How to convince programmers to implement their product (create a new startup) in their free time?

Question

Time Management

There is a product that is now working and earning money for the owners.
It is possible to turn this product type into a "boxed version" for sale and use by other companies.
There are programmers who saw this product, but there is one but .
The owners think or already want to sell the product itself and score on it without creating a boxed version.
IMHO terms to the beginning of the sale process 6 months.
The architect says that if you make a "box" during working hours (8 normal working hours), then you won't be able to make a box, you need to spend more time and money on hiring programmers, etc.
But programmers have the opportunity to cut down the box by spending additional free time on it (time for beer, TV shows, movies ...).
Those. before the start of development, agree with the owners on a percentage of the sales of this box and start sawing.
There are already potential customers , there are already potential projects for sale, there is money that customers can pay for a boxed platform.
The problem is that there are only 1.5 programmers who want to start selling the box, the rest think about the company))) and continue to want to work for a salary, I guess.
The question is how to convince others to spend six months of their time, but in the end get a big plus in material terms, get passive income and financial freedom.
The risk is 50% to 50%. Manage to launch - get a percentage. They don’t have time - they sell the product, and the programmers will continue to work for a salary, and possibly dismiss it - the new owners will file the box on their engine.

Answer 1

Sergey: Hello! Are you a programmer? Do you know WordPress or other engines?
I propose to be my assistant on the project. The project will have a development team.
The project is interesting, but without a budget, I will not pay for the work.
In the future, I will attract investors with whom I already have a positive relationship.
When financing, if I like your interest in the project, we will continue to develop the project in place already on a budgetary basis.
If the project does not interest you, please remove from the list of contacts.
If you are interested, let's continue communication, there is a technical specification, an operating time.
Sergey: ?
Gregory: Hello! Are you a human? Do you need to eat and dress?
Offer to work for me for free.
There will be a crowd of people just like you in the project.
The project is interesting, but I will not pay salary.
In the future, I will attract investors, and if you do not die of hunger and cold during this time, you may have a cheap salary.
Do you agree?

Programmers are people like everyone else. And they have monthly mandatory payments, like everyone else. They also need to eat, dress, like everyone else. Would you agree to work for a 50% chance of getting a salary? Just imagine, you come for a salary, and the accountant throws a coin and says: "Sorry, tails, this month you are without a salary." If you believe that the project is successful, then take out a loan after all. But to work for vague opportunities, excuse me, no one will agree to this.

Answer 2

What programmers might be interested in:
- Position. For example: Vasya, you will plow for half a year after hours, then you will become the director of the Boxed Product company
- Salary. For example: Vasya, you will plow for half a year after hours, then you will receive 3 times more than now
- Knowledge. For example: Vasya, you will plow for half a year after hours, you will be able to master % technology_a%, % technology_b% and % technology_c%
What programmers will not be interested in:
- Uncertainty. For example: Vasya, you will plow for six months after hours, but it’s not a fact that you will be interested in it, it’s not a fact that you will get something for it and it’s not a fact that you won’t die of hunger.