Is a 1.5 HP cyclone enough for my garage shop?

[Josh Kocher]

Your motor will likely draw more amperage then it is rated if you were to run it with no restriction. Too large a duct will not reduce CFM, in fact you will draw more a CFM (do more work) because of less resistance, but FPM will suffer as a similar volume of air will move slower through a larger area.

You could check the amperage draw with your motor allowed to open up for a short run and then compare it to the rating.

[Allan Speers]

Too large a duct will not reduce CFM, in fact you will draw more a CFM (do more work) because of less resistance, but FPM will suffer as a similar volume of air will move slower through a larger area. .

Ah yes, of course. I meant air speed, not CFM. My bad.

Your motor will likely draw more amperage then it is rated if you were to run it with no restriction .

But again, this is what I don't understand. It must be so, but it makes no sense to me:

A 3450 rpm motor runs at 3450 rpm.
How can having no load make it speed up?
If it DOESN'T speed up, and it has no load, how can it possibly pull MORE current?

What am I missing here?

[Josh Kocher]

With regard to rated air movement, this is what the published numbers Andrew cites are referencing. Machines running full out, likely above rated amperage that would burn out the motor if used continuously.

Woodworking equipment manufacturers are in the business of selling machines, not educating the public on real world performance expectations. If it were 1200 CFM at the end of 10' of 4" flex hose, because that's how it's intended to be used, then it would say so.

I looked at two popular woodworking equipment manufacturers and notice on their spec pages they reference a CFM. Yet on the same spec page they reference part #s for their system with a bag filter, a pleated canister filter, even with no filter. So which system is it that the CFM referenced is referring to? Obviously the greater surface area of a canister filter will outperform a felt bag, and no filter at all will move more air than both. The measurement is taken at the inlet with no filter. That's how they inflate the numbers and sell machines.

They don't want to open the can of worms with a real world fan performance curves... They might not sell machines if the consumer was educated...

And the educated consumers and the professional shops are already looking to other options, going in a completely different direction, that's not the target customer of the "mass market" equipment company.

[Peter Christensen]

Josh's post is why I wish there was a like or agree button.

[Josh Kocher]

It's not motor speed that determines work performed.

"Blowers do the most work with an open unlimited amount of airflow and the least work when all is closed off and there is no airflow. That makes sense because the more air a blower's impeller pushes against, the harder the motor has to work. When there is no airflow, the motor only has to keep the same air turning in a circle, so the motor does the least work."

This video is pretty good in describing the relationship...

https://www.google.com/url?sa=t&sour...=1556045899976

[Josh Kocher]

LOL... thanks Peter... just call it like I experienced it in my basement shop.

[Allan Speers]

This video is pretty good in describing the relationship...

https://www.google.com/url?sa=t&sour...=1556045899976

^ link doesn't work. I'd really like to see this. Any alternate?

[Frank Pratt]

That having been said, I don't think you can necessarily take this to the conclusion that the motor will burn up with a large duct.

Not necessarily with all blowers, but it's a very real risk with many. A blower is designed to work with filters, duct, etc and to have large enough motor to keep it from overloading when wide open is just wasteful expensive. I would certainly have a meter to monitor the load if I had a situation where the was very little restriction for the blower, eg: large duct, no cyclone or filter and vented to the outside.

[Jim Becker]

Let me bottom line it for you. I don't see a fan curve for any single stage DC. I don't know why that is, expections for usage are my explaination, what's yours?

The answer is simple...the manufacturer's don't provide them, either because they don't want to go to the expense to create them or because they don't believe they are necessary to sell machines to hobbyists that don't know about dust collection in any detail beyond "I want/need that".

[Andrew More]

The answer is simple...the manufacturer's don't provide them, either because they don't want to go to the expense to create them or because they don't believe they are necessary to sell machines to hobbyists that don't know about dust collection in any detail beyond "I want/need that".

Ah yes, the $500 impulse purchase. Maybe if they sold these next to the checkout lane with the M&Ms they'd sell more.

OTOH, you've got a bit of a point, it seems to be an industry standard to not provide the information with the 1 stage collectors. Why spend money if you don't have too? Not that it would take much, wood magazine was clearly able to do so for a simple article, and they had to buy all the collectors to boot!

None of which means that they're not providing the performance specs given, unless Josh has some sort of source for his claims? I mean I like making unsubstantiated claims about unnamed big, evil corporations as much as the next guy.

[Josh Kocher]

I'm happy to agree to disagree, Andrew.

But perhaps you can explain this performance sheet from a popular brand, why do all filter options list the same CFM for performance (1100)?

Screenshot_2019-04-23-19-41-24.jpg

Whether a high surface area canister filter, or lower area felt bag, same CFM. That doesn't align with reality.

I notice that they are careful in the manual to list the CFM under the base model with no filter...

Screenshot_2019-04-23-20-30-40.jpg

That's because they test it without the filter in place because they want to get a good number.

My source is my personal experience, and critical observation... no big evil corporations, just companies doing what they do... sell stuff... they are selling it with the limited info they need to provide, and consumers aren't demanding more, so why would companies go to the trouble of informing people that aren't interested (and may hurt their sales)?

$500 impulse purchase... I do it sometimes... and sometimes for more... sometimes I just need something and am not going to research the heck out of it or run all around town, sometimes what I really want isn't available locally or easily online so I just go directly to the local store and pick up what the sales guy tells me a little about, maybe has a name I recognize, and doesn't look like a POS...

I think that's what a lot of guys do...

[Jim Becker]

Many of us have been "watching" this stuff for decades now and the behavior of the mass market tool companies relative to DC hasn't changed at all other then them also offering some newer styles like the short-cone, portable cyclones as an alternative to a single stage. JDS kinda started that, if I recall, and then Laguna and others jump on it. Even Oneida had to adapt and come out with there own small, portable unit, although I think their design is slicker, IMHO. There are no "rules" about what these companies need to say so do they don't say much. The firms that are dust collection specialty houses have a little more incentive because while they certainly cater to the serious hobbyist, they also sell to the small pro shops where Osha, etc., starts to become a factor. Having employees brings a whole 'nuther dimension to this discussion sometimes!

Although it's been quite a few years now, I've personally been in the Wood Magazine test labs. (I did some writing for them at the time when online resources were starting to become interesting to folks) They kept the lab segregated from the "business" side of the operation in an effort to avoid any conflicts (or at least that was certainly the case at that time) and had no consternation about testing things correctly, including dust collection systems. They were careful about keeping a baseline and setting up the tests as exactly the same as possible as they moved from unit to unit and also published fan curves as you mention. Honestly, at that particular point, Oneida was about the only company that actually provided fan curves that wasn't a true industrial supplier. ClearVue wasn't even a "gleam in someone's eye" at that point. Grizzly didn't do cyclones back then. Etc.

I seriously doubt there will be any change in behavior about this from the companies I refer to as "mass market tool providers" unless there is something that compels them to do so. Not likely to happen, unfortunately.

[Andrew More]

But perhaps you can explain this performance sheet from a popular brand, why do all filter options list the same CFM for performance (1100)?

Whether a high surface area canister filter, or lower area felt bag, same CFM. That doesn't align with reality.

Thanks for posting a bit more information, though I wonder why you're concerned about saying "Jet".

It does look suspicious, and you could be correct. OTOH, it could also be that the filter or bag is not relevant to the final CFM throughput with their design, because the impeller, motor, or intake is the real bottleneck.

Since I was able to guess the manufacturer, I took another look at the other specs for this DC. First, you'll note that the Impeller is only 11 inches, which is pretty small. Grizzly has a similar model with a 12 3/4" impelller. Then they claim to have a 1 1/2 HP motor, which is probably rounding up, since the current draw is 11 amps, which means it's likely much closer to 1 HP or even 3/4 HP. Then they're rating everything at 4" intake, which is also going to reduce the CFM.

So maybe the filter matters, maybe not, but I don't feel we know enough to be able to say that they definitely tested without any sort of filter attached.

It's hard to compare, but the Grizzly G0562ZP, which has two canisters, has a similar rating to the G1030Z2P, which is a double bagger. Could be they're lying too, but I think I'd want to see some testing before just accepting that they're both doing it.

Many of us have been "watching" this stuff for decades now and the behavior of the mass market tool companies relative to DC hasn't changed at all other then them also offering some newer styles like the short-cone, portable cyclones as an alternative to a single stage.

Oh? The addition of the filters, ala Wynn environmental seems relatively new as well. I can't help but think it's because the knowledge of the dangers of fine dust have become better known.

I seriously doubt there will be any change in behavior about this from the companies I refer to as "mass market tool providers" unless there is something that compels them to do so. Not likely to happen, unfortunately.

I'd suspect that the ability to get information over the internet would help a great deal. If somebody with a relatively popular woodworking youtube channel was to do a comparison of these systems and publish some real numbers it would likely have a dramatic effect. OTOH, I suspect that most of the channels have a vested interest in not pissing off potential sponsors, and buying all the DCs would be a relatively expensive prospect.

The only real review I can find is the one from Wood magazine from issue 182, which is long out of print.

[Josh Kocher]

I'm not concerned, I posted their flyer, their manual, which is available on the public domain... but there isn't any reason to single one of these manufacturers out, because I suspect that they virtually all do it... that just happened to be the first one I pulled up... as you noted, other manufacturers have similar parallel claims.

Of course the filter type/size or lack of filter plays a roll in the resistance of the air movement... so they likely don't use it when developing these numbers. I would be interested in seeing the amp draw it takes to move that amount of air also.

I'm not here to convince you of anything. I'm happy to agree to disagree, I'm discussing my opinions and observations based on my personal experience and understanding of these systems, of yours is different that fine, I'm also happy to be convinced or shown otherwise...

I've been through my own 1.5hp bag system from a different machinery manufacturer, but virtually the same as these other brands, and seen how underperforming it was from the published numbers... Now I've seen my 2hp cyclone from a leading supplier, and been blown away at the real performance and accurate reflections of performance in the fan curve...

The funny thing is the stated max performance (cfm) from the manufacturers of the 1.5hp bagger and 2hp cyclone I have owned are actually similar, of course real world performance/results aren't even close.

[David Kumm]

A reason why hobby type collectors run curved blade impellers is they can be designed to not burn up motors, even if you take the restrictions away. I put a curved blade Oneida on a vfd. Increasing the speed only increased the cfm slightly and there was no speed within the limits of the impeller construction that could overamp the motor. The nature of the design is the impeller tops out within an rpm range which provides that a collector can be attached to different size ducts and filters and still operate without destroying the motor. They are also more efficient at low pressure than a straight blade impeller. A straight blade is more often used in a commercial application where all the components are designed to work together. That design will continue to increase cfm with speed until the motor burns out. The benefit is the straight blade will operate under higher SP so long runs or undersized duct don't reduce the cfm as much as would occur with a BC impeller.

When I look at fan curves, I assume the operating range to be 6" SP at best and 12" at worst. You can improve on that range somewhat but I figure 8"-14" is closer to the range for my long run 25+ drop system. Dave