Gyro Air Dust Collector

[Bob Michaels]

I did a search on SMC but could not find any threads on the new Gyro Air dust collector. I have an Oneida 3 hp system that is absolutely fantastic except the noise is unbearable. It registers 80 dB at the cyclone and 70dB 20' away inside the shop. My only interest in the new Gyro Air is their claim of 61 - 72 dB depending on the speed you run it at. It's a variable speed unit. I am not knowledgeable on dB values but I do realize they are not linear. I have no concept of how much quieter 70 dB is than 80 dB except for my measuring the values of my Oneida DC at the cyclone and then 20' away as stated above. Can anyone tell me what percentage quieter 70 dB is than 80 dB. Thanks.
http://www.woodcraft.com/product/162...processor.aspx

[Jamie Buxton]

Unfortunately, a dB number by itself is close to meaningless. It measures sound as received by an ear or microphone. Move closer to the sound source, and the sound received gets bigger -- that is, the dB reading on your meter would get larger. So Harvey's claim of 61-72 dB just doesn't tell us anything.

[Andy Giddings]

We've been discussing this unit over on the Felder Owners Group. One thing to bear in mind is the standard filter is believed to be 5 micron, with the possibility to upgrade to 1 micron. Most aftermarket filters (from Wynn Environmental for example) are 0.5 micron rated. Therefore really fine dust (which tends to be the most dangerous to our lungs) is going to get through. Also an impeller size of 12 inches is about the same as you'll find on a lot of 1.5-2HP single stage units, so unless there is something fundamentally different with this design compared to regular cyclones, flow rate is not going to be great for the cost involved.

[Jamie Buxton]

Woodcraft wants $4K for a chip collector that does 1100 cfm (likely without ducting). There's lots of collectors with that spec at half the price.

For somebody who already owns a good collector like your Oneida, you'd do a lot better on the cost by spending a few hundred bucks to wrap a closet around your existing machine.

[Bruce Page]

I think Bob's primary objective is to reduce noise. The Gyro Air's 4K price would build a pretty nice insulated DC closet for his Oneida.

[Wade Lippman]

I haven't looked it up, but I think 70 is one tenth as loud as 80.
But you already have to wear hearing protection for the tool you are using, so what's the big deal about some extra noise?

[James Zhu]

Bridge City owner John Economaki bought the Gyro Air dust collector and is very happy with it, check his blog post

http://www.bridgecitytools.com/blog/...air/#more-9423

Also the video about this new design of the dust collector https://www.youtube.com/watch?v=R5VtMvvF07U&t=43s

[Wade Lippman]

Bridge City owner John Economaki bought the Gyro Air dust collector and is very happy with it, check his blog post

http://www.bridgecitytools.com/blog/...air/#more-9423

The bird in the photo is fake. If they fake one thing, then perhaps more. (and why fake a bird?)

[glenn bradley]

I haven't looked it up, but I think 70 is one tenth as loud as 80.
But you already have to wear hearing protection for the tool you are using, so what's the big deal about some extra noise?

This is my feeling exactly. I am reminded though that other home dwellers may be the ones objecting to the noise. It certainly doesn't bother me as I am diligent about wearing hearing protection.

[mark mcfarlane]

I haven't looked it up, but I think 70 is one tenth as loud as 80.
But you already have to wear hearing protection for the tool you are using, so what's the big deal about some extra noise?

10db is an apparent doubling in volume Significant, but closer to 2x, not 10x. There are frequency and psychoacoustic issues to consider, but somewhere between 6db and 10db is what you will perceive as a doubling in volume.

[Van Huskey]

I haven't looked it up, but I think 70 is one tenth as loud as 80.
But you already have to wear hearing protection for the tool you are using, so what's the big deal about some extra noise?

That is true, not true and sorta true all at the same time.

Sound pressure level as expressed in decibels is a way of logarithmically describing a ratio. Every 3db increase is a doubling of the sonic energy but humans do not perceive that as a doubling of "loudness" our measuring instruments (ears) and interpreting instrument (brain) just doesn't work that way. While it varies from person to person 10dB is usually considered a doubling of loudness. This is also complicated by the frequency makeup of the sound since humans both measure and perceive different frequencies to be different levels of "loud" even if they have the same SPL and measured SPL will be presented with different weighting scales (A, B and Z). The human perception of frequency vs SPL is given in phons and the curve is visually represented by the Fletcher Munson scale. A weighting takes into account the F-M scale and is most accurate under 100dB where the C weighting is more accurate above 100dB and often used for peak measurements when there is a dynamic sound environment, Z rating is linear and rarely used.

What does this all have to do with machine SPLs? Since woodworking machines sold in the US do not have to present SPLs derived by regulated testing and reporting it leaves us with basically no information. To get an idea of the actual loudness and make legitimate comparisons to other companies machines one needs to know a lot of things and SPL in dB is just a tiny part, it is like saying I have a car that goes 200 miles... is that in a second, an hour or a year?

OK so a DC is rated a "80dB". We need to know the distance at which the reading was obtained. When distance doubles SPL is reduced by 6dB. So a machine "rated at" 80dB and measured at 10 feet is actually quieter than one "rated at" 76 dB measured at 20 ft. We also need to know the environment the measurement was taken. 2pi space, 4pi space etc and the reflectivity of the environment as well. A machine measured at 5ft in an anechoic chamber at 5 ft will show a significantly lower reading than the same machine measured at 5ft in a 10' concrete cube unless based on the frequency the measurement could be gated properly (that wouldn't happen in this example). Gating is a time based calculation that if done properly can disregard reflected sound and only measure the direct sound waves this would be practically impossible for machine measurements do to a number of technical issues. We would also need to know the weighting used to compare different machines. The bottom line is the "loudness" of a machine expressed as a simple "x dB" is 100% completely useless, this tells someone absolutely nothing, except it MAY be useful within one company's product line making the ASSUMPTION they measured each model in the same way.

For a DC to be "better" it needs to move more air, have higher filtration efficacy, be cheaper, smaller, better form factor or some combination of the above this unit doesn't appear to give ME any of the above and thus is a non-starter. In my eyes we have two benchmarks in hobby/small shop DC and those are ClearVue and Oneida and I think those should be the first choice unless you have a smaller budget (then cyclones like Penn State come into the picture) or need a shorter form factor or desire a near plug and play package (then Laguna et al become options). Sound can certainly be an issue with many people BUT for $1,000 to 2,000 someone can do a LOT of sound abatement to an Oneida or ClearVue, at that level of cost someone with a little audio DIY ability could probably build a very effective active noise cancellation system.

[David L Morse]

Van, that's an excellent write up. Your point about the effect of the environment on SPL readings is extremely important since the variation can easily be tens of dB. If someone doesn't have the time or patience to read your whole post they at least need to pay attention to your conclusion:

... The bottom line is the "loudness" of a machine expressed as a simple "x dB" is 100% completely useless, this tells someone absolutely nothing, except it MAY be useful within one company's product line making the ASSUMPTION they measured each model in the same way. ...

[Alan Schaffter]

Well, folks here is my take. With dust collection you have two issues-

First is to collect the dust from the machine (and work area) before it expands to the shop and is inhaled. To me that is by far the most important task. To do that requires a lot of CFM and some static pressure too. To do that you need a really good blower and low static pressure resistance (caused by ducting, filters, cyclones, etc.)

So, in that regard, the Gyro is a mixed bag. On the good side, being a roll-around you don't have much SP from ducting. On the other hand, with a small impeller, you don't have much CFM to begin with, and with those incredibly small diameter cyclones and final filters you gotta have pretty high SP which really can put you in a less than optimal point on your fan curve- low CFM. That is low CFM throughout the entire system starting at the dust pickup!

The second issue, is what to do with the dust- the Gyro seems to be spending all its effort and your money in that regard- it assumes you cannot discharge outside so need a cyclone and filters so you are able to recycle the air. This is a trap that many folks fall into. If you can do it, there are much better approaches- best is discharge from the blower to outside (no cyclone, no filters). Next best, again if you can do it, is to use a cyclone to separate out what you can (most chips and some of the fine dust), and discharge whatever is left to the outside. Worst, of course, is to have both a cyclone and filters. Remember cyclones (regardless of type and orientation) and filters, depending on design, can take a significant toll on CFM. Also, as the filter(s) start to load, that toll increases. Regardless of claims to the contrary, filters have a finite useful life because, over time, the media will become more and more permanently clogged (unable to be cleaned) and scouring can enlarge the air passages and reduce the filter efficiency.

[glenn bradley]

I think Bob's primary objective is to reduce noise. The Gyro Air's 4K price would build a pretty nice insulated DC closet for his Oneida.

Ding, ding, ding. The Gyro specs are not impressive for the price. Capacity would have you emptying the bins frequently and the filter size (if indeed 5 micron, the size of some talcum dust and tobacco smoke) is in the range of a good felt bag. I imagine it is top quality but, a quiet 'dust spreader' doesn't meet the needs of most hobbyists concerned about their health. I'd have to know more . . . what happens to the performance if a .3 micron filter is installed, is one even available, etc.

[Dave Haughs]

For somebody who already owns a good collector like your Oneida, you'd do a lot better on the cost by spending a few hundred bucks to wrap a closet around your existing machine.

x2

I built an insulated closet around mine with two layers of sheetrock and its not bad at all.