[johnnyr]

hi,

i have a friend that would like me to create a heat sink for him,

the profile looks like that
im a hobby machinist that over the years only done simple parts, i know i can create the code for this easy enough but where im getting lost at is the wavy profile, is there already a tool that would help me achieve this?

any and all help is appreciated.

[awerby]

to create undercuts like that. Picture a shaft with a larger ball on the end. These are commonly made for grinders, although I haven't seen them with the sparser flutes generally used for endmills.

Another way you could get this effect is by tilting the workpiece after cutting the ridges, so that you can access the sides with a ball-nosed (but not offset) cutter. But you'd have to do this twice, and it would be hard to maintain registration.

A third way to go would be to have a special form tool made, with the profile of the side of the ridges ground into its edge. This will cost some money, but this guy doesn't think he's getting this odd job done cheap, does he?

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

hi,

i have a friend that would like me to create a heat sink for him,

the profile looks like that
im a hobby machinist that over the years only done simple parts, i know i can create the code for this easy enough but where im getting lost at is the wavy profile, is there already a tool that would help me achieve this?

any and all help is appreciated.

[awemawson]

That profile was originally extruded in aluminium, and the extrusion die would have been cut with an ordinary end mill (or possibly wire edm) as it would have the plan shape that you see as as profile. To achieve the same disipating area can your friend not accomodate a shape more suitable for milling rather than extruding?

[stevespo]

Yes, that was my thought exactly.

If that "wavy slot" profile gives you (say) 25% more surface area than straight sided slots, how about just increasing the number of slots to gain back the area?

So, instead of making a series of 1/4" wide wavy slots, switch to 3/16" straight sided slots.

I'm sure heat sink design is much more complicated than just surface area, but for a one-off part I would want to keep it simple. I guess it depends on what he is cooling and whether a stock part would do the job or not.

Steve