Private lender for flip down payment

[Amy Atnip]

New member and fairly new licensed contractor looking for advice. I'm almost finished with my first flip. Another property has become available that I'm interested in flipping, but I don't have the cash for the down payment. If I use a private lender for the down payment only, what should the ROI be for him? How is that determined? Is there a split of profit, or is it just a straight percentage of the loan? Thanks for your help!