Trouble Curing SubG+

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kakapoopie
Posts: 115
Joined: Sun Jun 15, 2014 8:49 am

Trouble Curing SubG+

Postby kakapoopie » Tue Jul 08, 2014 7:31 pm

Hi all, I'm having trouble curing SubG+ :(

As a test, I'm putting a drop of resin on my build platform and waiting for it to cure with the projector at full blast white, on the bright setting (308W). I've left it for over a minute and it's still soft. If I hold the drops a few inches away from the projector, they will cure in a few seconds, but the projector can't focus that close.

From the build plate to the projector is about 10" with a 45* front surface mirror. Top down build.


The projector is an Optoma HD2200. http://optomausa.com/support/discontinued-products/detail/HD2200#

Am I doing something wrong or is the projector just not putting out enough UV?

Thanks,
Vaughan

hp_
Posts: 300
Joined: Tue Dec 24, 2013 10:25 am

Re: Trouble Curing SubG+

Postby hp_ » Wed Jul 09, 2014 4:29 am

Hi,

from what i hear, Projectors must have 2200 Lumen or more to be effective..

your projector is 1900 ANSI lumens.


Kind regards,
hp

kakapoopie
Posts: 115
Joined: Sun Jun 15, 2014 8:49 am

Re: Trouble Curing SubG+

Postby kakapoopie » Wed Jul 09, 2014 4:46 am

Bummer...I guess I will try pico with UV led then...

Finhead
Posts: 276
Joined: Fri Jan 31, 2014 12:56 pm

Re: Trouble Curing SubG+

Postby Finhead » Wed Jul 09, 2014 10:13 am

That's not actually correct, I have a test bed with a Optoma HD65 which is 1600 lumens with a end of life lamp and it will cure resin fine. It did however need a mod to focus closer and the color wheel removed or it would not cure resin properly.
So OP if you haven't removed the color wheel I would do so, you need to remove it from the light path and still have it connected and working. I was able to place mine to the side and fasten it down out of the way.
Also what is your focal distance for the resolution you are trying to cure? I found I had to put a spacer between the inner and outer lens to shorten the distance, it was over 300mm focal now around 250mm which made a very big impact in exposure times.

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PacManFan
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Re: Trouble Curing SubG+

Postby PacManFan » Wed Jul 09, 2014 11:13 am

Finhead wrote:That's not actually correct, I have a test bed with a Optoma HD65 which is 1600 lumens with a end of life lamp and it will cure resin fine. It did however need a mod to focus closer and the color wheel removed or it would not cure resin properly.
So OP if you haven't removed the color wheel I would do so, you need to remove it from the light path and still have it connected and working. I was able to place mine to the side and fasten it down out of the way.
Also what is your focal distance for the resolution you are trying to cure? I found I had to put a spacer between the inner and outer lens to shorten the distance, it was over 300mm focal now around 250mm which made a very big impact in exposure times.



In addition to what Finhead mentioned about the color wheel and projector mod, go through the optic path and see if there are any other UV blocking glass sheets that can be removed.

kakapoopie
Posts: 115
Joined: Sun Jun 15, 2014 8:49 am

Re: Trouble Curing SubG+

Postby kakapoopie » Wed Jul 09, 2014 5:16 pm

Ahh, thanks for the info guys. Maybe I'll try to find a broken projector online (or pico) to salvage, dont want to wreck this one. Also I have an old LCD screen lying around I'll test if that will let UV light through.

Phife
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Joined: Fri Jan 17, 2014 5:24 pm

Re: Trouble Curing SubG+

Postby Phife » Wed Jul 09, 2014 8:06 pm

kakapoopie wrote:Also I have an old LCD screen lying around I'll test if that will let UV light through.


It wont..dont bother.. ive spent nearly 2 years researching LCDs for 3d printing.. its not a simple task but it can be done. If you dont have a decent budget then stick to DLP until i release more info on the LCD mask based printer. Basically, you'll need a special LCD and custom optic system.

kakapoopie
Posts: 115
Joined: Sun Jun 15, 2014 8:49 am

Re: Trouble Curing SubG+

Postby kakapoopie » Wed Jul 09, 2014 8:27 pm

ah well, thanks for saving me the time. I'm still interested in Pico though...do you think its better to just usea 20W UV in or 3 5w leds where the old ones were?

android78
Posts: 41
Joined: Sun May 18, 2014 10:33 pm

Re: Trouble Curing SubG+

Postby android78 » Wed Jul 09, 2014 11:46 pm

Has anyone managed a mod of a mercury lamp projector to use UV LEDs? Even giving the LEDs their own power supply, I guess you'd have to trick the projector into thinking the lamp was still connected, but there should be a way.

Regarding the question about single or multiple UV LEDs, I imagine the best is to remove the dichroic mirrors and use a single LED, but I'm not expert.

dlp_builder
Posts: 19
Joined: Tue Feb 25, 2014 5:56 pm

Re: Trouble Curing SubG+

Postby dlp_builder » Fri Jul 11, 2014 11:09 am

Hi,

My infocus X9 is only 1800ansi lumens, and what is more important, my bulb is 180Watts
It cures my resin, Funtodo, perfectly within seconds.
Your projector has much more! 230Watts (about the same as the B9)
Your problem is the throw distance, you have to have the distance to the resin at max 25cm (prev. 20cm)
else you won't have energy left to cure anything.
Best is to try to modify the lenses by the use of a spacer so the distance between the first an the second lens gets bigger.
Removing the color wheel or other pieces of glass between the lamp and the dlp chip will shorten the life of the chip significantly (because it doesn't like the UV light and the hinges of the little mirrors will fry)

Hope this helps!

dlp_builder
http://www.funtodo.net

hp_ wrote:Hi,

from what i hear, Projectors must have 2200 Lumen or more to be effective..

your projector is 1900 ANSI lumens.


Kind regards,
hp


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