<p>What are the basic necessities needed to build a 3d printing machine.</p>

<ul>
<li>Workforce</li>
<li>Technology</li>
<li>Money</li>
<li>etc.</li>
</ul>

<p>I'm an undergrad and my friends and I would like to make a printer for a project. We wanted to get an idea of the prerequisites for this work. </p>

Prints could end up on tray for couple of reasons.
Vacuum force on early layers - Usually you should lose pieces on the center of platform
Put holes or channels on platform
Very slow speed on early layers
Use smaller platform
Use tilt mechanism
Use larger support structures
Use stickier platform - Anodized aluminum is specially good
Non-aligned platform - Pieces on side of platform end up on tray
Align platform / tray
Low cure times - you could lose pieces around platform for DLP and whole platform for LCD ones
Resin related issues
Resin designed for thinner layers - Decrease layer thickness
Pigment settled down - Shake resin before use