Thien Baffle inside Delta 50-850 DC

[paredown]

First post--been reading like crazy. First project is to improve my old Delta that I inherited.

So far:

• Removed constrictor plate on intake
• Built baffle per instructions. I was able to use the groove rolled into the bottom edge of the separator by cutting two circles out of 5mm stock, one circle slightly larger, and laminating the two. Then cut the 240 degree drop slot. The DC is not quite round, so the slot narrows a little along one edge. but should be OK. By getting the 120 deg section into the groove, I was able to hold the baffle in place with a single edge mounted screw and finger bracket screwed through the separator side @ 180 degrees. (We'll see if this holds OK. Nice thing about doing it this way is that I can rotate the baffle for testing.
• In a longish thread Phil suggested that those of us with the 850 (because of the wide throat in the separator) might want to try adding a donut to constrict the opening:
  
  

  I am going to suggest that you guys w/ the 850's make an MDF donut with an I.D. of 8" and an O.D. suitable for mounting in the existing funnel.  Find some flat flashing/thin aluminum approx. 3" wide and wrap that around the I.D. of the donut so it extends approx. 1" below the bottom of the MDF (just staple in place).

  http://www.jpthien.com/smf/index.php?topic=178.msg1035#msg1035
  
  As luck would have it, I had some 8" round HVAC galv. pipe so I added that 3" piece to the inside of my bottom collar piece per Phil's suggestion.

I have a Donaldson P182038 on order for the top (this is the heavy duty version of the 181038) and the next step is to make a mounting collar for the top of the unit. (I'm annoyed with the folks I ordered from--day three and not shipped despite the claim that it was "in stock".)

So my question--does it make sense to continue the same 8" pipe directly into the bottom of the canister filter?

Since the OD of the filter (17.58") is smaller than the ID of the top of the separator (~19.5"), it will be inset from the top. Some people have done a base ring, and then a second narrow outside ring to constrain the canister. (or blocks to do the same).

What I imagined would be efficient would be to make the 8" hole in that top mounting ring, and then add an 8" HVAC take off ring (flange towards the filter, attached male connector extending down into the 8" pipe sticking up from the new collar. So the center pipe would be continuous 8" to the bottom of the filer (filter has 11" ID).

Filter would seal against the top ring, and the dust would move directly from the top of the Thien baffle to the filter, and bypass the angle pan part of the separator.

Or does magic happen in the separator to catch more of the dust and I should leave the pipe open ended at the top (1" below--3/4" ply donut, so about 1 1/4" sticking up), and cut my mounting ring with the OD to fit the top of the separator, and the ID to match the inside of the filter?

[paredown]

I put the machine back together yesterday, after re-cutting the baffle. The canister filter is delayed so I wanted to test it.

Compared to it with just the constrictor removed, it is quieter, and from a 'hand over the opening' test, it has more suction. I need to do some other work, so by the time the canister arrives, and I pull the top, I will have a good test on the separation and whether there is a build up on top of the baffle