I can do duty cycle up to 2A on my linear amp with DC (HP) using a function generator. up to some KHz.
That looks gnarly. Mine is just a little rough but its only 4oz you have like a few pound copper there.
From what I understand
1) there is conductive sediment on the bottom of container that makes a parasitic electrode. Stirring negates it, filtration removes it. You can also do something with 'tea bags' but that part is just irritating me right now to think about making socks.
2) the OUP (object undergoing plating) should be hung with its mid point at the bottom of the electrode.
3) a circular electrode might be the best (which is why I got high diameter copper tube, I can TIG copper weld it into the perfect shape if I want to
4) my bath is very high throw (lots of H2SO4), for plating flat objects I think you want much less H2SO4. Mine was meant for vias. I would say it delivered, if it made 4oz plating. I just need to try it on a PCB
5) the balance should be 70% standard polarity or so square wave (soft square?) for optimum results on ... dc offset PWM. Not sure if you need a dead zone though (i.e. not simple PWM)
6) electroforming should be slow, 60mA/square inch or so. If you have filter and stirring it should get rid of the "my cell gets worse with time problems)
7) copper should be phosphorous copper type (0.03-0.06% phosphorous, rest copper. Apparantly plumbing tubing satisfies this condition)
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electrode need scrubbing eventually because of fowling. I have a 4x stir plate hot plate thing, I wanted to make a round robin thing with electrocleaning, cleanbath, etc. I suspect that the best way to clean this shit might be a citrate solution in ultrasonic cleaner, followed up by electropolishing. That should keep that electrode looking proper.
9) Cell is not efficent with copper, eventually the electrodes dissolve in it. Not sure how to determine this, the best I can figure it to burn and weigh a sample from volume. I.e. the idea is you remove 1/4 bath, and add H2SO4 and water, and additives in proportion, to dilute it to maintain your desired concentration. It is simple accounting for the copper, the dye... you can use a spectrophotometer and a cuvtette to control it... but the other additive (SPS and PEG) I don't know. I thought maybe you can track PEG using a viscosity tester. The SPS is a wild card however!!!! I don't know how to deal with that shit. a MS?? I imagine the best way might be to totally destroy/capture the additives some how (hydrogen peroxide? active carbon?) filter it, and add new additives by volume. You don't need alot.. it might not be absolutely necessary to conserve them). I bet someone knows about this.
**** or since its heavy, it might be possible to just weigh a 1mL volumetric flask on a precise scale to work out density! alot better then burning.
I don't know how far you can take those best practices anyway. At some point its going to lump and I assume what you need to do is take it out and sand it at some point, unless there is a trick, like periodic electropolishing after it gets a bit lump. It sounds like I would need a robot arm to move around between baths. I personally would like to find a solution that is minimum sanding, I notice that its smart to figure out ways to avoid abrasives, their a blunt instrument
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.. any cave life can rub something on a stone
Interestingly I can play with anodizing dutty cycle on a kepco I have if I ever fix it (never plugged it in for 2 years), I think it was broken, for the HV.
I think that all these control measures would just extend the time before bumps appear, and I doubt that you can take it that far to deposit pristine bus bars in a single bath very easily.
The best information is IMO the 1970's NASA videos, because they make rocket engine coolers with this technique, which may be replaced by metal 3d printing, maybe or maybe not. They put some seriously thick copper on those rocket, but it required machining, they did not perfect the method, and they might never because 3d printer is easier to manage and gets public approval for being fancy. The body of the rocket is clad with heat exchange channels that the fuel goes through to cool the engine down to reasonable temperatures (i.e. 'the rocketeer').I personally think in the far future electro deposition techniques will be perfected because if you figure out how its very simple and you can setup a rocket thruster manufacturing facility on any old planet with some copper ore. no dependance on mom to get you lasers and shit