Baffle for a 4 inch dust

[Woodcarver]

I've been reading many of the posts here and I'm quite impressed with the design and the input from everyone.  I followed the design and built a small unit with a 5 gallon bucket and shop vac ducting.  It worked very well.  Now I plan to build a larger unit for a 2HP dust collector and 4" ducting.
My question is should I still maintain the 1 1/4" gap at the perimeter of the baffle or should it be increased due to the larger ducting?  From what I have read here the gap should still be 1 1/4" but I wanted to ask before I started cutting.  The major diameter for my baffle is 22".

Thanks

[wizard of oz]

I made mine a 1.250" on a two hp. collector, and works fine.

Oz

[Woodcarver]

Thanks Wizard

I finished it up today - testing to follow.