Thoughts on remodeling "The Lemon Block"
 

As I have had "The Lemon Block"
http://www.customcooledpc.com/lemonsig.jpg
http://www.customcooledpc.com/lemonsig2.jpg
up and running for about 2 weeks strait and was not highly impressed with the temps over the original block that began this experiment.
http://www.customcooledpc.com/aluminumWB4/004.JPG
I have decided to remodel it and make it out of Copper! As I intentionally added air into my hoses to watch the air bubbles flow through the block I noticed it working almost exactly as I though it would!!! Almost all the channels where being used exept a few. The water went through the smaller channels around the pins and exited right into the larger channels around the side and split nicely both ways in to the outlets.

I have the base where the fins sit at 1/4" deep leaving a 1/4" base under it. This I am going to change to 3/8" deep and leaving 1/8" base so the heat can transfer a little more effectivly to all the pins. The outer channel is already 3/8" deep and will remain the same. I might also make fewer pins as I don't thing the outer rows near the barbs on the sides really do much. I think I will just mill those out.

The block still performs rather well, and possible better than anything I have made to date and I think a Copper version will utilize the extra surface area made by the fins.


Comments, suggestion, thoughts???

I realise it's hard to do on your mill, but how about making the little blocks as high as the plexiglass, and staggered, so the water has to go around 2 or 3 bends before it gets to the side of the block, in your current design the water could do just one turn before it goes to the side of the block.

Nice job Jaydee!
I think you should make the base thicker since you are using Cu this time, as it would probably lower your die temps considerably.

I try to keep my base between 0.15" and 0.20" thickness.

"I" would also try to make those pins smaller so you can make more surface area. But that probably not what you wanted to hear.
Great job using the drill press though.

Did you get your machine converted to cnc yet?Or was that someone else?

My mill has always been CNC! It was done with the CNC. I am not sure about base thickness. Cathar and BillA (unregistered) seem to think thinner is better or maybe I misunderstanding which is always a stron possibility!:D The base would be at .125" which would leave 3/8" for channel depth. If I went over .125 then that also shrink the channel size which may do more harm? Not sure what would be better deeper channels or thicker base. I could order some 5/8" material I guess and have both.

The blocks are as high as the rest of the block. The top sits on the pegs. Staggered would be a royal bitch but I like it!!! Never crossed my mind. Actually gives me a few new idea's aswell. I got a new job recently at an engraving/laser cutting shop which has Correll Draw 9 which is a little more user friendly than ACAD when it comes to curves. I will try to find time to draw something up. I may just start from scratch! I am also in town now!!! :) Doesn't look like I will be doing any traveling any time soon so i will have some time to work with the mill again.

If you increase the base thickness, you can decrease the channel depth. Thats been my experience.

Personally I would be more concerned about increasing the surface area of the flow section and worry less about the channel depth.
Whatever you decide to do, you can make up the difference with smaller pins , and more of them. Shouldnt be too hard to do if your under CNC.
Mill monster and Niagara make some pretty small diameter(under 1/8th")solid carbide endmills that usually have a LOC of 1/2"-3/4".
Yeah , they cost a bit more but finding a cheaper source for small diameter bits with a LOC that you require is going to be nearly impossible, if you decide to make the pins smaller so you can add more of em'.

I see you're using them fly cutters to plane your stock before you mill. I love them damn things!.....the best cutting tool I have is a flycutter(adjustable mini indexable endmill is my 2nd choice)

Good luck JAy ;)

With CNC making the pins round/rounded should'nt be 'impossible' should it?...
Good luck with the Cu dude :) ...

Not impossible, but it will add about 6hrs to the milling. Thought about that at one point, still havn't ruled it out. I still am not 100% convenced round would be better. With them sqrare it adds metal and it makes the water a little more turbulant. Still thinking about it all though.

I believe that triangular would be the answer here.

How about Diamond shaped?

Anyway I think "The Lemon Block" is going to be on hold for a while. I came up with a design similar to Cathar's microchannel block about a year ago and just never had the tooling to do it. Well I have in my possestion some bits that will do a small V shaped channel! The very end point range from .001 to .010. with the top of the V varying depending on how deep they go. Working out the design in the next few days and how I will make the bits work with the mill. Probably actually mill something next week as I am busy this weekend.....

Reminds me of the V shaped pointed carbide dremel bits :)

I actually just used a 1/8" flat end carbide bit to mill out some copper on my drill press. Just had to remove 0.2" so it wasn't that much. It did pretty well actually:dome:

I think Brad hit the nail on the head when he said stagger them, it's most important to prevent water taking the easiest route, fully utilising what you have...

Sorry to see a delay!

No the diamond shape is almost non-obtrusive. a triangle or round shape is optimal, but since round is out, and given the relative simplicity of a triangle, that's the way I'd go.

triangle turbulator
 

triangle turbulator:

how big are the 'pins' in your lemon block? And how well does it cool? (sorry for the stupid questions, i'm sure this has been posted elsewhere, but i'm new here)

anyhow, i'm just asking because i have a design somewhat similar (albeit bigger) than your block. it uses square 1/8" 'pins' and currently 1/4" base.

i also wan't to make a version of my block out of copper with a thinner base. I'll post pics of it in a different thread here

The pins are 1/8"x1/8" and 1/4" tall. The base the pins sit on is 1/4" and the outer channel around the pins making the lemon shape is 3/8" deep with 1/8" of base left. Temps where ok, roughly 15C (load) over water temp and 17C (load) over room temp with a XP1600+@1500mhz 1.90Vcore. A copper version should shave some degrees off that. I do not think the pins are being used effectivly in AL because the heat just isn't making it that far. Copper should be able to distribute the heat higher up the pins. In theory anyway.

I am going to setup the CNC mill at work later this week and try to make my micro channel block or at least a prototype. Have some cool tools there. Looks like I will be the manager of the place next week! :evilaugh:

yeah, would def. be nice to be a manager!! or at least someone with that power

that's true with the copper pins transferrring more of the heat, in theory at least. The longest row of mine are .75" tall, but I certainly didn't expect the heat to go up that high. I meant mine to more be for surface area at the bottom, and speed up the water velocity so it hits the bottom with a higher velocity.

can't wait to see how yours performs in copper. I am also wanting to make mine out of copper. right now mine performs about 7C above ambient temp with a duron 750 @ 1020 MHz and vcore = 1.98