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Bruce Seidner
05-06-2010, 11:02 AM
As I read and think about moving dust around I found this interesting contraption. I know that gentle bends have less of a CFM penalty than right angles. But as anyone pricing 6" wyes knows this gets costly fast. I have explored what it would take to make my own wyes and Pentz refers to a number of DIY solutions.

But what do others think of this junction box blast gate unit?

There is the introduction of more volume in the pipe line, but does it address the dynamics that make T-joints and right angles so problematic. I don't know what to think of it. file:///Users/bseidner/Library/Caches/TemporaryItems/moz-screenshot-1.png

John Lanciani
05-06-2010, 11:18 AM
Bruce,

I've got something on the same idea only larger. All of my large machines are in a central group with my dust collection dropping in the middle. There are seven 4" and two 2" blast gates on my manifold. It's not the perfect solution, but it solves more problems than it creates.

John

Mitchell Andrus
05-06-2010, 11:52 AM
Bruce,

I've got something on the same idea only larger. All of my large machines are in a central group with my dust collection dropping in the middle. There are seven 4" and two 2" blast gates on my manifold. It's not the perfect solution, but it solves more problems than it creates.

John

Wowie-Zowie. This looks like something from a Jacques Cousteau documentary.
.


For the young-uns out there... Google it.
.

Bruce Seidner
05-06-2010, 12:33 PM
Bruce,
It's not the perfect solution, but it solves more problems than it creates.

John

I think that is elegant, but then I am not an engineer. I have several machines in three work groups. Using 3 wyes to distribute to the work groups makes sense but for machines that are essentially side by side this sort of manifold looks great. What are you loosing by not having 6 wye connectors going off a branch down to 6 machines and by using this manifold?

What are the issues and compromises?

Greg Portland
05-06-2010, 12:41 PM
Bruce, I like John's solution vs the picture in your post. The reason being is that John's solution has a very small bend for each drop's path. The solution you show has a very sharp 90 degree bend. If you want a 3:1 blast gate wye I would build the item in your 1st post but make it in a triangle shape (main duct on bottom, 3 intakes + gates on top). If you really want to get fancy you could include some internal vanes after the blast gates (in the body of the triangle)... this would help reduce turbulence & improve performance.

Bruce Seidner
05-06-2010, 2:12 PM
I too am impressed with this manifold. It maintains the low angle of a wye and the addition of simple vanes make sense relative to the potential interactions when more than one gate is open. Though it is likely a true tempest in a teapot.

This makes sense for machines clustered like this. My guess is that there might be some loss of CFM with more than one gate open in the manifold compared to more than one gate open on a trunk with separate wye's and pipes to separate machines. But I have but two legs and two arms and have trouble thinking of a scenario where I would have a table saw and jointer going at the same time.

This looks like a winner to me. It also addresses the issue of two lines to a single machine like the top and bottom of a table saw or the mess that a miter saw spews and where both a hood/surround and feed off the blade are required if you don't want to feel like you are in Desert Storm.

Prashun Patel
05-06-2010, 2:32 PM
Holy Clam and Cuttlefish! It's Doctor Octopus!

That, Sir, is a shameless gloat pic of your bandsaw and jointer.

John Lanciani
05-06-2010, 3:31 PM
Bruce,

The biggest functional problem is with a small percentage of the heavier chips settling in the manifold depending on which ports I'm using. I figure that it's due to the airstream slowing down due to the cross sectional area being rather large. I'm sure that there is a small static pressure penalty but it can't be any worse than if I had all of the wyes and bends instead.

Operationally, the biggest pain is having to walk around and reach over machines to open and close the various gates. I'm toying with the idea of rebuilding it using eco-gates to open and close the ports as needed.

And yes Shawn, it was a small drive-by; it's a MM-20 bandsaw and a Rojek MSP-415(16") J/P with a Byrd head.:p The dust collector is a V-3000H. You should see the rest of the shop...

John

Prashun Patel
05-06-2010, 4:14 PM
And yes Shawn, it was a small drive-by; it's a MM-20 bandsaw and a Rojek MSP-415(16") J/P with a Byrd head.:p The dust collector is a V-3000H. You should see the rest of the shop...


Yeah, well at least yr still hayseed enough to keep rockin' the ni-cad 14v Makita drill, I see.

Kent A Bathurst
05-06-2010, 4:32 PM
Wowie-Zowie. This looks like something from a Jacques Cousteau documentary..

Nope.

Maybe from the first Alien movie, but more likely from the film Brazil. Just need DeNiro swinging in on a rope to fix it.


Me likey. Very clever way to create tool-holder space.

Bruce Seidner
05-06-2010, 5:15 PM
Bruce,

Operationally, the biggest pain is having to walk around and reach over machines to open and close the various gates.

John

In keeping with the Brazil theme, could you arrange handles and levers to accomplish this? For instance if there is a blast gate close to the floor on a table saw it is not hard to rig a lever higher up that has a rod on the end that is attaches to the gate. The arc of the lever makes it a small travel and you don't have to get down on your hands and knees to operate the gate. Of course why people put the gate down there in the first place is a bit of a mystery.

I am going to make some of these puppies in two and four gate variants. I will include internal vanes and a sliding bottom that will cinch up and seal with the machine on and relax and slide open easily to empty it when the machine is off.

They have a bit of a pagoda style to them so maybe hand rubbed red lacquer?

John Coloccia
05-06-2010, 6:04 PM
Wowie-Zowie. This looks like something from a Jacques Cousteau documentary.
.

I don't see what the Pink Panther has anything to do with this.

Paul Wunder
05-06-2010, 7:36 PM
Bruce,

it looks to me as you have one input from a flex line exiting to one of three flex line presumably to a choice of three machines. You also have a lot of restrictions from the 90 degree bends in the "junction box"

Have you tried using Bill Pentz's "Static Calculator" on his web site?

I do not think there is an off the top answer.

You need to consider the cfm needed at each machine and start at the beginning (at the collector) and calculate the starting cfm, the static pressure loss caused by each length of ductwork, each bend, each type and size of ductwork that you are using (pvc,flex, metal; 4",5"6").You also need to consider the "loss" at each "hood" at the machine. When your calculations are done using your real world situation, you will have your answer. it will either work for you or not.

For your calculations I would not consider your junction box as a "90 degree bend". I would add a significant factor for "turbulence". Bill Pentz talks of the effect of turbulence on his website.

We all want to be cost effective, but since we invest a lot of time and up front money to get results, I would suggest "the long view" and build what will work.

Paul

Mitchell Andrus
05-06-2010, 7:48 PM
Nope.

but more likely from the film Brazil. Just need DeNiro swinging in on a rope to fix it.




YES! I forgot about that one.
.

Joe A Faulkner
05-06-2010, 10:08 PM
Bruce,

And yes Shawn, it was a small drive-by; it's a MM-20 bandsaw and a Rojek MSP-415(16") J/P with a Byrd head.:p The dust collector is a V-3000H. You should see the rest of the shop...

John

John, I can't speak for Shawn, but I'd love to see the rest of the shop. How about a tour?

Bruce Seidner
05-06-2010, 10:19 PM
Bruce,

I would suggest "the long view" and build what will work.

Paul

This is good and kind advice. And, I have been of two minds.

I have read and tried to absorb what I could on Bill's site. Just as you rightly advise. I am aware of the best practices that he recommends. But I have failed, both conceptually and mathematically to design a system using this information despite the generous hand holding and support Bill provides.

That said it was not lost on me from the get go there are serious limitations inherent in my physical space. 3/4 of my space has a floor to ceiling height of 5' or less. My actual stand up space which comprises the rest of the garage is 7'. Most of my obsessing is caused by the tension of best practice v. actual physical space.

My solution has been somewhat backwards. Though I appear to be in good company and find it to be the rationale which is the predicate of the arms race and has accelerated the acquisition of weaponry wherein we possess the collective capacity to destroy this planet many times over.

So, when I failed to do what you appropriately recommend and calculate how much static pressure and cfm I need relative to the requirements of machine, connection, composition and length of runs for the work that I do, I went freaking nuclear.

I found the meanest, most beastly Mr. T of a blower I could after months of craigs list and ebay and other industrial surplus scavenging and came up with a 5HP 220v industrial blower which bellows, "I pity the foo!" at 10"SP 1111CFM. If using Mr. T, 6" S&D PVC and exhausting into 90sqft of fabric over a 12' long filter does not cut it then I will have to take up collective memory scrap-booking and start lusting after odd scissors the way I do over old wooden planes.

This is no way devalues your advise and I do appreciate that you are right. Mine is an inelegant and brutish approach, but it is what brought me to the dance and I imagine I will be leaving with it.

Alan Lightstone
05-06-2010, 10:40 PM
I'm real interested in your second picture, John. You also custom built a dual 4" suction box for your jointer? That would solve the chip problem I'm having with my Laguna jointer/planer.

Any plans for that collection box?

Also, with smooth walls / transitions, I think a manifold would present little additional turbulence. You may be on to something here. Seriously thinking about attempting something like this myself.

Paul Wunder
05-07-2010, 7:20 AM
Bruce,

You certainly have a sense of humor and a strong sense of determination about finding a way to add dust collection to your shop. I give you credit, for although I faced significant obstacles in my situation, I had nothing to deal with on a scale of what you have. Sometimes you have to move forward despite conventional wisdom.

Here's one for "Mr. T".

I wish you the best!

Bruce Seidner
05-07-2010, 8:00 AM
Bruce,
. Sometimes you have to move forward despite conventional wisdom.

Here's one for "Mr. T".

I wish you the best!

I have come to the conclusion that I am going to have to excavate behind the retaining wall area of the paved garage in order to have the head room for the cyclone. Head room, head case, I can get stubborn and while I accept gravity, entropy, and aging as non negotiable, people have been moving earth for years to meet their needs. For many species it is a way of life.

But they ain't got's one of these.....

Brewha.ha.ha....

jim finnegan
05-07-2010, 10:43 PM
elegant!

absolutely elegant!

glenn bradley
05-07-2010, 11:07 PM
I used something similar for a few years till I got the cyclone. It made gating the various hoses feeding my bag unit easy and kept the active run short. I did use a more straight line approach like John's but only for a 3 port junction like your OP.