I'd suspect those early cages were to prevent accidentally bumping into it, rather than child-safety.
Child-safety is a pretty high bar, even if it's common today. You not only have to prevent someone accidentally hurting themselves, but more-or-less intentionally doing so.
I bet the cages nowadays were the result from a lawsuit. A lot of safety precautions (and warnings) are from that. I'm not knocking it, people do need to be protected from themselves (and accidents), I'm objecting to the massive damages lawsuits.
This was designed in an era when safety was seen as the responsibility of the user, not the manufacturer. It was your responsibility not to stick your fingers in there, not the manufacturer's responsibility to prevent you from doing so.
It was not a finger-friendly time for technology. Here, take a look at the Farmall tractor/buzzsaw combination that is quite similar to the one I grew up cutting wood with (and probably only slightly newer than some of those fans) :
I grew up in the early 70s with one of these in my bedroom, probably from the 40s or 50s but still going strong. I never stuck my fingers into the blades, but I did like to toss crayons in and watch the pieces fly...
I took some 120mm fans out of some old servers my brother brought home from his tobacco factory co-op job.
I’d wire them to weird voltages (e.g. 12V and -5V, or +5 and -5), cover my eyes with a jewel case and drop small screws in them to hear where it bounced around incredibly fast...
I don't know about the torque on the desk fans. But modern ceiling fans have very low torque and kinetic energy: you will probably get away with sticking your hand into one of them with very little damage.
My grandparents had a completely open fan from the 60ies (although with plastic blades). You could stuck your fingers into it and it would just stop - it hurt a little, but no damage.
I love this: "My interests are with original and unrestored desk fans made prior to 1916."
Since they were invented in 1885 that is basically a 30 year window for a fairly expensive consumer good that probably sold in the neighborhood of a few thousand units.
There is something wonderful about diving deeply into a particular kind of thing from a particular time. My Dad has a cap gun collection with a similar narrow window, he even has a book which identifies various cap guns, their makers, their relative rarity etc. Why cap guns? Who knows. He has it significantly easier though since they were stamped out in the hundreds of thousands, maybe millions, during a similar period and were made so that kids could get them (ie very inexpensively).
It is a level of curiosity and dedication I can really respect.
I know, because 11-year-old me owned one, back when selling them was legal. The reason is nostalgia, or a yearning for the brightness of the world we knew then. Artifacts bring the memories back, in a sweet flood.
Experimentation revealed ways in which cap gun tech could be abused. We wanted a louder pop, so how about folding over the tape of caps to double up? Possible, but tends to jam. For a really loud "bang", how about setting a whole roll of caps down on the pavement edgewise, and hitting it with a hammer? Imagine the surprise when the hammer's head came flying back up, faster than it was brought down ...
Wait, they're illegal now? Where? I had those growing up in Canada in the early 2000s. If I remember right, we got them at the dollar store. And yes, I remember hitting a whole ring at once with a hammer.
Probably for the best here in the US. Police here jump on any excuse to use deadly force and hearing a bang sound from a cap gun would likely invite a hail of real bullets. Did you see a 9 year old girl was pepper sprayed recently? And that 75 year old man shoved over, banging his head on concrete, and bleeding on to the streets from it for having an imaginary police scanner? And the girl trying to give a guardsman flowers getting a direct hit from a flash bang in return? Imagine if one of them had a cap gun...not pretty.
It's a fairly common interest believe it or not; I was very interested in this era of fans while I was in grad school. In fact I was interested in an even more specific variety of pancake motor 6 bladed fan that pretty much every other fan-fan also wants. Since they're so bloody expensive I ended up collecting radios from the 1920s instead, which kind of scratches the same itch.
I thought they were too much when I was in grad school in the 90s and you could find them on ebay for $500.... $500 for a goddamned fan! Well, it's not like they made more of them since then, and many have been parted out or thrown away.
Yes, a long discussion of the starting problems of electric motors. That was Tesla's real contribution to motor design - he came up with effective ways to get AC motors started under load.
It's fascinating that desk fans have had such a consistent design for over 100 years. Most surprising to me is that they've been able to oscillate for that long, too (since 1904!):
> Direct current desk fans were added in 1899. After acquiring a patent from Charles Eck for an oscillating fan mechanism, R&M put into production their unique DC "lollipop" oscillator in 1904, followed a few years later by an AC version. A sheet brass disk in front of the fan was acted upon by the air from the fan causing the fan to oscillate back and forth. Stops on the base of the fan were contacted by a pin at the bottom of the lollipop shaft to shift the disc to the other side, resulting in the fan oscillating to the other side.
Even Dyson's overpriced fans aren't THAT expensive nowadays.
That said, I do think there is a market for quality products in a 10-20x price range, products built to last instead of built to be cheap and good enough for a couple years.
It seems to work because the brass disk is blocking the air stream on one side, so the other side of the fan acts as a jet engine to rotate it, which is actually really clever.
The quoted bit seems to take a very neutral stance on exactly how the brass disk is "acted upon". So it's probably correct no matter how things work just due to vagueness.
I think both effects are at work. Thought experiment/hypothesis: If you detached the plate and merely held it in front of the fan blades, I think the fan would still rotate due to the decreased airflow on one side of the fan, but it would rotate less quickly since the force that moving air is applying to the plate would no longer be acting on the fan.
Yup, I posted the original comment to quickly, the airflow indeed also pushes the brass disk forward, thus rotating the fan! An extremely clever solution that seems to be very easy and cheap to manufacture.
> the airflow indeed also pushes the brass disk forward
The force on the disk is caused by an opposite force on the fan blades, cancelling them out (since they are connected by the frame and the bearings), so it cannot cause the fan to rotate.
The rotation is due simply to unbalanced thrust from the fan. The unimpeded side produces more thrust than the impeded side, so the fan turns to that side.
Oh wow, I have a six blade Emerson that works except for the oscillator[0]. Absolutely quiet in operation and moves a lot of air. Very heavy and based on the wire guard not super safe around many children, well at least not the ones who want to see what it will chop.
In my case I chose it for the blade count and the old ship propeller vibe. There is a shop here in Georgia which does do repair work on fans and I hope to get this one up there one day.[1]
You can find a good number of fans, restored and otherwise, on ebay. As with with any ebay suggestion it is best to build up a history to understand pricing.
Based on the scanned catalog page from 1911 and an inflation calculator, it looks like those fans set you back anywhere from the equivalent of $800-1000 in today's money. Is my math correct?
Not too surprising. Keep in mind that at the time electricity was a luxury and there were very few home appliances that made use of it. The radio, the first piece of electronics more complex than a simple motor or heater that you might find in the "average" home, wouldn't come into widespread use for another decade.
agree - the person who had this would be somewhat like the modern equivalent of a non-technical person with a fully IoT'ed smarthome running custom controllers and audiophile quality home theater room 15 years ago.. wealthy, and willing to spend to have the latest novelty
The radio had more of a chicken and egg problem. Once there was a broadcaster, I’d assume there was suddenly a lot of radios.
Fans came more gradually because of the physics infrastructure behind electricity. And fans were more of a luxury than a radio that can be used all year.
47 comments
[ 4.8 ms ] story [ 102 ms ] threadThin blades can be less aerodynamically efficient than thicker ones, but plastic fans blades are not very efficient anyway.
The biggest disadvantages of metal blades are cost and safety.
Child-safety is a pretty high bar, even if it's common today. You not only have to prevent someone accidentally hurting themselves, but more-or-less intentionally doing so.
http://sketchesofalaska.blogspot.com/2012/08/farmall-tractor...
I have all fingers and toes, but you couldn't sell that shit today without getting sued out of existence.
I’d wire them to weird voltages (e.g. 12V and -5V, or +5 and -5), cover my eyes with a jewel case and drop small screws in them to hear where it bounced around incredibly fast...
Since they were invented in 1885 that is basically a 30 year window for a fairly expensive consumer good that probably sold in the neighborhood of a few thousand units.
There is something wonderful about diving deeply into a particular kind of thing from a particular time. My Dad has a cap gun collection with a similar narrow window, he even has a book which identifies various cap guns, their makers, their relative rarity etc. Why cap guns? Who knows. He has it significantly easier though since they were stamped out in the hundreds of thousands, maybe millions, during a similar period and were made so that kids could get them (ie very inexpensively).
It is a level of curiosity and dedication I can really respect.
That said I love fans. I especially love those big old fans that seem to have a speed setting of 'menacingly slow'.
I know, because 11-year-old me owned one, back when selling them was legal. The reason is nostalgia, or a yearning for the brightness of the world we knew then. Artifacts bring the memories back, in a sweet flood.
Experimentation revealed ways in which cap gun tech could be abused. We wanted a louder pop, so how about folding over the tape of caps to double up? Possible, but tends to jam. For a really loud "bang", how about setting a whole roll of caps down on the pavement edgewise, and hitting it with a hammer? Imagine the surprise when the hammer's head came flying back up, faster than it was brought down ...
This is also a big part of why 'Light guns' for video game consoles in the US looked more and more like a prop from Buck Rogers through the 90s
https://antiquefanparts.com/1893-meston-series-aa-12-desk-fa...
https://antiquefanparts.com/circa-1888-edison-x-motor-fan/
https://antiquefanparts.com/1890-riker-electric-motor-compan...
https://antiquefanparts.com/circa-1894-edison-sixth-hp-slow-...
https://www.worthpoint.com/worthopedia/antique-1901-general-...
My grail fan: https://www.youtube.com/watch?v=IZzkUC0TAhg http://www.hudsonscustommachining.com/images/1904emerson/lar...
They cost so bloody much, it's probably easier to just build a reproduction.
Those pancake fans are really cool!
Does anyone make good-looking modern reproductions?
https://www.youtube.com/watch?v=hQ3GW7lVBWY
> Direct current desk fans were added in 1899. After acquiring a patent from Charles Eck for an oscillating fan mechanism, R&M put into production their unique DC "lollipop" oscillator in 1904, followed a few years later by an AC version. A sheet brass disk in front of the fan was acted upon by the air from the fan causing the fan to oscillate back and forth. Stops on the base of the fan were contacted by a pin at the bottom of the lollipop shaft to shift the disc to the other side, resulting in the fan oscillating to the other side.
Put another way, it was a few weeks worth of the average salary for a railway or steel worker of the era (https://ahundredyearsago.com/2012/09/17/average-salaries-191...).
That said, I do think there is a market for quality products in a 10-20x price range, products built to last instead of built to be cheap and good enough for a couple years.
Is this an accurate description? Here is such a fan in action:
https://www.youtube.com/watch?v=Cm7DFuGaujg
It seems to work because the brass disk is blocking the air stream on one side, so the other side of the fan acts as a jet engine to rotate it, which is actually really clever.
I think both effects are at work. Thought experiment/hypothesis: If you detached the plate and merely held it in front of the fan blades, I think the fan would still rotate due to the decreased airflow on one side of the fan, but it would rotate less quickly since the force that moving air is applying to the plate would no longer be acting on the fan.
The force on the disk is caused by an opposite force on the fan blades, cancelling them out (since they are connected by the frame and the bearings), so it cannot cause the fan to rotate.
The rotation is due simply to unbalanced thrust from the fan. The unimpeded side produces more thrust than the impeded side, so the fan turns to that side.
In my case I chose it for the blade count and the old ship propeller vibe. There is a shop here in Georgia which does do repair work on fans and I hope to get this one up there one day.[1]
You can find a good number of fans, restored and otherwise, on ebay. As with with any ebay suggestion it is best to build up a history to understand pricing.
[0] https://i.imgur.com/Z1VglDL.jpg
[1] http://electrorestore.com/vintage-antique-fans-repair-servic...
https://www.reddit.com/r/Damnthatsinteresting/comments/b41rm...
https://imgur.com/a/gjlh0Gs
Fans came more gradually because of the physics infrastructure behind electricity. And fans were more of a luxury than a radio that can be used all year.