3D Computer Modelling – OnShape

Onshape is a cloud based 3D modelling software. Onshape’s website describes it as “an all-in-one platform for product development”.

Onshape is very similar to SolidWorks in terms of capabilites and purpose – but has key differences in its licencing model, collaboration and the fact it is cloud based.

Originally I had planned to learn Solidworks as one of my core skills. During my previous education I learned to use Autodesk AutoCAD for 2D and 3D drawing. While AutoCAD and Solidworks are tools used for design and development of products, AutoCAD is preferred for 2D drawing and non-parametric design approach. When taking a 3D design approach, Solidworks is reccomended.

I downloaded a 60day trial of Solidworks to learn it, and starting reviewing online videos. Unfortunately after months of lockdown and online learning of other programs etc through video, this method of absorbing knowledge was no longer working for me. I decided that I would hire a 1 on 1 tutor instead. One positive about this pandemic is that you can find almost anything you want online.

I found an Engineering PhD student who was offering online tutoring (1 on 1) for Solidworks and other cad modelling software. After our first call he reccomended I look into Onshape.

Given I had no experience with Solidworks before I decided this was a good idea. Onshape allows you free access if you agree to have your projects public. One of the problems with learning expensive software at school is that once you leave you no long have access to practice at home. Once learnt, learning Solidworks or other similar software that is preferred by employers will be simple.

Lesson 1 – discussing benefits of different CAD modelling tools and building a basic cup (1 hour)

In the first lesson we discussed the planes and workspace.

Onshape allows for the creation of 3D objects in a variety of ways. Similar to AutoCAD 3D tools, you can draw a 2D ‘sletch’ and then extrude it. The benefit of the planes in onshape allows you to start the sketch on one of the planes and build from there, depending on your design.

We started with a circle, using the extrude button to convert to a cylinder.

In onshape it is important to remember to define the dimensions of sketches to prevent them from being modified by dragging. If the line is blue then it is not defined. To define a dimension, click the dimention tool, then the line and type in the dimension. The line will turn black. The dimention has be deleted and modified later on if required but it is good practice to define dimensions as you go for accuracy in the model.

One a cylinder is created, we then drew a triangle shape and used this to subtract from the cylinder to make it look more like a cup with a tapered edge.

The column on the left hand side shows all the steps taken to get to this point. This means you can go back on any model and understand how it was created (as there are a number of different ways to create the same objects).

Lesson 2 – learning basic building tools by adding detail to the cup (2 hours)

In this lesson we went over a variety of methods to achieve the same results of cutting ridge details into the cup.

One way is by subtracting from the mass starting from the centre, and then adding to the void to chance the depth of the ridge. Another is by subtracting from the mass from the outside of the cup by creating a new plane and sketching the shape on that plane. The third method we used was to create a rectangular shape on the bottom of the cup and subtracting by extruding the rectangle upwards.

We also used chamfer so create a softer look, and revolve to duplicate the cut-out around the cup.

Lesson 3 – learning about components and working on digital screen modelling for my minor project (2 hours)

This lesson was about component parts and the beginning of assemblies. Instead of following along, in this lesson I built the components using the tools learnt in the first 2 lessons and with direction from the tutor created the beginning components. Parts (or components) can be loaded into the assembly from the Part Studio, and parts can be imported from other documents.

We also looked at different types of views, such as the section view, to get a better view and understand of how the pieces fit together.

Lesson 3 – Components, Assemblies and Drawings (2 hours)

In this lesson we looked at components, the assembly workspace and the creation of drawings from the models.

To start an assembly you need to import each of the parts you want to use in the assembly. These parts can be parts in the same workspace, or imported from other workspaces. Once imported, these parts can be manually moved around in the 3D workspace.

We then started to give the parts relationships to each other. Using the Mate Connector icons we explored different types of mates. You can use the Mate Connector main icon to start and then select the relationship, or you can click on the icon that represents the relationship. For example we used the Revolute Mate to connect two faces of parts together – but to have them spin around each other. It is important to make one of the parts fixed in space, otherwise the whole assembly will move around. To do this, right click on the selected part and click Fix.

To explore more of the available mate connections, we created a couple of extra parts to import.

The below video shows the final product from the lesson and how the movements of parts work. The video also demonstrates how changing which part is fixed in space can also affect how the assembly moves when manually manipulated.

To create the handle moving in the slot, we used Planer mates to define the relationship between the planes on the handle and on the slot it was to slide into. These two relationships keep the planes in parallel with each other. To prevent the part from sliding all the way out the end, or completely through a solid piece, we used the restrictions settings. Unfortunately, the software doesn’t stop two parts from moving through each other on its own. Its not designed at that type of simulation software, so entering restriction settings helps visualise what would happen in real world application without the need of a powerful simulation engine.

We discussed other tools such as the ball mate (if you were creating an artificial hip joint ball bearing style joint), as well as some of the more advanced features such as gear relationships etc. however, these are too advanced for my purposes, and are for more mechanical engineering type applications.

After creating assemblies, we looked at production of drawings from both parts and assemblies.

To start a drawing from an assembly, right click on the assembly tab and click create drawing. You can then choose either blank, or 4 view from the templates.

4 view drawing creation

If you select blank, or want to add new views, click the insert view button and a drop down appears, allowing you to select the options for the view you want. To create an exploded view, right click on the assembly in the instances, and then add exploded view.

Once you’ve created the explode view you want, you can select this from the dropdown on the drawing tab.

The top toolbar has a variety of features, such as dimensioning, and the addition of sections. Simply click on the tool and then on the area you want to dimension or section off, and click again to place on the page.

I learned a lot during these lessons about more than just how the software works, but also components, assembly and how things would be manufactured. Creating the 3D objects themselves makes this converstation and understanding much clearer.

I primarily used OnShape to create my models used in my Minor Project.