First Run with the new Tophat

[Rkapple]

I'm not completed yet but I had to try the new top hat out to see if it is going to work, pleasantly surprised to see how the material spins out into the collection barrel. I have to try and figure out where the optimum position for the outlet is in relation to the baffle. One thing I have noticed is that there seems to be a very appreciable drop in air flow before and after the separator and I seem to recall retired2 mentioned this could be a fairly significant drop. What are people out there finding in term of loss going through the separator? I would really appreciate any comments.
I was able with my poor pea sized brain to make a short video of the separator which, if the stars all align, you make be able to find at the included link. :)
Thanks to Phil for this very interesting concept.

http://www.youtube.com/watch?v=P-oyF5klvNE

[Rkapple]

I am making headway with the top hat. I made the top so I could easily remove it. I have played around with the height of the outlet in relation to the baffle and found about three inches off the baffle seems to give me the best results in terms of air flow. I didn't like the size of a manufacturer bell mouth as I suspect the wide flange could introduce a disturbance to the air flow. I made my own bell mouth from MDF and it only projects 1 3/8" from the side of the outlet yet it does basically shape a 45 degree angle which serves to reduce inlet pressure loss. The bell mouth does seem to relieve at least some of the loss through the unit.

[BernardNaish]

I love the bell mouth and the ability to remove the top plate. How do you seal the top plate?

[tvman44]

That is some fancy looking separator.  Sure makes it easy to experiment with.  :)

[Holbs]

I was going to purchase a 7" bellmouth from penn state..but has been forever out of stock.  might have to go the DIY bellmouth.  could you go into more detail about how you created your own?

[Rkapple]

Bernard - I didn't seal the top the MDF and the Acrylic top fit very cleanly and I could see no signs of any leaking - I am thinking when I am finished playing around I will run a bit of silicon around the top - let it dry and then it would basically act as a gasket when I snug the top down.

Holbs it didn't take long to make up the bell mouth - but as I think about it I have accumulated quite of whack of tools etc over the years. So I didn't have to make anything or buy anything. Anyway here is what I did.
I laminated two thicknesses of MDF and then found the centre.
I drilled an 1/8" pilot in the middle to centre my circle cutting jig - I have a small one I made that I mount on a laminate trimmer
I cut the outside perimeter first and made it 2 3/4" larger than outside pipe diameter - but the way when I drill the pilot hole I drill it on the drill press so it is dead vertical and then you can cut from both sides and everything lines up where the cuts meet.
I then routed the centre out - on one side I routed about 3/8" deep to the circumference of the outside diameter then I flipped it over and routed the balance out to the inside diameter - this created a lip for the pipe to seat against and the bell mouth is flush to the ID of the pipe.
I have quite a pile of router bits and I used a larger round over bit and a chamfering bit to get close to the interior profile and a bit of sanding smoothed the profile
On the outside I just flipped my bandsaw table to about 40 degrees and cut it free hand and tidied up the cut with a random orbit sander. It really didn't take that long
These are the bits I used and my laminate trimmer jig --Good luck :)