Baffle installed inside a Delta 50-850

[expo]

This weekend, I upgraded my Delta 50-850 by adding a Wynn 35A100SBOL poly filter as well as Phil's baffle.  Overall, things went smoothly for the baffle install.  I had more grief figuring out how to attach the filter to the DC (the turnbuckles Wynn provides are too small).  I finally decided to use bungie straps on the outside as someone else here had reported.

I fired up the new configuration last night and gave it a whirl (so to speak).  Overall, the suction is much improved over the previous clogged 30micron bags.  I'm using the clear lower bags that Wynn included with the filter so one gets to see the wood chips swirling off the baffle.  I do see some swirling dust down into the bottom of the bag even when no new chips/dust are being pulled in, I assume this is what is termed "scrubbing?"

After collecting about ~2gal of chips, I took off the cannister and peered inside.  Its not spotless, by any stretch of the imagination, but its nowhere near clogged.  Since I dont have any experience with running the cannister without the baffle, I cannot say what it would have looked like without it.  I know that with my old bags, they were covered in caked up dust...

I know this post is somewhat vague, but does this seem to be typical performance?  Just trying to determine if I need to tweak anything to reduce the amount going up into the cannister...

Thanks

Andy

[Vaughn]

I haven't looked at my filter since adding the Thien baffle to my Harbor Freight DC, and it had been used for over a year without one, so it already had been caked and cleaned a few times. That said, before I had the baffle, 2 gallons of chips and dust would have put enough in the canister to where I could hit the sides after turning it off and see stuff falling into the lower bag. It sounds like you only had a light dusting inside the canister, so I'm betting you're getting results similar to the rest of us. Even without the baffle, your lungs will be thanking you for the switch to the Wynn filter instead of 30 micron bags.  ;) With the baffle, you won't need to clean the filter NEARLY as often. (At least that's been my experience.)

[expo]

Yeah, I totally got the Wynn filter to improve the capture efficiency of the fines.  I'm definitely already seeing huge improvement there.   :)

Like others, I decided to try Phil's Baffle design primarily to cut down on the amount of material getting blown into the canister to 1) reduce the frequency of cleans 2) protect the filter from getting damaged by wood chips.  What is saw inside the filter was mostly fines, with a few larger curls...

So is it typical to see a little vortex/tornado of fines swirling in the bottom collection bag?

How snugly should 120deg portion fit against the side of the DC?  I got it really close, but I wonder if it would benefit from a strip of small weatherstripping to seal it tight?

[phil (admin)]

It should fit snugly, but weather stripping isn't necessary.

The baffle needs to be BELOW the inlet, not above the inlet.

For best performance, the ring of the DC should have a funnel with a 6-8" opening in the middle.  If there is no funnel, you can make an outlet tube.

When testing the unit, it is important not to feed material at an abnormally high rate.  No cyclone works well when "stuffed," they all need an adequate ratio of air to debris in order to separate.  Dropping a hose into a bag full of sawdust isn't a good test.

It may make sense to post an "above" and "below" picture of what you have so I can make sure there aren't any problems.

[expo]

Thanks Phil..

The baffle is about 1" below the inlet of the DC ring.  There is also a funnel incorporated in this design.  I dont recall exactly what the ID of this funnel is, but I can measure tonight and post pictures.

I dont think I stuffed the DC during my test, but admittedly it was a contrived experiment (I poured abotu 2gal of chips on the floor and sucked them up over 2min or so).  This weekend I'll get a chance to run the DC using real world conditions...

Andy

[bennybmn]

Seeing some dust swirling around in the bottom of the bag is OK I think. The "scrubbing" effect is when the bag gets fuller,(is that a word?), that swirling is much higher in the bag, and can kick dust up into the upper bag/filter, ADDING to the clogging, impacting suction, etc. So the baffle prevents true scrubbing, but there's always going to be air movement which may swirl some dust around.

[expo]

I took pictures tonight... the funnel has an opening of 11.5" ID.  The DC ring itself is about 19.5" OD.  Here's two images showing the relationship between the inlet and the baffle:




I also took pictures of the amount of dust/chips in the filter as well as the bag so you can see the relative amounts.  Here's the total amount of chips I vacuumed up in my experiment:



and here's a view of the chips that lodged in the filter:


Keep in mind this was a brand new filter...

[phil (admin)]

Interesting, the amount in the filter does seem on the high side, with large chips, too.  Looking at the baffle, the gap between the baffle and the ring seems smaller than 1-1/8".  Is that just an optical illusion?

You may need to run it real-world for a little while to get a better feeling.  You can always adjust the size of the drop-zone on the baffle, and/or add an outlet tube (6-8") down the center of the funnel.

[expo]

the gap is 1.125"... must be a illusion...

I think I'll run it this way for awhile... If I were to make an outlet tube, would you suggest making a giant mdf "washer" which would fit in the top of the DC ring and then attach the outlet tube to that?  how far down should that tube extend into the DC ring?  How far up into the canister filter should it go?  I assume this could significantly lower the CFM since it would restrict the air trying to escape through the canister filter.

Also, any guidance on adjusting the drop zone?  I assume you mean make it bigger than 1.125"?

[phil (admin)]

the gap is 1.125"... must be a illusion...

I think I'll run it this way for awhile... If I were to make an outlet tube, would you suggest making a giant mdf "washer" which would fit in the top of the DC ring and then attach the outlet tube to that?  how far down should that tube extend into the DC ring?  How far up into the canister filter should it go?  I assume this could significantly lower the CFM since it would restrict the air trying to escape through the canister filter.

Also, any guidance on adjusting the drop zone?  I assume you mean make it bigger than 1.125"?

Lots of creative ways to make an outlet tube w/ donut that sits in the funnel.  An 8" tube that sticks 1" below the current level of the funnel would be ideal.  Yes, it will reduce CFM, but not as much as you'd think.  Yet, there are no free lunches.   ;D

The drop done can be expanded beyond 1-1/8" if you're finding lots of larger shavings up in the filter.  Larger shavings in the filter often indicate that they're coming through in clumps that are too large to fall through the zone (especially if you work w/ lots of soft woods).  In those cases, increasing to 1-1/2" can be helpful.

But like you said, I'd run w/  it as-is for a while.

[bennybmn]

the gap is 1.125"... must be a illusion...

Sure you made the gap 1.125 and not the diameter 1.125 smaller?

[expo]

You almost got me!  I had to think twice, but then remembered I used a shop-built trammel, and i reduced the radius by 1.125...

[bennybmn]

 ;D

[Greg McCallister]

Expo,

The pic posted is something I wonder if anyone has ever tried.
Not the best as far a drawings but I think you can get the concept.
It could be considered as a neutral vain but not quite.
If the inlet to the separator were to be taken from round to a rectangle it would cause the air stream to ride the side of the cylinder. Also if it is pointed downward at a slight angle, it would cause the debris to enter the bag instead of the filter.
This is my logic on this - when a round stream hits into a flat surface the air stream will mushroom out pushing the stream upward, downward and inward. If the stream is forced to ride the surface sort of in a flat stream it will reduce or eliminate the mushroom effect, thus causing the debris to drop downward past Phil's baffle and into the bag, allowing much better separation.
Also note the position of the outlet is at the end of the baffle solid area instead of the beginning. I did this on my top hat version and seems to work great.
I hope this make sense...

[bennybmn]

Interesting idea... I think the main concern would be maintaining the area of the tubing when transferring it to rectangular.