CEO's join companies after they've been around for years to earn valuable sums of money for the skilled work and long hours they put in. It motivates them to turn around the company. It's not about the % they earn it's about the return they get.

You deserve just as much motivation as they do for the sacrifice you're making and asking less than 1/3 is wasting your time. The worst they can do is fire you so you can make more money. That's when you start your own clone if you didn't sign a non-compete contract. And if you did, work for what you deserve elsewhere until it ends and then invest all your newly earned savings into building the better product.

I don't think you know nearly enough to make that claim. You don't know what value each party is bringing, or their roles, and you don't know how much was done before OP joined. You don't know if the business has any particular strengths.

Assuming significant work was done before OP joined, equal equity is not realistic (or fair). Also, are the others taking any money out (i'm guessing not?). There can of course be some value in ideas and traction (although AFAICT there isn't a lot unique nor is there a lot of traction). Moreover, i'm guessing most big decisions are not made by OP since he seems to be relegated to employee. Only if OP feels they are crucial and replaceable should he go for 1/3 (or more). From the little i know, 20%+ would be a good aim. If you think you can do better elsewhere (that is, you don't believe the business has unique strengths) then consider that.

wow there are a lot of things i'd do on a budget but flying isn't one of them (i'm very risk averse by nature)!

It really is refreshing to see a non-web start-up mentioned here on hn. Well done to you guys and I hope the negotiations pan out for you.

No offense but I'm not sure posting this on HN under your own name is the best approach. You are, after all, discussing intimate business details. Maybe you could get it anonymized?