Note: This blog is originally written in Italian by Raise3D’s client 3dingrolab:
Learning the basic parameters for setting up Raft in ideaMaker.
In this article, Raise3D would like to explain how to correctly set up Raft in ideaMaker. However, to do this correctly, users need to know every single parameter well and understand how and where its effects are felt, as each slicer has its own way of processing information.
In the meantime, we will briefly explain what Raft is: it looks very much like a literal raft, which is essentially a flat base that greatly improves adhesion of the objects users want to print to the print bed, especially when using materials that tend to shrink and deform at the base during 3D printing, or for small objects that do not have a large enough area of support on the bed to ensure good adhesion.
For some materials, this is often indispensable. If users 3D-print using PLA, PETG TPU, using a raft will rarely be required, while for ABS, Polypropylene, Polycarbonate, PA-12 and other technical materials, it is highly recommended.
How is it formed? Basically, it consists of three elements: base, body and surface. These elements are nothing more than layers printed with high print flows, at different densities between each line. The whole is usually no higher than five millimeters.
Its working principle is to allow the object to anchor itself to the plastic of the Raft rather than to the print bed, as it is much easier for plastic to adhere to plastic. In turn, with the Raft being printed at high print flows, all that abundant extruded material will anchor itself better to the bed.
There is a downside to using Raft, and that is that it will have to be removed in post-production. As such, it is important to set it up correctly otherwise users may not be able to detach it, or worse, damage the base of the object to be 3D-printed.
It may also leave some aesthetic blemishes on the object once it is removed.
1 Platforms
As mentioned previously, one of the determining factors is the type of material users are printing. Some materials such as ABS, PP, PC, Nylon, Polypropylene, and PEEK are subject to warping, and tend to deform a lot during printing, especially at the base, because layer after layer, the extruded material furthest from the center cools down and tends to arch inwards, giving the object a twisted look.
For these types of materials, users need to use closed-chamber 3D printers, in addition to heated build plates, i.e. users have to keep the ambient temperature around an object as it 3D-prints to allow the plastic to cool slowly. Often these temperatures are as high as 100°C. However, if users are 3D-printing using PLA, PETG, TPU, risk of warping is lower and higher temperatures are not as necessary.
2 Raft Extruder
This parameter is normally changed if users have a dual extruder printer, as it allows users to choose which extruder users want to print the Raft with.
In fact, very often, when printing with technical materials such as PP, PC, Nylon, etc., that are very expensive high-performance materials, it is preferable to print the Raft with a cheaper ‘sacrificial’ material, such as ABS, which has roughly the same printing temperatures as technical materials. This is a great way to optimize the use of expensive materials.
3 Raft Offset
This parameter indicates how much wider users want the Raft to be than the base of the model. Normally 5mm can be set as the default value, while for materials that are more difficult to 3D-print, users can increase this distance. However, if users have two objects, users can place them side by side and set a very wide Raft value so as to create a wider Raft common to the two objects.
4 Raft Gap from Model
This parameter indicates the distance users want to set between the last layer of the Raft and the first layer of the model.
It is important to set this parameter correctly, because if set too low, users may have great difficulty in removing the Raft from the object in post-production, or conversely, if the clearance is too high, the object in print may not adhere well to the Raft, leading to a series of stability and deformation problems.
A distance of 0.17 mm is the suggested clearance, but if users have difficulty removing the object from the Raft, increase this value by a tenth of a millimeter.
5 Second Layer Z Lift
This parameter allows users to set a clearance between the first printed layer of the object on the Raft, and the next layer on top. It may be useful where users encounter difficulties in removing the Raft, especially when it does not come off easily and some of it remains attached to the base of the model.
By setting a minimum value such as 0.8 mm, the aim is to detach the Raft, along with the first layer of the model, and thus to have as clean a surface as possible at the base of the object. As always, do not make values that are too high, otherwise the print may become unstable.
6 Raft Lines Type
This simple parameter allows users to change the infill pattern of the Raft, with a choice between line and rectangular. The line type tends to remove itself better but tends to shatter much more easily at this stage, on the contrary the rectangular is more robust and tends to come off more compactly. Ideal for large Rafts.
7 Keep Holes in Raft Structure
By activating this option by ticking the check box, ideaMaker will create the Raft over the entire area of the base of the object, except for the areas where there are holes. Specifically, it will still create the Raft inside the holes but keeping the offset users have set.
This setting can be useful when users do not want to close holes in the object, which and can then rectify manually with a tool.
Now let’s move on to the tabs below the previous options: First layer; Middle layer; Top layer
8 First Layers
This parameter allows users to decide how many initial layers of the Raft users want to print. Normally two are sufficient to achieve good stability and guarantee easy removal in post-processing, and while increasing these layers certainly increases the adhesion of the Raft to the print bed, it can also increase the difficulty when removing the raft.
9 First Layer Speed
This parameter sets the speed at which users want to print the first « n » layers of the Raft users have set. As this is a very important stage of printing, it is advisable to print these layers at a low speed to allow the extruded material to adhere properly to the print bed.
10 Extrusion Width Percentage
This parameter set as a percentage determines how wide users want the first layers of the Raft to be. Normally this value is set to 200%, which is already a good value. In this picture, the value has been set to 400%, in order to illustrate the effect by exaggerating slightly and make it stand out better, as in reality, this value is difficult to achieve.
11 Layer Height
This parameter sets the layer height of the first layers of the Raft. As users can see from the picture, they are very high at exactly 0.5 mm in this case, which is well above the maximum limit of 0.33 mm for a 0.4 mm nozzle.
In these cases, however, since there is a significant print flow for these first layers, this value is set to increase adhesion to the print bed as much as possible.
Filling First Layer
By varying this parameter, users can decide the density of the filling of the first layers, i.e., how close users want the lines that make up the first layers to be to each other. Increasing this value beyond 30% increases the adhesion of the first layers to the surface, but on the other hand, it makes the Raft much more resistant and difficult to remove.
Fill Angle First Layer
This parameter allows users to set the angle of the lines of the first layer. Users may find it particularly tempting to change this parameter, though it is recommended to leave it with the default setting.
Tab Layer Central
Central Layers
With this parameter users can set the number of central layers they want to print in the Raft. The function of these layers is to prepare the surface for the last layer of the Raft, which is the one that will accommodate the first layer of the model to be printed.
Speed Central Layers
This parameter sets the speed of the central layers of the Raft. It is important to go very slow in the first few layers in order to achieve proper adhesion to the print bed. It is suggested to leave it at the default speed set by the Slicer.
Extrusion Width Percentage
This parameter, set as a percentage, determines how wide users want the layers that make up the central layers of the Raft to be. Normally this value is set at 150%, which is very good, as decreasing this parameter will diminish contact with the surface, making the Raft softer and easier to remove later, but at the same time stable and robust enough to support for the model to be printed.
Layer Height
This parameter sets the layer height of the first layers of the Raft. As users can see from the picture, they are very high at exactly 0.38 mm in this case, which is well above the maximum limit of 0.33 mm for a 0.4 mm nozzle. In the case of the Raft, this limit does constitute a limit, as all layers are printed with high fluxes, so they can safely weld to each other even with layer heights like these.
Filling Central Layers
By varying this parameter, users can decide the density of the filling of the central layers, i.e. how close together users want the lines that make up these layers to be. Increasing this value improves the stability of the Raft, and better prepares the base for the last layers, but on the other hand makes the Raft much more resistant and difficult to remove.
This parameter allows users to set the angle of the Raft’s central layer lines. It is not particularly useful to change this parameter, and it is recommended to leave it in the default settings.
Tab Layer TOP
Upper Layers
With this parameter users can decide how many upper layers they want to set for the Raft. The function of the top layer is to accommodate the first layer of the model to be printed, it must be rather dense and homogenous, and the success or otherwise of the 3D print will depend on this layer.
The parameters are the exactly the same as in the previous layers, so users can consult the previous entries to understand how it works.
This blog is shared by Raise3D’s client – 3dingrolab from Italy.