procedure(s) for determining exposure time

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sitzme
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procedure(s) for determining exposure time

Postby sitzme » Tue Jan 21, 2014 10:06 am

There are probably a couple ways of going about this. Some folks are using timed exposures on a drop or puddle and measuring the thickness of the exposed resin. I spaced a couple pieces of glass and tested the bond at the layer thickness and exposure that I calculated. This is one part of the build process that is important and it might be good to document successful methods here. Is anyone doing anything different in this area? Any rules of thumb when changing layer thickness?

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PacManFan
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Re: procedure(s) for determining exposure time

Postby PacManFan » Tue Jan 21, 2014 10:37 am

Most of the exposure testing I've done relates only to my resin. I'd like to come up with some sort of calculator that can help people determine a good ballpark figure for determining exposure time given a resin type, lamp lumen output, and layer thickness. I think in order to determine this equation, I could start by graphing/ plotting actual determined times.

sitzme
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Re: procedure(s) for determining exposure time

Postby sitzme » Wed Jan 29, 2014 10:47 am

I took a print setting found on the net and came up with 82.48 lumins per cm^2 per .075mm thickness. I used it as a starting point and it came close. I think that the value will vary depending on the resin but with my limited experience it seems to be linear. I tried to post my spreadsheet but got an error message. I used it to compare printers and print times, etc.

johnrpm
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Re: procedure(s) for determining exposure time

Postby johnrpm » Thu Jan 30, 2014 4:05 am

sitzme
What file extension did the spreadsheet have, csv,xls, we can check to see if settings allow it.
Random Precision

sitzme
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Re: procedure(s) for determining exposure time

Postby sitzme » Fri Jan 31, 2014 10:34 am

The file has been added. Thanks John.


It was .xls. I thought about posting the results as .csv but thought that people would have more use for the formula. As you can see it is pretty simple.
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3D DLP print time estimate.xls
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Thiengod
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Re: procedure(s) for determining exposure time

Postby Thiengod » Sun Sep 20, 2015 4:31 am

It not right with my printer
i use Viewsonic PJD 7822HDL with 3000 lumins
My build area X:116.47 Y:65.69
It use 17s to cured 0.05mm (Makerjuice SF Green)
It so long with cacutalor

Sorry about my english

sitzme
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Joined: Wed Dec 04, 2013 12:19 am
Location: Colorado

Re: procedure(s) for determining exposure time

Postby sitzme » Fri Sep 25, 2015 11:36 am

Is your color wheel still in place? My estimates were based on Sub G resin and there may be a difference.

Thiengod
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Re: procedure(s) for determining exposure time

Postby Thiengod » Tue Sep 29, 2015 12:35 am

I use projector without any modified. It may be a difference with your estimates. But it take a lot of time to cure