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I'd like to see one,just because of interest.Do ya'll think Woodcraft has them in store?
Google Aerodyne horizontal separator.Have threatened for years to "roll one up".We're well covered here on DC,heck..have parts to build another 2hp taking up space.It's sposed to be ceiling mounted,got to find help mounting(10'3 height),just not a priority.
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.Originally Posted by Bruce Page
"A hen is only an egg's way of making another egg".
– Samuel Butler
Member
That motor is almost certainly DC as that is the normal way to build a variable speed motor when designing from scratch. Variable Speed pool pumps, Variable Speed conveyor systems, electric cars, even the Variable Speed fuel pumps and radiator cooling fans in modern cars, etc.
On another note, the bird is clearly just marketing type cuteness. Art/marketing department guys are more artist and usually technologically challenged.
Contributor
Nope. That is clearly a 3-phase induction motor, and they even show the inverter (a Siemens drive). Using a VFD to produce variable frequency AC is a common way to realize a variable speed motor, especially at higher (>1HP) power levels. Even the new electric vehicles are using 3 phase, permanent-magnet synchronous motors with variable frequency drives.
Member
Dan, I am afraid you're right. Unless the Siemens distributor lied to me, the VFD (Sinamics V20) is only available as AC.
Contributor
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.
Mark McFarlane
Contributor
Even if it performs as advertised, a real world cfm < 1000 will have you breathing the bad air from the machine before it can all get into the filters. Generally it isn't the air exiting the filters that you need to worry about. Set a Dylos on a machine and see how much dust envelopes the machine before clearing to the collector. Dave
Member
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.
Of all the laws Brandolini's may be the most universally true.
Deep thought for the day:
Your bandsaw weighs more when you leave the spring compressed instead of relieving the tension.
Member
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:
Beranek's Law:
It has been remarked that if one selects his own components, builds his own enclosure, and is convinced he has made a wise choice of design, then his own loudspeaker sounds better to him than does anyone else's loudspeaker. In this case, the frequency response of the loudspeaker seems to play only a minor part in forming a person's opinion.
L.L. Beranek, Acoustics (McGraw-Hill, New York, 1954), p.208.
Member
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.
Member
Back to answering an earlier question. DB is a log based 10 scale, so 70 DB is half as loud as 80 DB. 60 DB is half as loud as 70 DB. 50 DB is half as loud as 60 DB and so forth.
Moderator
Yes, put that excellent Oneida system in a properly designed enclosure and you'll not have to worry much about noise. There are a number of discussions here that explore how best to do that. My Oneida system (and compressor) is in a separate closet and sometimes I forget to turn it off right away when I complete a machine operation. It's not silent, but it's very easy to be distracted by "stuff" since it's not loud at all.
--
The most expensive tool is the one you buy "cheaply" and often...
Member
The concept and method of separation Harvey is using is nothing new. In one application I'm aware of, the air intakes of helicopters have used similarly functioning centrifugal separators since the 1950's. In the air separator on a UH1 for example there are hundreds of small (+- .75 inch in diameter) tubes that have a spiral in them to rotate the incoming airflow. The dirt in the airstream is ejected centrifugally from the separators into the box the separators are mounted in and continuously purged using engine bleed air. The enormous airflow of a turbine engine pulling air through them plus the forward airspeed of the aircraft when in forward flight is he power source. How well the Harvey will work with just a 1.5 or 2 HP blower is very suspect. What I got from the Harvey propaganda is that they are presenting this as new and revolutionary technology, which it isn't. It does work well on the helicopters, very little dirt and dust gets through to the turbine engine. The little that does just goes through the engine causing little or no harm. The sub-micron bits that escape into our shops are of more concern to woodworkers.
For the very high price, I'm betting It does no better than a mid size cyclone. Only an honest head to head test will prove one way or the other.
Member
The technology was borrowed from the aviation world "the turbine effect" that explains the 4K price tag
I have wondered if turning a Cyclone on it's side would still be effective? I have a Dust Deputy I might try that, it is
sort of like does the light really go off when you close the refrigerator door? My son asked that question when he was five years old. He proved it does.
he put my cam Corder in the refrigerator and closed the door while recording. Sorry for the thread drift.
4k they are nuts.
Contributor
Tornados are just as destructive pointing straight up and down as when they are leaning.
Actually years ago on a forum I remember a discussion about tilting a cyclone and the original Clear-Vue owner said they angled the cyclone over until it was horizontal. He said it worked the same as when vertical except heavy chunks of wood wouldn't make it out of the bottom of the cone. They just spun around and around. Leaning the machine over to 45 degrees reduces the height a couple feet but takes up more wall space.
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