RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
Yeah, I was hoping the Tronxy's might not be too bad, but after looking at this video:
where even though he ends the video by saying that none of the problems it has can't be overcome, the middle part of the video was a horror show--so much so that I'm going to stay clear of it.
Final thoughts: After surveying the current market landscape, I think most of the corexy vendors are barking up the wrong tree: people don't need a corexy if they're printing on a 250x250mm, or 300x300mm, or 350x350mm build plate. The i3's have got that handled well enough, and a lot more cheaply too. Where corexy (as well as croxy) would really benefit though is at 500x500mm and above. For instance, I was quite surprised to read (referenced in a post I made earlier above) that the build plate on the CR10 S5 was 4.7 kilograms in weight, all by itself. And reading between the lines, it also seems that the thicker the aluminum plate (say, 8mm instead of merely 3mm), the flatter the build surface is likely to be, so if weight weren't an issue, you'd probably opt for something even heavier. From this point of view, the notional Voron design seems the best, since it doesn't move the build plate at all. Yet, the irony of it all is that the Voron currently only supports a maximum of 350x350mm--which, IMHO, should be below the low end of what it supports, not the high end.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
A good cross-over point might be 400x400mm or 450mmx450mm and above, in part because that market segment has relatively sparse coverage anyway. There can be other reasons for doing corexy also, such as better protection against ringing at higher speeds, so if you want to print faster without a loss of quality (and who doesn't?), that would count as a plausible justification. That said, I don't understand the appeal of Voron Zero, other than for its novelty or as a piece of functional art, unless maybe you're building exceptionally tall things with narrow bases or perhaps exceptionally heavy things. I suppose the lower cost might justify it as a getting-started machine to hone your skills and understanding so that you're confident in what you're doing when you build a bigger machine. Hmmmm.... Actually, that might be a good reason, since you do get a good machine in the bargain.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
@dimprov
Some people just prefer one design over another regardless of bed size. Personally for me, I would only use an I3 design for up to 300 x300. Anything more and the printer (imo) starts becoming unwieldy since your Y axis is, mechanically speaking, needing to be at least twice the y Length as the bed Y length. CoreXYs don't have that limitation, which is also a plus at the smaller sizes (diminishing returns but still a plus)
Since CoreXYs can obtain some pretty insane speeds, provided they have the proper hotends, there is an advantage imo even for smaller bed sizes. And seeing how tension on the belts need to be perfect, a smaller printer might be best to at least get used to the kinematics of the machine.
Might not be a bad idea to get a sub $500 CoreXY printer just to mess around with.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
@dragon1291
Thanks for adding your insight. You raise some good points I hadn't considered, and I find myself agreeing with you.
Aside from the Voron, all the other corexy's I've seen (including ratrig and hypercub) have a moving bed. Granted, it's z-axis, not x or y axis, but it is still moving, even if it's less. Question: does it matter? I've seen it rationalized as, "Well, it's only moving down one layer, and then only when you're moving to the next layer," but that isn't really true if you're doing z-hops to move around your print so as to better avoid collisions. Z-hops seem to be recommended practice....well, at least it's what Tom Sanlanderer recommends as a default. I'm not sure if other gurus agree with him about that or not, and the slicers by themselves don't default to it unless it's a part of a profile which is consciously assigned as the default.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
@dragon1291
Do you have an example of a good sub $500 core xy?
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Chuck H
3D Printer Review Blog
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
Yeah the core xy has the vulnerability that the bed is at the top moving down (except for the voron 2.x printers which have the gantry go up) this puts the mass of the bed at the top of the structure of the core XY printer making it less stable than something like a 2.x where the weight is at the bottom of the printer ... but it is still better than having a moving bed like on a cr s5 where you have this giant 500x500 bed chucked around back and forth.... proper printing has a cool mod for the s5 where the whole structure of the s5 is moving instead of the bed itself.... (this is his channel: https://www.youtube.com/channel/UCqfMW0tMZEciSXQym8x0EoQ ) might want to check it out. His videos have some of the most creative solutions ever and he has an awesome sense of humour. But if you go core xy, standard with the bed on top moving downwards, you might want to make sure it is a sturdy structure. If you go for a voron watch nero3dp's videos https://www.youtube.com/channel/UCmV40QWkVeRs_nAvEOE_P-g you can also find him on the voron channel and he will help out, he is a very cool guy and very knowledgeable when it comes to core xy, voron and these types of printers.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
And seeing how tension on the belts need to be perfect
By "perfect" do you mean within a well defined but fairly wide range, or in this context does "perfect" imply a narrow, hard to achieve and maintain range? On the Prusa i3 MK3, I set it once during the build, measuring it rather crudely by pinching the belt against itself between thumb and finger, and I never had to bother with it again. i.e. pretty painless and ho-hum. Is it like that on a corexy, or is the range so narrow that it's a lot harder to maintain or even set in the first place?
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
@dimprov
Personal Opinion but I don't like Z-hop as I feel it's a bandaid/shortcut and doesn't actually solve any issues. I've seen Z-hop suggested to be used for avoiding collisions as you said when the actual solution was a better first layer height/squish. That said, I am sure it has it's uses and won't discount it entirely. My biggest gripe against Z-hop is when threaded rods are used, and not ball screws, and you end up with some backlash. Now technically the weight of the build plate will take out that backlash a bit so it's not as much of an issue but with something like an X-gantry that's relatively lightweight you may be affected by the backlash during a z-hop a bit more.
As for the moving platform, tbh I would rather have small rapid movements in the Z than large rapid movements in Y. Even with Z hop you're only moving maybe .4-1 mm up and down. I guess you could have the entire XY gantry on a moving Z platform but I would rather have Y axis movement rigid to the frame since X axis guide depends on that.
@cwbullet
"good" I think is subjective. haha. Lots of people think their Sub $300 printers are good but end up throwing $200 worth of upgrades to get them to where they are. TBH, anything under $500 for Corexy is going to have some serious corners cut somewhere.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
@dragon1291
Do you have an example of a good sub $500 core xy?
Even though your question was directed at dragon, I've seen kits for Voron V0 at $399, such as https://www.formbot3d.com/products/voron-v0-corexy-3d-printer-kit-with-enclosed-panels and on Aliexpress.
Maybe dragon knows of other things as well though.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
@dragon1291
Do you have an example of a good sub $500 core xy?
Even though your question was directed at dragon, I've seen kits for Voron V0 at $399, such as https://www.formbot3d.com/products/voron-v0-corexy-3d-printer-kit-with-enclosed-panels and on Aliexpress.
Maybe dragon knows of other things as well though.
Haha please don't think of me as a professional of any sorts. I'm far from it, I just tend to do hyperfocused research on products before I even think about committing to purchasing them.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
@dimprov
This timestamped clip describes the whole tension thing:
I'm sure other printer designs have ways around this issue in terms of keeping things squre.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
Reporting back: I was emailed this photo and description of the as-yet unreleased but re-designed SK-Go, in case anyone is interested:
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I don't know what the price will be or when it might ship. Build area is a bit cramped for me, but it does look very sturdy.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
It does change my thinking about this size of printer, which before now I usually thought of as sitting on a table, which might therefore demand a very sturdy table to avoid resonance. By standing directly on the floor, I guess those problems might just melt away.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
@dimprov
Dang that's a Pretty printer. Looked up the Original SK-GO and it would cost (full kit mind you) about $900 with S&H. Need to remember to follow once they start selling them again.
In terms of your resonance concerns, remember the mass of the printhead & X carriage is so significantly less than the total mass of the machine that in most cases you're going to be fine. If you have a table that can handle a bedslinger (i.e I3 Design) then it should handle a corexy. But yes, due to the massive size of the things setting them on or close to the floor might be best to allow easy maintenance of the printhead assembly.
Just curious but why do you need such a large print area in the first place?
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
@dragon1291
Well, three reasons, but all 3 reasons derive from my printing a ton of drawer organizing boxes in all different sizes. It's a project very similar to this:
So, reason #1 is that some of the boxes are too big to fit on a Prusa printbed. Yes, in theory I could redesign the bigger ones in fusion360 so I could print them piecemeal and glue the parts together, but I'd rather the machine work for me than visa versa. Reason #2 is that if I can fill a large buildplate with not just a few boxes but a ton of them in parallel, then the printer can work away 24/7 without waiting on me to pop off prints and start new ones. Lastly, reason #3 is that with a big enough printer, I could print not just the boxes that go in the drawers but also the drawers themselves, which opens up whole new possibilities. Right now I'm buying inexpensive plastic drawers and gluing a grid in the bottom of them, but, meh, the drawers are far from flat, so I'm having to address that issue. If, on the other hand, I had a large enough printer I could print not just the boxes but also the drawer itself with the grid as an integral part of the bottom. That would be a better result, provided, of course, that the printing goes well and the printed drawers don't themselves warp because of non-uniformity in the heatbed.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
@dimprov
Dang that's a Pretty printer. Looked up the Original SK-GO and it would cost (full kit mind you) about $900 with S&H. Need to remember to follow once they start selling them again.
It looks as though the prior version was made from extruded aluminum, which is a different kettle of fish. I just hope the maker for it can get at least equal accuracy from whatever steel parts he fabricated. I watched a review on the Sapphire Plus corexy, which is also of bent mental design, and the reviewer showed it being pretty far out of tolerance.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
I pulled this screen capture that shows the heatbed traces of the Chiron heatbed (400x400mm) from the TH3D youtube review:
As you can see, the traces are inset from the side of the heatbed, which I'm pretty sure guarantees that the edges are going to be at a cooler temperature than the inner portion of the heatbed. It was similar with creality's Ender 5 Plus, and maybe that's why even though the Ender 5 Plus heatbed is actually 377x370mm, creality only claims it to be 350x350mm. Anyone know of any counter-examples? Is there a reason it's done this way? e.g. maybe it prevents the aluminum bed from warping or something? I'm beginning to think maybe all heatbed traces are done this way, and, if so, that pretty much confirms that if you want an even temperature over your build surface, you need to buy an oversized printer and then limit your prints to well inside the edges.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
By the way, the Prusa i3 MK3 has a much finer distribution of traces on its heating PCB, and it does a good job of getting traces right up to the edges, so it has much better heating uniformity, even near the edges. According to Tom Sanlanderer, the high-to-low temperature differences across the bed are around 5 degrees C, which certainly beats the 15C difference I was measuring on the Ender 5 Plus.
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
I guess this thread has fizzled out. Thank you to everyone who contributed. 😀
<<<end of thread>>
RE: Recommendations for a 3D printer with build area of 400x400mm or greater?
Well Prusa does tout "Heatbed with cold corners compensation" as a feature.
It very well might have to do with thermal expansion. Whereas near the middle of the heatbed you won't see much relative expansion, by the time you get out to the edges the aluminum may expand much more than the copper traces, leading to potential damage over time. Might also be inset like that to prevent damage to the traces from people using binder clips. If you look at the top left of the heatbed in the photo you can see the silver clip is pretty darn close to the trace.
Likely your best bet for a complete warp free printing is a heated build chamber. At the very least it could help even out the temperature difference on the heatbed.