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Build Your Own SLA/SLS • Simple Light control - Page 2
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Re: Simple Light control

Posted: Thu Nov 27, 2014 2:20 am
by dpizzle
DoctorProfessorGuy,

Can you share some info on your non UV blocking polarizer?
I think these are hard to find and very expensive at decent sizes.

If you needed/wanted to, which polarizer would you be replacing, or would you do both?

Doing the math it seems about 8 3.5" lcds (iphone 4 screen) would fit within the size of a 9.6" lcd (ipad screen).
And if 200W works well enough for 9.6, you might get away with 25W for 3.5". I'd try about 10 3watt LEDs, but the more power the better.

Re: Simple Light control

Posted: Thu Nov 27, 2014 8:17 pm
by Lagom
I've gotten curing through a colored LCD with 2 x 3W 405nm LED's with 5 degree collimating lenses. It did take a minute or so to cure however.

Re: Simple Light control

Posted: Fri Nov 28, 2014 10:53 pm
by DoctorProfessorGuy
Sorry, I meant to say I have a few polarizers that at least don't block much UV light. I've recycled them from various old junk and I'm going to see how well they work and what I can actually do with my LCD once it gets here...ebay shipping... An old LCD I took apart to see how easy it was has the polarizer as a film I could peel off of the glass. If I can't to that I will use a brighter LED setup. Right now I'm concentrating on getting the software to work though, which I'm still a bit lost as to how to do.
I will be getting a ~20-40W LED as a backup though.

Re: Simple Light control

Posted: Thu Dec 04, 2014 3:55 pm
by DoctorProfessorGuy
OK, I got a 20w UV LED, I think that should be enough. Any tips as to how to modify the firmware to get this to work?

Re: Simple Light control

Posted: Thu Dec 04, 2014 5:06 pm
by Phife
Youre using the wrong lenses, 5 Degree have a very dark center, I can see it in your pictures. Also, 20w leds are not enough for a whole LCD.

Re: Simple Light control

Posted: Fri Dec 05, 2014 5:30 pm
by DoctorProfessorGuy
What about a 3.5" LCD for which the LED will somewhere around 20cm max distance from it?

Re: Simple Light control

Posted: Fri Dec 05, 2014 9:13 pm
by Phife
Please explain your setup a bit better. What LCD are you using? Color? Monochrome?

What LED's do you have? maybe provide a link?

Be happy to help you out, just need more details.

Re: Simple Light control

Posted: Fri Dec 05, 2014 9:53 pm
by DoctorProfessorGuy
Generic 20W LED, 600ma 32-34 V, and a focusing lens. Its basically the same time as you'd find on ebay. Here's either it or a similar one on ebay: http://www.ebay.ca/itm/221420907620?var ... 1439.l2649, and a similar driver: http://www.ebay.ca/itm/161289627111?ssP ... 1439.l2649.

Re: Simple Light control

Posted: Fri Dec 05, 2014 10:12 pm
by Phife
If youre using the collimating lens and reflector setup for the 20w LED's and your LED covers the entire area of the LCD then perhaps it could work. I have no idea what the beam pattern from that lens looks like.

I know that when the cheap lenses say collimating, thats not always the case. You'll need to look at the light pattern to make sure its even and covers the area you want to print on.

What kind of LCD do you have? if its monochrome then it will be much better.

Re: Simple Light control

Posted: Sat Dec 06, 2014 11:37 am
by DoctorProfessorGuy
Well that isn't exactly the lens I have but it has the same specs on paper. Anyway my LCD is unfortunately multicolored. I could not find anything monochrome at that size that had a reasonable pixel pitch, or wasn't non-graphic, was a very small OLED, or from eBay and kind of questionable. You know what I mean. I'm still searching in case I can find something. DO you have any recommendations?