Need Help!- Dust collection :(

[mykrowyre]

Hi, I built a 65" x 24" CNC, and it runs great! However, I made a serious miscalculation... I grossly underestimated the amount of dust produced

Even with a shop vac held 1" from the bit the entire time, cutting MDF, my whole work area is covered with fine dust in just a few seconds. While trying to vacuum it up, I sucked 2 keys off of the laptop After digging through my shop vac I found and repaired the keys. Sigh.

I tried to make my own dust shoe but it did not work... the wet/dry vac was just not strong enough to pick up the dust unless it was 1/2" from the table which is not possible. I also built an exhaust deflector to send the router exhaust to the sides instead of down on the tool. This did not help much.

I've seen some affordable dust collectors in the range of $150 which are 900 cfm, with a 4" hose. Has anyone used one of these, and is it enough flow to suck the dust from the table a few inches away? Also, I would like to cut fiberglass sheet, and I am concerned that there will be particles smaller than 35 micron and that a dust collector would not catch these but make them airborne instead. I could place the dust collector outside when running, but I don't like the idea of throwing fiberglass dust out into the yard either.

I really need advice because at the moment my CNC is unusable without some way to contain the dust.

Thanks!
Tom

[brtech]

You can find a $139 coupon for the HF 2HP Dust Collector in woodworking magazines. It's one of the HF gems. A lot of folks have this unit. It sucks. You need to upgrade the filter on it. The recommended filter is a Wynn Engineering cartridge .5 micron. There is also a very clever thing called a "Thein Baffle" than can be installed in the DC that does a much better job of separating the chips and larger particles from the air stream. Google it.

[Senna]

Hi Tom,

I too was TOTALLY unprepared for the amount of MDF flour created while surfacing my table top. Had the same experience with the hand held shopvac wand where it failed miserably at collecting the flying stuff. Since I'm stuck with the shopvac option due to finances... I made an effort to improve the system to work as efficiently as possible.

First off... it sounds as though you are using the Hitachi M12VC as they have the bottom exhaust vents in the cast router body. I also made a deflector plate immediately following the surfacing fiasco but my end results were a significant improvement. I was able to create a complete null area below the router which help things greatly. I was still hand wanding with the shopvac for dust collection but now the pickup was almost 100%.

This caused a downstream problem in the shopvac itself. The filter would clog all too quickly and efficiency diminished greatly. Time to make a cyclone! I read a great deal of info about cyclones landing on the dust collection guru's site of Bill Pentz. Bill's Cyclone Dust Collection Research - Home Page Great resource... but geared to industrial or larger collectors... not the shopvac crowd. I then found this... DIY Cyclone Dust Collector - by SimonSKL @ LumberJocks.com ~ woodworking community and it was simple enough but most importantly for me... cheap enough to pursue. I whipped one up and have had terrific success at completely eliminating the clogged filter syndrome.

I then moved onto the dust shoe. Just finished it actually! It was an evolution rather than a quick birth but the results are impressive. I went through 7 or 8 iterations to arrive at success... but a shopvac system can be made to work and work quite well.

I realize you are asking about the industrial collectors... but the collector itself will not solve all the dust issues. Dust collection is a system that needs all components to be working together.

Hope this provides a bit of needed info...

Steve

[Phife]

Those cheap dust collectors are just that, cheap, I had one in the past and it really didnt move anywhere near 900cfm. You want a 1.75 or 2hp dustcollector. I now have a 1400cfm 2hp collector and it works great, I have hoses run to all my machines and it has no problem keeping up.

It also has a 0.5micron bag so nothing gets through the bag an into the air.

If you put your dust collector outside you create a vacuum in your shop, air has to be replaced in the shop from somewhere as its being sucked out. If you have a gas heater or hot water tank you risk sucking the exhaust fumes into the shop and that can be very dangerous.

If you have no gas appliances in your shop then as long as you have an air intake you should be fine exhausting outside, only issue is keeping the shop warm in the winter, since you will be sucking out all the warm air.

A good dust shoe is also really important, a good shoe makes a huge difference, if you can build a really good shoe then even your shopvac should be able to keep the dust under control.

[beermkr]

Steve,

That cyclone is NICE!!. You want to share your machining files for it?

R/
Mike

[mykrowyre]

Wow thanks so much guys for the help. I looked at the HF dust collectors and at 100 pounds, 33"x24" it's just not going to fit in my tiny work area. I have what is basically a 10' x 20' work shed. Even with a good filter, I'd prefer to vent outside for many reasons..noise being one of them. Moving a 100lb machine outside is not going to work so I am going to need to think of something else.

Steve, thanks for the cyclone info and especially the dust shoe design. I think I could manage with the cyclon inside and a shop vac outside... which shop vac are you using?

My concern is with <10 micron dust... I am not sure a shop vac has enough air flow to draw these in even with the dust shoe, but that can be resolved later with a larger vacuum. It's clear a dust shoe and cyclone would be key.

How much fine dust do you find in the shop vac container after use and how long before you need to clean the filter when cutting MDF?

Also, have you ever tried redirecting the router exhaust outside the dust shoe? Seems like this would allow more clean air to be sucked in around the skirt?

Thanks!

[mykrowyre]

Originally Posted by beermkr Steve, That cyclone is NICE!!. You want to share your machining files for it? R/ Mike

Same question but for the dust shoe

[MrWild]

Don't throw money at the problem. I had the same problem with dust. First i bought a heavy duty shop vac and had the filter clog in five minutes of MDF use. Then I bought an American made all steel cyclone which still let enough dust through the filter was plugged with dust in 15 minutes of use. 6hp Ridgid shop vac- $100. Cyclone with shipping-$105.

I then bought a HF like the one suggested and a Wynn filter. WOW Worth every penny. The Wynn filter allows twice as much air flow versus the filter bag. If I were to do it over, the cyclone and shop vac wouldn't have ever been bought. I have a router with bottom exhaust and the dust boot blocks this off. A huge difference in the amount of dust released. Also I suffer from asthma. While making the dust boot I turned on the HF vac and it did a great job of sweeping dust out of the air.

If you neck down the 4" hose to 2-1/4", buy a 4" Y and waste gate. Cracking the waste gate open allows the Vac to spin up and actually pull a better vacuum.

[beermkr]

I have a little roll around Delta unit that I bought at Lowes a few years back. It works really well but the bag fills fast and I see the suction reducing as it fills. The cyclone is the way to go I think but you don't really HAVE to have one of these huge vertical units (although they look like they are way easier to empty).

R/
Mike

[TSJ]

I recently purchased a small cyclone (Onida Dust Deputy) to place in front of my shop vac. It works great, may not have to clean the filter for years! This model sits on a five gallon bucket. I also purchased a metal one for use cleaning up milling machine and lathe chips, I thought the metal chips may be too abrasive for the nylon Dust Deputy, here is a link for two metal cyclones (bought the smaller one).

eastcaroga items - Get great deals on Crafts, Home Garden items on eBay.com!

I have not completed my machine but dust and cleanup is a problem with any router, so I bought a new Jet 3HP cyclone (surplus) that I plan to run on just the CNC machine. Hope it works.

Here are some links on dust collection I have collected for woodworking over the past.

The Dust Deputy
Bill's Cyclone Dust Collection Research - Home Page
ClearVue Cyclones, Dust Collection Cyclone
The Thien Cyclone Separator Lid w/ the Thien Cyclone Separator Baffle

[Senna]

Originally Posted by beermkr Steve, That cyclone is NICE!!. You want to share your machining files for it? R/ Mike

Hi Mike,

I tried but ran into the forum file limit issue. I tried EPS but that is an invalid file type and a DXF was too large to post. Same goes for the g-code!



Steve

[beermkr]

Steve,

I can host it on my hosting plan if you are willing. How big is the file? can you email it to me?

R/
Mike