Wanting faster curing time with my DLP printer (LittelRP) I decided to further hack my projector and remove the DLP color wheel. Here is a nice explanation of what a color wheel does and why it’s there. For DLP 3D printing, the color wheel gets in the way and (supposedly) blocks some of our coveted UV light.
Here is my poor Acer X152H, without the top cover. That red circle is the DLP wheel. We will need to disassemble quite a bit of stuff before we can reach it. Take out the light bulb, then open all those screws on the electronics board on the top right. Unscrew the lens optics housing and pry it all loose.
There is the DLP wheel, but sadly we can’t just disconnect it. The projector synchronizes the frame-rate with the rotation of the wheel, without the wheel it won’t even turn on. Our only option is to relocate it.
Since the insides of the projector are packed tight, I opted to mount it outside, glued to the top of the unit. I even covered it with a small plastic housing, so nothing would touch it. Remember – it needs to be somewhere it can spin freely, or the projector won’t function properly. Another option is to keep the wheel motor and remove the glass. I am unsure if the projector can cope with this, as the wheel will have a different mass and rotation speed.
Another thing I did at this point was to remove the bulb UV filter, which is a small glass window that sits right on the bulb itself.
EDIT: DO NOT REMOVE THE UV FILTER
A commenter has mentioned that after removing the UV filter the same lens exploded inside his projector. The UV filter acts as a heat shield, and removing it will kill your projector.
And now for the bad news
While putting everything back together, I accidentally placed the main cooling fan backwards. It was sucking air instead of blowing it on the light bulb. A few minutes into the first test print the projector overheated and shut down. Further inspection lead to a sad discovery, the first glass lens in the light path was shattered and half melted it’s way out of the plastic housing.
The projector still works, but the light output is now a fraction of what it should be, rendering it almost useless. Finding a replacement lens is impossible, I have no idea what are the required optical properties or even the overall shape. It exploded beyond reconstruction.
Honestly, I have no idea. Did the lens explode because I removed the wheel or because I installed the cooling fan wrong? Maybe it was a combination of the two? Perhaps the DLP wheel also acts as a heat shield. I really don’t know.
What do you think? If you have any ideas or questions, drop me a comment below.