Table saw dust hood - video

[Jon]

Table saw dust hood. By Cosmas Bauer. 6:25 video:

[metric_taper]

I purchased a commercially available overarm dust collector (Grizzly). Biggest waste of money for a tool I've ever made. Your OEM collector is very narrow at least letting you use it with only the most closets of rip fence to saw blade being in the way.
The other problem is the amount of air flow with my collector, it has a very long tube that is 75mm bore, and even with a dedicated dust collector for just this vacuum connection, through 100mm tubing, it just is too limited. I see that yours has a deflector that keeps the velocity and suction pressure up so that it can pull in the saw shavings.
The other ideas I've seen is below the saw table top, in the cabinet to have a compressed air nozzle perpendicular to the blade gullets to blow out the circulating dust right as the front of the blade drops below the table surface. I was in a wood working club a few years ago, and that was touted as a good modification. I've not done it myself yet.
I like the design of yours as it is low profile and appears to work much better then the commercial one I have.
I found a photo of the one I have, there is nothing to direct the flow of the vacuum source, and as the hood is large and wide, the velocity drops off to where it will only pull in the finest of dust.
Also, it is so large it is in the way, and I fear cutting my fingers off. So it now sits in the corner taking up space. Looks like you have some ideas to try to fix it.
Thanks for your post.