block with 2mm holes
 

my latest blocks are quit good, here's a pic from my GPU block

3mm holes, the holes connected by two dremel cuts giving a performance boost :)

building atm a CPU block:
pic with a broken drill bit:

for my next block, I want to use 2mm drill bits. I once tried that, but it broke off when I cut too deep. I'll be patient and use some quality drill bits as I know smaller holes will give me once again a nice performance boost, don't they?

in the local store they have these bits:
-cobalt
-HSS
-cobalt/HSS

what drill bit works best?
my holes will be about 4mm deep and I cut with a relatively slow drill

another question: how deep should my holes be?
I think they shouldn't be too deep, 3-4mmm: I think if the holes are quite deep and there a lot of holes, there will be stagnant water at the bottom of those holes.

if my holes are not very deep, will the water flow faster through the block?
after all a #rotor block has a great dissipation area, so there's a rather slow water flow in the block, perhaps causing stagnant water?

EDIT: check attechmints in my later posts

Needs less "You must register to view this image"

sorry, forgot that

cut :)

CPU block

http://www.bitsnbores.com/html/steels.html
hmm, doesn't really answer my question.

in my local store they had regular HSS bits, packaged and metal colored. on another shelf they had those HSS/cobalt drill bits that were two ~ three times more expensive then the other and colored black

How did you make the grid... Graph paper? Cause that would be a really good idea.

If I made a block such as that for my GPU, it would be nice if I could drill the holes so that they interconnect; leaving the part about the dremel out of it, but that would require immense precision.

Hmmm...

made the plans with paint

you don't need huge precision for that, killernoodle. if you hammer the holes in the copper first it will work...

just take care those pilot holes are made very carefully

Are you using a drill press? You won't be able to keep a hand-held drill steady enough to do it with 2mm bits.

By the amount of broken bit sticking out of your block, I can see that have your bits sticking too far out of the drill chuck. You'll get straighter, rounder holes the shorter the bit is. At the bottom of the hole, the tip of the chuck should be within a couple millimeters of the top of your block. Shove that thing farther in there!

Copper is terrible to machine. When it gets hot it gets soft and gummy. Instead of chipping off cleanly, it will stick to the bit and stick to inside of the hole. The result is more friction, more heat, more torque to your bit. Keep your copper cool, keep your bits lubricated.

High speed steel will do just fine for you. Cobalt steel will stay sharper longer, but you'll need to be vigilant with the lubrication because it is more brittle. Carbide is unnecessary unless you plan to make scores of blocks. Titanium-nitride coated bits are nice, because the coppper won't stick to them as much.

yes, it's a drill press offcourse ;)

thanks for the info. what stuff should I use to cool the copper and lubricate the drill bit? I hope the stuff I have to use isn't too greasy or dirty, so the garage and my clothes won't get dirty

I use a light cutting oil for lube. I only use a drop or two every couple holes, so not much mess. In a pinch, anything will work: WD-40, light weight motor oil, etc. Listen to your motor; it will tell when it's working harder.

For cooling, I use a bucket of cold water. When the block is too hot to easily hold, into the bucket it goes.

thanks for the info. sprayed WD40 on the drill bit four times, cooled my copper with cold water. and used gloves this time, I've already hurt my hands bad enough last days :/

the drilling went very smooth, thanks for the info :dome:

Cool! :cool:

Gloves, yeah, they're good. I'm all too familiar with the wounds on your fingers. It takes forever to get those tiny bits of copper out of your skin.

Teus why do u use this kind of layout?
You could make a block with a central inlet and 2 (or one) outlet at the side(s) with the tools you have, and it would perform better :)
(think of a white water look-a-like in which you drill canals)

I know. this block will be used for peltiers, so a dual outlet isn't usefull at all ;)

Oh i see :D
getting curious... :p

crap. my drill got clogged up and it killed my drill bit :(

(pic from before it broke)

broken bit, stuck in the block (i'll be able to remove it though)

Nothing special. remove the spiral copper thing, insert new drill part and continue.
No problem :D