J. Phil Thien's Projects

One more example of why it doesn't pay to try to help people.  I'm done!

Quote from: TX_Lenador on September 29, 2020, 08:48:10 AM
@retired2 - I think I have the photo problem fixed.

Photos are indeed working.  Your DC system is an award winning piece of engineering.  I don?t think anything I?ve seen on the forum compares.  Spiral wound pipe and matching fittings.

I do have one question.  Does your wife know how much this system cost? 

Quote from: Anonymous2020 on September 17, 2020, 12:40:53 PM
Sorry to be so slow to respond.

The bell inlet is interesting.  What is its purpose and where did you get it?

The purpose of the bellmouth is to improve airflow.  There is a table of test data in the thread for my build showing airflow with straight pipe, straight pipe with air straightener, bellmouth pipe, and bellmouth pipe with air straightener.  The latter provides the best airflow.  And TX_Lenador is correct, unless you have a large diameter separator, or a small outlet pipe, the flange on a commercial bellmouth might need to be trimmed off a little to minimize waste bypass.  Trimming a small amount off will not lose much of the benefit of the bellmouth.

That is a great piece of work.  If I were starting over, I would duplicate your design.  Unfortunately, I am not seeing the photos you included , not sure why.

How thick is your baffle?  What is the material?  Did you round over the top and bottom edge of the hole saw cut?

Quote from: Schreck on September 08, 2020, 10:43:14 AM
Sketches of your intent would help us to understand where the flare would be located.  If located on the outlet as part of the bellmouth, then one of the images in this thread suggests it would be beneficial: http://www.jpthien.com/smf/index.php?topic=550.0

You found it Schreck!  Unfortunately the article that was attached to that link has been removed by Porter Cable.  I have a vague recollection of someone finding it again somewhere, but that will be looking for another needle in a haystack.

I enjoyed rereading that thread, it brought back not so fond memories of Chuck Lenz who has been banned from just about every woodworking forum on the internet!

Schreck,

If anyone has the patience to look for it, I think a long time ago I posted a link to a woodworking magazine article in which the writer was extolling the benefits of radiused pipe ends for all the dust pickups on every tool.  As I recall he fashioned them from glued up blocks of wood and radiused the inlet with a large round over router bit.  The discussion would probably be about the time I suggested bellmouths for use in separators.

I used that writers suggestion on my floor sweep.  I built up the neck with a wood collar, then radiused the underside with the largest bit I had.

Quote from: bluemil on August 28, 2020, 01:18:02 AM
This is what I meant by the funnel size and the flare. As for the opening. It makes sense to me to make the opening of the bell mouth equal distance in area to the area of the opening of the exit orifice.

I think you are over engineering the bellmouth.  There is a diagram I posted a long time back that showed the benefits of various types of pipe endings.  What it showed is that just a flat flange on the end if the pipe is significantly better than a straight pipe.  It is not as good as a bellmouth, but it is surprisingly close.  What that suggests to me is tweaking the flare on the bellmouth will have negligible effects.

I must say I?m confused by all three of your comments.  Height equal to volume?   Bending the flare?  Funnel less than 15 degrees?

Quote from: bluemil on August 27, 2020, 10:47:27 AM
Thank you very much for your input. I am going to be building mine double high. as well I am going to be adding an inlet that is rectangular I don't have the sketch-up knowledge on how to make a top hat with a rectangular inlet I do have the art skills but not with a computer I will add a scale drawing on what my build entails in future threads.

I think you are on the right track.  Keep the outlet pipe below the inlet to minimize waste by-pass.  I seem to recall some builders experimenting with the outlet height but I don't remember the conclusions, is any.  For sure, you want it below the inlet.

Do you mean tilting the inlet downward slightly?  If so, I think it has been discussed, butI don?t remember anyone posting test data to prove any benefit.  There is a video buried in my build thread that shows the rotating waste stream circles in a bit of an oscillating pattern.  That might suggest there is little or no value to a downward angled inlet.  However, I could see how in a double high design, it might prove to be effective.

I have always been an advocate of rectangular tangential inlets.  Rectangular inlets that are tall and narrow put the waste stream along the outer wall over the drop slot, which is where it should be to optimize separation.  That argument would also seem to support the idea of angling the inlet down forcing the incoming waste stream toward the drop slot. 

Bottom line I doubt that it will provide a significant benefit, but is not likely to be detrimental.  But I think you would get more benefit from a rectangular tangential inlet.

Quote from: shorthanded on August 20, 2020, 06:58:25 AM
This site seems to be more of a show and tell forum than a place to get questions answered. Not even the person who first asked how to eliminate the plastic bag would answer a pm, Thanks Alan for your help  I think I will proceed with my own idea. shorthanded

shorthanded,

Forgive me for taking exception to your comments.  The truth is many people come to this forum, get what they need, and are never heard from again.  Those that take the time to show and tell should be commended for sharing their experience.  I have made over 700 posts on this forum.  The vast majority are offering help to others.  Only a handful of us have stuck around for years providing help to others.  I only offer advice on separator designs where my personal experience adds value.

Good luck with you build.

Retired2

Don?t underestimate the value of clear walls, it is much more than a novelty, unless of course you put the whole thing in a soundproofed enclosure..

I can?t help you with the static cling.  I get a little fine dust that clings to the plexiglass walls of my separator, but in operation the static has no effect.  If anything, the circulating waste stream keeps the walls from accumulating anything but the finest dust.

I did not take the time to look at your dimensional information, but don?t be surprised if the bellmouth results in more by-pass.  I have often cautioned about the use of bellmouths in small diameter separators.  The flange brings the exhaust air stream much closer to the circulating waste stream and picks up waste before it has separated out.  This advice has always been given to top hat builders, but I think it is still valid for your application as well.