Build Your Own SLA/SLS

Hey,
I'm trying to enlarge my printer. But now I have mysterious results. My prints are skew and so I tried to figure out the problem. I build just the supports of a plate but the result looks not very nice.
The only idea I have is that the power of the projector concentrate on the middle because the higher supports form nearly a circle.
Does someone have problems like that or an idea to handle it?

I'm using a Viewsonic pjd7820hd with 3000 Lumen.
The shown plate is 100mm x 120mm but the projector exposed an area of 268mm x 161mm

Regards Toby

PS: Sorry for my bad english

Hi Tony, this is the common problems with all DLPs I tired so far.
As I can understand all they have some sort of brightness concentrated in the middle and fading away to corners.
I couldn't do anything except for increasing cure time, but this unfortunately will probably burn your center area of the projection ...:*(

If you or anyone will find an alternative solution, this would be awesome to share here.

A number have users have noted this problem. One solution to this is to use a 'Mask' image to adjust your projector to an even brightness across every pixel of the image. The modifications I'm putting into Creation Workshop will allow a user to set a mask image on a per-projector basis, then use this mask image when projecting slices to even the brightness out. That is the simple part. Creating this mask image may be a little tricky because each projector is different. I think it may be possible to use the projector to project solid color pictures, then manually use a camera to take a picture of this image. After a little thresholding of the image and brightness/contrast adjustment, I think it's possible to create this corrective mask. Look for this feature in the next revision of CW.

Thanks for your replies. I read about this problem but didn't think it has so big effects.
I'm going to try to generate a mask and show the result here.

Dear Steve, I pray each day for such an option with masking solution, ))
as I print pretty vast objects and this problem drives me mad...