1 1/2hp dust collection, waste of money?
tcbaldmtn
| Posted in Power Tools and Machinery on
In the current issue they discuss dust collection. It states that a 1 1/2 hp unit should only have 4 ft. of hose connected to it. I have 15 ft. It seems to work OK. Am I missing something? In another article they suggest using a single 6″ hose. Is this a good idea? I thought about doing this soon, but am I wasting my money?
Replies
No they are being very conservative on this one. I had a 1.5 HP Delta sucking through about 40 feet of 6" and 4" PVC with 6 or 7 drops and only had a clog once and it was an extreme situation. Now I am running a 3 horse system and the only difference is that the RAS collects a little better and the dust dosent build up in the Unisaw like it did. Of course now when multiple machines are running it works better.
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
I have been using the Delta 50-760 1 1/2 Hp DC for a few years now, always running through at least 18 feet of 4" flex tubing and it has inhaled anything my jointer, planer or other tools can throw at it. I even hooked it up to my jointer AND planer at the same time once just to see if it could handle both operating at the same time, which it did.
Tom Hintz
Because there is always more to learn!
I have a Delta 1 hp 2-stage barrel collector (not a cyclone - it has a collar inside the first barrel that creates a bit of a cyclonic effect before feeding to a bag on top of a second barrel). I think it's been out of production for a decade. It has done an excellect job sucking up everything while planing 12" boards at the end of 22' of 4" PVC plus 6' of 4" hose.
I don't know if it will handle my new shop with a run of 30' to the table saw which collects dust at the guard and the cabinet base.
I would also like to upgrade to a system with a canister instead of a filter bag - I release a fair bit of very fine dust every time I deal with the bag.
tcbaldmtn,
It really depends on what you do and how you do it..
I have a 2 Hp collection system and with only 6 feet of hose it clogs regularly whenever I run my 20 inch planner.
I don't need to be planning more than a 12 inch wide board and it quickly clogs. If I double or triple pass the board it's better but anytime I need to hog off a lot of the surface of anything there simply isn't enough suction.
When I use the shaper (3 HP) it's the same deal I can move the planner out of the way and use the same 6 feet of shaper and the shaper will quickly remove so much material that it clogs the collection system.
However if I'm using the tablesaw, jointer, or any other machine I can have 15 20 or even more feet and never get a single clog..
I had the same problem with my unit, however I added a large plastic bin to the line with an air seal around inside the lid. I cut 2 holes in the top on of the bin for shavings in and one for air out going to the extractor. I placed a section of hose on the in side of the bin shaped to direct the shavings around the side and toward the bottom. This works really well and stops the shavings clogging the extractor. best of all it cost about $30.00 Australian for the lot.
Regards Luckyboy
Hello
If I were you Ide try buying a separate separator for your dust collector?( http://www.rockler.com/product.cfm?page=1515&SearchHandle=&filter=dust%20colectors ) Like this kind, works well.
I have two separators (one at each end of my shop) the separators ketch most of the debris and the collector never has any problems with clogging because the separators do most of the work by catching the big stuff, like plainer and jointers chips. only the small dust gos to the collector.
also the separators are much easer to empty than the collector's bag.
C.A.G.
Edited 11/22/2006 7:37 pm ET by Curtis
Curtis,
yes I have a seperator system right next to my dust collector. Actually dust collector is wrong sense it collects relatively little of the really fine dust particals, for that I have a seperate dust filtering system. Basically it means that the "dust collector" acts like a giant shop vac.
That too I've modified with it's own precleaner. I buy simple furnace filters and tape them to the filter. That way I can easily see when the main filter needs real attention and I wind up doing less monkey work.
I bought a box of them at a surplus store for 10 cents each but at retail they are only 99 cents..
Edited 11/23/2006 12:44 pm ET by frenchy
TC, This is the deal,1.5hp may well keep your shop looking good.Your lungs on the other hand might just be filling up on the finest/most dangerous particles.You need to move a lot of air to get the smallest.You also need a finer filter than the bag that comes on a 1.5.Upgrading to a better filter is an option but the new air filter restricts air flow.A 1.5 will do a much better job than nothing. Adding a real dust mask(one with replaceable cartridges)is better yet. Good luck with this.
TC: I think the article in FWW is just another facet of how our whole society is infected with "CYA" to the point of absurdity. No one can say anything straight out, a lawyer is needed to review every last detail of an article. Every thing we buy has warnings, even a new kitchen faucet has warnings about the lead in the brass. New power tools have pages and pages of warnings in twelve languages. That is why one has to decipher any written advice to get a reasonable suggestion. Kinda makes the whole concept of learning a craft from magazines futile. Duke
PS: I have a 1½ hp dust collector with 10 feet of 4" hose and it has never clogged.
"... if people did not die so untidily, most men, and all women, would commit at least one murder in their lives." R. Kipling
Duke,
Where was the Kipling quote from?
dave
Dave: I've read some Kipling but don't remember where the quote is from. Duke"... if people did not die so untidily, most men, and all women, would commit at least one murder in their lives." R. Kipling
The flexible hose really robs the DC of air flow, so you want to keep that to a minimum, run rigid pipe as much as you can. Put your biggest challenges closest to the DC (table saw, planer) -- they require to most CFM.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
What everyone needs to realize is there is a large (pun intended) difference between dust and shavings. A small DC will indeed pick up the large shavings of a jointer, as well as the dust particles above 15 microns or so. What a small unit is not good at is picking up the microscopic particles, the ones you cannot see.Dust collection is a SYSTEM, not a piece of hardware. You have to carefully integrate how it is picked up at the source (and rarely is that 4" diameter pickup hole enough), how it is transported, and finally, how the air is filtered and returned. You have to return it or you get less pickup. You need air to replace what air you have sucked out.You need a DC that will move enough air to handle the CFMs needed, and since it's closer to 800 than 350 on many tools, such as bandsaws and tablesaws, you would require air movement in the 10s of CFMs to move that much air in a 4" cross section, and by then, the duct will have collapsed from the pressure.Also, never use laundry or any other ducting sold by the BORG,as it's designed to push, not pull. The difference? Have you and a friend keep straws in your mouth. One of you gets to blow out to move a balloon, the other can only suck in. If you have a 1.5 HP single stage collector connected by 9 feet of standard flex hose, you have a glorified vacuum cleaner that will suck some large shavings at the source (i.e. a jointer with a chute that points down).It isn't rocket science, but it IS science. Air movement in these directions does require some careful analysis to get right, which is why larger businesses subject to OSHA regulations are more careful about it.
Daryl,
Excellent points.
Since many (most) machines have (at the largest) 4" dust ports, how much does a 6" or 8" hose from that port to the DC help in the system, assuming the DC can really move the necessary CFM through the hose. As with a 5hp standard or cyclone unit.
Any opinion regarding differences in system performance comparing rigid tubing to flexible?
Rich
You can get a lot of improvement if you use an adapter directly at the source. Not perfect, but it's still OK. My bandsaw came with a 4" dust chute, and I have a 6" adapter right there. Seems to do a lot. Flex hose is awful, and you really get what you pay for. The stuff from Woodworker Supply, Penn State Industries, etc. isn't worth anything. Flex hose generally reduces air flow efficiency by a factor of NINE. Ten feet of flex hose is like running 90 feet of rigid pipe. Keep them at a minimum, and even then, use Oneida's or Wilke's flex hose. Oneida has really goos stuff, like the cheap stuff in that it's coiled wire, but the plastic used is much heavier duty, so it bellows much less. Wilke's is molded, and fairly complex, but is much smoother on the inside. Both are very expensive, especially since you need diameters above 4" Generally, your flex should be 6".
Flex hose reduces the efficiency by NINE times>
Wow! As in reducing CFM from 900 to 100?
I don't know if the numbers correlate in terms of CFM, but according to Bill Pentz, he uses the ninefold reduction, so I am repeating it.My club on Long Island had a dust collection seminar last month, and the member who presented, Richard Strickland, had a very thorough approach. I think he's a physicist. He wound up virtually repeating what Bill wrote, yet he never heard of him. Just Richard doing a careful job of research and calculations. So I bet the 9 figure is accurate.
I don't have the option of ridgid pipe. I share my 20x20 garage with my wife. The DC sits in the corner out of the way. I need about 12' of hose to reach my machines when I move them. I guess if I buy 6" hose I'm not wasting my money?
I also share a 20 x 20 garage with my wife. I have some photos of my shop in my club website gallery. It's at http://www.liwoodworkers.org. I'm in the Gallery, the only Daryl there. I grant you, my cyclone is in a small shed outside, or I would not have fit it there. My tablesaw/shaper is fixed, everything else is on wheels. And I talk a good game. I do have 10' of 6" flex (from Oneida) that connects the jointer/planer and bandsaw, with a quick disconnect.
You need a DC that will move enough air to handle the CFMs needed, and since it's closer to 800 than 350 on many tools, such as bandsaws and tablesaws, you would require air movement in the 10s of CFMs to move that much air in a 4" cross section, and by then, the duct will have collapsed from the pressure.
It's interesting that most people seem to remember the 800 cfm figure from Bill's site, but not why. If you look at the collection diagrams for the individual tools, just about the only ones that need 800 cfm are those with two collection points:; e.g., on a table saw, you don't need to suck 800 through the 4" port on the cabinet: it's 440 cfm through the cabinet, and 350 through the blade guard. Same thing with the bigger bandsaws, which need ~700 cfm, but have two 4" ports. Planers that need in the 600 cfm range typically come with 5" ports.
In http://billpentz.com/Woodworking/Cyclone/DC4Dummies.cfm, go to the "#CFMRequirementsTable" entry
Note that two 4" pipes have about the same cross section as one 6" pipe. You could run two 4" pipes back to the DC, for the machines that need it, from their two 4" ports, and just one 4" pipe for the machines that need less.
Edited 11/24/2006 2:34 am by BarryO
Edited 11/24/2006 5:01 am by BarryO
Edited 11/24/2006 5:31 am by BarryO
TCB, Daryl is right -- that it's a science. Mr. Bill Pentz' site is oft-visited and oft-referred to in woodworking circles, so if you want to really exercise your mind and inform yourself, take a visit:
http://www.billpentz.com
I'd suggest starting in the Dust Collection Basics section. You'll find charts and such, but the paragraphed information is critical to understanding. My DC is still in the one-hose-at-a-time stage, so everything I've read at Bill's site has been forgotten, to be re-absorbed at a later time.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Ten years ago I bought an Oneida cyclone and powered it with a single stage centrifugal fan, driven by a 1 HP motor. A fan and motor that I had on hand from an earlier dust collector. Being an ancient design with a ruff cast aluminum rotor, the fan is no where near the efficiency of a newer unit. For all of that tho, it works splendidly. Pickup is via a spiral-flex 5 in hose which terminates in a 4 in pipe for a machine connection. The only times it has become plugged are when sticks are pulled in and jam crosswise in the line. Other than that, no problem.
For most of it's years, the cyclone was mounted outside of the shop on the wall. The only debris to ever exit the exhaust was when the barrel was full to overload. At that point, life gets messy in a hurry.
Two years ago after moving to a new location, I was forced to live with the noisy bugger in the shop. But it still operates without filtration on the exhaust. The area surrounding the exhaust gathers no more dust than that which accumulates generally. No dust is visible in operation. ..... which is not the same as saying that it's 100% effective. Nonetheless, I have no issues with dust operating the system as described. ......... tho, I do have an issue with noise from that old fan, LOL. It's not well balanced and vibrates a lot.
I have the Delta 1 1/2 horse DC sitting in an add-on attached to my shop. It is attached to approx. 28 feet of 4" PVC duct inside the shop, connected to several y branches with dust gates. So far, I have had no problems collecting chips/dust with this set-up. I make sure that any unused ports are closed off with the blast gates, and the heaviest chip producer (the 12" jointer/planer machine) is closest to the dust collector. The table saw hookup is furthest from the DC at the end of the 28 foot run, and have no problems here either.
The way mine is hooked up may be the reason I have no problems with this. The ductwork is on the same level with the blower, which is still mounted on the original stand that came with the DC. This is attached to a 6" HVAC metal duct through the shop wall (less than 2 feet) and then to the PVC. All this is approx. 16" from the floor.
I believe if there are no major elevation changes, such as from a ceiling mounted duct piping system, a system like this will work well. Keep in mind that I only have one machine at a time running in a one person shop, so that might make the difference. Be safe and watch those fingers.
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