AutoCAD Inventor :: Developing Parametric Spreadsheets To Drive Modelling

We are a transport engineering firm in Queensland and I would like to develop a spreadsheet that can formulate cross member distances and recalculate to add or remove cross members.

The basis of this is the overall size of the body we are building.

For example: The maximum width of a body in Australia is 2.5metres overall. Our cross members would be 6 mm shorter than the overall width of the body to allow for 3mm end caps to cover the open ends of the cross members. So the length of the cross member is width minus 6, or , parametrically the length is (overall width - (endcap thickness x2))

The body length is the tricky one. We have a maximum spacing on the cross members. This will vary from size of body to size of body. EG the spacing on the small 2 tonne body will be different to the spacing on the 12 tonne body etc. So lets say we want to have maximum spacing of 450mm and a minimu spacing of 300mm between centrelines of the cross members. The overall length of the body will also determine the number of cross members required.

On top of this there is the front and rear coaming to take into consideration.

So the formula would be ((overall length - front coaming - rear coaming) divided by cross member spacing)) then a check to see if the last space is what and then can we change the cross member size to take up that space without going over the maximum space. We would also need to take into account the width of the cross member section as well in this calculation.

EG if we have 150mm left at the end we could increase the cross member centres slightly to take up this additional space without going over the maximum space allowable.