"Partnership"

I think the problems with most partners are caused by feelings of resentment when one feels they are doing a majority of the work .
This seems to be the case here . The op feels like he is selling himself short . What he needs to understand is that he would only have half of what he has if he was not receiving the financial support from his partner . That and the trailer seem to be the only thing tying him to this agreement . Most partnerships end because one half feels they could do more alone . I suggest splitting the current load and everything that was paid for and keeping the friendship . In a few months you will see for yourself what works best for you . I also think it's great you work with your dad . Explain to your friend that you want to get him more involved and you could still get his help if a larger job requiring a trailer comes into play before you have one of your own .

Anyone looking to partner up has to set the expectations straight out of the gate to avoid any future problems . I prefer working alone unless a job calls for help , then I get to choose who I work with and pay them accordingly . I have friends who I help out that treat me the same . I guess what I'm trying to say is setting the expectation makes all the difference and no amount of scrap is worth a good friendship . Good luck and I hope it works out !