# Need something milled



## TigerhawkT3 (Jan 20, 2008)

I tried to PM modamag for this, but he's disabled his PMs, so I decided I might as well cast a wider net. This is what I was thinking:

I've got a 4"x4"x1" block of aluminum that I'd like to turn into an effective heatsink by putting some deep fins in the back. Does anyone have a mill I could use for this project? If you'd rather mill the fins yourself, I'd pay you for the job.

I'd prefer someone local (San Jose area). Either reply here or shoot me a PM.


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## greg_in_canada (Jan 20, 2008)

Wouldn't it be much cheaper to just buy a heatsink of a similar size? Here's some I found http://www.surplussales.com/Heatsinks/HeatSink1.html

Greg


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## Torque1st (Jan 20, 2008)

Like the above post, buy a heatsink. Many types and styles are available with specialized surface finishes that are much better than natural aluminum for heat transfer.


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## TigerhawkT3 (Jan 21, 2008)

Good link, but it doesn't look like any of those heatsinks have a good place to drill and tap a tripod mounting hole, which I have already done with my block.

I already got some black paint to increase the emissivity.

Any Bay Area CPFers with a mill? Jon? :wave:


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## weedle256 (Jan 21, 2008)

I tried this during machining class... it takes forever and broke the mill bit 

Heat sinks look like they'd be pretty easy to make but there is a lot of material to remove!


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## 65535 (Jan 21, 2008)

Paint has a high emissivity, but the layer of paint itself is thermal insulator, so any gains from high emissivity will be negated by the thermal insulation it has.

As for having it milled, you won't get good spacing or density with a milled piece because small endmills don't have long lengths, your best bet is to have someone mill it as thin as possible, and use thermal transfer paste and 4 screws to attach a real heatsink to the back of the thinned aluminum piece, that way you can keep your tripod mount.


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## TigerhawkT3 (Jan 21, 2008)

I guess I'll be buying a miter box and spending some quality time with a hacksaw tomorrow.


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## Torque1st (Jan 21, 2008)

Check your local surplus outlets. Some of them should have used or surplus heatsink material. Large flat plates are quite common. Used CPU heatsinks are also available. Drilling and tapping for a tripod is simple.


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## tedjanxt (Jan 21, 2008)

Man, I'd offer to do it, but our company just recently outsourced all our machining and sold their mills!

2 weeks earlier and you'd have been in like Flint. I live in San Jose too


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## modamag (Jan 21, 2008)

Tiger, you could give me a call or email me 
I found that I'm too slow with PM response to be effective.

As for milling out HS. It takes FOREVER and painful. Believe me I tried it, when I made my HS for a Makita light.

I recommend going to HALTED supply, purchase a CPU HS and go from there.


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## TigerhawkT3 (Jan 21, 2008)

Gotcha. I already got a small miter box at OSH and hacked in a few fins (four down, twenty-something to go...). I think if I need something similar in the future, I'll go with AAing a small chunk of aluminum (that I can drill/tap) to a premade stock heatsink.


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## Torque1st (Jan 22, 2008)

You are in for a long painful process to hack out a poor heatsink with a miter box. You phone book should have many listings for surplus dealers.


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## KC2IXE (Jan 22, 2008)

Perfect job for someone with a BIG horizontal mill, and a gang of cutters

That said - buy a heatsink, remake the mount for the tripod


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## KenAnderson (Jan 22, 2008)

Most discarded computers have a nice alum heatsync inside to cool the CPU. Dirt cheap as well.


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## PEU (Jan 24, 2008)

Old pentium III processors from brand name computers usually came with a nice heatsink instead of the tipical cooler, I have a couple of these and they are great. Also AMD Athlons come with a nice, beefy heatsink.

If you need more metal scratch the heatsink surface a little to add grip and artic alumina and bolt a piece of extra alu, you can use your miter box to fit it 


Pablo


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## J!m (Jan 24, 2008)

I would also saw it (rotary saw on a knee mill; or better still a horizontal mill with a gang of blades and do them all in one shot).

The gang will take 10 minutes (assuming good material and not gummy crap), if the saw width is OK. One at a time, it would be a minute or more per slot... This is why most heat sink is extruded in shape...

I could do it, but I'm in New York and you can find several styles, colors and flavors on-line, at flea markets and at scrap yards...

I could also give you the name and number of a machinist we use for a lot of our "one-off" stuff that is in CA. Having him supply the material will save you the shipping to him (if you have to ship it- I'm not sure exactly where he is).

His company is J C Machine, and he may come up with an on-line search...


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## tvodrd (Jan 24, 2008)

KC2IXE said:


> Perfect job for someone with a BIG horizontal mill, and a gang of cutters
> 
> That said - buy a heatsink, remake the mount for the tripod



Nah, buy an extruder and a wire EDM to make the die.  j/k

Larry


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## Torque1st (Jan 25, 2008)

PEU said:


> If you need more metal scratch the heatsink surface a little to add grip and artic alumina and bolt a piece of extra alu, you can use your miter box to fit it  Pablo


Never scratch or deform the mating surfaces of a heatsink. The increase in thickness of the heatsink compound required to fill the joint imperfections will decrease the thermal conductivity of the joint.

The thinner the layer of heatsink compound the better.


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## TigerhawkT3 (Jan 25, 2008)

My buddy Sasquatch1985 has access to a drill press with an X-Y vise, and recently found a mandrel to hold angle grinder cutting discs. I paid the few bucks for the discs, and he had fun creating this:













This thing is a refrigerator! I was blown away when I saw it. He said it took him a couple hours, and time just flew by. Now he can make other cool stuff for his own projects.

Tomorrow I'm going to OSH to get a tap and bolt so that I can secure the wiring to the unit.

Unfortunately, now I need a new excuse to buy an extruder and EDM. Maybe I could tell my parents that they're avant-garde patio furniture pieces that just happen to require three-phase power...


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## KC2IXE (Jan 25, 2008)

tvodrd said:


> Nah, buy an extruder and a wire EDM to make the die.  j/k
> 
> Larry



I have a friend - his company uses a LOT of custom heat sink - that's exactly what they did - of course when you order a truckload of heatsink at a time, the cost of the die becomes "trivial"


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## scott.cr (Jan 25, 2008)

Cool project, I'm glad to see it came together for you. Nice lookin' heatsink...


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## TigerhawkT3 (Jan 27, 2008)

The above pictured block has been turned into a 20W LED light, to go with its smaller sibling. If you want to see the whole process that went into it (with the results), the thread is here.


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