Let me first congratulate you on your work and efficient engineering.

I would like to ask you a few questions about the projectors:
1. What is the smallest image size that you can bring in focus using the lens mods?
2. Can you build 0.1mm walls with 20x aspect ratio?
3. Do you know of any DLP projectors that have interchangeable lenses?


Thanks!

Thank you for the kind words

I don't know what is the smallest but on my Optoma HD803 i can size it to approximately 10 x 7cm if i want to but you don't need to when your projector is 1080p, it won't make any difference.

I don't know about aspect ratio but 0.1mm would be too thin but if you manage to keep your supports well built i see no reason why it shouldn't be possible although i haven't tried it.

Don't know of any projector with interchangeable lenses, sorry. Haven't needed such features so far.

Thanks.

At 10x7cm that works down to ~60um pixelsize with 1080p. Nice. Can you mod the lens even further?

We need a very high resolution print but of just a few mm thickness. We use photoresist as a resin.

Can you estimate how much UV power do you project on your resin in mW/cm2? For instance the sensitivity of your resin in mJ/cm2 divided by the average exposure time should give the mW/cm2 in very approximate numbers.

I don't think you can. You probably could by extending the lens enclosure but like i said before... It won't make any difference fro the stock setup. I suggest trying to print with what is recommended first and if that doesn't work out, THEN modify the projector.

DLP projector fabricators measure the optical output in different ways and this value is not to be taken as an exact figure. In general terms, the higher the Lumen output of the projector, the faster it will cure the resin. Common values range from 2000 to 3500 ANSI Lumen. This is related to the wattage of your UHP light bulb but will also be influenced by the quality of your filters and optics, as well as if your setup uses mirrors or light-guides to redirect the projected image.

One last question.

I assume you need a PC with a graphic card that can support 1080p resolution for those projectors?

How do you create the powerpoint slides, is there slicing software that does this?

Yes, if you choose a 1080p projector you will need a graphics card that can support it. Something with DVI or HDMI output. The MiniITX computers in the shop do support up to 2 1080p projectors.

There is a short mention of how to create a slideshow in the documentation, under the MACH3 setup instructions.

Basically you need a slicing software like the Creation Workshop (available in the Files section) or similar, which shall be able to export slices into PNG images. After you have those images, you simply create a new slideshow in PowerPoint and import those slices.