Best place to put air filtration unit

[baltic_birch]

I found out quickly that MDF dust and my lungs do not mix.

This dust even made it home with me. Both my wife and I were coughing. Even weeks after surfacing my table this evilness is still around.

I finally figured it had to be the MDF dust.
I bought one of those Ionic breeze type air cleaners for the house....... we both felt better after about 15 minutes.

So I just got the JET air filtration unit for the shop. I've had it on for hour and already it is better in here.

I'm not sure where to hang it though.

My bot is in one corner, router tables are spaced around the rest of the shop.

Is it best just to hang it in the center of the room? Is there any reasoning to which way to direct the air intake etc??


Thanks.

And if you don't have one of these.... well go get one!

[wcsg]

I probably don't have the room you have but I have my JDS right between the table and panel saw 8' off the ground

[randy]

I don't remember for sure where I read it (probably Sandor Nagyszalanczy's "Woodshop Dust Control: A Complete Guide to Setting Up Your Own System") but I seem to recall that the air cleaner should be placed where it encourages the air to circulate around the shop. The recommended placement was midway along a wall. That is where my shop-built air cleaner is located.

[randy]

I found the source of my information. It is from a Nagyszalanczy work "Setting Up Shop". Here are a few quotes:

"If possible, locate the AFD unit near the source of fine dust..."

"Mount the AFD next to a long wall of the shop, with the intake side one-third the distance from the short wall."

He also gives a formula for calculating the size of the air filteration device:

Cubic-foot volume of shop x 8 = cfm air-moving capacity of AFD.

"8" is the number of air changes per hour for a full time shop. Change to "6" for a hobbist shop.

[drodda]

Randy, if I understand your calculations I need a 310,464 CFM AFD?
66' x 42' x 14' Shop x 8?

Where do you get such a device? all the ones I have seen advertised are about 800 to 1600 CFM?

I have had the very same problems with dust and would love to clear the air in the shop. Any advice or help would be appreciated.

-D

[donchapman]

Dave: I think the 310,464 would be the number of cubic feet of air that would have to be moved in one hour, so you divide that by 60 to get 5,174.4 cubic feet per minute. So it would take 3.23 of the 1600 CFM air cleaners in your shop. My 22'x36'x12' shop would need just one unit if it moved 1267 CFM. I might be able to get by with a smaller unit since my workshop is quite drafty so I'm already getting some air exchange.

I agree that MDF dust is the worst I've ever encountered. I had respiratory problems for at least 6 weeks last winter after breathing too much of the fine dust that remained in my closed shop despite the fact I have a good dust collector but no additional air filter.

This discussion is convincing me to buy one because such fine dust isn't just a nuisance since with enough exposure it can cause permanent lung damage, and the income lost from one or two days of illness could have paid for an air filter.

[randy]

Dave, Don is right. I left out part of the formula; so you will not need a filteration unit that is larger than your shop. Let me see if I can get it right this time:

Cubic-foot volume of shop x 8 / 60 = cfm air-moving capacity of AFD

[ed_lang]

Please remember that catching the dust at the source is the BEST way. Work on getting the dust at the bit first! The AFD will help a lot with the airborne stuff. You will be breathing the dust if it gets airborne.

I have a 5HP ClearVue cyclone for dust/chip collection and I ran 6" duct to each machine. I then reduce to 4" where needed to connect to the dust port. Since I heat and cool my shop year round, I have the cyclone in the corner and the cleaned air is put back into the shop.

When I surface my MDF table I only miss collecting all of the dust when the first pass around the edge is done. Half of the dust skirt from Shopbot is off the table and I miss some.

If you want more information than you ever thought possible to learn about dust collection, do a Google search for Bill Pentz and see what all he has done.

If I can help further, please ask as dust is a real health problem for those of us who work around wood being cut.

Ed

[wcsg]

I have the JDS 750-Er and I can't tell you how happy I am with it, three speeds, has auto on, and VERY quiet. Sometimes I forget it's even on

[paco]

This summer, at a woodworker show, I saw a 3 axis CNC router that has two kind of dust collecting device. The first, pretty usual, dust skirt at the tool bit/collet/chuck assembly to catch the most. The second system was a sort of hanging clear drapes around a much larger area to catch the finer thrown away chip and dust with a very large volume intake (6-8 inches). As the tool move around, those drapes were dragging over every obstacles making this closed (sealed) area around the whole Z axis. Since they were hanging from about a feet above, now way this dust skirt system to hit on clamps, scraps or anything.

I believe that it'll do very nicely for 3D carving and very lightweight material such as foams and MDF.

I can see something like that for my PRT style tool... I'm still looking for the right drapes material and figuring a practical way to install 'em (easy install, replacement and removing) on my tool.

Still, a room air clean is recommended.

Ed, thanks for the link; I've had lost it.

[Brady Watson]

Paco,
Seems we have similar 'dust foot' aspirations
Check this puppy out: http://www.precisionbrush.com/Item/PBSB.htm then, sniff around the rest of the site for inner brushes...I always thought that a big brush 'surround' around the whole Z axis would be ideal for 3D work, as the current foot can't do deep 3D extraction.

-B

[paco]

Thanks for the reference Brady.

I'd like to see through; I'm looking for clear flexible material like SB use on it's skirt. I will probably come up with a holder of my own.

Did you get any quoted price on 'em?

Keep me post on your development. Have you figured some way to fit this idea with the collector hose?

Another system that I've playing with the idea of is with the Loc-Line 3-1/2" vacuum hose. I could position two of those exactly where I need 'em. The problem is that they are quite expen$ive and I'm not sure how I would manifold 'em to a 4 inches hoses... This would be rather specific purpose so I'm not even sure it would justify about 150-250$ expense!?

[Brady Watson]

Paco,
I have not priced that skirt out...the SB skirt material appears to be 20 to 40# density clear vinyl, available at most boat stores (side windows etc)...It wouldn't be hard to make a longer version, but personally I think that the material on the SB skirt is too soft to go any higher, without a stiff inner support skirt. As it is I have a zip tie keeping the hose-side back fingers from blocking off the intake...it creates a clog.

We all have different 'collecting needs' and the SB foot works well for most 2D cutting. I would like to make the following changes to the foot for MY needs:

1) Open up the foot's 'intake port' or ideally move it towards the front, pulling from one side at a volute angle, and an open side port to create a vortex that spins the same direction as the router. You need an open port somewhere or it will suck to the top of the material, just like the shopvac does when you hold the open end against the table top.

2) Make the foot independent from the Z axis. You adjust it's height to the top of the material, like the old school PRT ones, except with a better mount & easier adjustability. The Y car (motor side) steel is a sturdy location for mounting points.

3) Make the foot in 2 pieces, held together with rare earth magnets to allow for quick tool changes.

4) Baffle the foot and/or get a better seal to the spindle snout. Many chips escape thru the spindle opening. A rubber boot would be ideal, but I am not sure it is practical when it comes time to change tools.

5) Make a larger outer skirt with long fingers to catch everything that the inner foot couldn't get. This may not be necessary if the other modifications work as planned...

I thought about the loc-line idea too & I think that it is too expensive. We DO afterall have a CNC...and I think that with some crafty 3D modelling and fiberglass cloth & epoxy resin, we could easily fabricate everything needed for this...the foot, the intake port, any size adapter etc...

-B

[baltic_birch]

Thanks everyone!!!

I got my jet from amazon, $229 shipped.
3 speeds and 2, 4, 8 hr timer setting.

That is the best $229 I have ever spent!

I can breathe!!!!!!!!!!!!!!!!!!!!!

MDF = Devil Dust

thanks

[bahed]

Is this type of skirt now available at Shopbot? I found this video on Utube of a PRS Alpha

http://www.youtube.com/watch?v=gcoOTqha8N8

[myxpykalix]

Thats the kind of skirt i got on my prt alpha 4 months ago. Call them i'm sure they will sell you one.