DIY, DMX controlled, Led Strip in a Box

McCready00

Active Member
Hello all,
I am planning to build up a frame with a LED strip surrounding the interior.

My project has nothing to do with a professional tour of production, but only for a personal addition on a few festivals I will work on in the next year.

What is your personal experience with DIY Led strips, controlled by DMX ?

Any great dmx drivers you found? Better strips?

12v or 24v?

Any pictures of your projects, and the equipements used for it ?

Anny recommendations ?

I found out alot of LED strips on alibaba.com. What do you think ?
 
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https://www.controlbooth.com/threads/modern-led-tape.42647/#post-369597

Ship is a wizard with this stuff. Read that thread as a start.

There are different kind of strips so you will have to be more specific. A picture would be a great start or a link.

Dmx driver will depend on how many strips you want to drive. Obvious 24 will drive more in line than 12.

The next thing you will need is a PSU. This will also depend on on what you want to drive.

So more questions than answers but I'd recommend staying away from alibaba unless you know people in China that you work with a lot.

So the final question is how much you want to spend on this little project.
 
What is your personal experience with DIY Led strips, controlled by DMX ?
  • I build them all the time for customers. It's a very marketable skill for people in the industry these days. Some southern California unions are even starting to have members specialize in custom fixture creation.

Any great dmx drivers you found? Better strips?
  • This one is kind of the defacto in this area. So much so I've even seen local companies go back to the Chinese manufacturer and get runs of them made with custom branding on them. For the most part, decoders are mostly the same unless you need 16-bit dimming. Make sure the decoder is rated for the current you want to use it for plus headroom. If you go really cheap, the PWM frequency might be too low for video and it might appear to flicker on the camera even if you can't see it with you eyes, just something to keep in mind.
  • I've purchased $80/m tape and I've purchased $0.25/m tape and unless you're really concerned with color temperature, CRI, or want 4 channel color (RBGW) it's mostly all the same. Just try and get 12mm wide stuff so that it's easy to replace.

12v or 24v?

  • 24V is much better to manage current wise, but there's a lot more available in 12V. 12V will be easier to find to replace later on as well. I usually try to find 24V, but end up going 12V for some other reason.

Any pictures of your projects, and the equipements used for it ?
Not as many as I'd like, but I did make a pretty cool piano once:
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~60m of RGB PixelDMX LED Strip from Environmental Lights. The strip decodes DMX on chip so no decoder needed. 13 Universes of Chauvet Art-Net-to-DMX distribution built into the piano.

This one is more similar to what you describe:
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~10m of green single channel and ~35m of cool white single channel. Strip and Decoder were no name cheapest thing I could find on AliExpress.

Any recommendations ?
  • If you're making white fixtures have a mix of warm and cool white LEDs. You can buy 2 channel variable color temperature white tape, but often separate reels of different color temp single channel tape is cheaper and easier. Cool, natural, and warm white on 3 separate channels can be really nice for video.
  • Waterproof can be nice if you need it, but can be a nuisance and an extra cost when you don't. Think about how you'll use you fixtures and plan accordingly.
  • Buy at least one package of LED strip connectors (the first result on amazon here). They can save a lot of time and effort when you're building custom LED fixtures. Even if you eventually choose to solder all your connections for long term durability (I often do) they are a life saver for prototyping and repairs.
  • MANAGE VOLTAGE DROP!!! By that I mean only go a few feet between home runs to the dimmer. I try not to go much over 2m. Sure a 5A dimmer can run a whole 5m strip of single channel tape, but you're going to have significant intensity drop as you go along. For your specific case, if you're running tape only around the perimeter of the enclosure connect both ends of the tape to the dimmer. If you're going to put a bunch of short runs next to each other then wire them up in parallel instead of series.
  • Pay attention to your current, and make sure you have a fuse(s)! When LED arrays get large, especially for 12V, the amperage can add up really quickly. All of the largest power supplies I've ever ordered were for LED projects. The 24 AWG LED zip cord from Amazon/AliExpress is handy, but if you try to run 20m of tape with a single run of zip cord it's a fire hazard. This seems obvious, but I can't tell you how many times I've had to explain it.
  • Heat shrink all your exposed ends. It's cheap, looks nicer, and prevents them from contacting anything conductive that they could short to.

I found out alot of LED strips on alibaba.com. What do you think ?

  • I prefer AliExpress for the quantities of less than 100m at a time. The pricing is more up front and I find it much easier to actually purchase things there. You can also compare shipping options which is great because both times and prices vary wildly from vendor to vendor (like varying from free 10day shipping to $50 for 4-6 weeks shipping for similar product). Just don't assume anything when buying there. The sellers I've interacted with aren't actively trying to screw you, but many sell hundreds if not thousands of different items so pictures may not be accurate and the description may not have the details you want. I haven't had a lot of luck asking for additional details, so if what I'm looking for isn't called out in the description I usually just move on.
  • I don't find the quality of the $10-15/5m stuff on Amazon to be much different from the AliExpress stuff, but when you find yourself one roll short Amazon Prime is a wonderful thing. Superbrightleds.com and environmentallights.com are great US based companies to work with that sell a huge variety of LED products. Their tape is generally 4-10 times the AliExpress price, but I know exactly what I'm getting, that it will work exactly as described, and if I have any issues they will stand behind their stuff. When I have a customer that is concerned about reliability and consistency I usually go with them.

This may not be relevant to your current project, but it's good to know that LED modules and high power single source LEDs are a thing. They can take a little more thinking to implement, but can be a great wild card to have in your back pocket for an oddball project.
 
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Pork has covered your questions very well so here are a few tips from my LED experience to be added to the recommendations section.

1. Always have a couple of spare reels of LED tape and some spare dimmers. With the prices from Aliexpress and the sometimes extended shipping times it is better just to have some spare laying around.

2. Pork mentioned connectors for the LED tape. I also recommend connectors for the leads, we use phoenix terminal blocks. They are a little pricey but only need a tweeker. Anything that requires crimping will make maintenance really difficult.

3. If you are looking to do something a bit more permanent look into getting a second layer of double stick. The sticky back on the tape might say 3M but that isn't always true. I like to use their VHB https://www.3m.com/3M/en_US/company-us/all-3m-products/~/3M-VHB-Tape-5952 It is a little wider than the LED tape so if you need to run an auxiliary power feed you can stick it to that. This is a very pricey double stick there are plenty of more price friendly alternatives. It is also not always needed if it is a temporary install.

4. If you are using color changing LED tape put a clamp meter on each individual leg before you go too crazy wiring up. RGB+X LED tape will have different amp draws per color. The RGB will be very close to each other but the +X, X being a white or amber or any other color, could draw more if it is in an every other chip layout. When I say different I mean almost 3 times as much, this can cause major problems if you are trying to get a dimmer to its maximum capacity.

5. Not many people need to know about PWM but it can be a live saver in two ways. With a low PWM you will get a better low end dim compared to a high PWM setting and with a high PWM you will be less likely to flicker on camera. If you are concerned about camera flicker always make sure to get a dimmer that has adjustable PWM frequencies. The fastest PWM doesn't do you any good if it is the same frequency as the camera.

6. If you are doing any LED install at scale look into a pair of these, http://www.all-spec.com/Manufacture...s/Stripping-Tools/Wire-Strippers/PA1113-65663 They can do up to 4 18AWG wires at once and will strip them the exact same length every time.

7. Fans. Depending on the size and type of power supply you are getting they might or might not have a fan. It might not be a problem for this project but it could be in the future be mindful of it.

Thats all I can think of right now, if I think of anything else I will add it.
 
Harrison reminded me of one more thing.

When sticking the lights down I put a dab of super glue every 8"-12" to reinforce the sticky back. Even closer together for really cheap tape.
 
I used to think I knew a lot about LED tape, but then I started reading what the other members have written. So here's my two cents:
For the record, there are LED strips that are just LEDs in series and are controlled by PWM and then there are LED strips that have decoders and PWM drivers of some sort built in (Neopixels, WS2812, APA102, etc.). LEDs in series are all controlled at once (the whole string is one color) and the others are addressed individually in a very clever way. There are other strings (as noted above) that are direct DMX controlled but I've not yet played with them. The DMX controller linked to above is for simple strings of parallel LEDs and works really well (I have several). The "addressable" LEDs require some sort of controller -- either purchased or home-built (Arduino, Raspberry Pi, etc). There is a great project on the Internet that does wireless/streaming ACN over wifi and controls strings of WS2812 LEDs. The hardware is cheap and can be built easily at home. I have built a couple and on a closed wifi network, they are very reliable. If the link doesn't work, Google "ESPixelStick". Strangely enough, the Christmas lighting and Halloween forums are full of information on how to roll your own system.

One of the differences between Aliexpress LEDs and LEDs from more mainstream sellers such as Enttec is the thickness of the copper traces in the power lines. The Chinese direct-sales LEDs have thinner copper power runs and are therefore susceptible to voltage droop at the end of a run unless you supply both + & - in parallel with thicker wires and "inject" it along the way. An RGB LED at full brightness will draw about 60mA, and that adds up quickly. The voltage drop over the length of a string of LEDs with underdimensioned copper power traces will cause the pixels towards the end to be be increasingly reddish (blue LEDs turn on at a higher voltage than red ones). Another difference is color matching. In my experience, Chinese direct-seller LEDs are more variable in color for a given input. This can be calibrated out, but the math to do it is beyond me. A couple of years ago at USITT, some students from Stanford showed an LED video wall they built from LED strings bought directly out of China for a ridiculously low price. They calibrated each pixel individually for uniform color. Very impressive.
 

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