DIY Floodlight Tower

Started by EBuff75, October 10, 2021, 12:27:49 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

EBuff75

Our CERT group just helped out with an event (outdoor Halloween-themed movie night in a historic cemetery) last night where we could have used a large floodlight to illuminate the area.  The best we had was a relatively small floodlight which I brought along and which we used to light up the concessions area during tear down.  It worked well for that, but the movie area itself was much larger.

So we've started talking about building something which could be used for situations like this.  Ideally, it would be battery and/or generator powered, easily portable, weatherproof, and provide enough light to illuminate an area maybe 100' - 150' across (around 30-45m for those outside the US).  Someone found some 10,000 lumen wet-rated work lights at Menard's and suggested mounting them onto a pole which could be raised and locked into position.

Presuming those are bright enough (we talked about getting four of them to build it with), the difficultly would likely be in a post which could be easily raised/lowered and would reach 20' (6m) or more in the air, and which could support the weight (probably 15-20lbs / 7-9kg) of the lights.  Additionally, we can't necessarily rely on using guy wires and stakes to brace it, as there are situations where we would need to set it up in a paved area.  We could potentially use the battery pack as a weight and mount the receiver for the pole on it, but we might need something to provide additional stability as well.

Figuring out the power for it is easy enough - we can always put together a waterproof box with batteries and an inverter or connect to a generator, but the mast is a little more difficult, particularly on a strict budget (we're probably looking at a max of around $500 for the entire build).  I've looked around online at radio masts, but those don't seem sturdy enough to support that amount of weight.

Has anyone done something like this before?  Any recommendations for us?

BTW, with enough advance notice, we can possibly get access to a real, generator powered light tower which our municipality owns (something like this), but it would be nice for us to have our own which we don't have to get prior permission to use (and which might not be available in an emergency situation anyway).
Information - it's all a battle for information. You have to know what's happening if you're going to do anything about it. - Tom Clancy, Patriot Games

EBuff75

#1
Also, if you have any knowledge of what would be a reasonable lux level to shoot for, that would be helpful.  It looks like we should probably shoot for around 50 lux at a minimum (I found some recommendations for 100 or even 200 lux), but it's hard to find guidelines to use.  It does appear that the recommended level for a parking structure is 50 lux, which seems like a reasonable target to aim for.

Determining a target for lux will help to guide us for how powerful the lights need to be when coupled with the height of the mast and the angle of output from the lights.
Information - it's all a battle for information. You have to know what's happening if you're going to do anything about it. - Tom Clancy, Patriot Games

NT2C

For guy anchors on hard surfaces I tie them off to buckets filled with sand or sandbags.  You can use water in a pinch but you'll probably want covers on the pails in case one gets tipped.  Hams like me often use 4' mil-surp aluminum or fiberglass poles intended to support camo netting.  There are several places that make fittings for them that act as a tripod hub of sorts that three pieces of pole form the legs and then you add vertical pieces to the desired height.  Those same places also sell round plates with holes for guy ropes that can be put between sections.

You can usually find folks selling these at hamfests.  I'll try to find you an online link to a seller.
Nonsolis Radios Sediouis Fulmina Mitto. - USN Gunner's Mate motto

Current Weather in My AO
Current Tracking Info for My Jeep

NT2C

Connecting hub

Mast set to use with above

Add a couple of LED yard floods and an extension cord and you're good to go.
Nonsolis Radios Sediouis Fulmina Mitto. - USN Gunner's Mate motto

Current Weather in My AO
Current Tracking Info for My Jeep

NT2C

Nonsolis Radios Sediouis Fulmina Mitto. - USN Gunner's Mate motto

Current Weather in My AO
Current Tracking Info for My Jeep

EBuff75

Quote from: NT2C on October 10, 2021, 02:25:08 PM
Connecting hub

Mast set to use with above

Add a couple of LED yard floods and an extension cord and you're good to go.

That mast is an interesting possibility.  It doesn't look it from the pictures, but those segments are actually 2 - 2.5 inches in diameter (presuming my ruler-on-the-screen-image calculations are correct), which I would think would be able to handle the weight. 

I'm less sure about the option from China, mainly because I can't really follow what the measurements are for it.  It looks like there are a bunch of different options for sizing.  It might not be a bad thing to have two of them, but it would also depend on how large it is when collapsed (we don't have a storage space other than garages of people in the group and a medium-sized trailer which we stage out of).

I've been playing a bit with a lux meter app on my phone and it seems that we could probably get by with 30-50 lux and have enough light for it to be usable.  From there it becomes a math problem of looking at the height and the angle of spread from the lights we select. 

Thanks for the suggestions NT2C!
Information - it's all a battle for information. You have to know what's happening if you're going to do anything about it. - Tom Clancy, Patriot Games

EBuff75

Just did a bunch of calcs using a 30ft mast and either a 40k or 80k lumen light setup.  (first time I can remember using Trig since high school).  Long and short is that the big thing is the angle that the light comes out at.  A 160 degree light would produce 137 lux with a 40k light and 274 lux with an 80k light.  Those are well-lit room levels. 

However, if the angle of light is 160, those same levels drop to 4.7 and 9.5 lux respectively.  (10 lux isn't too bad and would probably be okay for our uses, based on me playing with a downloaded lux meter app)

And if the light angle is 170, it drops to 1.17 and 2.34 lux.  You can see at those levels, but just enough to see where you're going.

This means that the output angle and how we adjust the lights at the top of the tower can have a huge effect on brightness levels on the ground.  I sent the link to this thread over to some people in the group, along with my calculations.  Kind of a weird way for this poli-sci major to have spent the afternoon!  :D
Information - it's all a battle for information. You have to know what's happening if you're going to do anything about it. - Tom Clancy, Patriot Games

NT2C

#7
Quote from: EBuff75 on October 10, 2021, 04:21:38 PM
Just did a bunch of calcs using a 30ft mast and either a 40k or 80k lumen light setup.  (first time I can remember using Trig since high school).  Long and short is that the big thing is the angle that the light comes out at.  A 160 degree light would produce 137 lux with a 40k light and 274 lux with an 80k light.  Those are well-lit room levels. 

However, if the angle of light is 160, those same levels drop to 4.7 and 9.5 lux respectively.  (10 lux isn't too bad and would probably be okay for our uses, based on me playing with a downloaded lux meter app)

And if the light angle is 170, it drops to 1.17 and 2.34 lux.  You can see at those levels, but just enough to see where you're going.

This means that the output angle and how we adjust the lights at the top of the tower can have a huge effect on brightness levels on the ground.  I sent the link to this thread over to some people in the group, along with my calculations.  Kind of a weird way for this poli-sci major to have spent the afternoon!  :D

I think your calculations are way off somewhere, or you gave incorrect figures earlier.  I'm sure you're familiar with yard floodlights.  Most houses have them and they're used other places as well.  I have a 30W LED floodlight on my shed.  It has three heads that are 10W each and puts out a total of 3,500 lumens.  My yard is a little over 120' long and 50' wide (rear yard).  When that floodlight gets triggered you could read a book in my neighbor's yards.  Okay, it's mounted to a shed and only about 11' off the ground but still.

In that same yard, I also have floodlights mounted on the peak of the house.  Those are indeed 30' off the ground and they are far less than 3,500 lumens.  There are two heads with screw-in bulbs.  Currently, they are 90W equivalent LED bulbs rated 950 lumens each.  One points to my gravel driveway, one points to my rear deck.  Just the single one pointing at the rear deck makes it bright enough to grill by and see how meat is cooking.

Something about your maths seems off to me.
Nonsolis Radios Sediouis Fulmina Mitto. - USN Gunner's Mate motto

Current Weather in My AO
Current Tracking Info for My Jeep

NT2C

I went and checked a few things and took some photos.



That light is a 175W mercury vapor light rated at 7,500 lumens.  It's about 18' off the grass.  This was taken well after sunset and with it having just rained, so cloudy and gloomy.



Those two spots are the LED floods I mentioned, rated 90W equiv and 950 lumens.



One is aimed right at that section of deck.  The beam angle on these is about 40 degrees, so more a spot than a flood but marketed as a flood in comparison to the 15 degree spots they also sell.
Nonsolis Radios Sediouis Fulmina Mitto. - USN Gunner's Mate motto

Current Weather in My AO
Current Tracking Info for My Jeep

EBuff75

It's been about 30 years since I took trig, so that's entirely possible!

I found a better online calculator to use for the trig, but now that I have a calculator (rather than trying to do all the calcs manually), I'm getting even lower numbers for lux, at least for the 140 degree solution (the others were the same).  Here's what I'm doing (and I'm rounding most of these numbers off a little):


       
  • Three calculations, assuming a 140, 160, and 170 degree beam angle out of the light (led light panels tend to be very flat with a great deal of spread), with the light pointing straight down
  • Split the angle in half (so 70, 80, and 85 degrees) for each side at the top to make a right angle triangle with the vertical height being 30 ft for the stand
  • Calculate the length of the side opposite the top angle (resulting in 82.4, 170, and 342 feet - the only one of these which is different is the first one; the other two agree with my previous calculations that I ran); this is the radius for the circle where the light hits the ground
  • Find area of each circle (21,320; 90,750; and 367,000 sq ft)
  • Convert each to sq meters (1980, 8430, 34100 sq meters)
  • Divide 40k lumens and 80k lumens into each of those to find lumens / m^2 (which is the calculation for lux)
  • At 40k lumens these are: 20.2 lux; 4.75 lux; and 1.17 lux
  • At 80k lumens they are all doubled, so 40.4 lux, 9.5 lux, and 2.34 lux
I think that all of it is correct, but it's been a while, so please check my math!  And all of this assumes no losses from the light housing or light which is scattered outside of the originally proposed angles.  I have no idea what sort of losses would happen there, but any lose of lumens at the source will further reduce the lux readings.
Information - it's all a battle for information. You have to know what's happening if you're going to do anything about it. - Tom Clancy, Patriot Games

NT2C

Further complicating things...

This gave me an excuse to play with a new toy, an Olight Archer flashlight.  535m throw, up to 1,000 lumens (72,656cd) using the barn doors on my shed from my deck, about 50' away.  My phone camera is going to try to adjust for the light levels so keep an eye on the amount of light off to the left from my 175W yard light to get an idea how much it's compensated.



5 lumens



50 lumens



300 lumens



470 lumens



1,000 lumens (I think... hard to get into turbo mode from high)

Nonsolis Radios Sediouis Fulmina Mitto. - USN Gunner's Mate motto

Current Weather in My AO
Current Tracking Info for My Jeep

NT2C

Quote from: EBuff75 on October 10, 2021, 06:58:20 PM
It's been about 30 years since I took trig, so that's entirely possible!

I found a better online calculator to use for the trig, but now that I have a calculator (rather than trying to do all the calcs manually), I'm getting even lower numbers for lux, at least for the 140 degree solution (the others were the same).  Here's what I'm doing (and I'm rounding most of these numbers off a little):


       
  • Three calculations, assuming a 140, 160, and 170 degree beam angle out of the light (led light panels tend to be very flat with a great deal of spread), with the light pointing straight down
  • Split the angle in half (so 70, 80, and 85 degrees) for each side at the top to make a right angle triangle with the vertical height being 30 ft for the stand
  • Calculate the length of the side opposite the top angle (resulting in 82.4, 170, and 342 feet - the only one of these which is different is the first one; the other two agree with my previous calculations that I ran); this is the radius for the circle where the light hits the ground
  • Find area of each circle (21,320; 90,750; and 367,000 sq ft)
  • Convert each to sq meters (1980, 8430, 34100 sq meters)
  • Divide 40k lumens and 80k lumens into each of those to find lumens / m^2 (which is the calculation for lux)
  • At 40k lumens these are: 20.2 lux; 4.75 lux; and 1.17 lux
  • At 80k lumens they are all doubled, so 40.4 lux, 9.5 lux, and 2.34 lux
I think that all of it is correct, but it's been a while, so please check my math!  And all of this assumes no losses from the light housing or light which is scattered outside of the originally proposed angles.  I have no idea what sort of losses would happen there, but any lose of lumens at the source will further reduce the lux readings.

Ah, but is that the lux at the edge of the circle or in the center?  And what is the lumens based on?  Lumens is actually luminous intensity at a specific distance, not a stand-alone value, though it is often used that way.

The lumens definition is: "a unit of luminous flux in the International System of Units, that is equal to the amount of light given out through a solid angle by a source of one candela intensity radiating equally in all directions."

Frankly, I think you're getting too bogged down in the numbers and missing the easy way, which is just looking at what the ratings of common area lighting is and going with that.  Most common LED streetlight heads are rated about 5,000 lumen.  Look at how much light a streetlight gives and decide if that's enough or do you need brighter?
Nonsolis Radios Sediouis Fulmina Mitto. - USN Gunner's Mate motto

Current Weather in My AO
Current Tracking Info for My Jeep

EBuff75

A couple of us went out there tonight and played with some regular work lights for a bit tonight.  The lights were rated from about 2500 - 3500 lumens and did a good job of lighting within about 35-40 feet.  Beyond that you could still see the ground well enough to walk without tripping out to almost 250 ft.  However, for being able to see clearly enough to do things like look in a bag for something, find a small item dropped in the grass, etc, that was hard to do much beyond 40 feet or so. 

One of the other guys is planning to stop by Menard's tomorrow to pick up a 10,000 lumen work light and we're going to test again in that same location to see how that does. I still think that the big trick will be to get any lights that we use up high enough that they aren't shining in people's eyes when they're walking around.  The others are still talking about just building a stand with regular 2x4s and putting the light about 8ft up in the air.  I think that's going to be way too low. 

I know that I was generalizing things like the center of the light being the same as the edges, but it would be too much effort to try to do the calcs some other way (I flat out refuse to try to remember how to do calculus)! 

Having to try to ferret out the real lumens on lights like this sucks.  My "10,000" lumen fishing/camping floodlight which I bought last week wasn't any brighter than the 3500 lumen work light that we had there to test and likely puts out about 1/4 to 1/3 of the claimed output.  I've seen a few of the non-name-brands admit that they make up numbers to improve sales, since they aren't using any type of industry measurements.  It's just a marketing ploy.  And even if they are using "true" lumens (most of them don't use the ANSI standard), the next question is how are they measuring them?  Is it at the LED? Past the glass? At a distance? (and what distance?)  Most of the time they're measuring right at the LED, in order to get the highest possible number.

We also noted the difference between an 800 lumen flashlight, with a decent reflector (I think it was a Streamlight of some type) vs the floody work lights that we were testing.  The flashlight (as you also demonstrated with the Olight Archer) was able to light things up at a far greater distance than the floody work lights (there was a very nice buck which wandered through and we lit him up with the flashlight at about 300 ft, no problem). 

A good apples-to-apples comparison is probably that I had a 3200 lumen Olight R50 Seeker Pro (very floody) which would illuminate out to something like 100ft (3x the distance of the work lights), but with about 1/3 the width of the area that the work light would cover. Since the lumen output was comparable to the work lights, it does a good job of illustrating the difference that focusing the beam makes.

Tonight we did discuss if it might be easier to set up multiple, smaller lights to cover the area in question, since we could then place them around the edges of the bowl where the movie is shown, pointed inward to even out the lighting.  It would be an easier approach, other than needing a lot more extension cords to power them all.
Looking over the specs on a few of those Generac light towers (I don't know which one our township has), they're putting out 188,000 lumens and are 23-25 ft tall (depending on the model selected).  At that height and output, they're providing 0.5 ft-candles (which translates to 5.3 lux), for an area which is 25,000 - 28,000 sq ft (2300 - 2600 sq meters).  That would be a circle with a radius of about 90-95 feet, which is only a little larger than my calculation for 140 degree angle at 30 ft height.  Presuming that their specs are determined by actual engineers using actual measurements done to industry standards, my calculations below appear to be extremely optimistic!

From my research today, I found recommendations of 10 lux for sidewalks, which is why I was sort of using that to find the "range' for the work lights that we tested.  Basically, we'd turn on one of the lights and then I'd walk away from it with my phone facing back toward it (using the lux meter app) and stop when it dropped below 10.  Then I'd pace off the distance back to the light.  That was generally about 35-40 feet.  If we were to drop that to 5 lux it would probably give us about 50-60 ft of range from one of the small work lights.
That's enough for my brain at 1:30 in the morning.  Time to crash...
Information - it's all a battle for information. You have to know what's happening if you're going to do anything about it. - Tom Clancy, Patriot Games

Raptor

#13
I bought a couple of these for an event and it worked well to light a dark area.

https://www.amazon.com/CONPEX-Beautiful-Upgraded-Removable-Telescopic/dp/B08GRFBV4X/ref=sr_1_4?dchild=1&keywords=telescoping+fishing+cob+lights&qid=1633970684&sr=8-4

These are similar.
https://www.amazon.com/Beyonds-Camping-Lantern-Telescopic-Waterproof/dp/B07RN73XFY/ref=sr_1_3?dchild=1&keywords=telescoping+fishing+cob+lights&qid=1633970621&sr=8-3

https://www.amazon.com/Telescopic-Fishing-Outdoor-Lantern-Camping/dp/B07NS4DYVC/ref=sr_1_2?dchild=1&keywords=telescoping+fishing+cob+lights&qid=1633970684&sr=8-2

These are 120 volt plug in 50 watt LED flood lights. They are designed to the screwed or bolted onto a surface but they are lightweight enough that a couple of good clamps could be used to mount them to a trailer or other structure. They could be powered with a generator or an inverter.

https://www.amazon.com/Outdoor-Halogen-Equivalent-Waterproof-Floodlight/dp/B01KFUZ1VC/ref=pd_bxgy_1/139-4218877-3088040?pd_rd_w=qBArK&pf_rd_p=c64372fa-c41c-422e-990d-9e034f73989b&pf_rd_r=SDC4AWACKQZJ2WSVTA6T&pd_rd_r=d79c787a-a2de-4c61-a778-6da4d58ee2ea&pd_rd_wg=oxtul&pd_rd_i=B01KFUZ1VC&psc=1


From my experience lighting parking garages and other commercial and industrial areas you are generally better off going with multiple lights spread out over the area. Even though they may be dimmer, they will more evenly light the area better than a single extremely bright source placed in the center.

In one application I eliminated fixtures that produced 3x the lumens of the replacement fixtures. We put in 2 replacement fixtures for each replaced fixture. The overall lumen output was reduced by a 1/3.  However the replacement fixtures were spread out over a larger area and while the result was measurably dimmer it actually provided a much better level of lighting coverage over the whole area. It actually looked brighter due the fact there were fewer shadows and otherwise dark areas were now illuminated.

The other is issue is that if a light tower fails the whole area is dark. Multiple fixtures provide redundancy.

 
Folks you are on your own...Plan and act accordingly!

I will never claim to have all the answers. Depending upon the subject; I am also aware that I may not have all the questions much less the answers. As a result I am always willing to listen to others and work with them to arrive at the right answers to the applicable questions.

sheddi

Thanks for the thread!

My application is much less demanding, just some area lighting for setting up and taking down a fireworks display in a few weeks. I've bought a couple of these that I plan to stick up (eg. on a 12' length of 2x2) and plug into my new power bank:
https://www.ebay.com/itm/164489892714

I've got a similar lamp (the AC model, not the 12V DC one) on my house that lights up my driveway well enough, to maybe 25', so I'm hoping two will give me a decent pool of light to work in.

EBuff75

Raptor, I chuckled a little at your first recommendation, because I just bought the Conpex 10,000 lumen camping light last week!  That was what we used during the tear-down at the event this past weekend, because it could run off of my small power station (using the 12v output) and lit the area up nicely.  Unfortunately, when I tried to test the suction cup mount, it immediately broke, so I'll likely be sending it back and asking for a replacement.  The 10k rating is far too high (I'd guess it's more in the 3000-4000 lumen range), but it's still a nice light. 

I actually considered the one you posted, but I was concerned about the number of watts that it draws on high and whether my power station would be able to handle it in DC mode.  With the smaller one, I ran the light for almost 2 hrs and the station hadn't even dropped a bar on the charge indicator.  I'm also REALLY impressed with the heat (or rather, the LACK of any heat) when running it.  That thing was barely any warmer than the ambient temperature, even after running for 2 hours. 

Tonight we went back out to test a 10,000 work light at the cemetery.  The pictures below were both taken at ISO 320 and are fairly representative of what we were seeing. 

3000 lumen work light test:


10,000 lumen work light test:


In the brighter one, the trees that you can just see at the edge of the light are about 70ft away and the large grave markers in the distance are about 100-110 feet away.  (the left side of the road is where we do the movie, but it's just an empty grass bowl and wouldn't show much).  The lights were both sitting on the hood of my Suburban for the pictures.  I measured 10 lux at about 90 ft with the 10,000 lumen light, so we're thinking that getting a few of those and then putting them on some type of mount would give us pretty good coverage.

We've ordered a 13 ft light stand tripod (for use in photography) which we were able to find as a reconditioned unit for something like $17.  We'll see how well that works, or if we need more height.  Someone volunteered to build a mount to put on it once it arrives.  The lights are about 3.5 - 4 lbs each once the base (which we won't need) is removed.

Right now we're leaning toward having two lights up on a tripod right between where the people sit and the concessions / vendors area, plus one more on the far side of the viewing area (the bowl where we show the movies is about 150 ft across). That way we'd be illuminating from two directions, which would hopefully help to even out the light levels.  By putting the other light up on the hill it would also help to provide additional height to shine down from.  The two lights on the main stand would have one aimed toward the bowl and the other would be pointed back toward the concessions / vendors / port-a-potties. 

With the 10k light set up in that central area, we were able to throw just barely enough light to be able to see to walk out the driveway to where it turns the corner (about 320 ft, according to Google Maps).  We then put up a small battery-operated work light at the corner and were able to illuminate the driveway fairly well when combined with the lights out at the main street.  It would probably be enough for most people to see as they're walking out after the event.  At least they wouldn't have to use flashlights the whole time.

We'll have to wait until the tripod arrives to do any testing with the lights up in the air.  I'll keep posting as I have updates.
Information - it's all a battle for information. You have to know what's happening if you're going to do anything about it. - Tom Clancy, Patriot Games

Raptor

Quote from: EBuff75 on October 11, 2021, 10:22:20 PM

I actually considered the one you posted, but I was concerned about the number of watts that it draws on high and whether my power station would be able to handle it in DC mode.  With the smaller one, I ran the light for almost 2 hrs and the station hadn't even dropped a bar on the charge indicator.  I'm also REALLY impressed with the heat (or rather, the LACK of any heat) when running it.  That thing was barely any warmer than the ambient temperature, even after running for 2 hours. 

In my application there was a power outlet within reach and was not an issue. In fact I foolishly did not see the 12 volt requirement unit it arrived. That said it appears as though the draw based upon the comments is between 65 watts and 110 watts or (65/12=5.5 amps to 9.1 amps). A simple series 31 battery should run one running at max for several hours.

Folks you are on your own...Plan and act accordingly!

I will never claim to have all the answers. Depending upon the subject; I am also aware that I may not have all the questions much less the answers. As a result I am always willing to listen to others and work with them to arrive at the right answers to the applicable questions.

sheddi

My 10W LED floodlamps arrived today. Pictured with one of the 3s2p 12v li-ion packs I bought from Aliexpress earlier in the year. (The box underneath was just a convenient photo stage.)



I don't have a convenient cemetery nearby but I did give one a go from my house. If I stick one out of my second-floor window (maybe 15-20' high) it lights up me entire yard (roughly 60' square) enough to read by.

For my purposes, that's more than adequate.

EBuff75

Quote from: sheddi on October 13, 2021, 01:39:40 PM
My 10W LED floodlamps arrived today. Pictured with one of the 3s2p 12v li-ion packs I bought from Aliexpress earlier in the year. (The box underneath was just a convenient photo stage.)



I don't have a convenient cemetery nearby but I did give one a go from my house. If I stick one out of my second-floor window (maybe 15-20' high) it lights up me entire yard (roughly 60' square) enough to read by.

For my purposes, that's more than adequate.

Nice!  And I'm not sure that I'd call the cemetery "convenient", just close enough that it's not TOO much trouble to get there (it's a few miles away from my house and part of it is technically in Detroit).  I've been considering adding some lights like that to the back of my house, but the wiring would be a real pain, so I'd be more likely to go the solar route there.
Information - it's all a battle for information. You have to know what's happening if you're going to do anything about it. - Tom Clancy, Patriot Games

RoneKiln

For a pleasant atmosphere at outdoor events, string lights are far better than one or two light towers and in many locations easier to set up. They're affordable and very versatile.
"Seriously the most dangerous thing you are likely to do is to put salt on a Big Mac right before you eat it and to climb into your car."
--Raptor

SMF spam blocked by CleanTalk