J. Phil Thien's Projects

I am new to the forum. I wish I had researched more before I purchased my Dust Collector.
I bought:
Harbor Freight (Central Machinery)
CFM: 1550
Horse Power: 2


I really like everything I have read and seen on the Thien Separator. Brilliant. Now I have info overload after all I have read (so many hours over the last week). I planned to use my DC with Separator. And Rockler's 4" Dust Right expandable hose to stretch from one machine to another. The hose stretches 4x the relaxed length. I bought the 3 foot hose and planned to go from machine to machine with it. Would I be better off building the Separator for a Shop Vac and caulk up the purchase of the DC as a learning experience?

Doug,

I have a original baffle design in my HF collector and it has been working fine.  The new Top Hat design is better and it can be used with your HF.

I would not use the expandable 4" hose from Rockler.  I have that hose for cleaning up around the shop but I would buy regular hose for my system.  I also think you might want to consider using 6" hose for the additional suction.  I am converting to 6" piping that you buy at HD or Lowes for AC.  I have seen a system that uses 6" with a dust collector like the HF.

You didn't say what machines you wanted to collect dust from, but if you want to collect from a tablesaw, bandsaw, jointer, planer and other large tools the true DC and baffle is the way to go. Choosing a tophat or a internal baffle would be a choice based upon your preference, space requirements/limitations and whether or not you want to mess with emptying the bag.

On the other hand if you are only collecting dust from hand held tools like sanders, routers and the like, I would choose a shopvac and a 5 gallon separator.

The high CFM of a DC provides the amount of air movement to correctly collect dust from the large chambers of the tablesaw, planer and other large tools. A Shop Vac has a high static pressure (how hard it sucks) but a lower CFM in comparison. The Shop Vac does a great job of collecting from small tools or areas. I use both in my shop and couldn't really imagine one replacing the other.

Steve

Quote from: Bulldog8 on January 16, 2012, 03:49:44 AM
You didn't say what machines you wanted to collect dust from, but if you want to collect from a tablesaw, bandsaw, jointer, planer and other large tools the true DC and baffle is the way to go. Choosing a tophat or a internal baffle would be a choice based upon your preference, space requirements/limitations and whether or not you want to mess with emptying the bag.

On the other hand if you are only collecting dust from hand held tools like sanders, routers and the like, I would choose a shopvac and a 5 gallon separator.

The high CFM of a DC provides the amount of air movement to correctly collect dust from the large chambers of the tablesaw, planer and other large tools. A Shop Vac has a high static pressure (how hard it sucks) but a lower CFM in comparison. The Shop Vac does a great job of collecting from small tools or areas. I use both in my shop and couldn't really imagine one replacing the other.

Steve

+1

Additionally, I have a HF DC system with a Thien TopHat and 4" piping. I also use it on one operating machine at a time.

• Does it operate satisfactorily and meet my needs? -Yes
  
• Could I improve it's performance with further improvements? -Yes, I'm sure I could.
• Is the Thien separator  the best part of my DC system? -I think so IMO.

The point being, I think you could proceed with your initial plan and be very impressed. If your budget and time schedule allow, make all the improvements you can.

Best,
Gale

So.

I'm not so new to the forum, but I am new to setting up a dust collection system. I read (and try to comprehend) everything in the several wood working forums I belong to on the subject.

And I am still confused.

Not about the value of installing a system--there are many and varied and often contentious threads on that subject. That dust collection is necessary (or "a very good thing to have") isn't in dispute. I believe that ANY dust collection system is better than no dust collection system. And I think galerdude is spot on saying that improving whatever system is employed in a shop is an ongoing endeavor.

No, my confusion is on what components I should incorporate in my own (and no doubt unique--or nearly so) system.

Based on more comments that the HF "2 HP" unit is a "very good value" and that I "won't be disappointed in the investment" I bought one. Out of the box, it's . . . meh. I mean, it sucks up "some" dust and chips and deposits most of it in the poly bag. But the filter bag is just pure garbage. There is no question that better filtration is required. It's obvious that modifications to the HF unit are required to improve dust collection.

I am 100% convinced that Phil's separator design is the cat's meow. I built one for use with a Shop Vac and am thoroughly impressed by how well the thing works. I will definitely install a similar device in my central DC system.

So maybe that's half the confusion cleared up.

The investment in a Thien separator and the HF unit is <$200. The budget director is pleased. But I haven't told her yet what the bill for the piping and gates and fittings and all is going to amount to. Way more than two hundred bucks!

Like most everyone, ultimately, I waded through Bill Penz's dissertations on dust collection, looked at what all the other pundits and number crunchers have to say on the topic. I became thoroughly frightened that my $200 investment was a "bad idea" and I should have hocked the Volvo and my pickup truck to buy a more powerful system. But if I admitted that, my standing with the budget director would be on very narrow footing. (She really likes the Volvo.)

One pundit says, to effect: "You can't move enough fines through anything smaller than a 6" diameter pipe." Another says, to effect: "It is impossible to move the output from your table saw or jointer planer with less than 400 CFM and that's not possible in 4" pipe." And: "don't use elbows, they destroy system performance." And so on. I know you've all read the same stuff.

So, having designed the DC layout for my shop using 4" pipe, I redid it using 6" pipe. I also bought a length of 2729 S&D and fabricated 90? and 45? sweeps. (Translation: fun with a bandsaw and several packages of JB Weld.)

Then I visited the Woodcraft store that isn't near to me, but is closer than any other, and looked at their classroom shop. It's approximately the same size as mine, has approximately the same compliment of machines, and it's plumbed all in 4" S&D, with those ubiquitous cast aluminum gates and there must be as many if not more fittings than I plan, and half again as many feet of run. I asked the guy there at Woodcraft how well the system works.

He said, "It works very well."
"It picks up all the dust?" I asked.
"Yep," he said. "Why?"

It was then that I laid on him my load of confusion (basically what you read above), and he just shrugged and repeated that their system works fine. Apparently, they use a 3 HP cyclone. I didn't see it, nor do I have any information as to the FPMs or CFMs, which I believe are more pertinent than the power of the motor driving the system. I also don't have any data on how many gates might be open at once in that classroom. I plan on using my HF thing with a Thien separator in front, and (when the budget director approves, a cartridge filter, such as supplied by Wynn). And as I work alone, there is no reason to have more than one gate open on my system at a time.

So now here I am, looking at these gorgeous 6" sweeps (well they're not gorgeous, really, but the are pretty cool), and am wondering if I'm obsessing about the thing too much. What if I did revert to the 4" layout (using similar sweeps in lieu of elbows)? It would certainly please the budget director.

The thing that gets me is this: If I invest in 6" pipe, what happens at the machine? The ports (or the logistics of space for anything larger) are all 4" or smaller. So isn't that the weak link? The inlet on the impeller of the HF is 5". I love physics but I'm not very good at it, yet I seem to recall that in a fluid system such as an air duct, as volume increases, velocity decreases.

If dust-laden air is sucked into a 4" pipe that fairly quickly grows to 6", things slow down. No? At some point, the little Chinese motor and 12" impeller at the HF unit are just not gonna be able to keep up. No? (Then I read that inserting a separator of any kind impairs the system even further. Yet I will have one of those!)

Here's my proposed layout:

Thanks for the input everyone. I was so discouraged before the replies. Bulldog, I plan to use DC for Table saw, Jointer, and Planner. Band saw if/when I get one. One machine at a time.

So, everyone pretty much feels the top hat is better than what I call the original with the elbow at the in-let? I have seen many pictures of the new design, but not enough to figure out how to make one. I'm not looking for dimensions, just how it goes together. I know there are many variations. I'm just trying to find simple sketch or something.

I have dreamed about setting up a shop since I was in High School wood shop. Now I'm 43. Over the years I have been buying tools. Have not really made anything yet.

Thank you

I never built an "original" Thien "elbow-type" separator...instead, I went right to the top-hat concept. So I can't comment as to the effectiveness of the elbow design--obviously it works or Phil wouldn't have shared it with us.

But I can say that the top-hat concept is close to 100% effective. At least with a shopvac. I'm still confused about the issue of pipe size, and all the other stuff.


ETA: Doug, do you have Sketchup? I'm glad to share my sketchup drawing for my tophat design.

Quote from: Dougp28704 on January 17, 2012, 03:43:10 PM
Thanks for the input everyone. I was so discouraged before the replies. Bulldog, I plan to use DC for Table saw, Jointer, and Planner. Band saw if/when I get one. One machine at a time.

So, everyone pretty much feels the top hat is better than what I call the original with the elbow at the in-let? I have seen many pictures of the new design, but not enough to figure out how to make one. I'm not looking for dimensions, just how it goes together. I know there are many variations. I'm just trying to find simple sketch or something.

I have dreamed about setting up a shop since I was in High School wood shop. Now I'm 43. Over the years I have been buying tools. Have not really made anything yet.

Thank you

Here are links to the two "how to" builds that finally got me building one.

http://www.jpthien.com/smf/index.php?topic=429.0 (http://www.jpthien.com/smf/index.php?topic=429.0)
http://www.jpthien.com/smf/index.php?topic=431.0 (http://www.jpthien.com/smf/index.php?topic=431.0)

There are other good threads too. These two just happen to be the ones that made it happen for me. Good reading!

Best,
Gale

galerdude, thanks for the links.

Peter, I dont have Sketchup. I do have SolidWorks. Can you export as Dwg, DXF, IGES, or any cad format? if not, a jpeg would be fine too. Thanks.

Peter,

The dxf design you send me came in fine into SolidWorks. I could build it directly from your design. All of my questions were answered. Thanks again.

I havent started making it yet, and I am already over thinking. If I mount my DC impeller in-line above my seperator, the direction is counter-clockwise when looking down from above. The same as in the jpeg you posted of you shop lay-out. Would you sugest that I mirror the design of the seperator? In order to have seperator rotaion the same as DC rotation?

I don't think you can go wrong with the orginal Thien Baffel "elbow" or the top hat design. I've been using the original elbow baffel with a central shopvac set up for many years and it works like a charm. I have 6 2.5" pipe drops run to all my machines and work areas. I am upgrading to a Delta 50-760 DC with a thien tophat seperator and 5" metal pipe replacing my 2.5 in pipe. I'am using 5" pipe because that is the size of the intake on the 50-760. I will run 5" pipe right to the machine outputs and use 5" to 4" reducers at the machine until I can figure out how to improve the machine ports. I'll continue to use my Thien shopvac for shop cleanup and small handheld tools.

From my experiance with the orginal Thien baffel I would not consider running a DC without a Thien Baffel based Seperator of some Kind. You will run into filter clogging issues if you do a lot of fine sanding but this is a problem with all DC systems.

I've attached a PDF file that shows the parts and deminsions I used to build a tophat seperator. The deminsion you should start with for a tophat is the inside diameter of your collection can, that would be the OD of your thien baffel dropslot. The inside height of the tophat can be the diameter of your input pipe. I used 5 15/16 because that was the width of the inner ring materal I had. I think a round to rectangular input transition is also a good thing because it reduces turbulance at the tophat input. At final assembly I will double back tape all the layers together to seal up any leaks.

I created these part drawings using DoubleCAD XT.

RonS,

Thanks.

I may stil be confussed about somethings. But I now understand how it all goes together. This is a great site with helpful people.

Quote from: Dougp28704 on January 19, 2012, 06:59:07 PM
Peter,

The dxf design you send me came in fine into SolidWorks. I could build it directly from your design. All of my questions were answered. Thanks again.

I'm glad it's of some use to you. :)

QuoteI havent started making it yet, and I am already over thinking. If I mount my DC impeller in-line above my seperator, the direction is counter-clockwise when looking down from above. The same as in the jpeg you posted of you shop lay-out. Would you sugest that I mirror the design of the seperator? In order to have seperator rotaion the same as DC rotation?

Yeah, I noticed that, too. I believe, based on comments hereabouts by retired2, that rotation of ANY air moving into the impeller is detrimental. (shrug) I arranged my set-up as you see because of physical constraints of the machine room and it's relationship to the workshop. I think I will try some sort of "air straightener" as implemented and tested by retired2. Thinking maybe a stack of aluminum "egg crate" diffuser in the inlet pipe just might do the trick...we'll see.

More important to me is whether to install 6" pipe or 4" pipe. I will use S&D PVC (ASTM D-2729) for two reasons: I can work PVC with significantly more success than metal, and it costs a lot less. 4" pipe and especially the associated fittings, is considerably cheaper than 6", but dust collection pundits claim it won't "do the job".

I am still confused over this issue, and no one's saying yea or nay to either, at least with enough supporting data for my satisfaction. Supposedly, you don't get enough "fines" removal in 4". The HF impeller unit has a 5" inlet. They don't make 5" PVC. I'm worried that necking up from 4" to 6" then back to 5" will result in a "less than optimum" situation. So although I spent two afternoons making 6" PVC sweeps (yeah, they're neat looking), I am leaning toward a 4" system. I can't see a scenario where I would intentionally use more than one drop at a time, unless I forget and leave one open.

And then I read that RonS is happy with his 2 1/2" system! sheesh. Will anyone weigh in on this issue?

Peter, could you give some detail on how you made your sweeps?

Woops-don't know how to insert quotes!

Quote from: sneezy on January 20, 2012, 08:06:49 PM
Peter, could you give some detail on how you made your sweeps?

Sure.
I use Sketchup as follows (refer to attached drawing.
1. Draw circle of desired sweep radius (at centerline). I use 15 inches radius and the default circle with 24 segments.
2. Draw radius lines at 90? to each other.
3. Erase all but the 90? arc, add 6" extension lines. This is important.
4. Make a box so the circle tool will draw a circle in a vertical plane.
5. Hold down shift key and draw the circle at the end of one of the extension lines.
6. Select the arc and both extension lines. Using the "Follow Me" tool, click on the small circle drawn in step 5.
7. Draw a rectangle enclosing the entire structure. Right click and select intersect faces with model.
8. Erase everything but the lines on the rectangle.
9. Extend the radial lines until they intersect.

At this point, Sketchup fails--they do not have a tool that can dimension angles. YOu can use the rotate tool to see them, but only temporary. So I exported the resulting drawing into AutoCAD, and discovered the angles there. The outermost angles (at the 6" extensions) are 7.5? and the internal angles are 15? from one another.

I set my miter gage on my bandsaw to these angles, and cut segments. It REALLY helps if you draw lines along the length of the pipe that are 90? from one another, so you line them up with something on the miter gage. Otherwise, the sweep can wind up going all over the place.

Cutting PVC on the bandsaw is messy.

Using very coarse sandpaper and a rasp, I eased the cut edges. Then, aligning the linear lines, I taped the segments on the INSIDE, one at a time. I used JB Weld epoxy to join the segments.

JB Weld is messy.

I was bothered by how lousy the joints looked so I sanded them down. Don't do this. Put up with messy-looking joints. They're stronger. Once the outside was cured, I gooped JB Weld on the inside joints. This is pretty easy with 6" pipe. It could be damned near impossible with 4" pipe. I'm gonna paint mine.

The 6" extensions will fit into the bell of a pipe or a fitting.

I tried making these with foil duct tape. It works, but man, it's hard! Glue is better. I suppose if I had a plastic welder, it'd be even easier. But I need like 4 90s and a couple of 45s, so it isn't worth the investment.

Hope this is helpful...and more important: useful.  ;D

Peter, I think that many people set up a system of 4" or 6" and are happy with it so they don't change anything. Therefore, it can be difficult to get comparative results. In my experience I have found that I have spent more money on DC accessories than the initial cost of the machine itself. (Grizzly 1029)

I first set up the system using 4" S&D pipe with a Woodstock trashcan separator lid on one of the two branches. The setup did pick up sawdust, but was quickly overwhelmed when I added a drum sander to my line of equipment. I then torn apart my first set up and added 6" metal mains, a Thien baffle top hat and a Wynn filter. The overall improvement is significant, but I can't say how the system would have worked with the 4" pipe because I changed everything at once.

In my opinion, the dust produced by woodworking is the most significant hazard in the workshop. Power tools themselves can be dangerous if used incorrectly, but brains, technique and set up mitigate those hazards. The only thing that can mitigate the fine dust hazard is equipment. So bottom line, I suggest getting the best DC system that you can reasonably afford and then use it within its capacity. Meaning if you have a machine that can only support 4" mains, fine use 4" mains and open one gate at a time. You will then get the best collection possible and honestly it's probably as good as a 2K system that supports multiple machines at one time. I'd hazard a guess and say that most people on this board (myself included) are hobby woodworkers or very small business owners.

Steve

Steve:

QuoteIn my opinion, the dust produced by woodworking is the most significant hazard in the workshop.

With this I am in total agreement. I am a weekend/evening hobbyist. Besides being generally broke, I am also lazy. I have the bad habit of leaving the mess behind when I make something, then have to deal with that mess when I wish to make something else. I can strive to correct that habit, but that's a tough one: it's been my bane for five decades! Why the budget director stays with me is a mystery.

So I figured installing a reasonable (note I am not saying perfect or best) dust collection system would serve to keep the workspace a lot cleaner than it has been for years. And in reading here, the HF 2HP unit seemed to be well-touted, so I bought one. I am already convinced that the Thien baffle and a good filter are a must. I can build the baffle; I can save up and buy a good filter. I can build the gates and install the piping.

All my questions, then, stem from the above limitations: given the HF unit, Thien baffle, one-gate-open-at-a-time situation, future Wynn and future air cleaner, and given that I have a 10" cabinet saw, drill press, band saw, sander, jointer, planer, I need to devise a system that satisfies this:

Quoteif you have a machine that can only support 4" mains, fine use 4" mains and open one gate at a time.

I haven't found anything that says "the HF 2 HP DC can suck workshop dust through A-diameter pipes of L-length with F-number of fittings".

And the reason I am pestering you guys about this is because I don't have the time, energy or budget to do it once, discover that is insufficient, and then do it over. It is definitely easier on my wallet to install 4" pipe. But if 6" will perform better with the HF unit then I can probably swing that.

Thanks for your patience.
Peter

Peter,

I guess I will make mine a mirror. Who knows. Can?t hurt though.

I am just going to use 4 inch for the reasons you listed.

Quote from: Peter on January 21, 2012, 12:23:30 PM
I haven't found anything that says "the HF 2 HP DC can suck workshop dust through A-diameter pipes of L-length with F-number of fittings".
Thanks for your patience.
Peter

I could be totally wrong here so please forgive me if I've missed something along the way but I don't remember reading about anyone having that information when they built their system. Most builds that I've read about have built a DC system using the available information and trying to apply it to their situation and do the best they can. And a lot of good folk try to share improvements and enhancements that they feel might help someone else. If you were to copy someone's system as in the same diameter pipe, same lengths and same fittings, would that be the system that would work for you? I know when I built my system I had to make some choices. Were they good choices? I dunno, it works.

Best,
Gale

Quote from: galerdude on January 21, 2012, 07:00:16 PMI could be totally wrong here so please forgive me if I've missed something along the way but I don't remember reading about anyone having that information when they built their system. Most builds that I've read about have built a DC system using the available information and trying to apply it to their situation and do the best they can. And a lot of good folk try to share improvements and enhancements that they feel might help someone else.

Which is why I am here, pestering all you good folks.

QuoteIf you were to copy someone's system as in the same diameter pipe, same lengths and same fittings, would that be the system that would work for you? I know when I built my system I had to make some choices. Were they good choices? I dunno, it works.

Obviously, it's absurd to copy someone else's system. At least, not in all details. And yeah, I appreciate that the choices you made, Gale, are specific to your situation. That the choices you made result in a system that works is super.

Now, not to say anything one way or another about anyone's choices (after all, it's the reasons you guys made those choices, that I want to copy if anything), but it seems to me that the more I inquire and gain information, the more evident it is that there is quite a bit of leeway in system design. The Woodcraft classroom shop, easily twice as large as mine, uses 4" pipe everywhere and the place was spotless. Maybe they use a super sucker fan, I dunno. I never saw it in operation. Some people here, and in other forums, use 6" PVC, 5" metal, 7" metal, and so on, with DC units that range from 1 HP to 5 HP. For the most part, everyone's system works. Rockler and Woodcraft and others, even Penn State, sell 2 1/2" systems. I don't know of anyone who uses such a thing, other than in small scale with shop vacs, but all the data I read says that it won't work.

Aerodynamically, the bumble bee can't fly. Yet there are hundreds of them every spring on the honeysuckle out front...flying.

The choices I have already made are as follows:

HF 2HP unit with Thien pre-separator.
No 90? elbow fittings and as few 45? fittings as possible.
All other "bends" made from segmented pipe sweeps with at least 2 1/2" pipe diameter radius.

The only decision that is missing, it seems, is whether to use 4" throughout, a combination of 4" and 6", or 6" as much as possible.

And, I guess, that whatever choice I make, there will still be those occasions when there will be dust and/or chips flying about the place that will have to be taken care of by the good old bench brush and dustpan.

It is not rocket science to calculate SP losses, velocities, and cfm for any branch of DC system where only one tool is running at a time.  You can run the calculations for 4", 5", and 6" pipe and see how the performance compares.  There are a number of resources on the web that will give you the basics.  Try Oneida Air, or Air Handling Systems. 

However, if you are starting with a HF unit, there is a very good chance that you will be missing the most basic piece of information, i.e. the true performance specs of the unit, or better yet, a fan curve.  Without that data, you are pretty much stuck with just building the system, and hoping for the best.  The truth is all three pipe sizes may work, but only one will work best.

I'm sure someone will find fault with this advice:  If you don't want to get into the design math then consider using 4" pipes for dust collectors smaller than 1.5 hp.  Use 5" pipe for 1.5 HP and 6" for 2hp and larger.  There is some point at which you could use 8" pipe, but that would likely be a 3 or 5HP cyclone and not likely found in a small hobbyist workshop.  I have no personal experience with the 2hp HF unit, but my guess is that it performs more like a 1.5 HP than it does a true 2HP.  What size is the inlet port?  If it is 5", that is a pretty strong clue about what size pipe you should be using. 

If you aren't into calculations, then here is link to the best advice you are going to find on building a DC system. 

http://americanwoodworker.com/blogs/shop/archive/2010/10/25/central-dust-collection.aspx

Yes, I know, you can't buy 5" plastic pipe.  Sorry, I can't help you with that problem, but if you are contemplating 6" pipes you need to look very closely at the test data I posted in the thread on my separator build.  I went to great pains to keep SP loss in my 5" system to an absolute minimum, and I have a highly rated 1.5 HP dust collector, but when the separator was added the FPM's dropped to a level that is marginal for conveying woodworking waste.  Anything lower and the debris may start dropping out in the line.  So, when a 5" pipe is providing marginal FPM's the answer is not switching to 6" pipe.

The Thien separator is a wonderful device and it really works wonders, but it comes with a pretty high performance cost.

Regards

If your intent is to have a spotless workshop like the Woodcraft example, you will have to get used to the idea of brooms and brushes to get rid of part of your sawdust. Using a 1.5 or 3 hp DC with 4" or 6" mains or any other size will not get all of the chips and dust with every operation. A DC system is limited not only by its design and capacity, but also the design of the tools it is connected to. Of the tools listed that you want to collect dust from you will find that the table saw will produce a fair amount of dust above the blade. This will either have to be swept up or collected above the table with an overhead device of some sort. The band saw normally has one port near the lower wheel, so what ever dust is lost before entering the lower cabinet will not be collected. The drill press, well I'm sure you can imagine the difficulty there, the material is generally large and slow moving making it harder to collect than from some other machines. I find that the jointer, planer and drum sander have the most complete collection of my tools.

None of this is meant to discourage you, but only to to interject that a DC system is only part of the clean shop arsenal. I seriously doubt that the Woodcraft guy was completely honest in implying that they simply used their system with 4" pipes and it was as clean as what you witnessed. True, it will get the majority, but I've yet to see a shop without brushes and brooms to do a second cleaning.

I do not keep my shop in a spotless or in many cases even a clean condition. I do however attempt to collect the largest amount of fine material possible with the equipment that I have. I then get rid of the rest with an occasional cleaning using a bench brush, broom and a shop vac.

Steve

btw there are @ 15 pages devoted to dust collection in the FWW Winter 2011/12 Tools & Shops mag. Everything from theory, cyclones, filters, separators, shop vac tests, portable work table with shop vac incorporated.

Here is a pdf of the article that appeared in Wood Mag Issue182 testing 15 Under $400, 1.5 & 2 HP DCs, the HF model 45378-1VGA was included in the test. This artical has been posted many times on this site and is a good reference for those trying to decide on which unit to buy. This test includes SP vrs CFM curves for all the units teste, one of the curves shows which of the units can support 6" duct work and which can support 5" duct work.
You might find this artical very interesting
Ron

Hi Peter. Look at the motor plate volts x amps / 746 = theoretical horse power. Example 120 volts x 15 amps/ 746 = 2.41 (perfect world) if you have a volt meter you could ckeck the voltage in your outlet, Usually around 110 volts. As far as the amps if it is 15 amps that is usually peak or start up amps, which means that your unit probably runs at less than 15 amps. And then we have line losses. So most motors that run on a 110 volt circuit are usually running at 1.5 HP. Now I have an offbrand DC that is rated at 750 cfm. and it will handle the planer, jointer or table saw individually no problem with a separator inline and 4" pipe no problem. I have upgraded to a 1 micron filter bag (much cheaper than a cartidge) and am in the process of adding a Thein Baffle. As of yet I do not know if my performance will be improved or not but from all the posts it seems like a no brainer. Regards Bob

Thanks Bob.

The HF motor, made in China, has as its motor plate a rather thick coat of shiny black paint. Apparently, they don't want anyone to perform that horsepower calc.   ;D  Some years ago, I slapped a multi-meter on my electric system with regards to determining its stability for my computers. Then, I got a voltage range between 105 and 115. I doubt that has changed much in a decade. There is, on the HF unit's filter ring, a sticker that along with the 2 HP claim and 1350 CFM (which is no doubt obtained by having nothing connected to either the inlet or outlet of the impeller!), states it runs at 14 amps. So plugging that into your formula, using worst case: 105 x 14 / 746 = 1.97 HP. I do not doubt that you are correct that the real life situation is significantly less.

I did run across some useful information at WoodMagazine.com and the .pdf suggested by RonS that indicates a solution closely matching your set-up, Bob. Although that .pdf is three years old (the Grizzly model they recommend is obsolete), it contains the only fan curve data I've seen for the Central Machinery (HF) unit. Based on that data, and forms found at FreeCalc.com, it appears that a 5" metal duct is optimum (as has been said by many others and thanks to them for being right), and that 4" PVC isn't optimum, but isn't significantly worse. (I still haven't found a way to calc SP losses in a long-radius sweep, where R is 4D+)

I also just found out the cost of 5" metal (26 gauge snap lock) available locally: $2.38 per foot, $5.12 ea for a 5-segment adj. elbow. Local price for 4" ASTM D2729 PVC = $1.06 per foot. A 45?? WYE = $10.20, and a 45? L = $5.43.

Cost for my layout: Metal = $230; PVC = $140.

I reported this to the budget director and she said about the cost for metal duct, "That's not so bad, is it?" to which I replied, "Hell, no." I went on to explain that the metal is optimized for my blower and results in fewer restrictions. (A 90? turn is accomplished in PVC by two 45? Ls whereas in metal, it's two 5-segment adjustable elbows, resulting in R/D of about 4, which apparently has about the same SP loss as the equivalent length of straight pipe.)

I'll keep y'all posted.

BTW, Doug: I'm taking a look at reversing the direction in my top hat, so that rotation matches that of the impeller. I'd still use the improvements suggested by retired2: his "air straightener" and bell mouth inlet. The only problem I face is that a long straight run into the separator winds up robbing me of about 4 square feet of floor space in my DC closet. The FreeCalc.com form suggests avoiding any changes in direction within 5D of the end of the duct (or ~2 feet in 5" duct). I have JUST 2 feet from the end of the sweep to the beginning of the cyclone in the top hat. Whew.

This is hard. Are we having fun yet?
Peter

Quote from: Carpenter96 on January 24, 2012, 07:50:52 AM
Hi Peter. Look at the motor plate volts x amps / 746 = theoretical horse power. Example 120 volts x 15 amps/ 746 = 2.41 (perfect world) if you have a volt meter you could ckeck the voltage in your outlet, Usually around 110 volts. As far as the amps if it is 15 amps that is usually peak or start up amps, which means that your unit probably runs at less than 15 amps. And then we have line losses. So most motors that run on a 110 volt circuit are usually running at 1.5 HP. Now I have an offbrand DC that is rated at 750 cfm. and it will handle the planer, jointer or table saw individually no problem with a separator inline and 4" pipe no problem. I have upgraded to a 1 micron filter bag (much cheaper than a cartidge) and am in the process of adding a Thein Baffle. As of yet I do not know if my performance will be improved or not but from all the posts it seems like a no brainer. Regards Bob

Bob,

Is your DC stationary and piped to each of your tools, or is it portable and you move it to each machine and connect up with a flex hose?  If it is stationary, how many feet of pipe and how many elbows to the farthest tool?

Quote from: Peter on January 24, 2012, 03:16:57 PM
Thanks Bob.

The HF motor, made in China, has as its motor plate a rather thick coat of shiny black paint. Apparently, they don't want anyone to perform that horsepower calc.   ;D  Some years ago, I slapped a multi-meter on my electric system with regards to determining its stability for my computers. Then, I got a voltage range between 105 and 115. I doubt that has changed much in a decade. There is, on the HF unit's filter ring, a sticker that along with the 2 HP claim and 1350 CFM (which is no doubt obtained by having nothing connected to either the inlet or outlet of the impeller!), states it runs at 14 amps. So plugging that into your formula, using worst case: 105 x 14 / 746 = 1.97 HP. I do not doubt that you are correct that the real life situation is significantly less.

I did run across some useful information at WoodMagazine.com and the .pdf suggested by RonS that indicates a solution closely matching your set-up, Bob. Although that .pdf is three years old (the Grizzly model they recommend is obsolete), it contains the only fan curve data I've seen for the Central Machinery (HF) unit. Based on that data, and forms found at FreeCalc.com, it appears that a 5" metal duct is optimum (as has been said by many others and thanks to them for being right), and that 4" PVC isn't optimum, but isn't significantly worse. (I still haven't found a way to calc SP losses in a long-radius sweep, where R is 4D+)

I also just found out the cost of 5" metal (26 gauge snap lock) available locally: $2.38 per foot, $5.12 ea for a 5-segment adj. elbow. Local price for 4" ASTM D2729 PVC = $1.06 per foot. A 45?? WYE = $10.20, and a 45? L = $5.43.

Cost for my layout: Metal = $230; PVC = $140.

I reported this to the budget director and she said about the cost for metal duct, "That's not so bad, is it?" to which I replied, "Hell, no." I went on to explain that the metal is optimized for my blower and results in fewer restrictions. (A 90? turn is accomplished in PVC by two 45? Ls whereas in metal, it's two 5-segment adjustable elbows, resulting in R/D of about 4, which apparently has about the same SP loss as the equivalent length of straight pipe.)

I'll keep y'all posted.

BTW, Doug: I'm taking a look at reversing the direction in my top hat, so that rotation matches that of the impeller. I'd still use the improvements suggested by retired2: his "air straightener" and bell mouth inlet. The only problem I face is that a long straight run into the separator winds up robbing me of about 4 square feet of floor space in my DC closet. The FreeCalc.com form suggests avoiding any changes in direction within 5D of the end of the duct (or ~2 feet in 5" duct). I have JUST 2 feet from the end of the sweep to the beginning of the cyclone in the top hat. Whew.

This is hard. Are we having fun yet?
Peter

Peter,

I wouldn't spend much time worrying about true HP.  Yes, there is a correlation between HP and CFM's, but as you can see from the fan curves in the test you referenced, the performance can vary quite a bit from DC's all having the same HP rating.  That is why a fan curve is far more useful than any other piece of data.

Some time back I posted information about the SP loses for 90 and 45 degree ells of varying radii.  As you might expect 1D bends like those found in plastic pipe impose very high losses.  However, increasing the bend diameter follows the law of rapidly diminishing returns, and after 2.5D the return is nearly zero.  Here is some data on equivalent length of straight pipe for 90 degree ells of varying sizes and bend radii.  You can simply halve these numbers for 45 degree ells.

                     1D         1.5D        2.0D        2.5D       

4' Pipe            12'          6'            3'             3'

5" Pipe           18'          9'            6'              5'

6" Pipe           24'         12'           7'              6'


Here are some SP losses per foot of pipe at 3500 FPM and 4000 FPM, which is most likely the range you will be operating in with a 1.5HP DC.

                       3500 FPM            4000FPM

4" Pipe             .055 in./ft.          .070 in./ft.

5" Pipe             .042 in./ft.          .055 in./ft.

6" Pipe             .035 in./ft.          .045 in./ft.


Convert all your fittings to equivalent straight length of pipe with the information above.  45 degree laterals or wye's should be treated as a 45 degree ell.  The straight leg of a wye should just be counted as straight pipe.  And of course, you need to add the actual length of straight pipe to the equivalent length of the fittings.  Then multiply the total by the losses per foot above.  Your not done.  You need to add losses for the entry port and the DC.  Assume 1" of SP loss for the tool entry port and another 1"-2" for losses at the blower.

Use the above instructions to calculate your SP loses for your worst case scenario, usually the tool farthest from the DC.  Take the SP loss to the fan curve and see if the remining SP moves enough air (CFM ) for the tool.  Most tools need 400-450 CFM.

And now for the bad news.  The above exercise does not take into consideration the losses from a Thien separator.   I took anemometer readings on my system to see how the separator affected performance.  Without the separator, I had 705 CFM at 5171 FPM, those are very good numbers.  After I installed the separator, those numbers dropped to 434 CFM at 3185 FPM.  At this level the performance is approaching speeds that are almost too low to keep the dust and dirt in suspension.

Hope this post helps.

Here is an artical from wood Magazine that has some of the infor and process metioned above by Retired2. It looks like this artical is dated 2007 and it is little blurry but usable. It is a process to determining your SP loses. Do a loss calc for your main run and then for each of your drops, add the main loss to each drop loss and look at your worst case run. I would use Retired2's SP loss for the Thien seperator in your main run.

Hi Retired2. My DC is portable and I just hook it up to which ever machine requires it. It has never been over whelmed by shavings. I could not justify the cost of solid piping and a larger more powerful DC. Regards Bob

Quote from: Carpenter96 on January 25, 2012, 04:03:30 AM
Hi Retired2. My DC is portable and I just hook it up to which ever machine requires it. It has never been over whelmed by shavings. I could not justify the cost of solid piping and a larger more powerful DC. Regards Bob

Bob,

I asked that question even though I was pretty sure of the answer.  I just didn't want anyone to get the idea from your original post that they can build a stationary dust collection system around a 1HP 750CFM unit.  With a Thien separator, it simply will not work.  In fact, even without the separator, it is doubtfult the performance would be acceptable.

Moving a DC from tool to tool will work with a smaller unit because the line losses are minimal, but anyone planning to build a stationary DC system should purchase nothing less that a 1-1/2 HP 1200CFM unit.

Regards

Quote from: Carpenter96 on January 25, 2012, 04:03:30 AM
Hi Retired2. My DC is portable and I just hook it up to which ever machine requires it. It has never been over whelmed by shavings. I could not justify the cost of solid piping and a larger more powerful DC. Regards Bob

Bob,

Did you make a cart so the DC, can and top hat all roll around? Or, do you use a flex hose to hook up to the various machines? Do you have your blower mounted sideways above the top hat?

Okay...First run on my Worst Duct calcs. It ain't pretty.

25 feet of straight pipe
3 90 Ls (2.5 R/D) = 15 feet
1 45 L = 2.5 feet
1 Wye = 2.5 feet
Total effective length = 45 feet  :o
Figuring the required CFM at the tool = 440 CFM, 4" duct allows 5000 FPM, 5" duct allows about 3200 FPM. (I'm gonna abandon 6" duct).  Loss per foot for 4" = .070, for 5" = .042. (about)
SP loss in duct, then is 3.15 @ 4", 1.89 @ 5". Allow 1" loss at tool, 1" at duct end, and 2 for the Thien.
Total SP Loss for 4" = 7.15; for 5" = 5.89.
According to the Wood Mag test, the HF unit (<6 " SP at 400 CFM) can't move enough air.

I'll need to relocate my machines. Damn.
I think I'm okay at my table saw, because it's only 29 feet (effective length) from the DC and loses 1" SP less. (6.4@4" and 5.4@5").

Y'know, if I didn't feel the need to walk around in my shop, I could just have the pipe at impeller level and avoid all these verticals and bends.  ;)

Am I assuming correctly, that if the SP losses in the ductwork add up to less than the overall SP at the desired CFM for the blower, the system will work?

Quote from: Peter on January 25, 2012, 02:51:12 PM
Okay...First run on my Worst Duct calcs. It ain't pretty.

25 feet of straight pipe
3 90 Ls (2.5 R/D) = 15 feet
1 45 L = 2.5 feet
1 Wye = 2.5 feet
Total effective length = 45 feet  :o
Figuring the required CFM at the tool = 440 CFM, 4" duct allows 5000 FPM, 5" duct allows about 3200 FPM. (I'm gonna abandon 6" duct).  Loss per foot for 4" = .070, for 5" = .042. (about)
SP loss in duct, then is 3.15 @ 4", 1.89 @ 5". Allow 1" loss at tool, 1" at duct end, and 2 for the Thien.
Total SP Loss for 4" = 7.15; for 5" = 5.89.
According to the Wood Mag test, the HF unit (<6 " SP at 400 CFM) can't move enough air.

I'll need to relocate my machines. Damn.
I think I'm okay at my table saw, because it's only 29 feet (effective length) from the DC and loses 1" SP less. (6.4@4" and 5.4@5").

Y'know, if I didn't feel the need to walk around in my shop, I could just have the pipe at impeller level and avoid all these verticals and bends.  ;)

Am I assuming correctly, that if the SP losses in the ductwork add up to less than the overall SP at the desired CFM for the blower, the system will work?

Peter,

In a matter of hours I will be leaving on a three week trip to India and Nepal, and I won't be able to help once I leave.  So, when it goes quiet on my end it is not because I am ignoring you. 

I have not checked your calculations, but your worst case SP loss is slightly less than 6", and I think you might be O.K.  Draw a horizonatal line on the fan curve at the at 5.89".  That shows you will still be moving about 500 CFM of air.

Remember there are a number of less than precise assumptions in this process.  Entry and exit port losses at 1" are probably conservative and they may not be quite that bad.  And the separator, could be more or less than 2".  But you have to start with something and if the fan curve for your unit is reasonably accurate, the 500 CFM might mean the FPM's are a tad low, but not so low it won't work.  You can readily calculate FPM from CFM.  You should have no problem finding the formula, it is simple math.

Another reason I think you will be O.K. is my system works with a longer equivalent straight length of 5" pipe than you have, but I do have the Delta 50-760 which has a better performance curve.

In any case, I think you are within the accuracy of the assumptions, calculations, and fan curve for you unit.  But you can see the value in this exercise.  4" or 6" pipe clearly would not have been a good choice for you.

Just out of curiosity, what tool is at the end of this worse case scenario? 
 

Retired,

Wow, have a WONDERFUL trip! Take a pic of Everest for me, will ya? (Or K2, I probably wouldn't know the difference ;) )

Anyway, I do appreciate your help. At the end of The Worst Duct is either: a group of sanders (disk, belt, spindle) or a thickness planer. There's a sketchup drawing of my shop layout in Post #4, where I hijacked this thread (Sorry, Doug!). It shows the planer at the end of Worst Duct, but I could move the sanders to just across the wall from the DC closet and put the drill press at the end of Worst Duct and the planer where I show the sanders.

One thing my calcs do NOT account for is the 3'-4' long sections of hose that connects the machines to the blast gate. If it weren't for the need to slide the machines away from the wall for accommodating longer stock, I could hard pipe them.

I don't mind sweeping up chips, such as might be generated by drilling huge holes in pine with a forstner, or by hand planing at the workbench. And, I am hoping that by investing in an air cleaner, I can trap some of the fines that the DC system misses.

Thanks again, sir.
Be safe in Asia.
Peter

Quote from: Peter on January 25, 2012, 04:05:06 PM
Retired,

Wow, have a WONDERFUL trip! Take a pic of Everest for me, will ya? (Or K2, I probably wouldn't know the difference ;) )

Anyway, I do appreciate your help. At the end of The Worst Duct is either: a group of sanders (disk, belt, spindle) or a thickness planer. There's a sketchup drawing of my shop layout in Post #4, where I hijacked this thread (Sorry, Doug!). It shows the planer at the end of Worst Duct, but I could move the sanders to just across the wall from the DC closet and put the drill press at the end of Worst Duct and the planer where I show the sanders.

One thing my calcs do NOT account for is the 3'-4' long sections of hose that connects the machines to the blast gate. If it weren't for the need to slide the machines away from the wall for accommodating longer stock, I could hard pipe them.

I don't mind sweeping up chips, such as might be generated by drilling huge holes in pine with a forstner, or by hand planing at the workbench. And, I am hoping that by investing in an air cleaner, I can trap some of the fines that the DC system misses.

Thanks again, sir.
Be safe in Asia.
Peter

Figure flex pipe as 3X the length of rigid pipe.  The fines from sanders require more air than the thickness planer, so if you are going to start moving things keep that in mind.

If I had not been so far along I would have incorporated one of Phils suggestions, i.e. move the separator away from the DC in a branch so it only separates the waste from the heavy chip producers.  Allow the tools that produce fines to be piped directly to the DC..  That gives maximum CFM to the machines that need it, i.e. sanders, etc.  It keeps the shop cleanest, and dedicates the separator to the task it handles best.  The down side of course is a lot of fines are going to end up in the filter.

Good luck.

Quote from: retired2 on January 25, 2012, 05:19:46 PM
If I had not been so far along I would have incorporated one of Phils suggestions, i.e. move the separator away from the DC in a branch so it only separates the waste from the heavy chip producers.  Allow the tools that produce fines to be piped directly to the DC..  That gives maximum CFM to the machines that need it, i.e. sanders, etc.  It keeps the shop cleanest, and dedicates the separator to the task it handles best.  The down side of course is a lot of fines are going to end up in the filter.

Good luck.

I usually tell people to put the separator in front of the heavy chip producers, and add a baffle to their DC.  That way they get the best of both worlds (sort of).  But adding a baffle to some of the Delta units is problematic.

Quote from: phil (admin) on January 25, 2012, 06:12:20 PM

Quote from: retired2 on January 25, 2012, 05:19:46 PM
If I had not been so far along I would have incorporated one of Phils suggestions, i.e. move the separator away from the DC in a branch so it only separates the waste from the heavy chip producers.  Allow the tools that produce fines to be piped directly to the DC..  That gives maximum CFM to the machines that need it, i.e. sanders, etc.  It keeps the shop cleanest, and dedicates the separator to the task it handles best.  The down side of course is a lot of fines are going to end up in the filter.

Good luck.

I usually tell people to put the separator in front of the heavy chip producers, and add a baffle to their DC.  That way they get the best of both worlds (sort of).  But adding a baffle to some of the Delta units is problematic.

Thanks for the clarification Phil.  I've got one of those problematic Delta's, so I'm limited as to what I can do. 

Quote from: phil (admin) on January 25, 2012, 06:12:20 PMI usually tell people to put the separator in front of the heavy chip producers, and add a baffle to their DC.  That way they get the best of both worlds (sort of).  But adding a baffle to some of the Delta units is problematic.

Something like this?

Planer (jointer, table saw) ? very short duct ? Separator ? ? ? ? duct as required ? ? ? ? Impeller ? Filter ring with baffle.

As opposed to:

Any machine(s) ? ? ? ? duct as required ? ? ? ? Top Hat Separator / Impeller ? Filter ring with baffle.

Hi Retired2 I agree that a larger system would be neccessary for a stationary DC but I don't really spend much time to connect my DC to each machine as I need it. Like I said it has never been overwhelmed by shavings or dust even when I planed a couple of hunred board feet. Yes I had to empty several times but very little was left around the palner. Regards Bob