Machinery set up costs

Looking for ideas really

How to set up machinery costs. So we manufacture U-bolts. The bill of materials just has the raw materials and we have realised this does not really work

So we need to add in machinery costs - presumably using operations and workstations. i can kind of see how that works, it takes 2 minutes to bend one U-bolt so we add that as an operation

So the BOM for 1 u-bolt has 1 length of metal and 2 nuts for the material costs, operations of threading and bending at an hourly rate

BUT

it also takes time to set up the machinery - 1 hour. This hour is taken whether we set up and make 1 u-bolt or we set up and male 1000 u-bolts, it still takes one hour

Can any one think of a way of doing this? I can’t add it to the BOM because the BOM is for 1 u-bolt. I am stumped