Hi, can you post some pictures of the hollow cube? and the printing settings? If it’s hollow and airtight, it needs a vent to print it and the vent should close to the platform.

Tall enclosed structures would impose a complicated resin level effect and cause deteriorated inner surface and eventually damage the wall, causing thin walls or holes, this applies to all top-down continuous SLA technologies. For any enclosed structures, resin inside will be trapped since the strucutre wall forbid resin from flowing into or out of the wall. To build the walls continuously, UDP mode consumes resin from both inside and outside of the wall. The resin level inside will drop significantly faster than outside, and depletes quickly. Once depleted, the walls will be broken either by insufficient inside resin or by the pressure from outside resin (if the outside resin level is high). Solutions are: avoid fully enclosed structures, periodic release holes in the vertical direction, or vertical release slots. The SLTV do not have such issue because of the side exposure setup and the resin can flow through a top (side) hole to refill. We also applied for another patent to resolve the top-down resin level problem, but it will involve a compliated hardware add-on to the SLASH, and will not be available in the short term. Thanks.  

On the other hand, rings and enclosed structures may be printed vertically with an opening on the side to let resin flow into and out of the structure.

Hi again.

I’m really upset about the UDP rules. I’ve purchased the printer for his speed… Now I will have a printer that prints like any other DLP. I’m feeling being stolen… You haven’t been fair at this point.

I need to print with UDP and you never told it during the campaign about the UDP printing restrictions. Knowing these restrictions I would never purchased the OL. If I need to print a ring and the printer can’t print a ring, it’s useless. The rings are closed… It’s really funny you saying that if we need to print a ring we must open it… Come on!!! The printer must print what I want…

With that rules it’s impossible to print nothing in UDP mode. I have hundreds of designs like the one I’ve sent to you, but none of them can be printed in UDP. 

I want a solution. I need the speed of the UDP mode for my models and parts.

Many thanks for your understanding, but I’m really upset…

Hi Antonio,

I just saw your issue and your shapeways. If you make the design by your own (with cad software), you could cut verticaly parts currently impossible to print with UDP.