When sending a wheel drawing to a potential supplier for a quote, the supplier suggested the following to reduce the cost of manufacturing the wheel:
- Removing the 3.3 mm boss completely, keeping the wheel a maximum of 31.7mm wide.
- The FAQs state that innovation is welcome, as long as it is compliant with the rules/tech spec/drawing with supporting documentation.
The boss is a given dimension - how far does 'as required' go? This would appear to be part of the technical spec, and non-negotiable?
We encourage innovation but would point out that it is the team’s responsibility to ensure that their design is a) safe and b) meets all of the Railway Challenge rules and specifications. This will need to be demonstrated in their design report.
In response to the specific question about the wheel we would make the following points:
- The total width of the wheel at track level is clearly defined by drawing RC04 as 31.7 mm
(+5/-0) and this is an absolute requirement for compatibility with the track system. It
appears that both of the above proposals would comply with this.
- The boss at the wheelseat is shown with a dimension of ‘3.3 mm or as required’. This can
therefore be varied to suit other aspects of the locomotive design.
- The recess between the wheelseat and the tyre is clearly labelled as ‘optional’ so can be
varied to suit other aspects of the locomotive design. There may be issues around manufacturing processes and/or fatigue but that is for the team to consider.