Aleph X alu front and heatsinking

[jojo]

While waiting for electronical parts there was enough time for layouting the aluminium aleph X case. The casing project is taking more time then I thought, because I want to pour the front and bottompanels in aluminium. I'm thinking of a way to diy-casting the heatsinks too but I've not figured out a way to produce the fins.
This first picture shows the creation of the frontpanel model, the lettertype is designed by myself. So don't bother to find them in a standard library. The background is a norwegian kind of flagstone (reproduction in rubber tiles). The letters are milled in perspex. Pictures of the test-casting will follows asap.

[Magura]

Wich alloy do you intend to use for the cast?

Casting heatsinks isnt a good idea, the heat conductance of cast aluminium is pretty poor due to low density.

Magura

[tiroth]

The rough texture is pretty neat visually! Sort of primordial, a nice compliment to a serious industrial design like Aleph-X.

[jojo]

"Wich alloy do you intend to use for the cast?"

I got 4 aluminium wheels from a friend. I think they are made of a kind of silumin. This means aluminium with 7 - 10 % silicium but I'm not sure of this. (all this beautiful knowledge comes from the internet)
The plan is to make 2 sinks per channel. each sink 150 mm high, 400 mm long and 83 mm deep including a 15 mm thick backbone. On these backbone are 32 fins.
Something like the Seifert KL-249 (150*250*83mm 20 fins). With this size it is 0,2 K/W. (5 W/K). When I multiply this with a factor 400mm/250mm I get 8 W/K this means K/W = 0.125 per heatsink.
The Aleph X is the 130 W version , According to AXE-1 spreadsheet heatsinks wil be sufficient (0,14 K/W per channel), even if the performance is less then 50% of a genuine heatsink from Seifert.


Jojo

[Magura]

Im planning on using engine blocks from volvo or BMW for my casts since i know approximately what it is.

My experience in casting is that thin blade sections usually end up bad. Furthermore if you expect to use sand for the mold, it tends to get in the alloy in thin walled sections for some reason

Great idea for the faceplate...I like the texture.

Magura

[jojo]

My crucible isn't big enough to hold an BMW engine

To be clear I posted this in two day's but it took me nearly three months to get as far as this. Below a picture of the casting of a test-model. It's not very big but it sure feels impressively heavy, this massive chunk of 18mm cast aluminium.

My oven starts to fall apart after these few initial heatings, so at the moment I'm building a more sturdy oven and a bigger diy propane-burner. In the meanwhile I'm building also the real models for the front, back, bottom (with ventilation gaps included) and top sides. I have to take notice of the fact that aluminium shrinks 1-2 % when cooling down. On a side of 400 mm thats 4mm short. That's too much to leave unnoticed. As told I'm still puzzling about the heatsinks.

I think the next progress-update will take a while. I hope the above will inspire other people in creating their casings.

grtz Jojo

[Leeuwarden]

Just curious what happened since...

[vpharris]

He hasn't checked-in since January of this year, so I doubt you'll hear from him. Maybe he's out mining bauxite so he can go the full-DIY route.

[Leeuwarden]

I guess so... we met at the first Dutch diy day. Just wanted to know what happened. I'm afraid we will never know

[jacco vermeulen]

Still interesting to keep this thread alive.

In case someome is thinking about giving the diy casting a go and is not aware:
there are tablets that clean the aluminium melt, sort of like the ones you put into your dishwasher.
Inpurities react with the additive, form a foamy substance,start floating above the melt and can easily be removed.