Robbers

[mtlgd]

I have seen a couple references to these, and I have a couple of questions.

1 What is their physical construction?

2 What symptoms would predicate their use?

3 What is the criteria for their placement?

4 Are these components considered (albeit small) into the surface area per Amp formula, or would the size of the part negate their impact?

5 How do you calculate the required size?

6 Are there some materials more demanding of their use?

7 With any plating in-particular, or in general?

I apologize for so many questions but my web searches haven't yielded much information on these....

[mcaswell]

Robbers are placed into the plating tank to "rob" any overages in current. For example, if you're zinc plating a part that requires 1/2 amp (20 sq in), and you can only control your power down to 1 amp, you can put a robber in the tank (some part that is another 20 sq in) to ensure that your real part won't get too much power.

1. Any metal that the plating system plates readily.
2. Having more current than your part requires.
3. None.
4. Yes, that's the whole point of using them.
5. Use the amps/sq in formula for the type of plating you are doing.
6. No.
7. Any plating really, although they become more useful in plating that has small current requirements such as zinc.

[mtlgd]

Ah, ok. Initially I thought maybe they were used to pull current from the part itself (attached to the part).

Thank you.