have changed. We saw the same thing as personal printers evolved in the 1980s. When the next gen of higher-res printers began appearing, they were subjected to entirely new scrutiny. This hasn't been as much of a jump, but I think now that 0.05mm resolution is a realistic capability for a new hobbyist, the level of scrutiny has gone up. Yesterday's "good print" is today's "unacceptable result". To evaluate results we need a level playing field with associated benchmarks. A little over a year ago, this might have passed as a decent print. I don't think it's horrid, but it's definitely not glass!:

I think Make: and others do need to include a "surface quality" test and subject printers under evaluation to the same objective evaluation (same print, same filament, same lighting). We also need some sort of target to aim against. Is "smooth as glass" the goal, or "as good as the best of today's technology"?

[...]The MK3 was and still is problematic compared to the MK2S simply because it was pushed out too early and the bugs with all the "Smart" features seem to be the problem. I agree with that to a point. I do think things are getting under control, and Prusa's managed to jump from a tiny company to a larger one successfully, which is an important milestone. I don't know if they could have done that without sales. They seem to be better than some tech companies with still supporting last years' devices.

[...] If someone can live with having the same quality prints as a CR10 or some of the other garbage printers, that's all on them. Id expect slightly better results from a $700+ dollar machine claiming to be better than everyone else on the market at that price point.
Looking at the 7 blue prints, I'd expect more from printers costing 2-3X that much as well!

Re: Prusa summer update

I'm a little confused by the discussion of GT2 belts. Apparently generic sometimes performed less well than Gates. Mine are simply marked GT2, so I'm assuming generic. I'm wondering what I should look for to determine if a swap to Gates would be advisable.

Now to print those upgraded cooling parts....

I tried replacing mine with a Gates belt yesterday(implementing the new parts), and while you can tell it is a quality belt, mine required a little extra clearance to fit in the gaps with the tolerances I had set when printing the belt holders. After fussing a bit, I decided that the originals were pretty of pretty good quality and tolerance (compared to some alternatives on Amazon). I'm sure I will go back and try again, but most likely when a failure occurs or a rebuild for some other reason. Perhaps when my MK2-MK2.5 kit arrives. It is still running its original Prusa belt from November 2016 ish, and still going strong.

Re: Prusa summer update

Again, I'm reminded of Megan Fox's thumb. Nobody noticed it until one day someone made a big thing about it. Then it was in headlines. She was still the same person she was the day before, but everybody obsessed about her toe-thumb.

I guess you could say "sticks out like a sore thumb" I first had to google Megan Fox, then Megan Fox's thumb as I was clueless with regards to either.

I tried replacing mine with a Gates belt yesterday(implementing the new parts), and while you can tell it is a quality belt, mine required a little extra clearance to fit in the gaps with the tolerances I had set when printing the belt holders. After fussing a bit, I decided that the originals were pretty of pretty good quality and tolerance (compared to some alternatives on Amazon). I'm sure I will go back and try again, but most likely when a failure occurs or a rebuild for some other reason. Perhaps when my MK2-MK2.5 kit arrives. It is still running its original Prusa belt from November 2016 ish, and still going strong.

There's very little visual difference between the supplied Prusa belt and the quite expensive, purchased from Motion Industries, Gates belt. Not saying that all Prusa belts are the same quality but in my case I don't feel the Gates belt is an improvement over the belt that came with my printer so therefore was a waste of money on my part. Being I had to buy a 50' minimum order I might consider selling a few feet at cost to anyone nearby if they really want a Gates belt.

Re: Prusa summer update

Justin / Bobstro,

I have 2 MK2S (pre-built) at work, and I have 1 MK3 (pre-built) at home. I've printed a lot of stuff over the past year on the 2 MK2S (some nicknacks, but mostly work related stuff). Some of the nicknacks that I printed on the MK2S I also printed on the MK3. I didn't see any real difference between the quality. I think I even mentioned that before in another thread when there were a few people stating that EVERYONE was having an issue with the MK3 and that it was lower print quality than the MK2/S.

Here's what I'll do. I'll print a test cube or other object - if you want you guys can pick what you would like to be a representative object. Tell me the parameters to print at (perimeters, layer height, temperatures (PLA only) and I'll use the standard print speed settings for each printer.

I'll make sure that all 3 printers are using the latest version of firmware, drivers, and Slic3r PE. I'll print using the SD card and not my Octoprint setups. Once done, I'll upload photos... and too make it a little fun I won't tell you which objects were printed on which printer.... you guys can guess first before I tell you.

Regards,
Scott

Re: Prusa summer update

[...] Here's what I'll do. I'll print a test cube or other object - if you want you guys can pick what you would like to be a representative object. Tell me the parameters to print at (perimeters, layer height, temperatures (PLA only) and I'll use the standard print speed settings for each printer.The 20mm cube printed in silver seems to be what's been used for most of the pics (of the Mk3) that I've seen, but I'm hoping Prusa will expand on the light-blue filament and hex shape they used. I personally would like to see 2 silver 20mm cubes, one printed on each printer, stacked and held under the same light that highlights the surface imperfections on the Mk3. 0.20mm layer heights seem to work well for this. So long as temps and speeds are the same, I think it'll be a fair comparison. I know that's vague, but very slight angles make a big difference. Holding them side-by-side tends to highlight one cube or the other (IME).

I'll make sure that all 3 printers are using the latest version of firmware, drivers, and Slic3r PE. I'll print using the SD card and not my Octoprint setups. Once done, I'll upload photos... and too make it a little fun I won't tell you which objects were printed on which printer.... you guys can guess first before I tell you.ABSOLUTELY PERFECT! If there's a way to run a poll for "pick the best", that would be great.

I noticed Prusa didn't associate their 7 prints with any particular printer. If they did mix in Mk2s results in there, that was a very clever strategy to highlight that a lot of this is subjective.

Again, I'm not trying to argue that the Mk3 is perfect and can't be improved. I just want an objective comparison showing what to shoot for.

THANKS!