I know you can disable the prime tower at a trade off in quality, but why not poop out the priming instead of wasting build plate space?
Am I missing a setting in Orca?
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Wiping to avoid dripping from the travel.
Sound advice outside of 3dprinting too
The purge area always has a wiper. I don’t see why you can’t prime into the purge chute - wipe, then move to plate.
Purging into the chute doesn’t leave the nozzle with the same pressure as priming onto a surface because there’s no resistance. So even if you retract the same after both, you’ll get a different line start. Priming onto a surface is the best way to guarantee that the next line start is identical to one that comes after a print move and not differently due to coming from the poop chute.
If you have a printer that has these features, try it out and see the differences for yourself. There’s probably a reason why it’s set up the way it is, but sometimes the differences are so minute that you don’t notice or care. If you run a few prints and the color swaps look like garbage, you’ll have a better understanding of why the printer and firmware are set up that way. If it turns out fine, congratulations, you’ve made a personal improvement to your machine!
I’d rather understand why than have a print randomly fail in the future. That is just because one model can print without a prime tower doesn’t mean all will work under all conditions.
I’d love to get a real answer.
That’s why I suggested testing it and seeing the results for yourself, not necessarily “turn it off and yolo”.
If you know firsthand what the outcome of changing the settings is, you can make a decision on your own based on your own experience when to use what settings.
Testing on a print means nothing. Just because one print works doesn’t mean it will work on every print. If I understood exactly why there is a prime tower instead of purging for prime I’d know under what conditions it could be disabled.
Maybe it’s a historical artifact from printers from 10 years ago. Maybe “build nozzle pressure” doesn’t work as well if you aren’t priming onto a surface that would create back pressure.
I’m sorry, maybe I’m not phrasing this correctly…
Just because one print works doesn’t mean it will work on every print.
I never said, “test on one print”. I said to test it. Test it on an object with many color changes, test it on a model with a ton of one color and only a small amount of another, test it with different infill percentages, test it on a prototype of something that’s going to be really important so you know how it will work in the end.
Everybody is going to have their own specific answer as to what works well and what is and isn’t necessary, the only way to find the right answer for you is to test things and figure it out yourself. The only way to get things 100% right 100% of the time is leave it how it is now and stop messing with it. Anything beyond that is going to vary on a case by case basis, and you’ll only understand what settings to change when, if you toy around with test prints.
I have been printing for many years. I understand that, “what works on one won’t always work on another”. Which is why I find it odd that you seem to be looking for an answer that works for one person, and therefore must work for every person, for every print. The only one-size-fits-all is going to be the most wasteful in material and time (purge tower and purging filament). If you want to cut back on what the manufacturer/ slicer devs are saying “this will most likely work”, you’re going to have to do some experimenting yourself.
Test it on an object with many color changes
Without knowing why, I would be wasting time. I could be changing colors when the problem is an acceleration condition created by a part shape causing underextrusion.
the only way to find the right answer for you is to test things and figure it out yourself.
The entire point of this forum is to gain knowledge that you don’t already. Instead of answering any questions, you could just respond “Test it yourself.”
Which is why I find it odd that you seem to be looking for an answer that works for one person
I’m not asking what works but WHY a feature exists. Understanding why allows you to design parts correctly from the start instead of screwing around and then randomly getting a good result that you don’t understand and therefore can’t replicate under all conditions.
Because of gravity and time.
It’s not like the slicer adjusts the prime tower to be close to the objects. In fact it does the opposite: It places the prime tower in the far corner.
From googling it seems like if you turn off the prime tower, it primes into the purge area. This means there’s no point to the prime tower except for printers that can’t purge.
Well, turn it off and see how the quality goes.
My experience in manually changing filament on my old printer. : There was often tiny gaps between color layers that ultimately made the model weak. Sometimes blobs instead.
(I would pause and change filament at a specific layer to get a multicolor print without a multicolor printer).
To solve this I would add a cylinder object to the plate so that the first place the head went after a color change was to the cylinder to get the filament back up to the right flow rate.
The pressure changes from changing filament is why the printer usually does a quick line at the start of a print. And why it’s necessary for multicolor changes.
Poop where?
If it just makes spaghetti randomly somewhere not on the build plate, a) it’ll leave quite a mess that would need cleaned up and b) it can end up where it shouldn’t be. In a belt gear or incorporated into the print in a way that sticks out and looks bad or stuck to the hot end in a big gob that causes it to not extrude right and blob up in the print or some such.
I suppose, depending on the other print settings, it might make sense use purged plastic to make up infill. That said, I don’t have any direct experience with multiple extrusion, so maybe that is a thing. Maybe slicers already do that to some extent but infill doesn’t typically take enough filament to fully purge and the tower is still necessary.
All that said, I don’t think just making spaghetti would work out very well.
Poop where?
That’s why I’m thinking it’s a legacy setting in slicers. All printers made in the past 5 years have a purge chute and wiper. So purge goes out the back and the nozzle is wiped before it starts.
Well except the new FlashForge multi head printer that purges off the edge of the build plate.
All printers made in the past 5 years have a purge chute and wiper.
Uuh…no, not even close to being true. There are still plenty of printers without purge chutes available on the market today.
I don’t see the full reason anywhere in the thread; the prime tower is essential to quality multicolour prints. Purging quickly shoots out a high volume of filament to quickly clear as much of the previous colour as possible, but then when it goes to start printing, the temperature and pressure are all out of whack and you get inconsistent flow.
So, if you skip the prime tower, you’ll get globby over extrusions and gaps from under extrusion on the first thing printed in that colour each layer, which looks terrible.
That said, the prime tower can be much smaller than default. I set mine to 3mm³ of priming and it comes out 95-100% perfect, with only very occasional blobs on the edge, which pop right off with a fingernail flick (or a deburring tool, if you’re fancy.)
Don’t skip the prime tower. I did for a few weeks before cluing in to why I was getting 1 bad print on every plate.
I suppose if you’re changing filament by layer, then you could maybe skip it, but then definitely don’t print outer wall first or you won’t get a clean print. But even then, a 3mm³ prime tower is tiny, so why risk it?
Hell, even the Snapmaker U1 uses a prime tower, and it has 4 hot ends; it’s needed to normalize the flow after a temperature/flow change (being idle). I don’t have one to test, but I expect it would greatly benefit from a bigger prime tower, since it hasn’t just been extruding filament as purge to get things flowing. But that’s just speculation, as I sadly don’t have one to test with.
Hell, even the Snapmaker U1 uses a prime tower,
I have a U1 which is what prompted this post. But Snapmaker doesn’t “use” a Prime tower. They took Orca and kept all the defaults. I was thinking that they might have intentionally kept the prime tower default because they don’t have a real poop chute but only a poop bin which would quickly overflow if they primed into it.
I don’t have one, but I expect they kept that default setting for the reasons outlined above, but because of a lack of poop chute.
I have a Creality Hi, and a 3D-printed poop chute off the side of the printer holds plenty of poop for typically-sized 4-colour full-purge prints.
For really huge prints, I empty once mid print, but those prints last for days anyway, so it’s no big deal.
With no need for colour/material purging, I would expect a purge tray to be plenty for a multi-toolhead printer. I can’t imagine it purges much?
The prime tower probably could be much smaller. Its size is mainly structural so that on a tall print it stays stable. But the poop tray on the U1 is pretty small. I could see it needing to be emptied after every large multi color print if it primed into the poop tray.
I suppose that makes sense. I almost entirely print short things, and when I do taller prints, it’s always single colour because it’s a functional piece.
I’m not interested in giant 3D print display art, personally, so I’ve never run into that challenge. Hell, I set my prime tower brims to 0 just to make it easier to get off the plate.
In a nutshell,
the prime tower lets the printer print a basic shape, and if it doesn’t look right, either you or the printer (depending on the model) can stop the print. It alsoit ensures that filament is flowing right between each layer change.edit: Fixed. The first point seems to be incorrect, but the second one is okay
The prime tower has nothing to do with “looking right”. It builds as the print goes and often looks bad while the print is fine because that is it’s purpose: to build pressure getting the filament moving in the nozzle before the head moves into place.
In the case of mixing filaments like PETG and PLA for support it looks really horrible because it’s laying down lines of plastic that dont stick to each other. But the part looks fantastic because the slicer creates actual support interface layers for supports.
Oops, I think I misremembered. I fixed the comment now. I typed it when I was very tired.
Now that I see your actual question, the main reason it’s a tower and not “poop” is because simply creating poop would mean the little wiper that pushes out excess filament to the poop chute needs to be used, increasing the time as there is a brief pause.
If it was poop, the printer is like “poop poop clean - wait a bit - now I print” between each layer
If it was a prime tower, the printer is like “tower tower >> actual print immediately after” between each layer
One more thing, if there is a drastic colour change (i.e. between darks and lights) then there needs to be additional stuff for the prime tower (which is why in many multi-colour prints, the prime tower has “infill” rather than being hollow)
If it was using many small bits of poop, the printer is more like “poop clean - pause - poop clean - pause - poop clean - wait a bit more - now I print” since if the poop gets too big it could damage the nozzle/clog it.
If instead it was a prime tower, the printer is like “whirr prime towerrr >> actual print immediately after”
