DC-1100 drop slot positioning

[morty343]

Hello,

I recently made a Thien baffle using 1/4" hardboard and installed it into the lower part of a Jet DC-1100, using a design very similar to this one:

http://www.jpthien.com/smf/index.php?topic=100.0

Mine differs in that I used four sections of 1/4-20 threaded bar with stop nuts to secure it in place, and I used foil tape on the underside of the baffle to attach/seal it to the DC wall. I also upgraded to a Wynn canister from the Jet "Dust Dog" canister that came with the unit.

It seems to work very well in preventing chips and larger fines from making it to the filter. However, the finest dust (flour consistency) seems to be accumulating on the filter, and while operating there is still fairly significant swirling action in the collection bag below. This makes me question if I properly positioned the drop slot in regard to the air inlet of the separator. It's approximately like the illustration below:



The slot width is appx. 1-1/8". On another thread, I noticed that someone had added a short piece of duct that extended into the separation chamber. Is this something I should have done to improve separation? Or is the accumulation of super-fines on the filter simply to be expected?

Thanks!

[Dougp28704]

That is correct orientation of the drop slot. Some have made the drop slot wider.

[phil (admin)]

Separating the finest flour is always a challenge.  Even people with large cyclones are challenged by drum sanders (for instance).

A couple of thoughts:

The Jet DC-1100 can be a challenge due to the way the bag attaches to the ring.  You have to make sure that the bag holder doesn't create a "ledge" or "shelf."

An improvement which can help for the finest dust is to add a collar or outlet tube which extends down into the separation chamber from the funnel.  The rule of thumb is half the diameter.  So if you use a 6" tube, you want it to extend approx. 3" below the funnel.  Some people use empty coffee cans.  You can also experiment with foil tape and just make a 1" or 2" collar that can be easily removed, to see if it makes a difference for your install.

[morty343]

Thanks for the replies,

Phil, I'm a little unclear as to where you are suggesting a collar be added. Do you mean this (which is what I observed in another thread, in which case I assume I would need to reposition the drop slot):



Or do you mean like this:



Thanks again!

[Peter]

I believe he means the condition in your side view.

[phil (admin)]

I believe he means the condition in your side view.

Correct.

[morty343]

The diameter of the funnel hole on the DC-1100 is about 9-1/2", and using the given formula, a ~4" collar would have it against the baffle itself. I may try a shorter one to see if there is a difference. Thanks again! Morty

[lllars]

morty, did you ever try making the collar?  if so, how did it work out?

i just finished adding a thien baffle to my dc-1100 w/ dust dog filter, using the same design.  i haven't run much dust through it yet, but i've got a lot of drum sanding to do in the next few days.  if i get a lot of fine dust in the filter, i'll try making a collar.