As part of a part C Computer Aided Design (CAD) module we were asked to design and analyse a user console for a treadmill. The project entailed organic surface creation, shape analysis, manufacturing process design, ergonomic analysis and to perform strength testing using Finite Element Analysis techniques.
The CAD software used for the project was Unigraphics NX 7.5. This software contains all the tools required to perform each stage of the project.
Various data translation methods were also looked at to help transfer CAD files from other file systems to be viewed and edited. This allows users to use files provided by other CAD modellors or component suppliers etc…
Please navigate various parts with the drop down menus below:
Once the basic layout of the console had been gained curve analysis was applied. The analysis allows checking of the curves to help create more smooth and constant curves. The line extruding from the main curve show the sharpness that the curve has. The resultant curve to this shows how smooth the curve is. As can be seen this curve is not very smooth as the curve analysis shows jagged edges. By adjusting individual points in the curve a more desirable and better curve could be produced.
After the manufacturing plan has been finalised it must be implemented into NX7.5 and used to check that it will work as expected. Initially all the tools are defined, in this case a 20mm and 10mm ball nose cutter has been selected.
Once tools had been defined using both NX verification and Vericut tools its possible to ensure that the process completes with no errors.
A final vericut run was performed to ensure that the enitire manufacturing process was free from errors. This then showed that the tool was having interference problems with the top of the original blank. In order to solve this the tool start and end point was raised by a further 10mm to ensure a good enough clearence was achieved. This solved the problems and allowed for an error free manufacturing process.
Ergonomic analysis is used to check that a wide range of people can comfortably use the treadmill. As humans vary greatly in size and shape the 95th and 5th percentile for females and males were used to analysis the performance of the treadmill. The specification of a pass or fail was whether a person could comfortably reach the safety critical aspects of the treadmill. This includes the use of the emergency button and the ability to use the handlebars. Other aspects such as program control buttons and iPod control would not have adverse effects to a treadmills performance if the person was not able to reach them during use. The white sphere in the images below represents the comfortable reach areas of the selected human.
As part of the British Standard for treadmills there are qualitative tests that can be performed to ensure compliance. One of the tests to be performed is a strength test on the handlebars. The handlebars are a vital component to help a user stand when over exhaustion or exercising beyond their capability. Therefore the components must be able to either meet or exceed the set standards force.
