BobbyZ
Well-Known Member
Do those cobs need the cones?
Nice job on that frame.
Nice job on that frame.
It's Time To Build A Grow Light
- Thread starter Old Salt
- Start date
- Thread starter
- #42
I have the reflectors, but will have to test the light with them on, and off of it. Timber Grow Lights no longer includes them, saying "Recent integrated sphere testing has shown a loss of almost 8-10% in PAR wattage using the reflectors vs not. Additionally, the light is able to be operated closer to the canopy with even PAR spread. "
I will put the reflector mounts on. I haven't done that yet to avoid damaging them since the catches drop below the frame.
I will put the reflector mounts on. I haven't done that yet to avoid damaging them since the catches drop below the frame.
Emilya Green
Well-Known Member
I may have to take my reflectors off and re-run some of my numbers to see if I can see an increase too. Using reflectors is not all about PAR though, it has to do with directing the light downward for additional penetration, or at least that's how it works in the HID world... a good reflector hood could make all the difference there, helping not to waste so much light to the sides. These COBS though, are directing light in at least no more than 180°, so already they are better than an HID in that respect, and we may not actually need to focus that light. There is still so much to learn about LED!
- Thread starter
- #44
Citizen published the following graph for the CLU048 1216s:
You can see that the light at 45° off center is roughly 70% of that directly under the COB. Since we're dealing with a flat canopy, the light should be reduced by about 30% due to the extra distance travelled. That means at the canopy you'd get 1/2 the light at 45° than you get directly under the light. If this is actually true, it means the height for the most even coverage would be half the distance between the COBs, or 15cm (6") for my light. I'll have to test this to verify it.
A HID is more or less a point source of light, radiating evenly spherically. That's why a reflector is needed to redirect the light back to the canopy.
Emilya Green
Well-Known Member
I have been thinking about adding 2 more blue COBS to my array for veg and have been thinking a lot about not putting reflectors on these so that this light would spread out and mix with the other full spectrum lights while in veg.
I still think the reflectors serve a purpose. There may be bright and dark zones at various places under this array, but I don't think this matters to a plant sitting under it getting brighter light in one spot over another.
Consider too that at 6" you are really going to have some bright light there, but at 12 or 18" you are going to have multiple overlaps of varying distances and angles, all additive.
But again, being able to direct all of that light downward, not just 70% of it, by using a reflector, has got to help with penetration through the canopy. A good reflector is going to give you 98% of that output going downward, right where it needs to be. I am just not sure how much having even coverage is more important than forming these strong beams of canopy penetrating light or whether that even matters with these LEDs.
I still think the reflectors serve a purpose. There may be bright and dark zones at various places under this array, but I don't think this matters to a plant sitting under it getting brighter light in one spot over another.
Consider too that at 6" you are really going to have some bright light there, but at 12 or 18" you are going to have multiple overlaps of varying distances and angles, all additive.
But again, being able to direct all of that light downward, not just 70% of it, by using a reflector, has got to help with penetration through the canopy. A good reflector is going to give you 98% of that output going downward, right where it needs to be. I am just not sure how much having even coverage is more important than forming these strong beams of canopy penetrating light or whether that even matters with these LEDs.
- Thread starter
- #46
You make some good points. Something else to consider is where the light is used. In an open area light is lost all around the grow area. In an enclosed space with highly reflective sides such as a grow tent much of this light is bounced back into the canopy.
It won't hurt to map out the coverage, even though it may prove to be an exercise in futility. In the end. the proof will be in the results. Due to the design of my light, a simultaneous comparison grow is impossible as I can't operate at two different heights. The results of sequential grows, even with the same strains would be questionable, since the environment (temp, humidity) will change. What I can do is test the penetration into the canopy, with and without the reflectors. This will have to be put on hold until my fall grow, as my current grow is just finishing, and the next grow will be a seed run.
- Thread starter
- #47
Let's do some testing...
I'll take Lux measurements for the peak and low intensities under the light, both with an open frame, and with the reflective mylar fabric installed. This will be done both with the reflectors installed, and removed. I'm not mapping the coverage, just looking for the highs and lows. I'll do it at four heights, 15, 30, 45, and 60cm. That roughly equates to 6, 12, 18, and 24 inches. Here's the initial test setup:
Open Tent Frame for Peak and Low Tests
I've taped landscape cloth to the bottom of the frame simulating reduced reflection from the canopy. It probably won't make a difference for the open frame test, but should once it is covered. I'll drag my cell phone across the floor of the frame in several places to capture the peak and low spots. I won't know where they are, but that's fine, at this point.
The app I'm using is Lux Light Meter by Doggo Apps. It claims to measure from 0-64000 Lux, but facing the sun I got a reading of 112,750 today. It will suffice.
I'm procrastinating getting started as my back doesn't want to play anymore today.
I'll take Lux measurements for the peak and low intensities under the light, both with an open frame, and with the reflective mylar fabric installed. This will be done both with the reflectors installed, and removed. I'm not mapping the coverage, just looking for the highs and lows. I'll do it at four heights, 15, 30, 45, and 60cm. That roughly equates to 6, 12, 18, and 24 inches. Here's the initial test setup:
Open Tent Frame for Peak and Low Tests
I've taped landscape cloth to the bottom of the frame simulating reduced reflection from the canopy. It probably won't make a difference for the open frame test, but should once it is covered. I'll drag my cell phone across the floor of the frame in several places to capture the peak and low spots. I won't know where they are, but that's fine, at this point.
The app I'm using is Lux Light Meter by Doggo Apps. It claims to measure from 0-64000 Lux, but facing the sun I got a reading of 112,750 today. It will suffice.
I'm procrastinating getting started as my back doesn't want to play anymore today.
- Thread starter
- #48
This post will present the open frame Lux measurements with and without the reflectors installed.
I used the light meter on my phone, with the light set on 16W. I clamped a cord between the body of the phone and its protective case. I set the phone against the left side of the frame and slowly pulled the cord to get the high and low Lux readings along the path. They are not 100% accurate as the phone sometimes pulled across angled a little. These measurements should be good enough to get a general idea of the coverage.
Phone Light Meter Readings
I feel that the bottom section of the table most accurately represents the Lux values, as these are averaged around the center of frame. It appears that with the reflectors installed more light reaches the canopy. It also appears that 15 cm above the canopy this fixture does not provide good coverage. The best coverage appears to be around 30cm or 12" from the canopy.
Next I need to install the reflective mylar cover for the tent, and take these readings again. This will give us an appreciation of the difference between an open space, and an enclosed space with reflective surfaces.
BTW, the fixture will go up to 530W. At that power my phone is unable to measure the intensity of the light. It stops at around 120,000 Lux.
I used the light meter on my phone, with the light set on 16W. I clamped a cord between the body of the phone and its protective case. I set the phone against the left side of the frame and slowly pulled the cord to get the high and low Lux readings along the path. They are not 100% accurate as the phone sometimes pulled across angled a little. These measurements should be good enough to get a general idea of the coverage.
Phone Light Meter Readings
I feel that the bottom section of the table most accurately represents the Lux values, as these are averaged around the center of frame. It appears that with the reflectors installed more light reaches the canopy. It also appears that 15 cm above the canopy this fixture does not provide good coverage. The best coverage appears to be around 30cm or 12" from the canopy.
Next I need to install the reflective mylar cover for the tent, and take these readings again. This will give us an appreciation of the difference between an open space, and an enclosed space with reflective surfaces.
BTW, the fixture will go up to 530W. At that power my phone is unable to measure the intensity of the light. It stops at around 120,000 Lux.
BobbyZ
Well-Known Member
Nice job... But how does she grow? 
Path 4, light 1 furthest from your numbered paths numbers, seems to be getting more power? Am I reading this right? I just thought there would be more of a balance in those numbers.
I'd use the reflector cones, every number increased... Thanks for the numbers.
Path 4, light 1 furthest from your numbered paths numbers, seems to be getting more power? Am I reading this right? I just thought there would be more of a balance in those numbers.
I'd use the reflector cones, every number increased... Thanks for the numbers.
- Thread starter
- #50
Nice job... But how does she grow?
That's coming soon!
- Thread starter
- #51
Nice job... But how does she grow?
Path 4, light 1 furthest from your numbered paths numbers, seems to be getting more power? Am I reading this right? I just thought there would be more of a balance in those numbers.
I'd use the reflector cones, every number increased... Thanks for the numbers.
Part of the problem is that the light wasn't level front to back. I'll pick up some small turnbuckles to fix that. The other contributor was the phone angling as it was dragged across the floor of the tent. An inch or 25 mm makes quite the difference.
I've got a couple of weeks before I need to press this light into service, so I've got the time to measure it again.
Looks awesome! I'm looking into building something like this for my cabinet as I'm finding it tricky to find something that ideally suits my space. So thinking sod it I will build my own. Do you guys know any good links to read so I can get my head around the principles of building one of these and make the right part choices for my requirements? Any help would be much appreciated.
- Thread starter
- #53
Try @PurpleGunRack's threads Build Your Own LED Grow Light and DIY Test Build with Samsung Q-series strips.
GrowMau5 has a good series of videos on YouTube.
Feel free to ask. Any of us would be glad to help.
GrowMau5 has a good series of videos on YouTube.
Feel free to ask. Any of us would be glad to help.
Thanks a lot. I'll make a start on my research there.
- Thread starter
- #55
I purchased the parts for the light hanger:
Parts for Light Hanger
I decided on 1" (25mm) aluminum u-channel for the frame, and 3/4" (19mm) pulleys. The diffuser ( 2 required) will be used as the carbon filter will no longer fit in the tent. This is due to the location of the ventilation openings in the center of the sides.
Oops! a Problem!
The tent poles were supposed to fit inside the u-channel. As you can see the diameter of the poles is a bit too large. Instead of fitting over the poles, I'll need to suspend the hanger from the frame. I'll use a metal strap for this, and rivet it together.
Whenever I embark on a DIY project, something almost always comes up requiring a change of plan. This is especially true if I don't have the parts on hand during the design phase. If this is my only problem I'll count myself lucky.
Parts for Light Hanger
I decided on 1" (25mm) aluminum u-channel for the frame, and 3/4" (19mm) pulleys. The diffuser ( 2 required) will be used as the carbon filter will no longer fit in the tent. This is due to the location of the ventilation openings in the center of the sides.
Oops! a Problem!
The tent poles were supposed to fit inside the u-channel. As you can see the diameter of the poles is a bit too large. Instead of fitting over the poles, I'll need to suspend the hanger from the frame. I'll use a metal strap for this, and rivet it together.
Whenever I embark on a DIY project, something almost always comes up requiring a change of plan. This is especially true if I don't have the parts on hand during the design phase. If this is my only problem I'll count myself lucky.
- Thread starter
- #56
Turnbuckles, a Pulled Apart Pulley, and a Nail?
OK, the turnbuckles are to level the light, both front to back and side to side. The pulley is one of those required for the hanger. They will be mounted on the top rail. Now a nail? What in the world am I thinking?
I wasn't able to locally find a suitable shaft for the pulleys. I started thinking, always an indication of trouble to come. I could use my lathe to turn the nail or a bolt into a suitable shaft, threads and all. Turn the nail to the proper diameter, thread it, and slot the head, and I'd be done.
Since there are some out there without a lathe in their workshop, and I want folks to be able to build their own, I need another solution. Tomorrow I'll visit Metals-R-Us and see if I can find suitable rod to make into the shafts required. This will require a tap, die, hacksaw, and drill. Folks are much more likely to have these tools. Perhaps not the tap and die, but they are relatively cheap when compared to a lathe.
HydroponicFireman
Well-Known Member
Very interesting.
I may have to start doing some research for a DIY LED instead of buying one. Keeping an eye on the thread
I may have to start doing some research for a DIY LED instead of buying one. Keeping an eye on the thread
- Thread starter
- #58
I've updated the concept drawing to show the force multiplier. Using it will limit the movement to about 1/2 the height of the tent.
Implementing the concept, this is what I've accomplished to date:
Overview of Light Hanger
Left Side Details, Rail Connection
The top rail was notched so it rests on the side rails. I used countersunk screws to fasten it to the side rails. Rivets can also be used. Pan head screws or bolts with heads that protrude above the rail should be avoided. These can damage the roof of the tent if they come in contact with it. I intend to weld this connection later. The screw will work nicely in place of a clamp. Welding is not required, but as I have the equipment...
Right Side Details, Force Multiplier, and Cord Connectors
The cord connector is simply a piece of scrap u-channel, with three holes drilled in it. I'll pass a rope through the hole in the bottom, and use a stop knot to hold it in place.
The Force Multiplier pulleys can be tied together, but I'll use a piece of scrap metal to bolt them instead.
The shafts on the sheave (or wheel) donor pulleys can be drilled out, but I ground them down, and punched them out. The blocks and pins are now scrap. The sheaves in the rails will be braced with washers for stability. These needed to be drilled out a little for the shafts, I went 1/64" oversize for a 3/16" shaft. A piece of rope wrapped around them prevents damage when holding them in a vice for this operation.
The shafts were cut from 3/16" rod. The rod was held in a vice between two blocks of wood, then had seven threads cut on it. The shaft was then cut to length. Two nuts were locked together on the shaft, and four threads were cut on the other side for the top and bottom side rails. The shafts for the main center rail were cut a little longer, and have seven threads cut on each end. I used #10-32 taps and dies for threading. This means 4 threads are required to completely engage the walls of the u-channel.
Left to do is fabrication of the supports to hang the top assembly, and hold the bottom assembly down. I'll use sheet metal, and rivet them to the assemblies to avoid damaging the tent walls. I'll follow with a coat of paint, do the final assembly, and I'll call it done.
Implementing the concept, this is what I've accomplished to date:
Overview of Light Hanger
Left Side Details, Rail Connection
The top rail was notched so it rests on the side rails. I used countersunk screws to fasten it to the side rails. Rivets can also be used. Pan head screws or bolts with heads that protrude above the rail should be avoided. These can damage the roof of the tent if they come in contact with it. I intend to weld this connection later. The screw will work nicely in place of a clamp. Welding is not required, but as I have the equipment...
Right Side Details, Force Multiplier, and Cord Connectors
The cord connector is simply a piece of scrap u-channel, with three holes drilled in it. I'll pass a rope through the hole in the bottom, and use a stop knot to hold it in place.
The Force Multiplier pulleys can be tied together, but I'll use a piece of scrap metal to bolt them instead.
The shafts on the sheave (or wheel) donor pulleys can be drilled out, but I ground them down, and punched them out. The blocks and pins are now scrap. The sheaves in the rails will be braced with washers for stability. These needed to be drilled out a little for the shafts, I went 1/64" oversize for a 3/16" shaft. A piece of rope wrapped around them prevents damage when holding them in a vice for this operation.
The shafts were cut from 3/16" rod. The rod was held in a vice between two blocks of wood, then had seven threads cut on it. The shaft was then cut to length. Two nuts were locked together on the shaft, and four threads were cut on the other side for the top and bottom side rails. The shafts for the main center rail were cut a little longer, and have seven threads cut on each end. I used #10-32 taps and dies for threading. This means 4 threads are required to completely engage the walls of the u-channel.
Left to do is fabrication of the supports to hang the top assembly, and hold the bottom assembly down. I'll use sheet metal, and rivet them to the assemblies to avoid damaging the tent walls. I'll follow with a coat of paint, do the final assembly, and I'll call it done.
Check out Rapid LED, they have some content that may help. They sell a lot of GrowMau5 gear like his pucks which are essentially the exact same thing as a QB but in a different form factor. Likewise, a search of quantum board will turn up a lot of content too.
Impressive build OS, excited to see this thing in action.I've updated the concept drawing to show the force multiplier. Using it will limit the movement to about 1/2 the height of the tent.
Implementing the concept, this is what I've accomplished to date:
Overview of Light Hanger
Left Side Details, Rail Connection
The top rail was notched so it rests on the side rails. I used countersunk screws to fasten it to the side rails. Rivets can also be used. Pan head screws or bolts with heads that protrude above the rail should be avoided. These can damage the roof of the tent if they come in contact with it. I intend to weld this connection later. The screw will work nicely in place of a clamp. Welding is not required, but as I have the equipment...
Right Side Details, Force Multiplier, and Cord Connectors
The cord connector is simply a piece of scrap u-channel, with three holes drilled in it. I'll pass a rope through the hole in the bottom, and use a stop knot to hold it in place.
The Force Multiplier pulleys can be tied together, but I'll use a piece of scrap metal to bolt them instead.
The shafts on the sheave (or wheel) donor pulleys can be drilled out, but I ground them down, and punched them out. The blocks and pins are now scrap. The sheaves in the rails will be braced with washers for stability. These needed to be drilled out a little for the shafts, I went 1/64" oversize for a 3/16" shaft. A piece of rope wrapped around them prevents damage when holding them in a vice for this operation.
The shafts were cut from 3/16" rod. The rod was held in a vice between two blocks of wood, then had seven threads cut on it. The shaft was then cut to length. Two nuts were locked together on the shaft, and four threads were cut on the other side for the top and bottom side rails. The shafts for the main center rail were cut a little longer, and have seven threads cut on each end. I used #10-32 taps and dies for threading. This means 4 threads are required to completely engage the walls of the u-channel.
Left to do is fabrication of the supports to hang the top assembly, and hold the bottom assembly down. I'll use sheet metal, and rivet them to the assemblies to avoid damaging the tent walls. I'll follow with a coat of paint, do the final assembly, and I'll call it done.