DrR1pper

Thank you @Torgeir for the clarification.

Thanks for the reply Torgeir. I have a limited understanding/knowledge of electronics in general let alone of stepper drivers. When you say "having installed this (A498X) series of stepper drivers" it sounds like you are saying that you installed a new physical stepper driver onto the printer. Is that correct or am i misunderstanding something. And just to confirm, you are saying this mod should work with any other 3d printer using different electronics than the um2? Thank you.

+1 Please do, then the print surface quality will be as good as the zortrax (i.e. no zebra stripes).

@gr5 - Thank you for that detailed explanation! Is there a particular 3d model that you would suggest i use to more clearly highlight the impact that different acceleration values have on the print surface quality or will a standard shell of a cube suffice? Lastly, do you think there could be less of an impact of underextrusion on the long straightaways if the printer uses a direct drive extruder and/or 1.75mm filament? @Torgeir - Would the wonderful modification you have found/implemented to remove zebra stripes on your UM2 also work on any and all 3d printers that suffer from this issue?

Does print location affect the print surface quality that much? Does is show like a z-wobble artifacts or something?

No problem. Those diagonally curved lines (that kinda look like very large finger prints lol) that you can see on the zortrax prints i posted are also on the um2+ however if you click on any of the images showing those diagonally curved lines in my post to see the full/higher resolution versions, you will see that they don't actually exist on the prints. It's just some artifact caused by the forum showing a smaller resolution version of the images for some reason. It's really hard to see in the pictures i provided but when i look at the two again really closely and in the right lighting, there are in fact the exact sane vertical lines on the zortrax print as well only they are far less visible. Interestingly the distance between each of the repeating vertical lines (i.e. wavelength) on the print surface are also the same. However they are far more visible on the um2+ print. I'm starting to think it is very possible (as you rightly called out on an earlier post of yours, sorry,) that this is purely due to the material being PLA on the um2+ and ultrat (an abs derivative) on the Zortrax since ABS material is matt vs PLA glossy, the matt will conceal any surface print irregularities much more where as glossy will highlight them. I have ordered some 2.85mm black ABS and will try this comparison again as it's not really fair otherwise.

Interesting gr5. May i ask what values you have found to produce the best print quality or does the optimal acceleration and jerk value per printer also depend on other factors? Thanks p.s. i went with the 800 mm/s^2 and 10mm/s values for the time being as a test because the wanhao duplicator 6 uses them and i've got a print sample from one which i've been using to compare print quality with.

Awesome job Torgeir!

m200 has two only two speeds. "Normal" and "High", lol. "High" speed prints don't look as good as "Normal" and since i am only interested in the best quality prints, i would only ever use "Normal". With the same infill percentage, and infill pattern (m200 only does rectilinear) and the um2+ using s3d (default speed 41.7 mm/s, outline underspeed speed 65%, solid infill underspeed 70%, x/y axis movement speed 100mm/s), print times are comparable. um2+ was also set to 800mm/s^s acceleration and 10mm/s jerk. Not sure what values are most optimal for the um2+ yet. I was suprised to find out that with the above settings, the m200 was printing the outer perimeter 50% faster than the um2+. Ofc the um2+ can be made to go quicker but need to run more tests first to find where what the speed/acceleration limit is where it starts to noticeable affect print quality. btw, the motors on the m200 are quite impressive. They're so silent (can easily sleep with them running in the same room) and the motors are barely even warm to the touch during a print unlike the um2+ which are ridiculously hot to the touch. There is something very special about them. Shame the printer doesn't print pla though.

Oh right, ok, thank you for letting me know. So this is the typical print surface quality on the um2+ and it can't be improved?

...interesting.

Sorry to hijack the thread with this slightly off-topic question but does anyone know if it is possible to significantly improve the z-wobble type artifacts present on this um2+ print (printed with 0.15mm layer height)? would be nice if you could get this level of layer upon layer uniformity/precision: Thx

I'm not sure if these are that helpful to you or not but some more close ups with different objects and differently lighting. Sorry for the shoddy camera work...best i can do. The more matt looking ones are from the m200.

I think so too. Here are pictures of a vertically flat surface printed on both (top is m200, bottom is from um2+). Same materials as before and both vertical flat surfaces were printed along either the x or y axis only (i.e. not diagonally printed across the bed). I agree material choice can hide or amplify print surface details and sometimes to quite an extent but i don't think it plays a significant role in this instance with the artifact we are observing and comparing.

Ah, yes. So sorry, forgot to state material. The um2+ was printed in PLA and m200 in ultrat (supposedly an abs blend with something else) i believe. I originally thought it might be a difference in the motor choice because as i understand from the specs i can find online, the m200 has an x/y precision of 1.5 microns whereas every other 3d printers specs that i have looked at shows 12.5 microns (including the um2+). However, Torgeir's post might have just killed that theory.

and the same part printed on a d5s mini for comparison (that i think i printed way too quickly, lol.)

If i understand what you are saying/asking Torgeir correctly, the stripes also appeared on my wanhao duplicator 5s mini and old prusa i3. The only prints i've seen that don't seem to have zebra stripes are from an m200. But this is just my limited experience with a handful of prints from different printers that i've checked for zebra stripes on. Here are two prints i have from these printers with as close to the same settings and print time as possible. Am i right in assuming those are zebra stripes on the um2+ print? UM2+ m200

An observation that may or may not be useful here, i've since seen in person benchy prints on both a zortrax and um2+ at different z angles on the print bed and i could not see any zebra stripes on the zortrax printed benchy.

Hmm, good points and idea. However to be perfectly honest, i would rather buy a pre-built printer than build one from scratch (again). The first time was painful enough but it taught me plenty and it's not that i wouldn't be able to do so again and i would certainly be able build a far better one the second time around, it's just that if there is a pre-built printer that works really well out the box and fulfills my requirements, i am more happy to buy it even if expensive (and yes, i consider £1800 expensive). However, the jobs i have lined up that involve printing high quality 3d parts will more than make up for the cost of buying one, even at the price of a UM2+. So money is not really the issue (up to a sensible limit though ofc) and either a zortrax m200 or um2+ are perfectly within my budget. Note though, the m200 is 22% cheaper than the um2+ at £1400 vs £1800 respectively. So even if i were deciding from a price stand point, the m200 is a good deal ahead however as i said this is a non issue for me, i can/would happily pay £1800 for the um2+ if the prints are better or not quite as good but still acceptable but that also comes with additional perks over the zortrax that i will definitely benefit from. So far i haven't seen another fdm printer produce prints better than the m200 but i'm trying to find out if this is just because i haven't looked hard enough or in the right places hence why i'm asking here. At the end of the day, i'm just trying to be thorough in my search of the right printer for me because the quality of the work that it produces will ultimately reflect my level of pay to some degree, hence why i am here asking help and advice from far more knowledgeable and experienced people than I on this forum.

Firstly, i want to make clear that i truly appreciate you taking the time and effort in replying back to me with your thoughts. But i have a few things i wish to raise with what you've said. Firstly that you don't have any first hand experience with zortrax prints for in person comparison with um2+ print quality. I don't think the fact that the um2+ appeared to match the same print quality as far more expensive printers means the zortrax can't do better still. Yes the pictures of the zortrax printed head have some flaws but i have not managed to find any pictures of raw prints from an um2+ that come even close to the surface print quality i'm seeing there. Perhaps i have not looked hard enough. But if you know of any i would genuinely be interested and grateful to see them please. Secondaly, the person who printed that head has both printers and says that between the two the zortrax prints better and i have seen photo's of the print quality different between the two. I can't think of a reason why i should be skeptical of what he is saying because he is not trying to sell me anything. He actually thinks the UM2 is a great printer and for the pla print and glass bottom like finish alone, it is worth keepingone around. However when it comes to print quality he believes that the zortrax wins. The pictures he shared of a gnome to my eyes seem to very much agree: UM2/Cura, 0.1mm: Zortrax m200, 0.14mm Now ofc there are different materials being used here so whether that plays a significant role in the layer visibility on the um2 print or not, i do not know. Thirdly, the zortrax seems to have received more favourable reviews (especially in the area of print quality) from what i can gather from the numerous reviews that i've managed to find on both printers. Also 3dHubs trend for the highest rated printer shows the m200 being way ahead of the um2 in this regard for print quality which again, only seems to align with what i've read, heard and seen elsewhere. So i'm at odds between what you are telling me and what the evidence elsewhere seems to be telling me. Could both be right (somehow)? For example, are the um2 prints of the gnome of poor quality and a bad reflection of what is truly possible with a um2? Finally, yes, the zortrax is very closed system and filament is expensive (around twice what i would otherwise pay for the pla i like to use). But if the print quality is as superior as i have been lead to believe, then to me at least the cost is worth it since (just speaking for myself) i am in need of very good print surface quality for the jobs i have lined up. Also PLA may not be the best suited material for my needs, need something stiffer and harder but equally as strong and also a little high temp resistant if possible, but i'm sure that is also doable with the material selections available to the um2+ (even if it requires a little modding such as the TF2K for XT-CF20 for example if that is the material i need).

So you have seen zortrax prints and compared them with um2+ prints of the same object in person?

Don't be. Consider writing a series of books if you like. It's all very interesting and very helpful to me. So you think one can get as good a print quality out of a um2+ as from a zortrax m200? Especially if you use something like s3d over cura? I'm looking for a print material that is like PLA in that it prints well, has practically zero warping issues and yet is a little stiffer, stronger, a little more resilient to degradation over time, whos print surface is really nice and is also non-toxic when printing so that i may be in the same room as it. Is HIPS the material i'm after? I must admit, the perforated bed is a little off putting for me too but i think i could easily live with it if the print quality is noticeable better than the um2+. And this is what's killing me....I really want to spend some time with both and see both in person but i can't.

Nice, thx for sharing. Are those nozzles compatible with UM2+ though?

Thanks again guys. I totally forgot about the zortrax m200 and have been thinking about that one too now. After speaking with someone whom has both a um2 and 6x m200's, as much as they like their um2 they do highly lean towards the m200 in terms of print quality, filament choice, ease of use and in terms of print speed they've thrown back some slicer estimated times from both and found that it's actually very comparable which i found very surprising. I showed him the Dream3D print comparison between these two printers which showed the m200 printed noticeably better (and slightly faster as well) and he said this was quite accurate of the typical print quality from each printer. Again, he says he likes both and has both and will not get rid of either but if he had to keep only one, he said the choice would be easy, the m200 any day. These were made (in parts) in Z-HIPS and required zero post-processing work (e.g. zero sanding). Which granted if true (but i can't think of any reason why i should doubt he is telling me the truth) is utterly jaw-dropping imo. This completely threw me off balance as before meeting him i was quite set on the um2+ but really not so sure anymore.

Thanks again! I wrote a somewhat lengthy response with follow up question a while ago but my browser crashed and lost it all. :( Maybe i'll write it up again a little later when i remember it all.