MechaTronix: MODULED 9950-B LED Star heatsink for 3590?

[thetr33man]

According to my calculations, this heatsink should be fine to passive cool a CXB3590 @ 700mA (producing <9w heat / cob).
What Im curious about is if anyone knows if the hole pattern will work for any commonly available 3590 holders... Has anyone used these or have opinions if this will work?
Price seems reasonable at about $8usd each.

According to the data I found, you need 990cm^2/cob of surface area and these have
Specifications:
Diameter:
99 mm
Height:
50 mm
Thermal Resistance:
1.34 °C/W
Total cooling surface (cm²):
1045.63
Weight:
356 g
Anodized Color:
Black
Dissipated Power Pd:
37.3 W
Material:
AL6063-T5

 

[frica]

3590 is most likely too big for it

 

[thetr33man]

I emailed the company to ask them about it.... Ill post once I get a response.

 

[Abiqua]

No....I use the active cooled version essentially, where the Rth is .48 C/W or so....up to 90 watts dissipated....

I am using CXB 3070 BB diodes @ 1050mA, which comes out to around 19 watts of dissipated heat and I would say the true Rth is more like 1.45 C/W

The mass only ways 200 grams....they just don't seem to be very practical, even though they look nice....My original Arctic 11+ cpu cooler @ 350 grams of mass and less efficient airstream cooling; is about 5-10 degrees LOWER than the Mechatronix heatsinks, even though I am using CXA 3070 AB's again @1050mA and Dissipating watts are around 21-22 watts.

I bet even at 9 watts dissipated, that the CXB3590 is TOO big, and they don't even list it as being compatible, so where did you get that idea in the 1st place?

 

[thetr33man]

No....I use the active cooled version essentially, where the Rth is .48 C/W or so....up to 90 watts dissipated....

I am using CXB 3070 BB diodes @ 1050mA, which comes out to around 19 watts of dissipated heat and I would say the true Rth is more like 1.45 C/W

The mass only ways 200 grams....they just don't seem to be very practical, even though they look nice....My original Arctic 11+ cpu cooler @ 350 grams of mass and less efficient airstream cooling; is about 5-10 degrees LOWER than the Mechatronix heatsinks, even though I am using CXA 3070 AB's again @1050mA and Dissipating watts are around 21-22 watts.

I bet even at 9 watts dissipated, that the CXB3590 is TOO big, and they don't even list it as being compatible, so where did you get that idea in the 1st place?

I got the idea cuz its got enough surface area, according to my calculations and its diameter is 99mm, the 3590 is about 35mm across and the holes on the top of the heatsink look far enough apart to use a cob holder, but I dont have exact measurments for distance between screws using the ideal holders.

 

[thetr33man]

These are the stats of the smallest heatsink rated for the 3590 cobs, obviously huge overkill and more than 3x the price.... Also has about 4x the surface area required for the 3590 @ 700mA!

Manufacturer: MechaTronix
Status: Standard
Datasheet: MODULED GIGA 152100-B-HBG DataSheet
RoHS Compliance:

Yes
Specifications:
Diameter:
152 mm
Height:
100 mm
Thermal Resistance:
0.52 °C/W
Total cooling surface (mm²):
363547
Volume (mm³):
566553
Weight:
1530 g
Anodized Color:
Black
Dissipated Power Pd:
95 W

 

[robincnn]

I got the idea cuz its got enough surface area, according to my calculations and its diameter is 99mm, the 3590 is about 35mm across and the holes on the top of the heatsink look far enough apart to use a cob holder, but I dont have exact measurments for distance between screws using the ideal holders.

50 mm for ideal holder.
Surface area calculations for fin heatsink, radial and pin heatsinks are not same. Also surface area requirements less for low power. Radial and pin heatsinks will outperform flat heatsink with same area. Air streams are actually more important. Details here
http://www.newelectronics.co.uk/electronics-technology/pin-fin-heat-sinks-point-the-way-to-more-efficient-cooling/18641/

The closest holes look like 25mm apart in center. 3590 is 35 mm x 35mm. So most likely you will have a hole under cob.
Given the large cob size, Instead of star or radial i recommend finding a small pin heatsink. 70 or 80 mm diameter. Mechatronics has a few 70mm to 80mm options on eBay, ships from Germany. May be cdiweb or someplace else has them to, you can check

Since the heat is actually too less you can just use heatsink USA profile cut into pieces for each COB.

 

[robincnn]

This would be nice at $11 but...
Cdi web has only 2 of these in stock and you have to tap holes on your own or use kapton
LPF86A68-8-B

 

[thetr33man]

I guess I would like to find individual heatsinks for 3590's run at 1A or less that are adequate without being overkill that are < 10$ us and predrilled for cob holders....

 

[thetr33man]

This would be nice at $11 but...
Cdi web has only 2 of these in stock and you have to tap holes on your own or use kapton
LPF86A68-8-B

Those are nice and light too! Too bad they dont come predrilled for standard cobs like their radial fin ones.... How important do you think it is for every area of the cob surface on the bottom be in direct contact with the heatsink? These are already being run WAY below max temps, if theres a 3-4mm gap with no contact, Youd think the ceramic base would be able to radiate that extra heat away at low power, like 1/4 their max...

 

[robincnn]

It's not gonna happen.
3590 is a big cob so it's predrilled heatsinks will be big and expensive. Commercial fixture don't run cobs at that low power.

Learn to drill and tap. Or use kapton.

I do not know if screw hole under cob will screw your cob. May be a hotspot under cob. Just bad design. May be you can fill it up with thermal paste and it might work fine. Can't say unless verified with FLIR.

 

[Abiqua]

I guess I would like to find individual heatsinks for 3590's run at 1A or less that are adequate without being overkill that are < 10$ us and predrilled for cob holders....

unfortunately, you would be the 1st at this point....not to say it wont happen, but pre-drilled is double that I would wager...

 

[Abiqua]

Those are nice and light too! Too bad they dont come predrilled for standard cobs like their radial fin ones.... How important do you think it is for every area of the cob surface on the bottom be in direct contact with the heatsink? These are already being run WAY below max temps, if theres a 3-4mm gap with no contact, Youd think the ceramic base would be able to radiate that extra heat away at low power, like 1/4 their max...

its important, but hardly the only factor in determining the thermal path, in fact by itself, it tells very little of the thermal signature as @robincnn alluded to a littler earlier...

Important, but really only in the context of diode selection, Rth, thermal interface material!!!, etc etc etc... Is the Tc going to be 25C 50C or even 80C? Is it assumed for one of those numbers...then even on top of that, calculations again have to be "construed" some more to account for heatpoint radiation, because heatsinks warm up gradually in most cases and are not instantaneous heat sources located all over every cm2 of the heatsink....it gradually warms up and radiates from a single point source.......its a little more than you seem to think

Google Texas Instruments Thermal Design, very complete, if not completely dry

 

[thetr33man]

Ok, so I did some measuring and there are 2 sets of holes on the MODULED 9950-B that are almost exactly 50mm apart, see picture below....

So it seems like this should work for the 3590's, now the question is, does this heatsink have the dissipation ability to remove 9w of heat at 700mA or 14w of heat from 1A? Its rated to dissipate 37w, so Im thinking it SHOULD be fine... Opinions? It is possible some of the screw holes might be under the cob surface, but they are only 1.7mm across. At relatively low power id guess this wouldnt pose an issue to the cob?

 

[Greengenes707]

I hate mechatronics.
Every radial sink they make will not put a completely flat surface under a 3070 or 3590. And many times is missing under actual parts of the LES, not just the outer parts of ceramic.

 

[thetr33man]

Well thats good to know!!!

 

[welight]

I hate mechatronics.
Every radial sink they make will not put a completely flat surface under a 3070 or 3590. And many times is missing under actual parts of the LES, not just the outer parts of ceramic.

big statement Gene, so you tried every radial heatsink Mechatronix make? I don t disagree in principal as every heatsink manufacturer has sinks with issues of coplanarity, however my personal experience is Pin Fins are typically much better than extruded styles, in terms of radial products, especially if machined
Cheers
Mark

 

[Greengenes707]

big statement Gene, so you tried every radial heatsink Mechatronix make? I don t disagree in principal as every heatsink manufacturer has sinks with issues of coplanarity, however my personal experience is Pin Fins are typically much better than extruded styles, in terms of radial products, especially if machined
Cheers
Mark

I know you are all hot to trot on your new kits...but I've been on pin sinks for a while bro.

Do you doubt me for some reason? Do have proof showing either me blowing smoke or a sink that fits that I over looked???
I've tried the giga, 2 mega's and an activecool.
They all have the same issue, and they were designed for 3070/3590. The ones that I actually would like to use do not come close to the required flat surface area needed.

So again...my statements come from REAL WORLD USE in addition to data sheets and stats. If you have something I overlooked, or where I have shown anything false...please present it.

 

[welight]

I know you are all hot to trot on your new kits...but I've been on pin sinks for a while bro.

Do you doubt me for some reason? Do have proof showing either me blowing smoke or a sink that fits that I over looked???
I've tried the giga, 2 mega's and an activecool.
They all have the same issue, and they were designed for 3070/3590. The ones that I actually would like to use do not come close to the required flat surface area needed.

So again...my statements come from REAL WORLD USE in addition to data sheets and stats. If you have something I overlooked, or where I have shown anything false...please present it.

Dude I dont doubt you, I am just saying you said
'Every radial sink they make will not put a completely flat surface under a 3070 or 3590'
If you havent tried everyone, then its a big statement. The one's you mentioned above are not Pin fins. I totally agree you need to have a level surface with CXB as they are ceramic and subject to cracking if you tighten down a holder on a bad surface, Yes we are pushing a kit solution and our coolers tested are coplanar. Happy to send you one to test.
I think its is important to note TIM selection and correct torque on holders can mitigate coolers that are not totally true
Cheers
Mark

 

[Greengenes707]

@welight
I did say every RADIAL sink they make. Pin sinks are their own category with almost every supplier, or search category...including mechatronics. Mechatronics can call their radials Modulars all they want. Still a basic radial design that do differ from pins.


Don't quote me unless you have real information or a suggestion about what you're quoting. Not a vague saving face cause I mentioned one of your suppliers in a bad way. You can come and SHOW whatever, for whatever reason. But if you quote me to do it, you better be on point and have something behind it.