He deserves a lot of credit for working out a visually pleasing way to mount each component. There wasn’t any type of substrate used, but a few lower gauge wires were picked as the rails and they add some mounting stability. Before casting, he took the case of each of the three jacks apart and sealed the seams with some of the casting resin to prevent the final pour from filling them up.
The look of this crystal clear resin brick is pretty amazing. Rupert Hirst decided to encase his amplifier circuit in a block of polyester resin. We just hope he got everything in his circuit right because there’s no way to replace any of those parts now!
Eagle CAD was used to design the mold. He printed it out on some card stock, then used a hobby knife to cut the pieces out and super glue to assemble them. A second layer of super glue was run on each seam to ensure they’re water tight. After the casting was made [Rupert] spent plenty of time sanding, routing, and polishing the brick to achieve this look.
This makes us wonder about heat dissipation. Do you think it will be a problem? Tells me what your opinion by leaving a comment.
2 comments:
Here's the answer,
There is nothing there that will get hot.
It’s an current. All currents need to get hot are electrons and a little bit of resistance in the wire.
A classic cMoy has a peak current of about 40mA and a 9v battery. Combine those to get power, and you have about 360mW, or about a third of a Watt.
A third of a Watt is about 1300 Joules per hour, or 22 Joules per minute. 1 calorie is enough energy to heat 1cc of water 1 degree C, so at most, this amp could channel enough power to heat 22cc of water at a rate of 1 degree C per minute.
I doubt that would be a problem, but the parts that could potentially get hot are buried deep, and resin is a good insulator. Any heat will stay close to the components that generate it. While that might not cause component failure, it will cause the resin at the center of the block to expand, with a possible risk of causing the plastic to crack.
My suggestion is to measure the temperature with an IR thermometer, run the thing at full power, and measure it at 1 minute, 5 minutes, 10 minutes, 30 minutes, and 1 hour (assuming you don’t see any alarming readings). Keep taking readings until you see the curve flatten out, at which point you’ll know that it’s reached a point where it dissipates heat as fast as the amp generates it.
You may see nothing.. if so, enjoy, and props for a beautiful build. If you do see a rise in heat that causes you concern, dial back the power until you get a curve that looks comfortable.
Here's the procedure to make the mold.
http://partsbyemc.com/pub/mold-making.htm
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