DIY led panel - again

[edd07]

Yes! Lebbloke's LEDs! Ledbloke LED come both on aluminium and copper stars. Alumiium were cheaper, but if i could go back, i'd buy the copper ones.

Hum, i've got a little worry. To drill the aluminium heatsink to attach LEDs, or to buy a thermal glue?? Do performance fall down with glue?

 

[perkint]

Screwed down with good thermal paste is the better option. But good thermal glue will do the job. Just not quite as well.

Tim

 

[oreo57]

Screwed down with good thermal paste is the better option. But good thermal glue will do the job. Just not quite as well.

Tim

I send this.. BTW: related but a bit o/t.. Stainless steel or nylon?
Nylon heat rating always bothered me. I believe it was about 150F..
Granted that shouldn't be real close to what is sees but...........

 

[perkint]

I would always use insulating washers (usually silicon or nylon - nylon preferably) and stainless steel screws. Cheaper than nylon screws

Tim

 

[oreo57]

I would always use insulating washers (usually silicon or nylon - nylon preferably) and stainless steel screws. Cheaper than nylon screws

Tim

Nylon more expensive than stainless steel..??
$50 for 2500........
http://www.mutualscrew.com/Nylon-De...sh-slotted-pan-head-machine-screws-13238.html
not in my world..
s.s are at least .10 each...

 

[perkint]

Always have been when I've been looking (not spent that long looking, admittedly) but maybe the purchase volume makes a difference (i buy lots of 200 for a few quid, normally!).

Mind you, the ones i have bought in the past have been bad enough to stop me using self tappers and get machine screws and tap the holes myself.

Tim

 

[zachts]

Nylon more expensive than stainless steel..??
$50 for 2500........
http://www.mutualscrew.com/Nylon-De...sh-slotted-pan-head-machine-screws-13238.html
not in my world..
s.s are at least .10 each...

~7.5 cents at bolt depot for 316 stainless. Of course unless you plan on frequently splashing your LEDs with salt water the cheaper "18-8? stainless are just fine at $1.76 for 100..........

 

[zachts]

Nylon more expensive than stainless steel..??
$50 for 2500........
http://www.mutualscrew.com/Nylon-De...sh-slotted-pan-head-machine-screws-13238.html
not in my world..
s.s are at least .10 each...

~7.5 cents at Bolt Depot or FastenAll for 316 stainless. Of course unless you plan on frequently splashing your LEDs with salt water the cheaper "18-8? stainless are just fine at $1.76 for 100..........

 

[oreo57]

~7.5 cents at Bolt Depot or FastenAll for 316 stainless. Of course unless you plan on frequently splashing your LEDs with salt water the cheaper "18-8? stainless are just fine at $1.76 for 100..........

so let us just say the bottom line is they are fairly equal w "smart shopping".
Still no answer to the question of the heat limit of nylon.
Personally nylon would always be preferred due to electrical isolation..

Melting or stretching from thermal expansion is still a concern though..

Fastenal:

#2-56 x 1/4" Slotted Fillister Head Machine Screw 18-8 Stainless Steel
18-8
Wholesale:
$0.0852 / each

Compare
Fastenal Approved Vendor
2/56 x 3/4 Nylon Binder Head Slotted Machine Screw
Wholesale:
$0.0662 / each

Close enough to even..

NOT close:

Fastenal Approved Vendor
#2-56 x 5/16" Phillips Pan Head Machine Screw 316 Stainless Steel

Wholesale:
$0.321 / each

In case you are wondering.. I consider 4-40's too big...and 2-56's are a bit too small w/ out head shopping..3 whatever's too uncommon.

apparently stars are designed for Chinese metric..

ONE confirmation, sort of:

They should, yes. You'll be damaging the LEDs before getting hot enough to kill the screws. But you could always use a bit of silicon grease over the SS ones

Tim

http://www.reefcentral.com/forums/showthread.php?t=2477888&page=3

 

[perkint]

Yeah, but having said that, I'm not sure if prolonged heating and cooling would kill one before the other (it can kill both, eventually!). But in my experience, the thermal paste works pretty well as a glue itself after a while, so the screws become a secondary safety measure after things have settled down with a bit of use.

Tim

 

[oreo57]

Yeah, but having said that, I'm not sure if prolonged heating and cooling would kill one before the other (it can kill both, eventually!). But in my experience, the thermal paste works pretty well as a glue itself after a while, so the screws become a secondary safety measure after things have settled down with a bit of use.

Tim

I think I made a research mistake.. Initially I thought nylon screws were rated to 150F..
seems I may have been wrong.."Probably" stay stable to 200F..
T

he 428 °F (220 °C) melting point of nylon 6 is lower than the 509 °F (265 °C) melting point of nylon 6,6

DUPONT NYLON PER MIL P-17091-B AND M-20693-A.

PROPERTIES:

* -MELTING POINT : 485 DEG. F
* -MAX. WORKING TEMPERATURE UNDER LOAD: 250 DEG. F
* -TEMPERATURE RANGE: -70 TO +250 DEG. F

Sorry, don't mean to diverge this thread so much..

 

[perkint]

Funnily enough, I'd found one of those pages as well, to check what i was saying

Tim