But people were reluctant to share their equipment. Everyone had their own ideas that they wanted to make. Even with the promise of "if we stick with one project for now, and get it finished, then we can do another and eventually yours will be done" people couldn't get into the long-term mentality.
You gotta be more decisive than that when making a group. Don't describe your reasoning unless people specifically ask for it. It's important to be speedy and concise, because all the piddly poddly "If/then" reasoning is slow and you can't reason with a group that way anyway.
What you should have done was pick an idea, very fast and at random (speed is very important in these situations, you can't let individuals gain much footing within the group, can't afford for individual members to get their bearings,) and say "this is what we're doing now. We'll get to the other stuff later and if you don't like it, shove off."
A few might leave at first, but they'll be back so long as a sizeable portion remains and you don't show any notice of them leaving. Group people hate being alone.
If you don't want to be the leader, you can wean leadership onto someone else over time, probably the person who came up with the idea in the first place. It's just important to get the group focused on one idea fast before they turn into an inefficient democracy.
*I should add that this is more for working in large groups like the group described in the OP as opposed to small, two person groups in which everyone has a unique job.