Overview:
-Slicing software
-Computer workstation
-FDM 1650 modeler
-Modelling material
It uses Fused Deposition Modelling to turn CAD model geometry into that can be used for design reviews,manufacturability studies,investment casting patternsand marketing.
FDM 1650 features the BASS allowing the designers to create the models with greater speed and precision.The support tip extrudes a melt that supports any overhanging portions of the model geometry.When the model is completed the support is easily broken off leaving behind the final product.
Each CAD file is converted to an STL format.The STL file is read into stratasys slicing software called Quickslice software.Quickslice breaks the model into individual slices,with each slice representing one layer of the material.Quickslice then generates tool paths to fill the slices.These tool paths form the SML files.
After slicing an STL file and creating a SML file the SML file is down loaded to the FDM hardware for modelling.In the FDM hardware the FDM head in two horizontal axes across a foundation and deposites a layer of material for each slice. The material is heated by the FDM head so it comes out in a semiliquid state. The succsive layers fuse together and solidify to build up an accurate 3D model of the design.
It is a boundry representation of 3D volume geometry using triangular facets. each triangular facet consists coordinates of surface pointing away from the material.
The specification of an STL format states that the model must represent a solid.Due to nature of RP and the difficulty for many CAD systems generally correct files,all STL files must be verified and repairing processes must be automated.Large models must be split so they can be built and subsequently glued back together.
Another limitation of faceted models relates to accuracy,which including topology in the RP model files would clearly speed up processing.eg.model slicing and ensure model validity.Lacking this informatin is clearly a shortcoming of an STL file format.
Select slice interval based on slice top and part accuracy.If we need better accuracy we need minimum slice interval.
Now we create slices with this interval and save the SLC file.Now we check for open curves for all slices.If there is an open curve then we have to edit curves and merge or close those curves properly.For this we need to know editing and how it looks like in different levels.
An SML file sent to FDM hardware.It contains a list of instructions for FDM hardware to perform the actions necessary to build a 3D model. These instructions are FDM head movements, nozzle selection, material flow rate, and wait statements. In these instructions WAIT statement play a important role which allows the material to harden as bound to the previous layer of material.
For the creation of SML file, we take the STL input file. Then STL file loaded in QUICKSLICE SOFTWARE. Then STL file get in to the model envelop. If part is not fit in to the envelop,it is too large for the model with that dimension . In this case we need to reorient the slice curve.
Creating supports-
When a model has a part of eometry without a solid surface underneath it,supports might be required.Supports are structures designed to hold a bead material up while it is extruded.After the model is finished,the supports are removed,leaving the supported section of the model in place.
The kind of support needed for a model is detedrmined by specific geometry of part.Supports can be created as a part of CAD program and imported as a part of STL file.
The following are support options for creating supports-----
This allows the operator to create release material base underneath the entire part.The base can be any no. of layers,thick and can be offset larger than the part.
Direct supports are used to automatically create support curves under all unsupported sections of a part.Use of direct supports can minimize both the build time and material used.
If a part has several large areas of its geometry unsupported,it might be necessary to use containment supports.Containment supports are generated more quickly than direct supports but the build time for finished product can be substantially longer.This is because more material might be used to support the entire part.