Ah ha ha, I bought a Pro Cinema 1080 UB used for $600. Ok with an all black screen up I could see six of more Spalding sized dust blobs. I worked for Optoma and had to open a couple of hundred projectors to input a video upgrade to the video board which made the panning on certain movement up to the level and the DC3 H79. Anyway it was easy opening up the 1080ub.
You remove all the bottom screws and the small black screws on the back input panel. The top prys up real easy from the back to the front. You then remove the ribbon connector to the video board and take the whole top off. Man I had cobwebs in there and a bunch of dust. I used a vacuum we have that has a power slider so I didn't hv to use full power. If you don't have one just stay a half inch off of everything. I also used a lint free cloth to clean all the dust on under the top cover and used the vacuum on it afterwords.
Oh did I fail to say after I was done I put up a full black video pattern and there wasn't one dust blob / zero gone.
I moved the ribbons loops away first and used the vacuum cleaner on each panel.
I made this air puffer from a solder sucker, had to drill the tip a bit wider to fit a piece of a clean air blower nozzle tube. About 1 and 1/2 inches length outside the blower nozzle
I used this last and shot about 4 puffs down into each side of each panel. You'll see the ribbons for each panel and an opening. Just move back the loop from each panel and slide the nozzle in the 1 & 1/2 inches and puff away them specs of dust. An hour and a half told buy Epson my butt. It takes like 10mins.
So if the blobs on your 1080ub are getting you down give this a try.
Another tip, don't ever vacuum the ehaust vent. This just sucks dust all around inside the projector. I did this when I had just 3 dust blobs and ended up with six.