How to source/build this "modeling" fan?

<p>I was watching a YouTube video by photographer Karl Taylor, and saw this nifty fan used by one of his assistants to blow the model's hair. The fan appears at 04:22 in the video titled, "One Day Fashion Shoot by Karl Taylor," located here: [

]. Here's a cropped screen-grab of the device:</p>

<p><img src="http://studio460.com/images/modelfan.jpg" alt="" /></p>

<p>Looks like a simple centrifugal blower used in a variety of mechanical air movement applications. this looks about the size you might find in a wood stove or some kitchen exhaust fans. Check that auction site:<br>

<a href="http://www.ebay.com/bhp/centrifugal-blower">http://www.ebay.com/bhp/centrifugal-blower</a></p>

<p>Looks like an ordinary squirrel cage fan with a snout cobbled onto the exhaust port, and a grip cobbled on to give the assistant something to hold.</p>

<p>I'm safety conscious so I'd modify a few other things: a smaller mesh intake screen to minimize the risk of someone's hair being sucked in; same on the exhaust port to minimize the risk of projectiles hitting the model's face and eyes.</p>

<p>Squirrel cage or utility fans aren't designed for handheld use. They probably aren't double insulated to protect the person handling the modified fan from electrical shock. The electric cord attachment probably won't be designed with a flexible shield to withstand repeated bending: note the way most handheld power tools are made, as well as personal household electrical devices such as hair dryers. Electrical shock is a potentially serious danger in makeshift studio environments with concrete floors, which may be damp and conductive. Check to be sure the outlets are equipped with ground fault circuit interrupters when using doodads like this.</p>

<p>And any modifications shouldn't introduce additional safety hazards. For example a poorly constructed or attached screen could itself become a hazard.</p>

<p>The fan in the video is a high velocity low volume device with a small opening for directivity control. It's useful if you only want to blow the model's hair without disturbing her clothing, but then CFM will be important depending on the blowing distance relative to the photographer's framing. </p>

<p>If you're thinking of building one with Lex's safety concerns in mind, consider a relatively high capacity fan, put it in a box with a switch and add a speed controller available on that auction site for about $25. The box can sit atop a pan/tilt mount (or a tripod) for directional control. </p>

<p>Hey, thanks for the tips, guys! Much appreciated! Any additional sourcing recommendations would be most welcome as well!</p>

<p>Michael said:</p>

 

<blockquote>

<p><em>Check that auction site: <a href="http://www.ebay.com/bhp/centrifugal-blower" rel="nofollow" target="_blank" data-skimlinks-orig-link="">http://www.ebay.com/bhp/centrifugal-blower</a></em></p>

</blockquote>

<p>Thanks, Michael! Those do look very similar. You'll notice in the video, that theirs looks just about "right" for hair. I'm not exactly sure how I would estimate an appropriate velocity/volume specification (other than the size of the inlet/outlets and specified CFM?), but thanks again for the help!</p>

<p>Lex said:</p>

<blockquote>

<p><em>I'm safety conscious so I'd modify a few other things . . . Squirrel cage or utility fans aren't designed for handheld use. They probably aren't double insulated to protect the person handling the modified fan from electrical shock . . .</em></p>

</blockquote>

<p>Duly noted. Yes, I'm extra paranoid about electrical safety, and blowing things at high velocity at models myself. I'll look into incorporating your suggestions once I select a blower. Thanks again for your help!</p>

<p>Ralph, the "spot wind machine" is described here:<br>

<a href="http://www.viewfinderphotography.co.uk/products/Spot-Wind-Machine.html">http://www.viewfinderphotography.co.uk/products/Spot-Wind-Machine.html</a></p>

<p>The air velocity is spec'd at 5.5m^3/m which is around 195 CFM and the fan speed is variable up to 2,600 RPM. The closest substitute I found is linked below with a separate link for the speed controller:<br>

[<a href="http://www.ebay.com/itm/Dayton-Model-1TDR3-Blower-273-CFM-1640-RPM-115V-60-50hz-4C447/151149749059?rt=nc&_trksid=p2047675.m1851&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%26asc%3D261%26meid%3D3739336263545379819%26pid%3D100005%26prg%3D1088%26rk%3D1%26rkt%3D5%26sd%3D181289073612%26">The Fan</a>] & [<a href="http://stores.ebay.com/Electric-Motor-Warehouse/Speed-Controls-for-Fan-Motors-/_i.html?_fsub=3471549012&_sid=16838242&_trksid=p4634.c0.m322">Speed Controller</a>]</p>

<p>A cheaper solution (or something to experiment with) is a common leaf blower which might be adequate since continuous duty isn't required. <br>

<a href="http://www.homedepot.com/p/Toro-Power-Sweep-160-mph-155-CFM-7-Amp-Electric-Leaf-Blower-51585/202218544">http://www.homedepot.com/p/Toro-Power-Sweep-160-mph-155-CFM-7-Amp-Electric-Leaf-Blower-51585/202218544</a></p>

<p>Thanks again, Michael! Very much appreciated! I was pretty excited to see the Viewfinder product listed until I saw it was a 220VAC/50Hz unit. Thanks also for the CFM conversion numbers. I think rather than try to build something myself, maybe a lower-velocity, battery-powered leaf blower may do the trick (since I was planning to operate this from an inverter anyway for location use). Here's an 80-CFM, house-brand blower from Home Depot:</p>

<p>http://www.homedepot.com/p/Worx-120-MPH-80-CFM-Cordless-Electric-20-Volt-Lithium-Ion-Sweeper-Blower-with-Air-Accessories-WG545-1/204700898?N=bxavZ1z0zy8i#specifications</p>

<p>Here's a better picture of the short nozzle (lower right) for the above model, sold though Sears' site:</p>

<p>http://www.sears.com/shc/s/p_10153_12605_07172359000P</p>

<p>I thought with its varied attachments, I may be able to fashion its output more appropriate to my application. Also, I thought that a slightly lower CFM specification may make up for the smaller exit (which would increase velocity, right?), aiming for a somewhat safer tool to point at a live model.</p>

<p>Here's one with a wider nozzle:</p>

<p>http://www.sears.com/cel-cordless-leaf-blower-18-volt/p-07102286000P?prdNo=3&blockNo=3&blockType=G3</p>

<p>It looks like the optimal design for this application is a low-amperage, large-cage unit, with a large exit-duct (as depicted in the Viewfinder model). The leaf blowers use low-voltage, high-amperage motors, employing smaller cages, and smaller exit ducts. The Viewfinder blower draws 5.5A @ 220V, drawing approximately 97 Watts (in comparison, the Worx blower runs at 7.5A @ 20V drawing approximately 120 Watts).</p>

<p>Ralph, sounds like a plan, and I suppose you can always exchange it if it doesn't meet your expected needs. </p>

<p>The CFM rating is the volume of air it can deliver per unit time, and the "MPH" is (I presume) the exit air velocity measured with a Pitot tube. For blowing hair, I imagine you'd want some minimum volume of air over a given area ; too small an area will just blow one side or the other, and moving further away to gain coverage might reduce air velocity so much as not to achieve the desired effect.</p>

<p>I think it'll take a bit of experimenting to gain the necessary experience, and I'd love to hear any feedback you might have on the exercise. </p>

 

<p>If you check the video frame at 4:27 you can see it's a rather small motor. You could build one yourself but I'm not sure it would be more cost effective than just buying their ready made unit, unless you already have a workshop with plenty of spare bits lying around and tools to attach the mounting bracket, etc.</p>

<p>I'd still be concerned about safety issues, and whether it meets US standards for electrical safety, etc., particularly if I employed an assistant to use it. </p>

<p>More options:</p>

<p>A bit overkill, but completely pre-wired, and very green (literally): http://www.homedepot.com/p/B-Air-High-Velocity-Lightweight-Crawl-Space-and-Attic-Mini-Air-Mover-Blower-Safety-Certified-CP-1-ETL-GREEN/203074022?MERCH=REC-_-product-3-_-203074026-_-203074022-_-N#specifications<br>

The guys at modelmayhem.com seem to like this Stanley blower: http://www.homedepot.com/p/Stanley-Pivoting-Blower-Fan-655704/203423260?MERCH=REC-_-product-3-_-203074022-_-203423260-_-N#</p>

 

<p>Guys, don't even THINK about pointing a 120 or 160 mph leaf blower in someone's face! Keep in mind that 120 mph is roughly the falling speed of a skydiver.</p>

<p>I've used one of those little Stanley blowers, as in ralph's last link. (Not for photography, rather to ventilate a room.) I think the air velocity is probably in the range you want, at least on the low speed. Unfortunately, though, the air stream coming out the front is pretty narrow. You would need to keep the blower some distance away, perhaps 6 ft or more, to let it spread out enough to cover someone's face. Or possibly you could rig your own diffuser to spread the air stream out wider.</p>

<p>It might also be a good idea to put some filter material over the intake to make sure that no particles get blown into the model's eyes.</p>

<p>Don't let the numbers scare you, Bill. The 120 MPH is right at the nozzle output at peak velocity. Stand 8-12' back as you might for a full body shot and it might be just right. In reality the air velocity is not much more than the output of a ShopVac's exhaust port.</p>

<p>I think you'd probably want an assortment of fans for different applications as you might with lights, and that Stanley unit sure looks fitting but something as outrageous as a leaf blower can also play a part. <br>

</p>

<p>My observations on leaf blowers (I don't own one) are from what I see my neighbors use--and the factor I find most annoying is the noise. In a small to medium size studio I would think all conversations between photographer and model would end up as shouting matches! I have used a few different sized 'conventional' fans and the larger ones can make some racket--but a leaf blower? I think I'd have to wear hearing protection!</p>

<p>Why not just buy a cheap wet/dry shop vac and attach the hose to the outlet instead of the inlet?</p>

<p>The hose will give you the control you need, directionality, while the size, combined with the outlet of the hose will give you the air speed needed for a specific job. These vacuums frequently come with attachments that reduce the inlet size and therefore increase the air speed (though not the CFMs). Using these seem attachments but with the hose attached to the vac's outlet, will have the same affect on air speed.</p>

<p>The nice thing is that you can save the vac just for photo use. There are many small, portable models and the electrical aspects are already taken care of. Of course, they house an internal filter to address shooting items with the air at the models face.</p>

<a href= "http://www.magnificentrevolution.org/wp-content/uploads/2009/07/Van-de-Graaf-Generator-web.jpg">Van de Graaff generator…</a>

Or use a blow dryer with a fan tip or conical tip....

<p>Chirs said:</p>

<blockquote>

<p><em>Why not just buy a cheap wet/dry shop vac and attach the hose to the outlet instead of the inlet?</em></p>

</blockquote>

<p>Thanks for everyone's suggestions! A number of modelmayhem members suggested the same, and claimed this actually worked quite well. But since I'm planning to run the fan on-location from a battery-powered inverter, I'm probably leaning toward one of lower current-draw solutions.</p>

<p>It's just too bad the Viewfinder product is 240VAC, since I'd much rather just buy something off the shelf, rather than engineer something myself.</p>

<blockquote>

<p>But since I'm planning to run the fan on-location from a battery-powered inverter, I'm probably leaning toward one of lower current-draw solutions.</p>

</blockquote>

<p>I don't know what batteries you're looking at, but if 12 volt, might be worth trying to run a blower straight off the battery. Obviously (?) this means a 12 volt DC motor.</p>

<p>Automobile blowers come to mind, but these generally aren't complete - they insert into built-in ductwork in the car. However, there HAVE BEEN some, if you have the patience to go on a search.</p>

<p>I'd suggest that you look at the boat market, for 12 volt marine or bilge blowers. Of course, you'll have to rig them yourself, with mounts (or handles) and screens over the inlet/outlet, but at least you won't have to worry about 120 VAC. And being marine parts, they ought to be pretty weather resistant.</p>

<p>Here's an example: <a href="http://www.boatersplus.com/itt-jabsco-12-volt-3-port-flangemount-marine-blower.html">http://www.boatersplus.com/itt-jabsco-12-volt-3-port-flangemount-marine-blower.html</a> It's a Jabsco 12 volt, priced at about $70 US. It moves about 100 cfm, which is fairly low, but if that's enough for you, it should be pretty easy on the batteries. I think the squirrel-cage blowers are your best bet - they're fairly quiet and can move air against fairly high static pressures, which means a gust of wind won't stop the airflow.</p>

<p>Thanks for your suggestion, Bill! I was planning to use Paul C. Buff Vagabond Mini-Lithium AC inverters to power the fan (I also own Dynalite XP1100 inverters, but they're <em>very</em> heavy).</p>