There are two major approaches for SLA printers: top exposure (TE) and bottom exposure (BE). In the former the light source is above vat of resin and the build platofrm sinks into the vat as the part is built. In the latter the light source is below a shallw resin dish with a transparent bottom and the part moves up as the part is built. The major tradeoffs are these:

1. Resin volume: TE machines require that the resin covers the top of the part as it's built, the BE machines don't. Resin is not cheap, so BE machines have an advantage. There are techniques for TE machines to mitigate this, but they are not easy, and I don't see Gizmo3D using them, although I don't know for sure.

2. Slosh: BE machines rigidly control the resin thickness and have no slosh uring exposure, so layer thickness is uniform and layers are flat. For TE this is more of a challenge and requires settling time for the upper surface to flatten out. Care must be taken in managing this, otherwise the parts will have non-uniform layers and not very good Z dimension precision. BE has a bit of an advantage in this.

3. Speed: BE machines need to either break the part away from the bottom of the build dish or make VERY special arrangements to make sure that the part doesn't adhere to it in the first place - this requires time. This is also difficult to do as size goes up. TE machines don't have to do this. Furthermore, TE machines don't have glass to attenuate the UV light source, so they can have shorter exposure times. TE has strong advantage in this.

4. Continuous printing: TE machines can print continuously, while only one BE machine can do so (Carbon3D). Unfortunately, not all profiles are amenable to it, so utilizing this capability requires a bit of support in the software and skilled use. Still - a major advantage to TE (and to Carbon3D).

There are others, as well. Net-net: if you don't mind paying $$$$$ for a large amount of resin up front, you can get larger parts and your parts will be printed faster with most TE machines. TE machines are slightly less complex, so should be less expensive to purchase, as well.

Having said all of this, it looks like Gizmo3D machines are TE (http://www.gizmo3dprinters.com.au/#!3d-printers/c19zf) and look like they've seen fairly extensive engineeering. So yes, I do think they'll be able to print relatively fast. The only other major comment I have is that because they're going for large size, the pixel resolution of the DLP will limit the X-Y resolution of the prints.

Overall, I think this is a very interesting design, and I wish them well.

Ben.