Ask HN: How should I split equity between my partner and I?

The business revolves around refurbishing vintage electronics, which I've been doing for the last couple years.

My contribution to the business:

   - Funding (around 10-20k in the first three months. Most likely more after)

   - Sales channel from my other business (will provide enough orders for my partner to work full time, and most likely onboard an employee or two).

   - Managing and training my partner on how to run the business (essentially treating him as an unskilled employee) - Hosting all the software needed (inventory management, storefront, task management, email etc)

   - Technical knowledge. I am an electrical engineer, and some parts of the job require some engineering. This is however a small portion and mostly only relevant with certain refurbishments and repairs. It can be taught.

His contribution to the business:

   - I expect he will work full time on the business

   - He will be managing everything on the ground, looking into new products, etc.

My expectation is to have little stress related to this business - I don't want to be harassed about operational issues once it's up and running, and of course my equity should reflect that. I will not be working full time on it. However I also want to be able to develop and implement strategies for the business, and also control over pricing for my sales channel, so I would ideally like over 50 percent ownership. Is this fair? How would you split it based on the above?

Another option I have is to hire him. I will be able to do this financially in 2-3 months. Should I wait until then? I want him to be motivated to cut costs and grow the business though, so I am not sure if this is appropriate.