Distance from inlet to the start of the 1 1/8" slot

[dragonflyoh]

After two months of planning I have my DC almost finished. I need to cut the 1 1/8" slot and cannot find information on location. I have 120 degrees for the opening, I can place it in line vertical with the side wall but do not know where to start or end it. Any help would be appreciated.
Jim

[Bulldog8]

I borrowed one of Retired2's pictures for illustration. The opening should be 240 degrees. The 120 degree portion of the circle is solid.

http://dl.dropbox.com/u/36801256/Separator-35.jpg


Follow the link to the picture. The dust and debris will come in go around 120 degrees of the circle, and then enter the drop slot portion. In the drop slot area the cyclonic action will cause a large portion of the dust to settle below the separator. A small amount will continue around a few more times before being "collected."

Steve

[dragonflyoh]

Thank you. I will position the slot so it starts at the left side of the inlet as shown in you photo.

[retired2]

Thank you. I will position the slot so it starts at the left side of the inlet as shown in you photo.

Here's a shot that shows the slot a little better.

[retired2]

After two months of planning I have my DC almost finished. I need to cut the 1 1/8" slot and cannot find information on location. I have 120 degrees for the opening, I can place it in line vertical with the side wall but do not know where to start or end it. Any help would be appreciated.
Jim

Jim,

Unless I missed it, you did not say what type of separator you are building.  If it is a "lid" type, then the previous post and the link given are applicable and should be followed.

If you are building a top hat with a round inlet, you should look at Pitbull's video's because the last change he made after testing was to cut the inlet nozzle back due to turbulance.  The relevant video can be found on YouTube.  I think it is Video #5 in his series.

If you are building a top hat with a rectangular inlet like mine, and it is flush on both sides as well as the ceiling and floor, then the inlet pipe can stop anywhere short of the sharp corner since the separator itself forms the inlet port.  I doubt the incoming air knows where the metal ends and the wood or plexiglass begins, especially since the outside wall is contiguous, smooth, and tangent.

[dragonflyoh]

Top hat with 1/4" hardboard for the floor, sheet metal for the wall and 3/4" plywood for the ceiling. I am using a rectangle for the input opening. I will attach photos when it's finished. Thanks for the help.
Jim

[dragonflyoh]

I finished the DC and all is working well. I made a few adjustments along the way. I tried the rectangle opening and had trouble with getting the input port lined up with the wall so I went with a 6" round input port. I used 3/4" plywood for the floor and then used a 45 degree router bit to reduce the edge of the opening to 1/8". I am using a motor and impeller from a  Model 200S Cincinnati Fan dust collector. It is a 2 HP 1100 CFM with a  12 1/4" impeller. I only run the DC when operating the power tools so I chose to exhaust the output outside rather than through a filter. My work shop/garage is not heated so I don't think it will be a problem once the snow falls. I was helped immeasurable by all of the information posted here. Thanks to everyone.
One question. Is it normal for the dust collecting in the barrel to spin?
Jim

[retired2]

I finished the DC and all is working well. I made a few adjustments along the way. I tried the rectangle opening and had trouble with getting the input port lined up with the wall so I went with a 6" round input port. I used 3/4" plywood for the floor and then used a 45 degree router bit to reduce the edge of the opening to 1/8". I am using a motor and impeller from a  Model 200S Cincinnati Fan dust collector. It is a 2 HP 1100 CFM with a  12 1/4" impeller. I only run the DC when operating the power tools so I chose to exhaust the output outside rather than through a filter. My work shop/garage is not heated so I don't think it will be a problem once the snow falls. I was helped immeasurable by all of the information posted here. Thanks to everyone.
One question. Is it normal for the dust collecting in the barrel to spin?
Jim

Jim,

I think the sheet metal was a good choice for the walls, and I think the fan being mounted almost directly on the top of the separator will be beneficial.  What size is the outlet pipe/blower inlet - 6"?  It may be an illusion, but it looks like the diameter of the separator is pretty small relative to the inlet size.  When the inlet gets too close to the outlet, by-pass can become a problem.  Maybe the smaller size is keeping the air velocity high and therefore mitigating the problem.

Don't know what part of the country you are in, but in the northeast even an unheated garage is a little warmer than ambient conditions on many days.  And don't forget, you and your tools are adding a little heat to the garage when you are working there, so pumping that heat out on a really cold day may not be the best choice.  Conversely, in the summer months pumping air out may be exactly what you want to do.  You might want to think about plumbing for both options.

I can't see inside my waste drum while it is operating, but I can tell from the way the waste accumulates in the drum that there is definately a circular air pattern occuring.  I don't know if it is a weak or strong current, but it is there.

Retired2

[dragonflyoh]

Retired2,
All pipes are 6". The diameter of the separator is 22". I ran my thickness planner and all of the chips are in the drum. If there is any bypass I cannot see it. I ran the collector after dark and passed a light through the exhaust and along the exhaust line and did not see any dust.
I live in Ohio and will see how the shop temperature is affected by the DC. Like you say I might need a dual setup but for now all is great! I picked up a couple of leafs and you can see them going in circles. Will keep an eye on things once the drum starts filling up.
Jim

[Rick T]

Looks like you've got an excellent result. The real test would be fine dust, maybe from a wide belt or edge sander running light passes of hard maple. With your setup.. solid pipe, 2 hp and a larger 12 1/4" impeller you may be moving enough air through the 6" pipe to handle the very fine dust very well too.

[dragonflyoh]

I shall do the maple test and let you know how it works. Won't be today as it a nice day to be outside and get the yard ready for winter.