I have now completed my taught modules in Solid Edge, so as the final piece of coursework, we were to complete a modelling task that would illustrate our competence at the most recently learnt techniques. These techniques include a procedure called surfacing, which contains a completely individual set of tools.

It is in this report that I will illustrate my methodology, including any observations when using these new tools.

Introduction

My decision to model a rubber duck for this project was based on the level of complexity of their shape. I wanted to model something that would be a challenge, and it did in fact turn out to be one. There are fewer curves to this than there could be for other choices, but it still allows me to utilise all the commands inside Solid Edge that I have learned over the past six months.

The duck design I finally chose is more complex than some things I could have chosen (inside the bracket of children’s toys) like rattles, Lego characters etc… It is for this reason that I am satisfied my choice will stand up to requirements.

Methodology

Tools

There are many useful tools for creating models within solid edge, as well as many differing ways to go about the same task. The following few paragraphs are explanations of the commands used, and the tools used therein.

Sketching

Generally, sketching is one of the first things to be done. A few sketches are normally produced, and from these, the model can be created. I created my model in stages, taking one aspect of the duck at a time, and modelling that; as a consequence of this, I have several stages worth of sketches. Out of all the features available while sketching, I used: Line, Tangent/Arc, Circle by Centre, Fillet, Dimension Tools, Trim, Connect, Concentric, Horizontal/Vertical, Parallel and Equals. Some of the newly taught methods I employed include: Mirror, Lock, Construction Lines, Include, Offset, Convert to Curve and Split. These tools all have fairly self explanatory names, with exception to possibly Include, Offset and Convert to Curve which are all used alongside an already prepared sketch; Include to include a sketch from a different plane, Offset to create a sketch with layered curves/lines and Convert to allow editing of shapes with previous definitions. I will demonstrate the instances where these were used in my Techniques section.

Surfacing - BlueSurf

BlueSurf is probably the most intuitive tool inside the Solid Edge package. It is possible to create surfaces no other tool could, using an intelligent approach to sweeping, lofting and vertex mapping. The process for creating a BlueSurf surface traverses three steps: “Cross Section Step”, “Guide Curve Step” and “Insert Sketch Step”. Only the first is necessary, the latter two being powerful enhancements. As a cross section, a vertex, a point, or a loop can be selected; cross sections can vary in type, but only in certain combinations. The Guide Curve Step adds a layer of functionality so that the surface (defined in the previous step) can take on a more moulded look, and essentially could be any shape desired (as long as the surface doesn’t self intersect). One or more guide curves can be used, but only as long as all the curves intersect all the cross sections at ‘pierce points’ (being where one sketch is attached to another or a specific point). ‘Insert Sketch’ is functionality which adds yet another level of dynamism to the tool, letting the profile of the surface be mapped onto a specific plane and be translated into a sketch. This sketch can then be altered, altering the surface at the same time. It is required that this sketch does also cross all the cross sections however.

There is one final thing to note about BlueSurfs, and this is the presence of additional properties which can affect the final outcome of the surface. They can change the end-style, the vertex-mapping and the way that ‘Insert Sketch’ performs; among other similar changes.

Surfacing - Revolved Surface

This tool is simple to use and implement. It requires a sketch profile and an axis about which the profile is rotated. The settings of this can be changed to have a partially revolved surface with solid/closed or open ends to having a fully rotated (360°) form. One thing to note is the fact that the profile must not cross the axis of rotation.

Surfacing - Bounded Surface

A bounded surface is as simple as it sounds. It simply creates a surface between a closed loop of curves, as long as the resulting surface doesn’t self-intersect.

Curve Tools

Curve tools are used to create less basic surfaces. They include: Cross Curve, Intersect Curve, Project Curve and Split Curve. Cross Curve takes the data from two existing curves (drawn on 2D planes), and extrapolates this into 3D form; this is another way to create a complex surface, as this can be used as an input for any surfacing tool. Intersect Curve draws a curve where two surfaces intersect, allowing them to be trimmed, or even a new surface to be created from that point. Project curve projects a 2D form onto a surface. And split curve which allows an existing curve to be dissected anywhere along its length.

Techniques

I used a variety of the tools I highlighted above, alongside some others, in the production of my surface model. Below I have constructed a list illustrating an instance of each, alongside some information about how it is completed.

Sketching – Insert Image This was the very first tool for me to use. I imported three different pictures of my rubber duck, and these placed onto their respective planes – xy, xz, yz.
Sketching – Line/Curve Tools When first constructing my sketches I used these tools, the example illustrates my defining of the ducks rear end, using curves and lines, and attaching it to the existing surface
Sketching – Mirroring The example shown is my mirroring of the ducks tail profile. This is to ensure the tail is symmetrical, as well as helping with dynamically editing it.
Curves – Cross Curve I used cross curve many times in my project, these range from the ducks tail (shown), to the beak, and even the tongue.
Curves – Project Curve I needed the base of the wing to follow the profile of the body, so I first sketched the side profile of the wing, and then projected it onto the body.
Curves – Split Curve Split curve was useful to me when creating the wings, as I had projected the wing as an ellipse; I then needed the ellipse in two sections to BlueSurf between them.
Curves – Intersection Curve In order to thicken the surfaces successfully into a solid part, the internal structure must be un-sectioned. I achieved this by creating intersection curves where surfaces met (ie. head and body) so I could trim them internally later.
Surfaces – Trim For reasons stated before the internal surface need to be trimmed. The example here is of when I trimmed the body of where the head will fit.
Surfaces – Bounded Surface The simplest of the surfacing tools – used here to complete the base structure.
Surfaces – Revolved Surface I utilised the revolve surface a few different times, I used full rotation for the head (shown) and half for the front body and eyes. The axis can be clearly seen here.
Surfaces – BlueSurf The tool I used most in this project. Here it can be seen completing the tongue in two separate sections. On the picture, the yellow pointer shows the vertex mapping (virtually rotation as the vertices are joined) and the other blue curve is the guide curve (and its plane).

Problems

In all, I had five different attempts at completing this model. My second attempt nearly became complete, but was not stitching properly. They were all a slightly different take on the look of the duck, and each employed a different method for modelling the body. Some of the problems were, as I said, due to the stitching; but some were down to the method used not being appropriate for the shape required.

Attempt 1 This was my initial choice of how to pursue the problem, using a swept surface. This choice resulted in fundamental aesthetic problems, and also the closer the duck came to the sketches I imported, the more complex and bloated it became.
Attempt 2 This attempt was also less like the duck I chose, as it was a continuation of the above attempt. My design continued all the way to adding the cheeks when I realised that it would refuse to thicken the model no matter what I did to circumvent the problem.
Attempt 3 This is the design that I came back to and would produce the model from. The only problem here is the way I went about using the tools.
Attempt 4 This was initially a last ditch attempt to produce a working body model. As can be seen from the picture, it also has less of a resemblance to the actual rubber duck. This method also refused to thicken, so I was at a loss, until…
…Attempt 5 This method was a rehashing of attempt three. It ultimately comes to fruition because of a tolerance set when stitching the surfaces together. This model is a near perfect likeness of the real rubber duck.

Conclusions

I have learned a lot from this exercise. It has taught me how to surface properly, and has made it easier for me to judge how a surface will need to be constructed. One thing I definitely didn’t appreciate before starting this work was how to plan ahead. This resulted in my multiple starts, and their disconnection form the actual look of the physical rubber duck.

Working with surfaces is actually more forgiving than I initially thought. They do actually give a level of detail previously unavailable, and are fairly easy to implement.

As I have already said, the one thing I would do differently is the initial planning; as this would save time and effort in less false starts and would probably result in a better looking (and built) model.