350x200 mm Build Platform, UV laser or DLP Projector?

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ave_maker
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Joined: Thu Mar 26, 2015 1:04 pm

350x200 mm Build Platform, UV laser or DLP Projector?

Postby ave_maker » Thu Mar 26, 2015 2:21 pm

Hello everyone, this is my first post on the forum and I hope we can share our enthusiasm.

I want to make a SLA printer with a 350 mm long (about 14'') build platform​​ and an approximate width of 200 mm (8' '), with the highest possible resolution and lowest build time. My idea is to print artistic pieces (like a shoe sole) with high level of detail, in both, Z and XY axis. I had thought that a DLP projector was the best option as it cures a whole layer at once, instead of the laser that must to do a raster of the entire layer. What I am not clear is whether, for a large area, can a projector guive me the resolution I need, or only works fine for small parts?
I think any of yours have had the same problem, and surely you can give me ideas about this.
If the solution is more expensive projector, would be no problem.
Can anyone tell me which is the most suitable metod for this size of piece and an high resolution? Thank You!

Zenon
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Joined: Tue Feb 24, 2015 6:37 am

Re: 350x200 mm Build Platform, UV laser or DLP Projector?

Postby Zenon » Thu Mar 26, 2015 3:37 pm

A projector will give you 0.18mm xy resolution. But you can use multiple projectors to get better resolution, though that might be a little trickier to do (aligning them properly)

dangre
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Joined: Wed Jun 25, 2014 4:20 pm
Location: SW Michigan

Re: 350x200 mm Build Platform, UV laser or DLP Projector?

Postby dangre » Thu Mar 26, 2015 4:04 pm

Ave,
The math is simple: HD projector is 1920x1080
printer resolution = (build area size / projector resolution)
350/1920=0.18mm
Dan - mUVe 1 DLP

Phife
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Re: 350x200 mm Build Platform, UV laser or DLP Projector?

Postby Phife » Thu Mar 26, 2015 5:11 pm

Sure the projector will go up to that size, while sacrificing resolution, but also light intensity. Cure times will go way up at that size. Tiling projectors is not such a good plan, difficult to implement and expensive. A Laser can be used at that size but then youre giving up speed.

ave_maker
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Joined: Thu Mar 26, 2015 1:04 pm

Re: 350x200 mm Build Platform, UV laser or DLP Projector?

Postby ave_maker » Sun Mar 29, 2015 2:14 pm

Thank you all for the answers. Now I am clear that the projector choice is the most expensive. I have seen HD projectors (4096 pixels), so I get a 0.078 mm resolution, but the cost is approximately 20,000$ :(
I think the laser choice is the most affordable for testing. While the laser is slower, there is always the option of dividing the build area into equal parts, and several lasers works simultaneously, but it's something I'll have to evaluate.
Anyone know what resolution can be achieved with the UV laser?

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odino
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Joined: Sat Dec 13, 2014 8:44 am

Re: 350x200 mm Build Platform, UV laser or DLP Projector?

Postby odino » Sun Mar 29, 2015 2:47 pm

I haven't a laser printer, but I think that with a laser+galvo you can obtain a discrete print speed.
Some time ago I have seen in action a professional/commercial galvo-laser printer (made from digital wax), with a lager build area (I think about 250mmx250mm), and it was pretty fast.
Maybe not like a DLP projector, but pretty fast. On they web site they said they could print 3000 mm/sec.

And it has a nice resolution!
Check this image (sorry for the bad focus)
This is a sample they give to me. i think it's made with wax-like material.
link to image
http://www.indiegearlab.com/wp-content/uploads/2014/04/WP_20140407_006.jpg

laser+galvo is an interesting build pattern. But I'm "to afraid" (lol yes...) to work with laser at the moment...

zerospace
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Joined: Wed Feb 19, 2014 10:13 pm

Re: 350x200 mm Build Platform, UV laser or DLP Projector?

Postby zerospace » Sun Mar 29, 2015 5:02 pm

Hi all, thanks a lot for useful info.
I'm a DLP user here, which gives me 192x108 mm build area max at 100 micron XY.

I'm also very interested in increasing build area,
anyone can please give good advice re GALVO laser setup?
some more info. - huge thanks in advance!

ave_maker
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Joined: Thu Mar 26, 2015 1:04 pm

Re: 350x200 mm Build Platform, UV laser or DLP Projector?

Postby ave_maker » Fri Apr 03, 2015 1:16 pm

Thanks odino. I have been researching these days and I have found that all DLP projectors work with a galvo laser inside, so I think the best choice is to use a projector, as the galvo laser, when performed very wide images, the laser beam is not a projected dot (because a diagonal section on a cylindrical beam generates an ellipse section) and XY resolution is lost in the image edges.
I'll take another path. I have a question about the projectors. In most cheap DLP printers, the build area is between 50 and 100 mm wide. Does anyone know what happens if you try to make a total print width of 20 mm? ¿Resolution is lost by loss of focus, or must be changed the optics to get this total build area?
My idea would be to get a high resolution XY (about 0.02 mm) into a small object, divide the piece in parts, print each piece separately, and then glue the pieces together.

I hope someone can give me some advice about this. I think it should be a good solution. Thank you !!

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odino
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Re: 350x200 mm Build Platform, UV laser or DLP Projector?

Postby odino » Sat Apr 04, 2015 3:11 pm

I think the only problem is the focus distance.
To have a 20mm wide image the projector must be very very close to the resin.
Don't know if is it possibile to have such a near projection without losing the focus.

I'm quite new in this world, maybe someone else can give you more adivice!

arlingtonarcher
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Location: Canada
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Re: 350x200 mm Build Platform, UV laser or DLP Projector?

Postby arlingtonarcher » Thu Jan 11, 2018 6:02 am

I got much information about DLP Projectors from this thread.