Here's a mockup of my controller layout. In all these pictures I only have 1 transistor unpackaged since I don't want to ESD damage them! A quarter shown is for scale. The blue box on the buss bar is the LEM current sensor (hall effect).
And here is the real thing, mounted with 5/16" bolts near the cable attachment points and a pair of 3/16" bolts at the far end. My copper was too short so I kept extra space by using smaller bolts :P
I've left the bolts longer than necessary until I pin down the final arrangement. Measure a thousand times, cut once!
Here it is with components placed for reference. Note only one diode's leads are bent correctly. From another angle:
So the biggest problem I see is one of heat dissipation, apparently copper is very bad at it. I didn't really grasp that until I felt >100°C copper. Very cool with your hand nearby, very painful to actually touch. So these heat sinks I have may be invaluable. Instead of the placement in the picture, I am debating putting them between the copper and acrylic, then making slits in the acrylic to place an 80mm fan underneath to help dissipate heat. Perhaps I should buy other heatsinks, these are slightly too tall to fit, and would require a lot of bending. Anyways I plan on testing it out, seeing how hot the bars get, and going from there.
Next steps:
1. Epoxy one diode and one mosfet to the bars, after using copper pipe flux to clean them.
2. Mount a capacitor bank. This will ride a piece of copper clad, extending out from the 3/16" bolts, mechanically connected to all three bars (electrically only between the outer two).
3. Connect the driver circuit to the mosfet and test with the tiny motor.
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