5", Rectangular Inlet, Bellmouth Outlet with Air Straightener, Top Hat Separator

[retired2]

All credit for design goes to Retired2.  Amazing build!

I'll take credit for the "amazing build" and some mod's, but the concept is Phil's.  Without his work and ingenuity, I'd be like a lot of others on this forum, i.e. cleaning up dust and wood shavings with a 24" push broom and a snow shovel.

[sk1pp3r]

Fair enough.  Credit to Phil as well although that's a given seeing it's his site and all the research he's done.  ;D

Here is a start. Those silly curves are no joke in sketchup.  ::) I have the 1/8th offset and will make a note to make the end of the curve on the left of the intake tighter, like Retired2 did, to decrease turbulence.

[sk1pp3r]

OK, Here it is.  I'm still creating scenes to show the measurements in an easy way.

I included more support on the bottom underneath the baffle so you don't need a support rod.  Someone on here earlier did that I think but can't remember their name. 

Currently the bellmouth outlet pipe is 3.75 in from the top.  Looks like 3" produces better numbers.  I'll update that in the sketchup file. 

I tried to create an irregular curve on the bellmouth, after reading the article Retired2 posted, but it's not very noticeable here.  I did a 9" circle for the bellmouth, I'm not sure the actual diameter of the one Retired2 used.  This looked about right.  I have yet to add the air straightener but it will be an easy fix.  Any final suggestions on what distance it should be from the opening of the bellmouth, or how far it should travel up the outfeed pipe?



From the bottom you can see the extra support.  The left side under the baffle could be beveled to ease airflow but I was really having trouble trying to do this in the sketchup file. 


Here is some detail from the inside looking at the inlet.  You can see the Lexan that is recessed in the frame on top and the ends.  It seems the consensus is Lexan and not acrylic. (I think I said that right).


If anyone has any suggestions to add to the file before I finish it let me know.  I'm going to add little dimension tabs in each scene so there is more clarity for others trying to build this design.  Many Thanks again to Phil Thien, Retired2, Plauale, and any others I forgot!

[retired2]

Nice job sk1pp3r!  I envy your sketchup knowledge, I wish I had the time to learn it, but the last thing I need in my life right now is one more piece of software.

[sk1pp3r]

Thanks!  I envy your knowledge to do the testing, a lot of which I don't understand.  I'm learning more and more every day but still have a long way to go with engineering.  I somehow skipped physics in high school and college, while becoming a physician assistant, so I started on Khanacademy last week.

[BernardNaish]

Nice work. The bellmouth should idealy have an eliptical shape. See:

http://www.jpthien.com/smf/index.php?topic=1098.msg5988#msg5988

There is something to be said to make this a 1 1/4 or 1 1/2 top hat. EG height of chamber is inlet height x 1 1/4 or 1 1/2. Its thought this may help separate fines.

Are the sketchup files available?

Good luck.

[sk1pp3r]

Nice work. The bellmouth should idealy have an eliptical shape

Thanks BernardNaish.  That's exactly what I was trying to say when I typed "Irregular Curve".  I just couldn't find the words at the time  :-\ 

There is something to be said to make this a 1 1/4 or 1 1/2 top hat. EG height of chamber is inlet height x 1 1/4 or 1 1/2. Its thought this may help separate fines.

It is just as you describe.  I wasn't aware of the suggestion you posted but was merely following the dimensions posted by Retired2. You guys know way more about this than I do.  I'm just trying to post some directions on making the thing haha. A picture is below.  My inlet is 4" and the outlet is a 5" circle to connect to my Harbor Freight DC. 


The Sketchup file was too large to attach here so I had to share the link below:
Retired2 Thien Dust Separator by Justin Hill

[retired2]

Sk1pp3r,

Here is a link to a table with dimensions for off-the-shelf bellmouth fittings.  I'm sure Bernard is right that an elliptical corner is optimal, but I'm pretty sure the stock fittings will yield most of the benefits.

[sk1pp3r]

I missed the link

[retired2]

I missed the link

Oops!  Try this:

http://www.spiralmfg.com/hoodsf.htm

[ORBlackFZ1]

OK, Here it is.  I'm still creating scenes to show the measurements in an easy way.

If anyone has any suggestions to add to the file before I finish it let me know.  I'm going to add little dimension tabs in each scene so there is more clarity for others trying to build this design.  Many Thanks again to Phil Thien, Retired2, Plauale, and any others I forgot!

Thanks for posting the Sketchup drawings.  They look very professionally done.  My Sketchup drawing is not as well done as yours, but I would be happy to post it if it would help. 

Here are a couple of details that I included on my 6" Top Hat build, that you might be interested in:

1.  a lip, the thickness of the Lexan, right below it.  This keeps the Lexan from slipping down and provides a nice shelf to set it on when assembling.

2.  a notch, for the Lexan to slide into on both ends.  This keeps the Lexan from slipping out of place and really makes assembly easy.  The notches were chamfered at a 45 degree angle on the outside edge to minimize the air flow disturbance.

3.  a strip of 1/16" X 3/4" red oak.  This strip was glued to the bottom lip the lexan was sitting on.  It overlapped the Lexan approximately 1/8".  The top edge was chamfered at a 45 degree angle.

4. a notch in the top to hold the Lexan in.

Including notches for all sides of the Lexan, created a leak-free Top Hat for me.  I did not have to apply any adhesive to seal any of the Top Hat.

It is always educational for me to see how others tackle a problem, so make sure that you post some photos during your build. 

Thanks and have fun,
Eric

[sk1pp3r]

1.  a lip, the thickness of the Lexan, right below it.  This keeps the Lexan from slipping down and provides a nice shelf to set it on when assembling.

If you look at the sketchup file it does have a little lip.  You may be able to see it in the inlet detail picture above.  In my case though, the lexan is only 0.08, instead of 1/8in thick, so I had to change the diameter of the outer baffle circle to accommodate it. I also have the notch in the top for the lexan which you can see in the sketchup file.  It is .25 inch deep. I like the idea you posted though about the chamfer and oak piece and may incorporate that. 

Anything to make it leak free, thanks for the tips!

[DominicG]

Thanks to all who participated in this thread. Especially sk1pp3r for the Sketchup model. Using rough dimensions from that model helped me design my own. I drew up mine in AutoDesk Inventor.

Once I get the drawings all finalized I will post a link to a PDF version of them.


I also need to find an economical (and local) source for 5" or 6" flex hose and light wall pvc sewer pipe. This separator isn't going to do much good unless I can connect it to my DC. And that has a 5" OD inlet.

[DominicG]

OK, I finished the layout for my separator


This will be hooked up to my Penn States 1HP DC1B. I have a very very simple, short run of (2) 4" dia PVC pipes that can be hooked to my bandsaw, tablesaw, lathe (when sanding), surface planer or jointer via a short run of flex hose. None of y tools are more than 12 to 15 feet away from the DC. This system works OK with my current rather inefficient trashcan separator. So I'm pretty sure the installation of this new separator will be an improvement.

My new Separator has a 5" air inlet since my DC has the same size. As I mentioned before, I need to find a source for 5" flex tubing or just use 6" (which I'd rather not do). If I can't find 5" PVC tubing, fittings, and flex hose, I may end up using 5" HVAC fittings. Not optimal, but better than nothing.

Like the model shown in this thread, the dust inlet for the separator is 3 7/8" x 5 7/8". I have a 4" round to rectangular transition shown in my model.  Unless someone tells me that'll cause unending problems, that's what I planned on using.

I planned on buying a HVAC fitting and modifying it to fit, making my own transition, or finding someone to make it for me. I have AutoCad Inventor and their sheet metal package does a nice job of providing flat layouts on sheet metal components.

Any comments?

[ORBlackFZ1]

DominicG:

Thanks for posting the Sketchup drawing. 

Regarding: "My new Separator has a 5" air inlet since my DC has the same size. As I mentioned before, I need to find a source for 5" flex tubing or just use 6" (which I'd rather not do). If I can't find 5" PVC tubing, fittings, and flex hose, I may end up using 5" HVAC fittings. Not optimal, but better than nothing."

Here is a thread that I started from another forum (http://www.woodworkingtalk.com/f32/pipe-diameter-vs-performance-59625/index2/).  Here is the text: 

"Grizzly has good prices on their flexible hose. I am very pleased with the 5" and 6" diameter hoses that I received from Grizzly. They are very good quality. I would not order 5" and 6" diameter hose from Woodworker's Supply again. They are ok, but they are definitely less flexible than Grizzly's."

http://www.grizzly.com/products/5-x-10-Clear-Wire-Reinforced-Flexible-Hose/W1035

Here is another link for you: http://www.woodworkingtalk.com/f32/4-dust-collection-flex-hose-64176/.  Here is the text:

" Here are some of my favorite places to get anything related to dust collection (in alphabetical order):

1. Grizzly (http://www.grizzly.com/)
2. Harbor Freight Sales (http://www.harborfreight.com/)
3. Rockler (http://www.rockler.com/)
4. Woodcraft (http://www.woodcraft.com/)
5. Woodworkers Supply (http://woodworker.com/)

2 thru 5 have retail stores in my area (Portland, Oregon). All of them have web sites that you can purchase from.

Try using Google with the "dust collection flexible hose" search phrase."