making froups of products to shipping with different custs

[avantix]

i people, im trying to make a modification to the table shipping module that is supposed to :

 

- look at the weigth of the products that are in a order

- agregate the products with have less than 1 kg untill the amount of 30 kg

- all the products above 5 kg will have to be shipped apart.

 

example:

 

table of costs: 5:10 , 10:12.5 , 15:17 in weigth

order:

- 1 printer - 10 kg :shock:

- 1 CPU - 1 Kg

- 1 MotherBoars - 2 Kg

- 1 Scanner 7 Kg

 

so the script needs to agregate the cpu and the mother board as a total of 3 Kg, and the printer and scanner will go separately.

 

So the total shipping costs are:

printer - 12.5

Scanner - 5

The agregate products - 5

Total: 22,5

 

GOT it??? any sugestions???