Minimalistic multichip DIY LED build

[jerpa]

Arguing about what should and shouldn't be allowed isn't a discussion for this thread unless everyone wants to see it closed. There's a wealth of information that would quickly lose relevance if it is closed. The mods have made it pretty clear what's acceptable IMO. If you feel someone else violated the rules press the red triangle and report them, slinging insults back and forth accomplishes nothing with relevance to multichip LEDs. We can disagree until we are blue in the face but it's their forum and their rules. Just sayin...

 

[tomservo]

I would opt for a ball bearing fan if possible. A small high speed fan can be used, but it will need to be shrouded well to be quiet. I like the idea of a massive copper heatsink that will prevent rapid chip failure in the event of fan failure. However, the CPU coolers that utilize heat pipes (shown here and in other threads) are likely going to be much easier to adapt. The shadowrock products get good reviews for performance and silence as does the Noctua NH-C12P

I don't think copper transports heat quickly enough through thick sections to handle power densities much past 100w. At least my experience with the zalman 7000 or whatever is that the temperature at the bottom of the base is significantly higher than at the top, this section is almost an inch tall and the fins don't really start until above that so the heat has to move through a lot of copper before it really gets to a large surface area.

I've always wondered what the velocity of the vapor in a heat pipe is.

At any rate, I've been sick as a dog all week, haven't gone to work yet but I was feeling good enough to drill 4 holes and install the light support bracket properly. It's probably not appropriate to post it since I'm a product tester according to our resident expert, but I'm going to do it anyway, I blame cold medicine for any poor judgement.

I have plans to put a shroud around the lens of some sort, I just haven't remembered to look for a piece of ~2" ABS at the hardware store.

I also adjusted the lights up by 3%/3% to 175 PAR from 150 PAR, this is measured with the lid in place.

 

[BrianD]

omg, outrageous, who do you think you are sir?
We have rc mods crawling out of every orifice on this thread, yet this is allowed with no sanction!

What rubbish!

If there are no sanctions for your kind if incivility then the forum becomes like anarchy.

It is best to refrain from speaking on subjects you know nothing about. Actions taken by moderators aren't always visible to the public eye.

Arguing about what should and shouldn't be allowed isn't a discussion for this thread unless everyone wants to see it closed. There's a wealth of information that would quickly lose relevance if it is closed. The mods have made it pretty clear what's acceptable IMO. If you feel someone else violated the rules press the red triangle and report them, slinging insults back and forth accomplishes nothing with relevance to multichip LEDs. We can disagree until we are blue in the face but it's their forum and their rules. Just sayin...

Jerpa is a wise man. We have bent over backwards on this thread, overlooking some problems in order that the information shared on it can continue to be shared by our members. A few of you are doing your best to give us no choice but to close it. In the interim, I have deleted some posts and will be contacting a few of you.

Under no circumstances is it acceptable to attack other members. None.

 

[FDAWG]

What a great thread!

I used a screen shot utility to capture all 130 pages of this thread and put it into PDF format. Just in case it gets closed.

 

[nettraptor]

The fan would not be easily replaced by a standard fan unless you took it apart and adapted it to the Zalman perpendicular mounting bracket. It's a good quality double bearing fan that should last a long time. The price is low enough for the whole cooler that you could have one as a backup fan. The larger CPU coolers can likely cool a 100w chip without the fan should it fail.

Fans are one of the weak links with multichip fixtures. Salt creep and moisture is the major concern. There are a lot of LED arrays on the market that have PCBs and drivers that are exposed to humidity and salt splashes. I don't think they will last more than three years in that kind of environment. Most multichip fixtures use water resistant drivers and silicone seals around the lenses. Running the drivers remote from the fixture is also a good idea. Running drivers onboard will dramatically shorten the life of the drivers, unless they are rated for outdoor use.

Adding a temp sensor that shuts off the light is always a good investment. Some fixtures like Radion dim the light when the max (warning) temp is reached.

there is a product called PLASTIK

provides a thin layer of protection around the object you spraying..
i spay all my electronic equipment inside my aquarium

 

[BeanAnimal]

I don't think copper transports heat quickly enough through thick sections to handle power densities much past 100w.

Agreed. After looking at some thermal profiles, a quality heatpipe based cooler with a failed fan will provide better thermal management than a thick copper heatsink with a failed fan.

 

[mr.wilson]

there is a product called PLASTIK

provides a thin layer of protection around the object you spraying..
i spay all my electronic equipment inside my aquarium

Thanks. That isn't what I had pictured.

This is the one I used...
https://shop.weicon.de/bertaplus/productsheet/TDS-13050085-29102012-EN.pdf

 

[Johnyrotten]

Tagging along

 

[acabgd]

there is a product called PLASTIK

provides a thin layer of protection around the object you spraying..
i spay all my electronic equipment inside my aquarium

Found it on seller's website, but I still don't understand if it's a permanent protection? Do you think it will withstand saltwater, or at least salt spray?

Thanks!

 

[BeanAnimal]

It is simply a lacquer based conformal coating sold in EU markets. In the US you can look for products from Chemtronics, MG Chemicals, TechSpray, etc.

Allied Electronics has a fairly decent selection. They come in dips,aerosols, silicone based, acrylic based, lacquer based, with or without UV protection, etc.

 

[dwolson2]

So what is the best, cost effective multi chip cooler for a 80 ish watt chip and how have people been attaching them lately? Are we able to use thermal adhesive like the 3w chips?

 

[megadeth72]

Best or cheapest? You can go crazy with heats inks, if under 100w any p4 and up CPU heats ink should be fine

 

[mr.wilson]

It is simply a lacquer based conformal coating sold in EU markets. In the US you can look for products from Chemtronics, MG Chemicals, TechSpray, etc.

Allied Electronics has a fairly decent selection. They come in dips,aerosols, silicone based, acrylic based, lacquer based, with or without UV protection, etc.

Most of Europe has switched to using Sprühkondom for everything these days.

 

[mr.wilson]

So what is the best, cost effective multi chip cooler for a 80 ish watt chip and how have people been attaching them lately? Are we able to use thermal adhesive like the 3w chips?

Any CPU cooler with heat pipes will be fine for an 80w chip. I would advise against a simple aluminum fin cooler as it will likely shorten the life of the chip due to operating temp.

 

[BeanAnimal]

Most of Europe has switched to using Sprühkondom for everything these days.

Wow... you learn something strange every day. ...


One thing absolutely perplexes me... "Easier to operate..." Puzzling.

 

[FDAWG]

That seems light considering many 2-3w fixtures have overheating issues with a finned aluminum heatsink and fans mounted directly over the fins blowing down.

I've noticed throughout the thread that many of the projects have passive heatsinks that are undersized. I'm not talking about the fan cooled heat pipe CPU coolers, but the simple aluminum fin heatsinks like you see on 3w builds.

Maybe I'm overkill, but I thought I would mention it.

 

[megadeth72]

That seems light considering many 2-3w fixtures have overheating issues with a finned aluminum heatsink and fans mounted directly over the fins blowing down.

I've noticed throughout the thread that many of the projects have passive heatsinks that are undersized. I'm not talking about the fan cooled heat pipe CPU coolers, but the simple aluminum fin heatsinks like you see on 3w builds.

Maybe I'm overkill, but I thought I would mention it.

that's because those blocks with fans are friggin terrible at cooling, heat soak is more like it

 

[FDAWG]

If you are getting 130-150 at the bottom without lenses, then 120˚ optics should bring it up to 200-250 where his metal halide & T5 was.

I agree, there is not enough red light in his fixtures to bleach corals, as metal halide has much more.

It's quite possible that there is simply too much blue light. Tanks with heavy blue light invariably have poorly pigmented corals. Greens, yellows and oranges show up great, but there is little in the way of blue, ed or purple pigmentation.

These bright colours may vary well be within the corals, but covered by a "lens" of green/brown zooxanthellae.

It's equally as possible that the cheap chips you have are way off the mark with regard to spectrum. You really get what you pay for with LEDs

 

[megadeth72]

I've owned both, I dont think you get what you pay for unless you are talking about efficiency, which is not a concern of mine

 

[mr.wilson]

That seems light considering many 2-3w fixtures have overheating issues with a finned aluminum heatsink and fans mounted directly over the fins blowing down.

I've noticed throughout the thread that many of the projects have passive heatsinks that are undersized. I'm not talking about the fan cooled heat pipe CPU coolers, but the simple aluminum fin heatsinks like you see on 3w builds.

Maybe I'm overkill, but I thought I would mention it.

I agree 100% and have mentioned it throughout the thread. The price difference for a proper heatsink is minimal, yet some people insist on pushing their luck.