Here we go!
This is the 120x60x20 copper block. It weighs a ton, 3 times as much as the aluminium version. The skiving is done very well and the finish on the block is nice and smooth.
This is the template that I have printed, with notches for the mill and mounting holes.
The block inserts like this, which should make the use of the template more clear. The tiny holes are for a 1.5mm drill and the large holes are for the mill.
First comes drilling ad tapping. The template also serves to keep my tap straight. Tapping an M2 hole is stresfull as the tap is so tiny and brittle...
Phew, that went well! Fun fact, I used high fat milk as cutting fluid because I read on a couple of forums that it works well with copper. Aluminium goes well with WD40.
Now for the milling. I'm using a simple 4mm HSS mill with 2 flutes. You can see the template guide around the end mill which should explain how it will work with the 3D printed template. This is a 10mm template guide so the cur will be a little bit smaller that the holes I have in my template, 3mm to be exact. (3 mm border + 4mm mill + 3mm border = 10mm)
The printed template is bolted to a wooden scrap board, which is clamped to my table. This thing won't move anymore. Always use safety glasses when milling!
Cut in progress... You may have noticed, it's cold here!
First cut done! I'm cutting off 0.5mm at a time. Rather a few thin more cuts than destroying your end mill. The surface finish isn't the best on some places, but I think that's mainly because there is some flex in the plastic template.
This should do it. I cut off 3.2mm from the 3.5mm base, but as you can see, I got through at some points. Tolerances are probably not really on point at my end.
Back inside. Warm again, phew! The parts where I went through the base look a bit whack, but that will hardly be visible once mounted.
I found these threaded offsets for m.2 drives but supposedly they're the exact format I need for mounting the block without putting too much force on the silicon.
Followed by some silicon washers...
And mounted! The stock backplate works well, I only needed new M2 screws because the original ones didn't work with my design.
Fitment is great. This is a part where I didn't go through the base so you can see how little reserve there is. The memory got new 2mm thermal pads, the original ones where too thin and sticked to the heatsink too hard.
The I/O bracket cannot be attached to the heatsink as it's too short so I just bolt it down with M2.5 screws.
Et voila, inside my case! Unfortunately, the fan position doesn't line up 100% with the heatsink on this revision of my case, but I'm working on a new revision using the HDPlex 250w GAN psu.
Now for some thermal results... The results are good, that's a start, but not as great as I was hoping. It beats the aluminium version by about 2-3C but I was hoping the difference would be more profound. I'm guessing it's still a solid result nonetheless, as it's actually a bit smaller and the fans don't line up perfectly. But in practice, I don't notice any substantial difference between the two.
I will run some benchmarks at various fan speeds later on to compare the two heatsinks. For now, they both excel at what I needed them to do: keep the A2000 cool and quiet.