I have been tasked with reverse engineering this Toggle Clamp.
What is Reverse Engineering?
Put simply, Reverse Engineering is taking something that exists, measuring it, and re-creating it from measurement.
Step1. Measure.
There are several different methods as to how to measure an object. For this Toggle Clamp I elected to use a digital caliper.
Step 2: CAD
Using the measurements we have collected, re-produce the object into a CAD software.
Lessons Learned
Lessons learned from this assignment:
When I first approached this assignment I didn’t really read or understand what the Top-Down design method was and actually approached the construction in a Bottom-Up method. Using that method I had created five separate CAD files with the different pieces of the Toggle-clamp and attempted to assemble them in an assembly file. That actually proved to be rather difficult and when I approached Nate about it he informed me that I was going about it in the wrong direction.
I reapproached the project Being sure to use a Top-Down approach and created all of the components in one assembly file.
I have to say that I do prefer the Top-Down method now that I have had a fair bit of experience with it. Adjusting parts in the assembly is much more efficient and less time consuming.
I had to use the “Joint” function several times and became well versed in the way that works.
The Rivets I created after I had Jointed the rest of the components and I accidentally dis-associated them from the file and they became separate parts from the file. I'm not aware of a way to re-associate them with the file.
Step 2.1 CAD Joints
When modeling in Fusion 360, and you create an object that has several components that you intend to have interact with each other, you will need to establish this by creating a defined relationship between those components.
In Fusion 360 this is referred to as a "Joint" and they must be defined based off of the characteristics of the desired component interaction.
Before creating a Joint it is important to know that Joints can only be created with Components and not Bodies. So for any bodies you want to use the Joint function on, you must first convert to Components. This can be easily done by right-clicking the bodies in the Browser.
The different Joints available in Fusion360 are:
Rigid- locks components together and removes all degrees of freedom.
Revolute-lets a component rotate around the Joint Origin, with no additional translation.
Slider-moves a component along a single axis.
Cylindrical- lets a component rotate around and move along a single axis (think of a screw's motion).
Pin-Slot- lets a component rotate around one axis and move along a different axis(rotation with axis movement).
Planar-lets a component move along two axes and rotate around a single axis(think of the way your computer mouse move, if it were secured to the table).
Ball- lets a component rotate around all 3 axes but affixes its relationship to another component.
After selecting a joint type, we have define how we want the components to relate to each other within the context of that joint.
We do this by defining the planes, faces, and edges that we want to determine an axis of travel.
For example if I want a rivet to sit Rigid inside of a hole, I would select the "Joint" command, select the circular inside edge of the rivet body as one "Component 1", then select the edge of the hole that I want the rivet to sit in as "Component 2" then select "OK"
Different joints will require different levels of instruction on how to have components interact with each other.
For the joints on the toggle clamp I had to create 13 different joints to translate the motions I was looking for in the components.
6 of these were Rigid,
5 were Revolve,
1 Slider,
and 1 Cylindrical.
Here you can see where the Joints are assigned.
For the Joints associated with the links between the handle and the plunger, each connection required three joints to stay together properly, as there were Four different components involved in each connection.
For the plunger I placed a joint defining the path of the plunger in the frame as well as a cylindrical joint to interact with the bolt at the end of the plunger.
Materials
Now that we have created model in Fusion that has the physical attributes we were looking to create, we need to assign those components materials.
We do this in Fusion by clicking the "Modify" tab in the top banner, and coming down to the "Physical Materials" tab.
This will open a box giving us options to too click and drag to each component.
We can further edit the material qualities to reflect a desired appearance or physical characteristic such as density, mass, ect.
For our toggle clamp I have assigned the base "Cast Steel" and changed the appearance to a black color, matching our original.
The plunger I have determined to be a "Stainless Steel"
The links, rivets and handle seem to all be made of the same material so I have assigned them a general "Steel"
The Handle grip is a plastic. I'm not exceptionally confident in identifying plastics so I have assigned it a general "Plastic" with a corresponding Red color.
All of these materials can very easily be adjusted at a later time if needed.
The Nut and Bolt at the end of the plunger are McMaster Carr products downloaded from their catalog.
The description they give in the catalog of their material is a that they are a Zinc-plated , Hot dipped galvanized steel that meets ASTM A307. Fusion does not list this specific steel so I had to look up the properties and assign them manually.
The Result
The result is a Top-Down Reverse-Engineered Toggle clamp rendered with material and appearance to mimic the physical product as well as assign attributes to the model that mimic it's physical properties.
Note the Mass, Volume and Area in the Properties window.
Lessons learned
This Task of Reverse Engineering put me in what I felt like was the driver seat of Design. Reverse engineering is not to far off from creating new products.
A lesson I did learn quite quickly was the difference between Top-Down and Bottom-Up design. I initially used a Bottom-Up method that proved to be difficult and in-efficient when making edits to the design that had effect on multiple components.
After struggling with the Bottom-Up method I restarted and utilized the Top-Down method keeping al of the components in a single file. This method I found to have a much easier flow and I was able to complete the design in a considerably faster time.
Reverse engineering in my opinion is an exceptionally useful tool in the design process. I for-see myself using the skills I have learned in this module in many future endevors.
Rendering
Because in many cases we want to produce objects in CAD that are appealing to a consumer Rendering them in a life-like environment that is similar to the one that they will eventually be in is a very useful.
Fusion360 has a rendering option that gives users the ability to do that. The software give the user the ability to place the object into a space as well as adjust the lighting on the object to that space.
This does take a fair bit of planning and understanding of some lighting and photography principles.
Below is a before screenshot in the "Design" space of Fusion360, followed by the same toggle clamp in the "Render" space.
In the Render space, appearance and scene settings are available. Appearance gives the option to adjust the colors and effects of surfaces. There are a variety of different textures and colors that can be assigned to materials that can also be further adjusted to produce the preferred appearance.
When you have decided on an appearance you are happy with, you can ask Fusion to begin the render.
Renders take do take quite a bit of graphics computing power, because of this Fusion gives you the option to render locally on your computer or in the cloud on a server.
Animations
One of the features of Fusion 360 is it's ability to produce Animations that can communicate the a product's features and the relations they have with each-other.
We do this in the animation workspace:
In this space we are able to manipulate components over a time space that can communicate a variety of useful information about the product.
The most common information that this is used for is the construction of a product and how the components fit together.
Within the animation page you can use the "Transform" commands to move components within the product and have corresponding time values to their movements. These time values are displayed and edited in the "Animation Timeline" window
The finished product is an animation of your finished product.
Assembly Drawings
A useful feature of the Animate Workspace is that the dis-assembly that you have created can be converted to a Drawing. This can be done in the animate workspace by clicking on the workspace option button in the top left, scrolling down to Drawing and then selecting from animation.
After selecting the "drawing from animation" button a window will appear asking questions on the preference of the drawing. This also gives the option to add the drawing to an existing drawing.
Once your preferences have been selected and you have clicked "OK" a new Drawing window will be generated. If you have "exploded" the assembly that position of your components should transfer over to the drawing workspace.