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SoliForum - 3D Printing Community → 3D Printer Discussion → Whats with these 1st layer shapes people use?
Raft to me looks like this:
But I see this a lot too:
https://www.youtube.com/watch?v=o60-s0B3_30
Whats this? It doesn't look like a raft, it's only 1 (1st) layer and doesn't look like a skirt either.
Whats it good for and does it serve any purpose a "regular" raft or skirt don't do well themselves already?
It's just a different kind of raft. Simplify3d makes a different kind than slic3r. Your first picture is from the simplify3d documentation.
I never understood the use for them myself. Why print on top of ABS when you can start on the glass?
The main purpose for raft as far as I have seen is for when you have an irregular shaped item. One that really has no good surfaces to make contact with the print bed.
I could be very wrong,..but just trying to help.
I think that's what Support is for. Though they look alike so I guess could be used for same purpose, though seems pointless.
Looking at the Slic3r manual, it just says
Raft layers will add additional layers underneath the model and stems from the early days of 3D printing. It can help with prints without a heated bed, or where the bed is not very flat, but it is usually not required and is not recommended.
The Simplify3d tells a different story:
A Raft is a horizontal latticework of filament that is located underneath your part. Rafts are used primarily with ABS because they provide separation between the part and the heated bed. This separation helps to minimize uneven cooling that could cause warping or uneven shrinking on the bottom layers of your model.
I don't really get it. If you have warping, how is Raft any different to not warp itself and affect the actual print above it in the end?
How is it a separation if its also made up of ABS and connected to the print above it? At best it seems to slow down the heat distribution a bit.
I remembered something now, I accidentally enabled slic3r Raft few months ago and that unusual Raft shape resulted in my printed model being so stuck to the glass bed I broke a piece of the glass when taking it off. I don't get the magic behind it because it was just 1 layer tall. Maybe the finned, "heatsink" shape has something to do with it?
Or maybe it was something else I cant remember not related to that raftat all...
The purpose of the raft is for beds that may be warped or slightly higher/lower on one side. If you printed straight to such a bed there is a chance your first layer will not stick on the higher area. A raft however come out at a higher extrusion rate then your first layer would. It will fill in the higher area and make the print surface level. Once your object is done the raft can be peeled from the model. It just leaves whit marks where it was making contact.
Thanks all.
It seems there are two types of rafts Slic3r and Simplify3D are talking about.
Both are the same in the sense that they are below the model's first layer.
Difference is however that Slic3r had in mind making sure the print sticks to even an uneven surface by smearing an overextruded pattern below the first layer to the bed to really stick it in place, while Simpify3D is more about controlling how heat goes from the model to bed or vice versa to prevent warping, though I still don't understand how that will work, even if the raft doesn't get knocked off from the bed from lifting itself (which is happening to my models right now), I'd personally need more than a cm or more of it in height so the warping wouldn't reach the model.
I think something more is happening with the fin-like pattern the Slic3r raft uses than the manual mentions to help with sticking.
Otherwise just overextruding the first layer would do the trick, right?
Thanks all.
It seems there are two types of rafts Slic3r and Simplify3D are talking about.
Both are the same in the sense that they are below the model's first layer.
Difference is however that Slic3r had in mind making sure the print sticks to even an uneven surface by smearing an overextruded pattern below the first layer to the bed to really stick it in place, while Simpify3D is more about controlling how heat goes from the model to bed or vice versa to prevent warping, though I still don't understand how that will work, even if the raft doesn't get knocked off from the bed from lifting itself (which is happening to my models right now), I'd personally need more than a cm or more of it in height so the warping wouldn't reach the model.I think something more is happening with the fin-like pattern the Slic3r raft uses than the manual mentions to help with sticking.
Otherwise just overextruding the first layer would do the trick, right?
I think you are over analyzing. I have been printing 6+ years and a raft regardless of the software generating has always served two purposes regardless of it's design.
That is to aid in making a level surface and adhesion. Nothing more. The only reason for the different look is conservation. You can actually control the raft size and design in most software and make it solid or sparse, your choice. The other reason for a sparse raft is it is easier to remove once cooled.
I think you are over analyzing. I have been printing 6+ years and a raft regardless of the software generating has always served two purposes regardless of it's design.
That is to aid in making a level surface and adhesion. Nothing more.
Not according to Simplify3D, which I quoted already.
Rafts are used primarily with ABS because they provide separation between the part and the heated bed. This separation helps to minimize uneven cooling that could cause warping or uneven shrinking on the bottom layers of your model.
Original link: http://www.simplify3d.com/portfolio-ite … and-brims/
carl_m1968 wrote:I think you are over analyzing. I have been printing 6+ years and a raft regardless of the software generating has always served two purposes regardless of it's design.
That is to aid in making a level surface and adhesion. Nothing more.
Not according to Simplify3D, which I quoted already.
Rafts are used primarily with ABS because they provide separation between the part and the heated bed. This separation helps to minimize uneven cooling that could cause warping or uneven shrinking on the bottom layers of your model.
Original link: http://www.simplify3d.com/portfolio-ite … and-brims/
Simplify3d is new software and they are trying to rewrite the industry. They are hoping they will be the go to software for noobs and thus are making up their own definitions. Google 3D printing and Raft and you will see a different definition. Or checkout Reprap wiki.
The softwares that have been around know what it is for and describe as such. You don't want ABS isolated from the bad as it will then cool unevenly. By their very definition and design they are defeating the purpose of the raft.
But hey who am I to question the pros that sell software for 150 bucks when there are free ones that out perform theirs?. Can we say Craftware?
Simplify3D is a good slicer. Its Processes paradigm makes a lot of sense and offers an extreme amount of control. The only problem I have with Simplify3D at the moment is it does not allow fine control of extrusion widths like slic3r. This is a huge deal and has a dramatic impact on printing time so slic3r it is for now. And yes I own simplify3D and have used it extensively.
Don't get me wrong I am thankful for the work done on slic3r but I fail to see a reason to criticize Simplify3D for making money on their product. Slicers are right up there with compilers in terms of software complexity (and I've contributed to and written a compiler). Besides that anyway, Simplify3D is a host, mesh repair tool and slicer. So it's not a trivial piece of software someone wrote just to make a buck--it was very expensive to make at a programmer's salary with a team of multiple people.
Simplify3d is new software and they are trying to rewrite the industry. They are hoping they will be the go to software for noobs and thus are making up their own definitions. Google 3D printing and Raft and you will see a different definition. Or checkout Reprap wiki.
The softwares that have been around know what it is for and describe as such.
These are a lot of plain claims. How do you know they want to "rewrite the industry"? How do you know they are "making up their own definitions", rather than maybe just using an old term (which is not even a new word created by reprap) for something new?
EDIT: This claim is poo. Other commercial printers use this kind of raft too...
As much as I admire the Reprap project, even they went a bit far with their own definition of "self-replicating machine", but that's off-topic as well.
But hey who am I to question the pros that sell software for 150 bucks when there are free ones that out perform theirs?. Can we say Craftware?
This is also a huge claim. Out perform how? And what about the possibility that a software with certain features missing in another one might itself have certain features missing itself which is present in others?
I also like free and especially open source software, but I don't get why you're bashing a software and making too many negative assumptions about their team.
You don't want ABS isolated from the bead as it will then cool unevenly. By their very definition and design they are defeating the purpose of the raft.
How will it cool unevenly? What they call raft is also ABS. And how is it not heating and cooling unevenly already? Its heated from the bottom by the heatbed and not the sides or top. How is it any different? And how is it any different from support structure?
Just think about it: the lifting of the sides of the model is usually less than few cm max. If you'll print few cm under the actual model that can be removed later, you won't have warping on your actual model, even though thats a lot of wasted filament.
Sadly this doesnt solve the problem of the print (raft or the actual model) lifting so much to get knocked off by the hotend which I currently experience.
This is what I'd like to discuss rather than the company behind Simplify3D. That's not helpful to me, this thread or the community as whole I believe.
SoliForum - 3D Printing Community → 3D Printer Discussion → Whats with these 1st layer shapes people use?
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