Thread: Dust Extraction for new shop

Originally Posted by pippin88

It occurred to me whilst reading this thread, that an impeller may be easily laser or water cut.
They are quite simple designs
One round plate with some slots cut into it
Then the fins with some tabs
Shouldn't be too hard to bend the fins

That's the easy part - the hard/expensive part is getting it dynamically balanced - especially of you expect it to run at 3600 rpm. I know someone who made their own and balanced it at slow speed but it took him a long time to get it true.

Cody, based on your shop size and activities a Clearvue MAX will be the go. Yes the lead time is slow and installation is longer but is such an effective extractor there's nothing else that beats it.

Use the lead time to build the support stand, sort out the bin, maybe build an enclosure of you plan to locate inside or outside your shed,

RE: the $400 VFD
You can by the VFD direct from the Factory in China and save about 50% - use the lead time to order and get this sorted - Chris Parks can guide you on this. Its worth every penny to have a DC running on a VFD

Bob is, as usual, on the money about getting the impeller properly balanced and because of my aviation background I would have it crack checked too. A magnetic particle check can locate cracks in or adjacent to the welds. Some fabrication shops have the capability in house otherwise there should be some non destructive testing companies near you. Now you will have an inkling as to why impellers are so expensive.

With you having 3 phase power in your shop now as long as you get a dual voltage (220V/ 440V) Delta Star wound motor you can add the VFD later. If you want to boost/reduce the rpm in the shop you have you can get one that controls 3 phase to 3phase. If you decide to move and the new shop only has single phase you can get one that takes 220V single phase and outputs variable 3 phase. That gives you the most options should circumstances change. Should you ever get a modest wide belt sander you will want all the capacity you can get.

Good luck with your quest.

Pete

The impeller in a dust extractor is a low speed device and I have yet to see any issues or any signs of dynamic balancing from any manufacturer. I think CV do some rudimentary simple balancing but not anything more than that. There was a chap in this forum who made an impeller bigger by extending the vane length and I can't recall any problems in service from balance issues. I am not sure CV do any balancing but recently I was told that there was some evidence of it. Peter, you have an unassembled CV, have you looked at the impeller to see if there is any evidence of dynamic balancing. They may do a simple static balance but dynamic balancing requires complex equipment.

Originally Posted by Chris Parks

The impeller in a dust extractor is a low speed device and I have yet to see any issues or any signs of dynamic balancing from any manufacturer. I think CV do some rudimentary simple balancing but not anything more than that. There was a chap in this forum who made an impeller bigger by extending the vane length and I can't recall any problems in service from balance issues. I am not sure CV do any balancing but recently I was told that there was some evidence of it. Peter, you have an unassembled CV, have you looked at the impeller to see if there is any evidence of dynamic balancing. They may do a simple static balance but dynamic balancing requires complex equipment.

I agree that 3600 rpm is a relatively low speed but the diameters are large and the rotating mass is significant.
The 3 CV impellers I have looked at closely all have evidence of balancing ie holes drilled in the base plate.
Even my budget 13" impeller has this - the two slightly rusty dimpled holes in the upper RHS of the base plate.
IMG_2997.jpg

One of the mens sheds extended the vanes on their DC's 16"? impeller by a couple of inches. That DC is driven by I think a 10HP motor. The only did a static balance but the impeller was already balanced which is different than building an impeller from scratch.

There are a couple spot drilled spots on the backside of the impeller so most likely just a static balance.

Pete

Originally Posted by QC Inspector

There are a couple spot drilled spots on the backside of the impeller so most likely just a static balance.

Pete

They are building from scratch and deem that dynamic balancing is not necessary. A shaft and a bearing is all that is necessary for that, the weight can be adjusted in any number of ways.

Cody, I really don't have practical advice, but I do have some observations.

You are a carpenter and want to do woodworking as a business. Funds are limited for dust collection. Having been self-employed for many years, I would be very cautious about trying to save money by using your time. If you think it is fun to build a cyclone and impeller and want to do that as a hobby, then that's totally reasonable, but don't think of that as your business and do it after business hours. If your goal is to get a cyclone to support your business, it would probably be more efficient for you to use the skills that you have to make extra money to buy whatever you need. If you are tired of carpentry, but get paid for it, you might take on some extra jobs and think of that time as "cyclone time." That has the added benefit of getting you talking to customers, which could lead to more work in the future. If instead you spend all that time calling around to get an impeller and cyclone built, that doesn't really help your business. The time vs money calculation for that often works because it is using what you are most efficient at (carpentry) as well as the efficiency of the impeller supply chain.

Since you are planning to build an air tight closet that vents outside, you could consider not having a cyclone and instead getting a 3HP single stage collector. Because it is single stage and doesn't have the losses associated with a cyclone, a 13" impeller works. Just make sure the impeller is big enough. The downside is that you will have bags to empty and if you do a lot of fine sanding the filters might clog quickly, but those are all time vs money calculations. At some point it might become too time consuming to deal with that machine and at time you can make a trade off of time vs money to upgrade to a cyclone.

(BobL may come back after you listed your shop size, etc. and say that a single stage is not big enough, but it is worth a thought.)

Mark

The mass distribution on these impellers is quite compact in the axial dimension, so maybe it's not easy for them to be dynamically out of balance. And so also, difficult to correct the dynamic balance. The circular back plate is quite close to the center of mass axially, and the forward outer edge of the vanes is not a practicable location for adding or removing mass.

My guess is that the impeller rpms are high enough for dynamic balance to be an issue, if it could in fact be significantly out of balance. Just guessing though.

If anyone needs a short read on what dynamic balance is..
http://www.buffalohtfan.com/PDF%20Pa...0Explained.pdf

Originally Posted by mwells

BobL may come back after you listed your shop size, etc. and say that a single stage is not big enough, but it is worth a thought.)

I agree, given the info provided by the OP, a single stage 3HP with a 13" impeller could be made to work.
I've had a similar shed/machine setup to the OPs specs for 9 years and been running particle counters for about 10 years and have not seen a problem provided I remember to turn on the DC. Given most of my machines are located within about 15 m^2 I can't really justify autoblast gates so now run pressure switches on my 4 most dusty machines which will not start unless the DC is on AND the relevant gates are open/closed.

I reckon dust extraction solutions are still too focused on extractors and not enough about using 6" ducting, opening up machinery so they can utilise the increased air flow, and forced ventilation.
I've visited many dozens of weekend warriors shed most could get away with a modified 2HP or 3HP DC and couple of bathroom exhaust fans.
Remember, at 50Hz a 6" pipe from most 3HP+ DCs will all pull about 1250 CFM, this is more than enough for medium size machinery and if there is one user only in a shed the extra is overkill.

Back to the OPs specifications.
Shed size - at about 50m^2 its not too big/small, and the roller door will help.
A really big shed helps dilute the fine dust problem especially of only one person is working there.
A really small shed with no ventilation is-potentially more dangerous

Machinery - The machines are only what I would called "medium" size so don't need 1000+ CFM rating

Multiple users - The OP mentions other people using the shed but only fr non-ww purposes. Even if they were to use a machine every now and then it's not a big deal.

Dust exposure to emptying bags - High dust exposure while empty sawdust bags is over blown.Yes it is nuisance but if the sawdust is left in the plastic bags and disposed of in teh bags, its far less of nuisance. Even cleaning out the bags is not a risk factor. see Dust Exposure while empty DC bags and cleaning filters

Resawing. - Based on the size of the machinery indicated by the OP I simply can't see lots of large scale resawing taking place - and what there is would be easily taken care of by a smaller DC.

In this situation, if you have the pennies and can cope with the other requirements a $3000+ cyclone is nice but its not essential for safe operation. If there were to be more than one user, bigger machines and more resawing then th pendulum swings more to a larger DC etc.

FWIW my mate has a small wood working business.
He's in a 140 m^2 shed with 5m high ceilings. with roller doors at each end
12" thicknesser and 20" resawing BS.
Large, 14" Austrian sliding table saw.
Small belt sander and 10" drop saw.
Loads of Festool gear including their vacs (all well maintained)
He services all these with a 3HP Felder twin filter bag DC using 6" ducting - the DC is inside his shed but parked right next to one of the rollers where the prevailing winds flush fine dust out on a regular basis
Resawing only every now and then.
About half the shed area is storage and assembly area.

When he first bought the business he was very concerned about dust so we ran particle counters in his shed for a couple of weeks. The highest we observed was 32 µg/m^3 when resawing otherwise his shed was almost always at ambient dust levels. He's also VERY fussy about tidiness - if visible dust was to be laying around every where he could be upgrading his DC in an instant.

What's really helping him is
- shed volume ie LARGE so the dust has plenty of space to escape to.
- Roller doors at each end of the shed won't concentrate the fine dust inside.
- machinery mostly concentrated at one end no really long ducting runs.

Originally Posted by mwells

The downside is that you will have bags to empty and if you do a lot of fine sanding the filters might clog quickly

If you equip a twin bag 3HP DE with pleated filters that have paddle cleaners cleaning filters is a quick, clean and easy chore.

Here’s another thought...

Most small shops use Donaldson Torit DCE extraction. They do everything you need, and often you can find them at auction for not much. There is one right now on machines4u for $4K, which would be good value, but you can likely find one cheaper eventually. They are three phase, which limits their appeal to most home shop guys.

Originally Posted by codycook

Hi Bob,

My factory space is approximately 3.4 x 7.5 x 7 (This is the planned space size. The actual space is about 50% larger but I am planning to build a wall to divide the space. I am splitting the space with my fiance who is an artist so the DE will become important in keeping dust away from her artwork, finishes on my furniture, etc.). Furthermore I plan to build an airtight enclosure for the DE that vents to the outside. I don't have the ability to house the DE outside of my factory space but I am confident I can build an enclosure that is very close to airtight. I have a roller door directly in front of where I am planning on setting up my woodworking shop area. The area of the roller door fully opened is 2.7 m x 4.3 (11.61m2).

The shop equipment I plan on purchasing is as follows:

-16" Thicknesser
-6"-8" jointer
-12" Table saw
-Festool orbital sander and Festool Domino hooked up to Festool Dust Extractor
-Bandsaw (10"-14")
-Router Table
-I am sure there will be other machines I use but I believe the above will be the most dust producing machines

I will be the only one working in the shop to begin with. However, my fiance is sharing the space with me and will be using the other portion of the space as a graphic design office, artwork studio. Part of the business plan is for me to build frames for the artworks she creates.

I do plan on resawing/resizing as much timber as possible. My current plan is to use as much recycled timber as possible. I have even toyed with the idea of fabricating my own miniature bandsaw mill to mill small logs and build furniture from the very first stages through to the end. This may be a bit of a pipe dream but a dream nonetheless.

Thank you for your response and for taking the time to read/ respond to my enquires.

Many thanks,

Cody

Hi Cody, sounds like a really exciting project.

This is less DE related but just wanted to provide comment on your machinery setup.

I went on a similar journey, woodwork as a hobby, then moved from hobby to 'business' and now its back to hobby while I reno a house and spend my time at my day job (school teacher)

I would just make the broad comment these while these machines might be a nice hobby setup, I would expect they would quickly become a huge slowdown in workflow for a business operation.

Production work needs production machines to make money (in my experience).

Yes, you can make a dining table or waterfall edge kitchen benchtop or whatever with a cabinet saw, 6 inch jointer and 15 inch thicknesser, but you could make 3 or 4 in the same time with a panel saw, and big combination jointer-thicknesser (sanding and finishing aside)

If you consider what your time costs, big, second hand machines will very very quickly pay for themselves, and allow rapid, repeatable machining of components. If you shave you machining time to a third, then you can easily double your output - It wont take many tables etc to pay for that used SCM, felder, etc etc panelsaw and jointer thicknesser or whatever you might source.


Good luck!

Steve.

Originally Posted by sleake

. . .. . If you consider what your time costs, big, second hand machines will very very quickly pay for themselves, and allow rapid, repeatable machining of components. If you shave you machining time by a third, then you can easily double your output - It wont take many tables etc to pay for that used SCM, felder, etc etc panelsaw and jointer thicknesser or whatever you might source.

That's why I asked about the size of his shed which turns out to be only about 50m^2 in area.
Unfortunately BIG machinery requires a lot of room and once they're shoe horned into a small footprint shed there's stuff all room left for storage, assembly, or awaiting assembly, the latter 2 being really important.

My shed is wall to wall stuff so I'm left to assembling larger stuff on the back veranda or patio.

Thank you BobL and everyone else for your replies! I have decided that I am going to try to piece together my own dust extraction set up and see how it goes. I am currently working on beginning to build a Bill Pentz cyclone out of MDF. I know this is a very unconventional material to build the cyclone with but I am going to give it a try. My plan is to build the whole thing and see if it will hold up. My main goal with building the MDF cyclone is to get my head around how the whole thing is assembled. I know it most likely won't last very long but I am hoping I can use it for a short period of time. During that short period of time I plan on building a second cyclone out of sheet metal that will last much longer. This way I can use the cheap materials to make my mistakes and hopefully have a much better product the second time around.

In terms of the impeller sourcing issue - I have been looking on facebook marketplace/gumtree/grays online etc trying to find a large enough diameter impeller. I think I might be able to find something that will work.

I will do my best to post some pictures of my progress as I go.

If anyone has any questions or advice they would be greatly appreciated!