Oneida Dust Cobra?

[gnlman]

Hi all. Sorry to be so long getting back to this thread.
Since I found so little info on the Dust Cobra when I was shopping for a replacement for my shopvac and Dust Deputy setup, I thought I'd share my experience with both Oneida and the Dust Cobra. While this is a little bit of a long read, as a hobbyist with little dust collection experience, I'm trying to make sure I give the information I was seeking when trying to make a decision, hence not so much technical detail just a bit of real world use.

Firstly, this is a fairly expensive unit (especially for a hobby guy ) and I bought it after a lot of reading about dust collection and the difference between small and large collectors and learning which type of collector works the best on which types of tools.
I have been using this unit for close to a year now and I must say it was worth every penny. It has performed flawlessly, and the build and fit of the unit was quite refreshing compared to other purchases I've made. In addition to the information Oneida provided me pre purchase, I did at one point of assembly need to call Oneida for a bit of advice. My call was answered by a person, quite a knowledgeable person I might add, and she not only addressed my issue, she even took my contact info and spoke to the engineering dept regarding my concern and contacted me later that day...Very good customer support indeed.

I also have a Festool CT36, and while the Dust Corbra and the CT are both different animals, they do much the same thing...suck sawdust, but of course they have their differences and their place in the workshop. I did take a few measurements of both units and it's not meant to be a comparison, just info to allow others to make a choice for which collector is right for their application.

My shop is a 16 x 32 detached garage. I have a smaller room at the front of the shop (16 x 12) where I have workbenches, my MFT3, Festools, and tools I like to keep warm as the small part of the shop is heated all winter. The larger part of my shop is where my cutting table, and large tools are. I usually heat this mostly on weekends or if I have a project I know I'll be working on during the week.....I have electric heat...bit spendy....lol

I keep the CT 36 under my MFT3 99 percent of the time, unless I take it in my house. The tools I use in the small part of my shop are sanders, routers,ts55, domino and Kreg jig.....of course  the CT36 works great for these tools and was a great choice for that part of my shop.

I had been using an old craftsman shop vac ( 200 cfm with adjustable suction) with a Dust Deputy in the larger part of my shop It worked great with my TS55 cutting up full sheets of plywood, great with routers, and actually not bad with sanders if I turned  down the shopvac.....I started buying some other tools that would live in the large part of my shop, and this was when I decided I needed something more powerful. I added a router table, drill press, a Kapex, and more recently a Dewalt 735 planer and small Dewalt table saw.The shopvac alone could do a pretty good job til the filter clogged, but once the Dust Deptuy was added the suction loss made the dust collection less than satisfactory at the tool...great separation which kept the shopvac filter and canister dust free, just not enough suction for my needs.

I started reading more about dust collection, and at first was looking at larger single stage units, larger cyclone units and such....this is when I discovered the difference between the larger collectors and dust extractors and how they differed....this is where my reservation came in once I started looking at the Dust Cobra as I was looking for a one Dust collector solution for the tools I had at the time, and the tools I planned on purchasing. I soon discovered from other members of this forum who helped me out with information that is not really possible depending on what tools you are going to use. After speaking with someone from Oneida I decided that the Cobra would look after my needs for the tools I had at the time, and since I had to order this online as there are no dealers in my area, this was a bit of a leap of faith.....

Like I said earlier, I've been more than pleased with my purchase. It works great with my Festool TS55, routers, Kapex and even the domino. While it has too much suction for the sanders, I do my sanding in the small part of my shop with my CT and if needed I can bring the CT out to the larger part of the shop. I even tried using the 27mm hose with the sanders thinking it might cut the suction, but still too much. I also have a Kreg router table which has dust collection on the fence. I added a dust collection box around the router, and I made my own Y with hose going to the fence and the back of the router enclosure. the Cobra keeps up with this just fine. I have also tried it with my planer, and while it handled the chips and kept the table clean, I suspect it would fill quickly...but for small jobs it works just fine. It also works really well on the Dewalt table saw...I still get dust, but it's an overhead issue I still need to solve.
I also added a small 2 1/2 inch hose system with blast gates which I plan on extending to the Kapex once I finish the cabinets and miter station. You will see in the pictures that I have a line that goes up to the ceiling and ends in the center of my cutting table. I also have the Cobra plugged into an Ivac switch which gives me tool activation like the CT. I found that there was minimal suction loss thru this little amount of 2 1/2 inch hose system, if memory serves me correctly, it was less than 5 percent. I do plan on reducting with some sort of plastic pipe once I get the miter station finished, which will help as well.

I don't have the most expensive measuring tools for sound and cfm, but here is some of the information some of you may like to have. The cfm test was done with a 36 mm 10 foot hose, as well the DB ratings where both done at 10 feet from the CT and the Cobra. Both machines had clean filters,bags and where empty.

CT36 - CFM 134, DB 73

Cobra - CFM 240, DB 76.8

The Cobra is by measurement a bit louder than the CT, but there is no screaming frequencies like you find in a shopvac. It reminds me of a high quality vac you find say at a carwash...I have to look at it once I start a tool up to make sure it's on.....

I hope the pics load ok, I think it's my first time posting them on FOG....lol
If you have any other questions, I'd be happy to answer them, but as I've said already.....great choice for what I'm using it for.

I did just recently buy a single stage collector (craftex 400) as I do have plans of eventually buying a jointer and and a bandsaw....I also think the planer will be better served by the larger collector as well. I have plans of running it thru a super dust deputy with hopes the suction loss is not too bad....the craftex claims 1700 cfm.....we'll see.....lol

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[Claimdude]

Gnlman,

Thanks for the update. The Cobra is much more compact than I envisioned. How much of a hassle is it to empty the barrel when it gets full?

Thanks
Jack

 

[gnlman]

Hi Jack.
The Cobra is a little top heavy for sure, but not too bad to lift off the barrel. Since that picture I did purchased the proper set of wheels for the machine which really increases it's mobility. I basically just remove any hoses, roll it out of it's spot to allow room to lift off the top of the machine to get at the barrel. The barrel has a snap clamp holding the lid on so you just remove it and the unit lifts off the barrel. There is a tygon tubing hose that attaches to the barrel from the body of the cyclone that provides suction so the bag in the barrel does not collapse, but there is plenty of hose which allows you to take the top part off without having to disconnect the tygon tubing. So basically I lift the cyclone off, place it beside the barrel close up the bag, replace the bag and put the cyclone back on the barrel put the snap clamp back on and it's back in business. I also believe the barrel is a a standard size compared to a 45 gallon drum, so it would not surprise me if the lid assembly might fit on a larger barrel....I find the size of the barrel to be just right as once the bag starts getting full it's heavy enough to lift out....not sure I'd want to lift a larger bag due to increases weight. I did not buy the sensor unit for it, but if you did, that part of it stays attached to the lid and the cyclone so it does not need to be removed to empty the unit.
Greg

PS I wonder if a mod might fix my pictures.....I need to read how to have them show up right side up......lolol

 

[grbmds]

Hi Jack.
The Cobra is a little top heavy for sure, but not too bad to lift off the barrel. Since that picture I did purchased the proper set of wheels for the machine which really increases it's mobility. I basically just remove any hoses, roll it out of it's spot to allow room to lift off the top of the machine to get at the barrel. The barrel has a snap clamp holding the lid on so you just remove it and the unit lifts off the barrel. There is a tygon tubing hose that attaches to the barrel from the body of the cyclone that provides suction so the bag in the barrel does not collapse, but there is plenty of hose which allows you to take the top part off without having to disconnect the tygon tubing. So basically I lift the cyclone off, place it beside the barrel close up the bag, replace the bag and put the cyclone back on the barrel put the snap clamp back on and it's back in business. I also believe the barrel is a a standard size compared to a 45 gallon drum, so it would not surprise me if the lid assembly might fit on a larger barrel....I find the size of the barrel to be just right as once the bag starts getting full it's heavy enough to lift out....not sure I'd want to lift a larger bag due to increases weight. I did not buy the sensor unit for it, but if you did, that part of it stays attached to the lid and the cyclone so it does not need to be removed to empty the unit.
Greg

PS I wonder if a mod might fix my pictures.....I need to read how to have them show up right side up......lolol

I am considering upgrading my 20-year old Oneida to one with HEPA filters. I have the following questions:

1. From your pictures, it looks as it it may be possible to use a 4" hose instead of a 2 1/2". Is the Cobra made just for 2 1/2" hoses? My old one actually hada 5" inlet which needed to be stepped down to 4" and 4" works well for my Dewalt 735 Planer, Jet 8" Jointer, Incra Router Table, and Rikon 14" Bandsaw. For all other tools I've found my Festool CT48 works best, especially for the TS55, Domino, and sanders (regardless of brand).
2. Did the Cobra come with a mobile base or is that one you made? I couldn't really tell from the picture.
3. From your feedback, it sounds as if the Cobra would not adequately handle a planer or jointer since you are considering buying additional dust collection.

Randy

 

[Claimdude]

Greg,

If you will open the pictures in the stock Windows viewer (assuming you are running Windows 7) you can rotate them there and they will be save back to your hard drive rotated.

Jack

Hi Jack.
The Cobra is a little top heavy for sure, but not too bad to lift off the barrel. Since that picture I did purchased the proper set of wheels for the machine which really increases it's mobility. I basically just remove any hoses, roll it out of it's spot to allow room to lift off the top of the machine to get at the barrel. The barrel has a snap clamp holding the lid on so you just remove it and the unit lifts off the barrel. There is a tygon tubing hose that attaches to the barrel from the body of the cyclone that provides suction so the bag in the barrel does not collapse, but there is plenty of hose which allows you to take the top part off without having to disconnect the tygon tubing. So basically I lift the cyclone off, place it beside the barrel close up the bag, replace the bag and put the cyclone back on the barrel put the snap clamp back on and it's back in business. I also believe the barrel is a a standard size compared to a 45 gallon drum, so it would not surprise me if the lid assembly might fit on a larger barrel....I find the size of the barrel to be just right as once the bag starts getting full it's heavy enough to lift out....not sure I'd want to lift a larger bag due to increases weight. I did not buy the sensor unit for it, but if you did, that part of it stays attached to the lid and the cyclone so it does not need to be removed to empty the unit.
Greg

PS I wonder if a mod might fix my pictures.....I need to read how to have them show up right side up......lolol

 

[gnlman]

Hmmm the pictures on my PC were rotated correctly and upright until I uploaded them.....I've seen and heard a few people mention this, I'll have to do a search and find out what to do.....
Greg

 

[grbmds]

Hmmm the pictures on my PC were rotated correctly and upright until I uploaded them.....I've seen and heard a few people mention this, I'll have to do a search and find out what to do.....
Greg

Looks like the higher end Oneida dust collectors are more like the one I bought a long time ago. The Cobra seems to be, as was said here, more like a replacement for a smaller vacuum based on the inlet size and the CFM rating. My older Oneida dust collector is rated at about 600 cfm I think.

 

[jacko9]

I would suggest that you look at the Oneida V-Systems.  I have the V-3000 and it's perfect hooked up to my Jointer, Planer, and Table Saw with stubbed extensions for future expansion.

Jack

 

[grbmds]

I would suggest that you look at the Oneida V-Systems.  I have the V-3000 and it's perfect hooked up to my Jointer, Planer, and Table Saw with stubbed extensions for future expansion.

Jack

Checked  that suggestion out. For me, that won't work. The height is too much for my ceiling clearance in my basement workshop. You must need to step your V3000 down from the 7" inlet. I know none of my machines have a dust port that size. My Oneida has a 6" and it's stepped down at each drop while the permanent central duct is at 5" by Oneida's recommendation. My current Oneida works great, fits with my ceiling height. The only problem is that the internal filter is not HEPA. I've never been sure how much of the finer dust it does get, but I do have a ceiling air cleaner from JDS and run that all the time on a timer when I'm working and for about 30 minutes after. That should clean about 7 - 8 times an hour with its airflow and my shop size. No HEPA in that either and it's not economical to get one for the JDS since they do not have reusable HEPA's. Anyway, I really don't have residual dust sitting on the floor or machines, so I think it's mostly gone. I am overly conscious about the dust - CT48 for Festools, dust collector for the big tools, and a powered dust shield when I'm working in the shop. Just don't want to damage my lungs, but I think I'll get along without a new dust collector for awhile.

 

[gnlman]

Hi grbmds. Yes you are correct. The cobra is more for 2.5 inch hose, and is basically a shopvac but with a cyclone and a lot more suction than my shopvac with a Dust Deputy. The gate on the Cobra fits a 2.5 inch hose on the inside (it has a sleeve inside the blast gate), and the od seems to be perhaps a 3 inch blast gate. While it does work on my planer and does take all the chips away, my planer also has a blower, so not sure how effective it would be on different models without a blower.

Yes the mobile base is something I made as the Oneida base was on backorder. I did get the proper base which gives the cobra much better mobility and the casters lock, and appear to be good quality.

I do not have a  jointer or a bandsaw yet, but they are on my tools to buy list. I did buy a single stage collector while it was on sale, and from all my readings planers, jointers, large table saws and bandsaws will require more cfm and larger capacity to be effective in dust collection. I did try my small table saw (2.5 inch port) with a 4 inch adapter with the single stage and to be honest didn't really notice any difference from the cobra, but I also do not have overhead dust collection for the saw yet. I also tried the single stage on my router table and it worked great.

My plan is to modify the single stage collector with a oneida super dust deputy and the way my shop is layed out I will need to roll the planer, bandsaw, jointer over beside it so I will be probably be using a 5 or 6 inch hose to one machine at a time. The single stage is rated at 1700 cfm....which might be a bit over rated, but it is a 2hp with a decent size blower....not something I think would work well with ducting running to several machines, but it was in my budget and I am hoping by only using it one machine at a time, and a short larger size hose it will work effectively.

I think you should perhaps be looking at one of the larger collector from Oneida to make a suitable replacement for your current collector, and yes you are correct the Festool Ct takes care of all the smaller power tools very well.
Greg.

 

[grbmds]

The Mini-Gorilla appears to be almost an exact replacement for my current Oneida (with HEPA external filter). The Mini has, I would guess, essentially the same motor, same CFM rating, and the same size inlet (5"). It would just substitute for my existing I would guess but might require some adjustment to my installed central ducting (not much though). It's much quieter also. Mine requires significant hearing protection and I'm sure is way above 76 db. It's just really a question of whether I gain enough to make the purchase, which is about $1,100 with the 17 gallon drum, base, and shipping. I actually have to say that, although I'm not able to get a HEPA filter for mine at this point, it does do an excellent job for my planer, jointer, bandsaw, and new router table. My old table saw and miter saw were a problem for dust collection, but I doubt that was the collector. I'm a big fan of Oneida. They have provided great support and seem to pay attention to designing and engineering great dust collection cyclones; were a pioneer in the smaller cyclone industry when no one else was making anything like it 15 - 20 years ago.

 

[Qwerty_Adelaida]

Hi guys.

I am new to the forum and not even a festool owner.

However I was researching on the difference between the Dust Cobra and Festool dust extractors and ended up here.

I had a couple of phone conversations with Oneida but still can not get the picture clear so would really like to have an input from one of the owners. My application is for a CNC router cutting composite material with occasional woodworking. So we are removing mostly plastic and aluminum chips. Right now it is hooked to Ridgid 6 HP unit which serves the purpose quite well but is not very convenient. I also suspect it blows fine dust back into the shop when the router cuts into the waste board.

So I was researching a more sophisticated and safe chip/dust collection system.

Festool boasts 96" of water column pressure while Dust Cobra is only 70" which makes me assume that Festool vacuum unit (motor itself) is more powerful. Now Cobra has more CFM but it can be due to larger hose diameter. Oneida was not really clear on how Cobra will behave tied into a thinner hose or how strong it is in comparison with festool unit.

If this is true than connecting a CT-36 (or even smaller) to a drum ($50) with cyclone on  top (clearvue mini for $75) should really produce better suction results with same dust separation. Also it seems easier to unplug the CT from drum/cyclone (leave it stationary at the router) and use the vac elsewhere if needed instead of rolling Dust Cobra around. I think Dust Cobra looks plain ugly and will also flip over whenever the chance arise.

Cost wise Dust Cobra is about $1,200 which seems way overpriced for an "industrial sealed motor" with $35 filter installed on top of metal drum/funnel on dolly assembly. I would assume that motor is the main expense.
CT-36 is not cheap either but with that unit you at least get some electric board and not just "motor bolted on to the drum". If the strength of CT connected to external cyclone is comparable to Dust Cobra I would rather go with Festool (and become a festool owner ).

On the Gorilla (similar high volume dust extractors) vs Cobra comparison from what I understood from Oneida: Gorilla's motor is not sealed (fan on top of motor) which means that suction in low air volume movement will not even be comparable to sealed version motor of Cobra. So for small tools, where the main idea is to remove chips and not dust, gorilla with it's high cubic feet movement will not lift anything. Works more like an air filter rather than a shop vac.

So, gnlman, as you have both machines (CT and Cobra), can you please answer how Cobra and CT-36 behave in suction strength comparison? Spec wise festool seems to be stronger but if this is true than I do not even understand how Oneida manages to sell any Dust Cobras. So there has to be a catch somewhere.

 

 

[grbmds]

Qwerty Quote: "On the Gorilla (similar high volume dust extractors) vs Cobra comparison from what I understood from Oneida: Gorilla's motor is not sealed (fan on top of motor) which means that suction in low air volume movement will not even be comparable to sealed version motor of Cobra. So for small tools, where the main idea is to remove chips and not dust, gorilla with it's high cubic feet movement will not lift anything. Works more like an air filter rather than a shop vac."

I have recently been in contact with Oneida as I need to either replace or upgrade an old (about 18 years old) cyclone I bought from them in the mid-1990's. It's my understanding that the Cust Cobra is not really meant to be a true dust collector. It's inlet and hose, at 2 1/2", will only produce air movement around 245 cfm. I would guess that you get better results from a Festool CT, but it depends on the kind of tool you are collecting dust from.

I already have a CT48 for my shop. It does well, for handheld routers, sanders, the TS55, the Domino, and I would imagine most other portable power tools. I have an Incra router table an it is borderline for that. I generally use my old Oneida dust collector for the router table, my 13" planer, 8" jointer, and 14" bandsaw. The CT simply doesn't create enough air movement even when reducing the outlet from these machines from 4". Also, capacity for dust before emptying will also be an issue with the CT's (but shouldn't be nearly as much of an issue with the Cobra since you are collecting into a 17 galong drum.

The Mini Dust Gorilla, on the other hand, produces 600 cfm as long as the hose or duct run does not exceed 10'. This will handle tools like a table saw, planer, jointer, bandsaw, and my router table quite well I think as long as the 10' maximun hose length is not exceeded. It is a one-tool collector though. I won't handle more than one at a time. It seems very portable and can be bought with a dolly on which to mount it. At 120 lbs, including the dolly and drum, it shouldn't be that difficult to move around a workshop, but might not be easy on a worksite. The Mini Dust Gorilla is comparable to a single stage dust collector, but much better as it has HEPA filtering, is a true cyclone, and is designed to produce a true 600 cfm, which exceeds the requirements of small planers, jointers, tablesaws, bandsaws.

If you are looking for something to move to and from a jobsite, I doubt either the Cobra or Gorilla would work well; mainly just to difficult to move around and in and out of vehicles. If you are looking for a small dust collector for the shop for a single machine at a time, I'd say the Mini Dust Gorilla is the way to go. If your needs are greater than that, you'd need to let Oneida help you figure out which of their dust collection models will be sufficient.

I believe Oneida is a great company and been in the lead with regard to dust collection and filtering since they started in the 90's. If you review their HEPA filters, they exceed most other HEPA's in terms of the size of particle filtered and will get almost all possible from a tool like a planer assuming you size the collector right.

Sorry this got long, but I've just been looking into this and will most likely upgrade with one of their collectors. Mini Gorilla seems like it can't be beat for a portable collector in the shop with everything except price. Oneida's stuff is not cheap.

 

[Qwerty_Adelaida]

Thanks for the reply.

To get a better idea of what we are planning to use Dust Cobra/CT 36 for, here is the video of a simmilar setup:

http://www.cncroutershop.com/us_en/pf-e-h-s-z-high-capacity-pressure-foot.html

There is really not a lot of air movement inside the pressure foot assembly so I was trying to see which motor provides better suction.

And while Oneida claims their Cobra is 3 times more efficient than shop vacs, they were not able to proove it to me. However they did explain that neither Gorilla nor any other "dust collector" will work for our application as they are designed for filtration of dust rather than chip removal.

Wanted to see if someone who ones both sees significant difference in perfomance of one over the other.

I am leaning towards Festool with either Dust Deputy or Clearvue cyclone connected to the cnc router itself.

Just can't justify the price of Cobra.

 

[grbmds]

Thanks for the reply.

To get a better idea of what we are planning to use Dust Cobra/CT 36 for, here is the video of a simmilar setup:

http://www.cncroutershop.com/us_en/pf-e-h-s-z-high-capacity-pressure-foot.html

There is really not a lot of air movement inside the pressure foot assembly so I was trying to see which motor provides better suction.

And while Oneida claims their Cobra is 3 times more efficient than shop vacs, they were not able to proove it to me. However they did explain that neither Gorilla nor any other "dust collector" will work for our application as they are designed for filtration of dust rather than chip removal.

Wanted to see if someone who ones both sees significant difference in perfomance of one over the other.

I am leaning towards Festool with either Dust Deputy or Clearvue cyclone connected to the cnc router itself.

Just can't justify the price of Cobra.

I would think the Cobra would be borderline, at best, for your application. There just isn't enough air movement, only about 250 cfm, for the amount of chips and dust you would likely produce. If Oneida's contact didn't believe it would work, I'd guess that's correct. I don't believe they have ever been wrong when I've contacted them nor have they ever tried to sell me something that wouldn't handle what I've told them I need it to do. They're collectors are built well, have the best filters in the business, and mine has lasted 18 years so I'd say it was a good product when it was sold.

 

[Qwerty_Adelaida]

I believe you that Oneida is a good company as I have not seen anything negative about them other than coming from Clearvue reps.

They actually told that Cobra will work and Gorilla will not.
Cobra has 70" of water column lift while gorilla is only couple of inches. So the suction of motor is significantly better in Cobra when there is not a lot of air movement.

I have just had a conversation with Festool and their 26/36/48 units have 96" of water column lift however they were not able to explain the diameter of water column lifted. (But neither did Oneida). So I am assuming 70" vs. 96" is not an apples to apples comparison.

Another thing Festool rep mentioned was that they do not warrant their extractor if connected to any kind of cyclone as the electrostatic charge in the cyclone will cause damage. So even if I connect the CT with 10 feet of static free hose to a barrel it is a no go in his opinion.

This makes the decision even harder to make.

 

[grbmds]

I believe you that Oneida is a good company as I have not seen anything negative about them other than coming from Clearvue reps.

They actually told that Cobra will work and Gorilla will not.
Cobra has 70" of water column lift while gorilla is only couple of inches. So the suction of motor is significantly better in Cobra when there is not a lot of air movement.

I have just had a conversation with Festool and their 26/36/48 units have 96" of water column lift however they were not able to explain the diameter of water column lifted. (But neither did Oneida). So I am assuming 70" vs. 96" is not an apples to apples comparison.

Another thing Festool rep mentioned was that they do not warrant their extractor if connected to any kind of cyclone as the electrostatic charge in the cyclone will cause damage. So even if I connect the CT with 10 feet of static free hose to a barrel it is a no go in his opinion.

This makes the decision even harder to make.

Wish I could help. I don't understand the movement of a column of water in relation to cfm an air velocity. My guess is that the air velocity figures in and, if you go to Oneida's site and look up the "Quick Quote" under Technical Specs on the Mini Dust Gorilla there is, in fact, a wind velocity chart to compare the Mini Gorilla cyclone with other generic single stage dust collectors. I confess to not understnading it and don't understand the concept of wind velocity in relation to cfm, much less movement of a column of water. I do know that, when Oneida gives cfm ratings, they are actual air movement ratings within their guidelines of use and are accurate for the uses for which they are suggested. The other factor is probably inlet diameter. The Mini Dust Gorilla has a 5" inlet versus 2 1/2" for the Cobra. That does impact on wind velocity. Since the CT's use a 27mm or 36mm hose to a 50mm inlet (just under 2"), the wind velocity is higher, which, I would guess is why their CT's work so well with routers, sanders, the Domino, and the track saws. That is what you need for those tools. Hopefully someone else can explain this better than I have. I understand only enough to attempt to make sure I use the right vacuum/collector for the right tools. So far, no complaints from myself and my shop stays relatively clean and free of surface dust.

 

[jacko9]

I can't add to the discussion as far as comparitive flow numbers however, I can let you know what I experienced with Festool CT22 and with my Oneida V-3000 (which is a different system altogether).

The CT22 is great for collecting dust and chips on my Sanders and Domino Joiner but using it with my Leigh Dovetail VRS dust collection attachment the 27mm hose was the choke point.  I resolved this with the 36mm hose which I also use on my Kapex but the point is the flow is restricted at the choke point and in the case of the CT system it's the hose.'

I do have the Oneida Shop Cyclone system and it moves a lot of air and it works great with my 12" planer and 8" jointer something I wouldn't ask of my Festool CT extractor.  I spent a lot of time working with the Oneida engineers designing my shop system and I trust them to do an excellent job.

Jack

 

[Qwerty_Adelaida]

I found another thread on similar question.

http://festoolownersgroup.com/other-tool-reviews/ultimate-dust-deputy-video/new/?topicseen#new

In the end Peter Parfitt figured out Dust Cobra produces 17,500 Pascals of vacuum pressure and Festool has 24,000.
However the airflow of Dust Cobra is 6,940 Liters per minute vs Festool's 3,700.

I emailed Oneida rep to see what is more important in my application: better airflow or stronger vacuum.

I'll see what he will recommend.

 

[gnlman]

Hi. Finally home so I can address your post.
In my review I did some "basic" testing, and I can tell you that the cobra has a lot more suction than the ct36. The cobra is used by floor finishers that use large mobile drum sanders for hardwood floor refinishing for the most part. Cyclones are used to separate dust and chips before hitting your filter hence keeping the filter clean and allowing the machine to keep operating at max airflow while the debris falls into the collection drum.
As mentioned in my review, i found that the dust deputy did a great job of keeping my shopvac filter nice and clean, but at a price. I felt I was losing around 20 percent suction in my setup, and i was using the supplied hose from the Dust Deputy to my shopvac which is about 200cfm. The Dust Deputy is very efficient, and collected a high percentage of the debris and dust and it works great. I still have the Dust Deptuy, and use it on occasion with my shopvac for reno tasks like stripping/sanding paint ect. as it works great for that, but was not meeting my small dust collection needs. In addition I found that once I put a hepa filter in my shopvac it further cut my  suction and had my shopvac screaming for air.
I use the cobra on my router table which collects from the bottom and top, my chop saw, drill press and have even tried it with my planer. It keeps up with all these tools and I find almost no dust after using it. If I just use it on the fence of my router table and if the cut is not closed off, there is no dust...the cobra really sucks......my ct can not keep up with these tools as well...it has it's place, and it can keep up on the fence of my router table but not like the cobra.
As I said in my post, these are two different machines, and for my needs I bought them both, and I am happy I did, they are both very good quality units, just do different things.
I would think in your case the Cobra might be the better choice for your cnc depending on how much you use it. you will be quickly filling bags on the ct and in my experience if you put a cyclone inline with your ct, you might find the same suction loss I did....with the cobra, the debris will fall into the 17 gallon drum, and will last a lot longer between bag changes. The bags for the Cobra are super cheap, and sure you could use some type of garbage bag as well..
Here is another thought for you to consider. The super dust deputy is less than a hundred bucks....hepa filter is around 40 bucks....not sure on the specs of your shopvac, but perhaps this combo might solve your issue with the cnc machine and be more cost effective as long as you still have enough suction to move the debris from your cnc. I have not tried my dust deputy with my ct as the ct vacs don't seem to loose too much suction as the bag fills, which is a real bonus over shopvacs...
If I have time tonight or tomorrow, I could try the dust deputy with the ct and take a measurement or two for you it you'd like. I understand that the ct will serve dual purpose for your cnc and woodworking setup which is a money saver as well....also wondering what the duty cycle of the ct would be like compared to the cobra, as the cobra is made to run for long periods of time....also the cobra is quite well balanced, and the steel drum compensates for the top heavy appearance...no issues with moving it around.
Sorry my reply is kind of rushed as my lovely bride is home from work and dinner is on the way...lol
Hope this helps
Greg