It shouldn't have battery effekt, but i think, if you use such needles as cups to the heat wouldn't be brought away from the DIE as efficientely as if the cups were drilled, because there you have two materials connected together.

but the "floor" of the cups,where the water jets hit, would still be the 2mm piece of copper.

also, this would only be an alternative if someone didnt have tiny drillbits, and wanted to try this.

quite an interesting idea. It would also give you an idea of how much heat is transferred to the water from the walls of the holes in the cascade. I wonder how thin you could make the baseplate though and still keep it stiff enough.

Probably cheaper and easier just to buy a suitable drill bit. They aren't all that expensive.
For instance a 5/64" (1.98mm) drill bit costs less than $1, probably much less than a load of extra stainless steel tube.

Grassi, to stick your needles in place I'd suggest epoxy resin (eg Araldite, if that exists over there). Put it on the needle rather than in the hole if you don’t want to have to clear them out afterwards…
Silicone isn’t that much of an adhesive - especially if it's applied thinly - so it probably wouldn’t be a good idea.
You could also try superglue (cyanoacrylate ?), but it does dry rather quickly :D

As for using more tube for the cups, I'm not sure that it's a good idea because:
- I don’t know if you can solder stainless steel?
- You'd have to make the holes further apart
- As said above, stainless steel is more of an insulator than a conductor of heat.
- Drilling 1.8 to 2mm diameter holes in copper is not a problem anyway :)

Nickel (Stainless Steel plating) will still have a battery effect. The question is to which extent it will. (Or is the plating Chrome?!?)

Here's one:
http://www.mcnallyinstitute.com/CDweb/g-html/g001.htm

Here are a few more interesting bits of info:
http://www.engineersedge.com/galvanic_capatability.htm

http://rds.yahoo.com/S=2766679/K=gal...alv_series.htm


You can take the baseplate thickness well under 1mm, with the right jet tube configuration.

Drill bits will leave an angle at the bottom of the "dimple", which is undesirable. A square cutting endmill would be much preferable.

You can still use the endmill in a standard drill-press for cutting purposes, right?

Also, how much would an endmill like that cost. I remember my high school shop teacher bitching and moaning at me (and rightfully so) about how expensive those things are when I broke one of the endmills we had. :shrug:

maybe you said it already and I missed it, but how much, if at all, do the tubes intrude into the cups? or are they level at the top of the cups?

Looks very nice

According to that link Stainless steel is 0.50 and copper 0.35 meaning they aren't that bad for battery effect. It's actually less different from copper than solder (0.65). Besides, I've run Al and Cu mixed without issues, just use some anti-corrosive additive in your water.

Check out the link I posted in my block design thread ("Radius", in sig) for a cheap source of endmills. Yeah, the big ones can be expensive. Yes, they'll fit a drill press.

The ones I found are "solid micrograin carbide". A really really cheap one would be made of HSS (High Speed Steel) but it won't last long at all.

How good is a normal drill press at actually milling stuff? What does it not do that a real mill does?

The bearings in a drill press are not designed for side to side loading, they will not cope with a large end mill for very long. The headstock of a mill is designed to deal with these kind of loads and is typically far more accurate.
That said, a small endmill in a drillpress and an XY cross-slide would probably work for small jobs although I'd say you'd be breaking bits frequently because of the vibration which will occur when the bearing starts to wear. Also a drill chuck is not suitable for endmills.
So answer is, not very good.

Cheers

Incoherent

Incoherent's answer to this actually made a great deal of sense ;) I would add that in many (most?) drill presses, the chuck is press fit onto the spindle, typically with a JT33 taper, and no retaining hardware. This works fine when it's used as a drill, but side loading will often cause the chuck to fall off. At best this damages the workpeice, and / or the tooling, at worst it can cause user injury... :oops: :cry:

Gooserider

Put the chuck in the freezer for a while, then put it in and hit it with a hammer and it will never come out... Guarenteed :D

What about changing the bearings on a drill press to something that deals with side loads a little better?

Another question... I am planning to use woodworking router bits to mill out the cavity in the plastic on my GPU and NB waterblocks... will this work ok?

good idea:) except that on my drill, the chuck is the "female", therefore I think it would be the other way round, ie put the drill in the freezer.

lol:D:D:D

what would happen if you replaced your standard bearings for side load bearings in the motor of your drill press? My brother works for SKF bearings and im sure could source me bearings that would be capable of side load... A 150$ drill press sure beats a 5k+ mill any day... my old high school used an old 1960s drill press with a movable table, and it seemed to work.

if your in the states and are looking for needles you might be able to get them for free, depending on location. At least where I used to be they did a needle exchange program whee they would give you clean needles for dirty ones. They would offer a free starter kit with like 2 needle, then you'd just have to get them to accept them back without the tips...

BTW, stainless steel isn't plated (that's galvansied steel which is usually zinc plated). Stainless is an alloy of chrome, nickel and iron in various proportions (usually around 15-20% chrome and 5-10% nickel).

Thanks for the correction: I thought it was still plated.

Putting bigger/better bearings in a drill to increase it's milling ability is really not a viable option in most cases. Especially if you don't have a mill handy to reshape the bearing pockets (and if you do, then what's the point???) The problem is only partly the bearings, which are usually the best available for that application already.

The key problem is that the column on a drill press is to skinny to support the side loads imposed by trying to do milling with it. If you compare the column diameters of a normal drill press and even a cheap mill you will note that the mill column is probably at least 2 X the size of the drill press. This means the column flexes less, and puts less load on the bearings because of their bigger sizes. Also while both machines use bearings that must allow axial movement while resisting radial movment (up/down is OK, but not sideways) the mill bearings are chosen with more attention to handling side loads.

Gooserider

i would imagine a mill probably uses roller bearings or tapered rollers, whereas drill presses would use ball bearings.

That's likely, Ozzy, but probably not the entire story. Bearings tend to be such that they aid movement in one plane, and resist it in others. Thus I would expect a mill to have dual bearing sets with one that allows easy up/down motion, and the other that allows easy rotation, but both resistant to side loads. A drill press is more likely to have a single set of bearings that would try to handle both jobs.

Gooserider