Advice on family member as partner in STR

[Seth Mather]

Looking for ideas on setting up a partnership with a family member in a STR. I have never done a partnership and would like to try to keep things simple. Family member is older and wants to help out with initial cost of purchase but would then like to be hands off and just get paid a split profit from the STR. The extra cash infusion would def help lower my own capital expenses for purchase and renovating. Ideally, I would like to split the total revenue 60-40 in my favor because I would be doing all the self management duties of an STR.

Plan:

1. Purchase price for STR $1.65m. Annual revenue estimated at $180k/yr. Total profit estimated at $80k/yr.

2. Split the initial purchase requirements of down payment closing costs (Total cost $355k w/ 20% down payment. So we each paying about $178k). 

3. Family member wants to sell a property no longer needed and put all of it into our STR ($600k).

I'm not sure how to structure the calculations on what a fair split would be after my family member deposits the extra $600k towards the mortgage. Suggestions???