Yet another 3D printer? Why?
As for the trustworthy part, it's not just the video, it's whether or not you can prove you have a chance of delivery.
Two 16 year old kids who have (presumably) zero experience delivering a product, is well, not very convincing.
It doesn't matter if you post daily updates, what do you have to show, now?
Do you have any sort of track record of documenting progress on a project? (that would help a lot)
If the answer is nothing, then I don't think many people are going to back two kids to have a go at developing a 3D printer from scratch. The odds that you can deliver a tangible product at the end are obviously not good. So unless people are just going to back some kids to "have a go", then I suspect this one isn't going to fly.