A Thread On Tapping

frica

Well-Known Member
With this heatsink, which base seems to be pretty thin, would I still need tapping? http://www.tme.eu/es/details/rad-a4291_1000/disipadores/ tapping equipment is expensive stuff around here, and I would rather avoid it if I could. My mechanical skills are not the best either, but it seems quite doable anyway. If it can be avoided without making much of a difference, I would really appreciate it.
By the Especification the Midadas it has the dimensions in an image.
The base is 5mm thick.

It would work... probably.
Of course tools are better but it does the job.
 

EfficientWatt

Well-Known Member
I'm waiting on 90Kg of heatsinks, got 2000$ worth of cobs ... but I have NO experience in tapping (yet) :roll: :lol:

I'm having trouble with the tapping and screw lingo :oops:
Everytime I decide to read about it, it's like a buffer overflow DOS in my brain ;)

I got myself some m3 4-40 screws and this m3 'spiral" tapping bit : http://www.ebay.com/itm/221968726813?_trksid=p2057872.m2749.l2649&var=520850150910&ssPageName=STRK:MEBIDX:IT

... just realized it might not be the right one as it says "hand plug" :dunce:

What actual tapping bit and drill size would be recommended for those m3 4-40 screws ?
 
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Abiqua

Well-Known Member
I'm waiting on 90Kg of heatsinks, got 2000$ worth of cobs ... but I have NO experience in tapping (yet) :roll: :lol:

I'm having trouble with the tapping and screw lingo :oops:

I got myself some m3 4-40 screws and this m3 'spiral" tapping bit : http://www.ebay.com/itm/221968726813?_trksid=p2057872.m2749.l2649&var=520850150910&ssPageName=STRK:MEBIDX:IT
... just realized it might not be the right one as it says "hand plug" :dunce:

What actual tapping bit and drill size would be recommended for those m3 4-40 screws ?

Do you want holes that have a bottom [blind holes] use this.....
http://www.ebay.com/itm/4-40-H2-Spiral-Flute-Bottoming-ANSI-CNC-Tap-HSS-V-TiN-Coated-YG-1-Part-F8162-/151621686729?hash=item234d5b55c9:m:mNjJ-8pqF1B389592uHET3g



But if you are just making holes all the way thru the metal and just want threads.....

Just about anywhere that sells tapping equipment, will probably have a 4-40 Spiral Tip...
 

EfficientWatt

Well-Known Member
Thanks Abiqua,

I was planning on having blind holes, but I guess it's not a deal breaker if i have to go all the way thru...

Is the one I bought completely useless then ? :lol:


Do you want holes that have a bottom [blind holes] use this.....
http://www.ebay.com/itm/4-40-H2-Spiral-Flute-Bottoming-ANSI-CNC-Tap-HSS-V-TiN-Coated-YG-1-Part-F8162-/151621686729?hash=item234d5b55c9:m:mNjJ-8pqF1B389592uHET3g



But if you are just making holes all the way thru the metal and just want threads.....

Just about anywhere that sells tapping equipment, will probably have a 4-40 Spiral Tip...
EDIT : The bottoming tap seller is asking for 45$ for shipping to europe :/ looking for another source grrr
 

Abiqua

Well-Known Member
Thanks Abiqua,

I was planning on having blind holes, but I guess it's not a deal breaker if i have to go all the way thru...

Is the one I bought completely useless then ? :lol:




EDIT : The bottoming tap seller is asking for 45$ for shipping to europe :/ looking for another source grrr
just search for spiral flute bottoming tap 4-40 and you should find all kinds!!

and as far as your current tap....I would suggest making a couple of test holes 1st and see how the threads work with your existing M3 screws and definitely not for blind holes!....but looks ok!
 

Fastslappy

Well-Known Member
http://www.amazon.com/Speed-Steel-Thread-Metric-Spiral/dp/B01A5O09VK
on a small power hand drill should do just fine , myself i'd use my drill press .
You need practice with sprial taps as that tap will pull it's self down in AL there is no need to back turn as the sprial lifts chips
I have my doz of 3590 in hand atm , I am testing a self tap screw but it's not really available
that I can find
they come outta electronic gear & less so in PC's unless you might find some on Dell & the like
they are for punched steel & have a straight cut tip but it's a nub that has no threads at the end
This screw has threads that spiral down so it sinks fast , sets in AL nicely
as for hold they do fine I worry about stripping by over torque
that nub helps set the screw & with alignment
 
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J-Icky

Well-Known Member
I just used a hand drill, drilled holes in the HS(Alpine 64 gt x 6) a little deeper than the length of the screws, used a much larger drill bit spun by hand to clean up the burr on the surface and then slowly screwed in the screws with a hand screwdriver. If I felt any resistance on the screw i backed it out and blew off the threads on the screw.

I didn't break a single screw. In fact the only problem I had was I somehow messed up and drilled a hole to close to the other. So while i could use the one hole fine the other was only half visible through the other hole in the Vero. For that I just turned the cob slightly and redrilled the second hole. The cob isn't perfectly square but is on the heatsink base solidly and I don't think the plants will care that its slightly tilted.
 

benbud89

Well-Known Member
Good stuff. Makes me more inclined to do it that way, just need some self tapping quality screws. Then I hope to now screw it up. Pun! I am so eager to get all my stuff, I really feel confident that I can do it now. Thanks a lot everyone!
 

flexy123

Well-Known Member
I am a little baffled that I myself never came up with the idea to fix COBs with zip-ties. I mean I am using zip-ties all the time for other stuff. I realize it's "ghetto", but it might work if someone isn't too confident tapping. (The fact that I don't have experience with tapping is the ONLY reason I have my lights built and don't do DIY from scratch). TBH, I'd rather use zip-ties than a permanent thermal *adhesive* which basically destroys COBs. And in the meantime, while you use zip-ties, one can always learn how to drill/tap...and then you can tap the sink when you figured it out. I like that idea, saves me from having my next light built by others again!
 

Fastslappy

Well-Known Member
I ordered that spiral tap set by mistake had in my amazon cart
But looks to be put to use on the a/c64's i got I want the ac64's tapped
as if I ever sold the coolers with the cobs att'd I'd want tapped holders IF I was the buyer (that's how i roll )
 

flexy123

Well-Known Member
can you point me at where you seen zip ties used as attaching a cob holder to a sink
The OP mentioned it casually. I didn't see any threads but I can see this being doable if the heatsink is not that wide, like say 10-20cm or so. It should be easy to fix the COB holders, say, for the CXB3590, on the sink, attaching them to the holes on the holder (on each side of the holder)..and then guide the ties around the sink.

(If it works with PC fans which I mount on heatsinks all-the time using some way with zip-ties, I am sure it would work for COBs too)
 

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Fastslappy

Well-Known Member
at the $$ investment costs of a 3590 I'd not do it as I don't think you can get enuuff downward contact pressure to transfer heat correctly off the cob with a ziptie there's no way to control/fine tune that pressure imo
 

AquariusPanta

Well-Known Member
LOL @flexy123

For my very first DIY COB project, which took place many moons ago, I bought some heat sinks that made it nearly impossible to drill holes into for screws, as I didn't have a solid surface to drill into but instead fins.



I just decided that zip ties would do and they did. Definitely not an optimal alternative for securing Vero 18s down but I went with it and had no visible problems taking that route and the bounty was well worth my DIY-related efforts. :weed:
 
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