My Homemade Cyclone or My Version of
the Thien Separator Lid with Baffle

Page 2


lidcenter.jpgLid Baffle
The center of the baffle, lid and trash can should all be the same. I measured the circumference of the inner circle to obtain the size I needed for the baffle. The baffle should be the same size as the inner circle of the lid. I cut the lid from ¼” plywood. I used the circumference of the inner circle (50.25”) and divided by three (16.75). I marked the top of the baffle board near the edge. This can be done anywhere as a starting point.  I started at this marking and measured around the circle 16 ¾”. I placed a mark at this point. From this point I continued around the circle for another 16 ¾”. I did this another time. Now I had three marks around the circle. I needed to locate the center of the circle so at each mark I started my tape and measured ½ the circumference of the circle. At the half point a made a mark then used my straight edge to line up the two marks across from each other and drew a line. I did this for each mark. I forgot to take my camera to the garage so I don’t have any pictures of the above explanation so I hope it makes some sort of sense. The baffle should now look like the photo. Beside locating the center, the line also tell me where to cut the baffle.


marking the baffle

Next, at each line, I measured and marked 1 ¼” in from the edge of the circle. I then drew an arc at the 1 ¼” mark to 4 of the lines. I put a nail through my measuring tape and placed it at the center mark. I then used my pencil to make the arc from point to point. The area I just marked will be removed with my saw. This will form what is called the drop slot.



cut baffle


Cutting the Lid for the fittings
DON'T GLUE ANYTHING YET. I used actual dust collection fittings but I’ve also seen photos of lid where PVC was used. I used a 4” dust collection hose splice and a 4” 90 degree dust collection elbow.  I located the center of the lid the same way I located the center of the baffle. I centered the 4” hose splice on the lid and outline the hole. I made sure the circle I drew was smaller than the hose splice. I drilled a starter hole for the scroll saw blade and cut out the circle. Since I cut the circle smaller I used the spindle sander to clean the circle and slowly increased the size so the dust collection fittings is very tight and just slides into place. Remove the splice.

draw circle of elbow


Next I outlined the mark for the elbow. The elbow should be placed as close to the edge as possible. Again I drilled a hole for a starting point for the scroll saw blade.  As before I made the hole smaller than required and sanded until it was a snug fit. The elbow will be aligned to get as close to the side as possible.



test fitting the elbow


Test fit the elbow. Before removing elbow read the next paragraph.







lining up the baffle with lid The placement of the baffle drop slot and the elbow is very important.  The elbow should empty out at the start of the sold part of the baffle and not at the drop slot. Another words the end of the elbow should be set about an inch after the drop slot ends and the solid part starts. This is very important. When the elbow was in the lid, I marked where it ended on the lid. There’s a very light line near the ruler where I marked the lid.  




place lid and baffle on a piece of scrape wood

I placed the lid on a piece of scrape wood on the garage floor.  The inside of the lid should be facing up. Place the baffle over the lid. Take care in lining the two boards.


I made sure the baffle didn’t more and drill 3 starter holes completely through the baffle and top.  The holes are drill through both pieces so the hole will be aligned.  When I drilled the holes I made sure they wouldn’t interfere with any of the dust collection fitting. These holes will be later used for the screws holding the dowels between the lid and baffle. 


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