Welcome to the SeeMeCNC Community

So,

The other day (8/12/2014) steve and JJ and guanu and I were talking about printing LARGE parts with a resin printer, and the difficulties with tilting a vat of platform with a large surface area.

Then

....


Steve came up with the idea of curing 'sections' of the layer one at a time, with a lift sequence between, so that the surface area of the cured resin that is trying to stick to the vat would be minimal. Effectively the sticking force would be minimized by only curing a small section of the layer at a time. Instead of curing a whole 100 square mm layer in one 'shot' why not cure 5-20 sqaure mm areas each, which would have the effect of 20% of the sticking force of the one large part! Then, we came up with concentricly offsetting the perimeters of the parts inside themselves, so that the last 'layer' or cured area would be the outermost section of the print, that way theres no blending or visible blemishes from the multiple cured areas. So imagine rings of a tree, with a software setting to specify the maximum square area to allow to be cured at once, and the software would generate 'rings' around each part, up to the max surface area, and print those areas before moving up to the next layer

That, is a good idea right there,

Thoughts???

By noon today, 3DSystems will have filed a patent on this.

Hence, my edit with the date first conceived Trivial I know, but just in case

I think the idea is sound; however, my thoughts that all of this is software driven. I'm dying to get into this more...

I think that's a great idea. Partial curing is used in the Helios though I don't know if that is laser or DLP based.

Do you think this will drastically increase build time? You'd be lifting far more often, which means more time spent lifting, increasing print time, right? Or did I misread something?

John, I'm dangerously close to attempting my first print on DropLit. I know "0" about this format of printer! I've not had time to do the research myself so...

What is the purpose of tilting the vat in these printers? Is it to allow the part to release from the "non stock" surface with less force, to agitate the resin, a combination of these, or something completely different?

Cheers,
Michael

Just to release the part from the vat.
Even with the nonstick surface you have the vacuum between the part and the glass, if the ares is small enough it's a none issue, but for larger contact areas, you need to peal it off. Hence the tilting or sliding mechanisms various machines use.

What about a clamp system on the vertical shaft thingy? A thumb screw?

The idea of curing and lifting in sections would probably work, but it will *dramatically* increase print time. It's linear...if you break a layer into, say four sections to be cured individually, you're multiplying your print time by four. I mean, you could do that...or you could add a tilt mechanism.

Since many resins have greater tensile strength than shear strength would rotating the build vat allow a cleaner separation from the release layer in the vat? Or do the release materials work so well that it is a matter of suction making the separation a problem?

This is a very stupid idea amd probably very impractical but here goes.

If you could design the part in such a way as to have a channel or channels inside, then you could pump the fresh resin from the top of the part through the part all the way to the bottom. The pressure on the bottom would facilitate lifting the part and braking and connection to the vat (both hydraulic pressure wise and any connection formed during curing.