Has anyone built a cyclone-type dust collector as shown in Shop Notes or Wood Magazine? If so, did it work well? I’m thinking of building one myself, using an HVAC blower as the fan. How do those compare to the impeller types? Can I find a fan curve for HVAC blowers? Where would I find a good filter? Any info would be enlightening at this point.
Thanks,
Scott
Replies
Hi,
I have been considering building a 3hp cyclone myself, for a couple months now and using the Penn State blower/motor.
Your idea of using a squirrel cage type blower/motor is interesting and I don't know how that would work.
Penn State industries can supply you with all the accessories for the system. pennstateindustries.com
Keep us informed on your progress!
regards,
Tom
Guys,
A squirrel cage does not have the static pressure need for a dust collector. That is the major reason that the duct work is so large for a heating system. they require a "free" inlet to function. They are designed for high volume with low pressure.
Joe Phillips
Plastics pay the bills, Woodworking keeps me sane!
In the interest of time, I will buy the 1HP State Penn ;) collector and make a pre-separator "cyclone" with a steel garbage can. The good thing about the Penn State is removable motor/blower. When the need arises and time permits (at least 2 furniture projects from now) I will build a cyclone and put the Penn State blower on top.
How do you like the Penn State?
Scott
Prarie,
I don't have a penn state but have been evaluating either building my own 3hp system with their components or shelling out for the 3hp Onieda system for 1,850.00 (ouch).
At the moment I'm planning on building my own with the Wood Magazine plans which I purchased.
The only difference from the Onieda would be probably a lesser quality blower moter from Penn State and the impeller would be steel instead of cast aluminum on the Onieda.
If I got a bunch of furniture work I would buy the Onieda!
Tom
Since reading the dust collector review in the March 2002 issue of Wood Magazine and doing some friction loss estimates for my shop, I have opted for the 1-1/2 hp Delta DC. Initially, if I wheel the thing from machine to machine, the 1 hp would be fine, but once that gets old and the DC system grows up to become a stationary with a preseparator, then the addition CFM will be a necesity. The blower is still separate from the bag housing, so if I want to put it on a home-made cyclone, I can.
My current question is about replacement bags. Any suggestions? The delta bags (1 um) look like they would hold up well. Those offered by Woodworker's Supply are rated better (98% of 0.1 um and larger) but look like that thin cheasy spun synthetic that might not stand up to real use.
Thanks,
Scott
Hi Scott,
Did you check out the Penn State website for their components?
http://www.pennstateind.com/products.html
I think the pleated filters would be best, JMHO.
Also, you might want to think a few years down the road as to what your shop will be like then. Will a 1 1/2 hp system be adequate then? Just suggesting that if you are going to go to all this trouble make sure it's a system you can grow into.
That's why I'm going with the 3hp. I know it will handle some additional capacity down the road.
Regards,
Tom
my 2 cents-
get the most CFM you can afford now -
a few years down the road or an upgrade or two in equipment, you'll be buying another collector in addition to what you have now or be sad that the collection is not what you had hoped for -
Robert
I ended up with that DC too. I purchased the upper bag that Wood magazine used in the tests. It's from CFF, C??? Fabric and Filter, (the contact info is in the article). With the oversided 1 micron top bag there is enough CFM so I can use a plastic trash bag as a liner for the bottom bag. I used a 3 mil 'contractors cleanup' bag from Home Depot. I've got great airflow through the system and could run multiple machines at once, (if I only had a clone!). The upper bag was not cheap but it appears very well made and I'm betting it will hold up well. I think it was a good investment.
later,
Note that a number of maufacturers tend to use aluminum rather than ferrous metals for fans and/or housings in dust collectors because ferrous metal will cause sparks if the fan were to come loose and rub against the housing . With the wood dust in the system , the sparks can cause fire or explosions .
Marp,
Actually very few dust collector fan impellers are aluminum.
The only one I know of that is available for small cyclones is Onieda. I think all of the single stage collectors are steel impellers.
However unlike a single stage dust collector which sucks everything directly throught the impeller, a cyclone system separates the vast majority of material out before anything reaches the impeller.
Also, the reason for the aluminum impeller is not really for a loose impeller contacting the housing so much as a stray piece of metal that has been drawn into the system that may cause a spark. A nail cut by the saw blade for instance.
Tom
I have an older unit ( note sure of the make since I picked it up used ) and it has a cast aluminum impeller and cast housing. The main point is to realize that a spark in a dust collection system can lead to a dangerous situation wheather it be from a nail that gets cut and sucked in or another source.As you state, putting a cyclone in front of the collector minimizes the chance of anything reaching the fan.I believe it is still prudent to look for an impeller housing combination that minimizes the chance of a spark developing. A lot of the off shore models today have metal housings and metal housings.
Marp,
Just out of interest what hp is your collector?
I've never heard of one with cast alum. impeller and housing.
Sounds like an industrial unit. Nice buy to find it used!
Regards,
Tom
2 HP, 220v . 1 phase, I believe it to be about 30 years old.
Scott,
I have the Penn States 1HP DC-1B and have made a type trash can cyclone to use with it. The cyclone I made sits atop a 30 gallon trash can. In profile, it looks like the upper portion of a cyclone, with the trashcan where the cone should be. It works nicely at separating the bigger wood chips out when hooked to my router table, jointer, or planer. But by no means is this combo good enough to use as a whole-shop DC system. It just doesn't have the power.
While the PSi unit is a very nice machine, and great to roll around from tool to tool, it is not sufficiently powered to enable you to use it's blower & motor in a cyclone.The WOOD magazine cyclone uses a 1 1/2 HP blower/motor combo. You should really stick with something long those lines.
I built the WOOD cyclone last year and am just getting around to buying a 2 HP motor for an old Jet DC-1200 blower that I salvaged. I plan on using this combo to sit atop the cyclone and generate the air flow I need for my DC system. When I originally built the cyclone, I used the chart in the back of the plans to increase the size of the cyclone to fit my 2HP DC.
Not to preach to you about cyclones, but there is a good amount of math involved in designing one. Getting a 1HP blower and deciding to build a cyclone for it might just be an exercise in futility. You might find that the system doesn't work as well as you thought. And another thing, cyclones typically "rob" a DC system of 2" to 3" of static pressure (SP). The more loss, the weaker the system.
Sorry to bend your ear! Good luck with your DC system.
A DC needs high volume/high pressure
low volume/low pressure - most cheap bladed fans found around a house(before AC)
high volume/low pressure - squirrel cage blower(central heating/AC)
high volume/high pressure - dust collectors
low volume/high pressure - most 'shop vacs'
Technically, anything that will move air will work to some degree, but serious dust collecting needs high volume/high pressure. Such fans will have enclosed turbin type blades moving at 3400+ rpm, with a 1.5+ HP motor.
PlaneWood by Mike_in_Katy
PlaneWood
Well if you are bit of a pack rat like myself than you may be able to get a few ideas and cobble something together from this guy.
Check it out.
http://www.wwforum.com/faqs_articles/saw_dust_collection.html
Scott C. Frankland
Newfoundland Wood Worker
Hi,
If you think outside the square, using a squirrel cage fan works very well in certain circumstances. (A warm climate being one of them)
Having observed the very fine layer of dust lying around shops with bag DCs, their cost, noise and the hassles of emptying bags I started thinking about using a cage blower and dumping the fine dust straight through the wall and out of the shop.
I quickly learned that ducting and chip collectors weren’t an option due to the low pressure and after trying out several set ups I finished up with a blower salvaged from an old roof mounted evaporative air conditioner. I installed it on the floor at one end of my shop with the outlet discharging through the wall into the garden. It blows a veritable gale – the motor is about half horse. The noise is comparable to a washing machine on spin.
There is no ducting. My machines – saw, jointer, thicknesser, router table, mitre saw etc are all located nearby. Fresh air comes in through a door at the other end of my shop.
Fine dust is non existent. Saw dust falls from the saw and creates a trail toward the blower. Jointer shavings likewise grade themselves by size, the small bits disappear completely and heavy chips fall on the floor. I have incorporated a chip collector under my thicknesser which gathers most of the chips. I’ve taken the dust bag off my sanders and replaced them with a short length of flexible vacuum hose that redirects the dust forwards and I sand facing the blower.
Dusting off work for finishing or blow cleaning the machines is done with compressed air – again facing the blower.
The small amount of spray painting I do requires no spray booth although I do have slight doubts about fire risks but nothing has exploded yet!
A periodic sweep up toward the blower is all that is needed to keep my shop totally clean.
Fumes from welding, thinners etc never make to my face. My desk with it’s computer and printer is located at the business end of the shop and has just had it first wipe down in eighteen months.
Interestingly the isn’t a trace of sawdust or shavings in the garden but neighbours know when I’m varnishing.
Ray - Australia
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