Three of us are starting up a new company.
Partner A brought the original idea. He also has the IP, the development of which was paid for by a third party. Moving forward, A will only dedicate 10% of his time to the company (and has for the past six weeks).
Partner B has invested significant effort on the technology and has manufactured a prototype, being compensated by a third party. He will dedicate 50% of his time to the company (and has for the last six weeks).
Partner C didn't develop the technology. He joined recently and is organizing the business case and finding strategic partners. He will dedicate 100% of his time to the company (and has for the last six weeks).
What would be a fair distribution of equity between A, B, and C?
1/3 each works for me
Companies that don't have full-time founders focused on building the venture tend to fail. It is often difficult to raise money or recruit top talent when the founding team isn't working on the venture with all their energy and resources.
Six weeks isn't a long time; certainly not long enough to estimate the long term commitments or working relationship quality.
Regardless of how you split it, have vesting in place.
No one here will be able to provide a good answer because there's just not enough details.
The only way I can see you guys figuring this out, is to translate everything into money.
50% of B's time is worth this much, and 100% of C's time is worth that much, and the IP is worth X and developing a prototype is worth Y.
Otherwise, it's all guess work. Except for the worth of the IP everything else should be pretty easy to quantify.