Modifying my old Grizzly DC

[john t]

I have a 1980's four bag, 3hp DC similar to the 1030 model now being offered. I upgraded it with felt dust bags on the top and plastic collection bags on the bottom. Now I'd like to add Wynn filters and thien baffles as described in a 2012 article in FWW.  However the 19.5" diameter rings which hold the bags don't seem to lend themselves to the modifications described in the article. Mine each have a 5x5 inch inlet from the fan which open just above a downward sloping cone in each ring. These cones have about a 12" hole in the middle. If I install baffles just below the inlets and above the cones there would only be about a 1/2" clearance between the baffle slot and cones. Not good. I could drill out the spot welds holding these cones which would give me two nice clean 10" or so deep rings to convert to thien separators. Has anyone ever done this? Will it ruin the function of my DC (can't afford a new one and the SWMBO wouldn't let me buy one anyway)? What is the purpose of these cones? Thanks for any advice you can give.
John

[Schreck]

As far as I can tell, the purpose of the cones is to make sure the dust falls into the center of the bag  ;D

The cone does add strength to the ring, so complete removal is probably not a good thing. Consider swapping the two rings and installing them upside down.  This would place the inlet below the cone and allow a baffle to be installed.  If the cone extends up too far past the ring, it may need to be trimmed in order to fit the Wynn filters. 

Here is my 2-bag Grizzly from the 1980's; my plan is to flip it upside down.

[phil (admin)]

I think those rings come from a time when Asian manufacturers were trying to copy what they had seen elsewhere, with no real understanding of WHY things were put together like they were.

Some have reported that the welds don't even need to be drilled-out, that you can pop the spot-welds with a screwdriver or something else used to pry a little.

If you can get the cones out, you could make a plywood donut to sit on the top, and then the filter could attach to the donut.  The donut would have an outlet tube the size of a large (old) coffee can sticking down into the ring.

Use Google to find images of "wynn filter donut" to see what I'm talking about.

Like this:
https://www.google.com/search?q=wynn+filter+donut&source=lnms&tbm=isch&sa=X&ei=M5YLUvTkEsSr2wWe3IG4Bw&ved=0CAcQ_AUoAQ&biw=1600&bih=1065

[john t]

Thanks for the responses. The rings are 11" deep and made of some pretty heavy gage steel. The cones are force fit and could be removed by popping their spot welds where the sheet metal is joined. I'm gonna remove them. The 5x5 inlet is about 1.5" from one open end and about 4" from the other open end. Which end should the baffle go on? I can mount them either end up.
I'm assuming a 6" dia. outlet into the filter area is sufficient since it about matches the size of the inlet, yes?
Lastly, I have a 2 branch, 6" piping system. My DC has bags for collection. They fill up very fast and are difficult to empty. My Jointer and planer are on one branch. I'm thinking of adding another Thien separator with a big barrel to that branch to ease the collecting/emptying problem. From this separator the flow would go directly to the DC with no tools in between. Any opinions on if this will work or would I so reduce the airflow that it would be unworkable? Thanks again for your help.

[phil (admin)]

(1) You can go even larger than 6".  8" or 10" would offer less resistance (a good thing).

(2) Adding a separator in front of the large chip producers is something I've advocated for a long time.  It will put a hit on your CFM, but collection from the jointer and planer should still work fine.  You will have an easy to empty drum.  And when you are using tools that produce fines (that are on the other branch of your network), you have no separator in front and get maximum CFM.

[john t]

Thanks for all your great information. I removed the cones today w/o much difficulty. Since the inner surface of the rings is not perfectly smooth, I'm going to line it with sheet metal. Judging from these posts, smooth is very important. The 5x5 inlet is about 1.5" from one open end and about 4" from the other open end. Any thoughts on which end the baffle should go? I can mount them either end up. I will try to take some pics of this remodel and post them. Thanks again for your help.

[phil (admin)]

(1) Install the rings with the inlets UP (towards the top of the unit).

(2) You don't need to line them with SS, they are smooth enough as is.