[sdiy] Board manufacturing questions

[Aaron Lanterman]

Howdy y'all,

So, I've got board layouts ready to go for the timbre circuit, the  
LPG, the envelop generator, and the balanced modulator of the Music  
Easel. (I've got four other boards almost ready to go, but I figured I  
should actually order and build and test some before working more on  
the layouts.) I've actually had these done last January, and am just  
now getting around to seriously look into getting them fabbed.

I like the idea of trying PCBCART since they take Eagle files straight- 
up, without having to export Gerber files (and worry about if I'm  
doing the export right, including all the files, etc.)

PCBCART kind of sucks for prototyping because if the "one-time tooling  
fee," but after that it looks pretty cheap (in case I happen to luck  
out and say a board actually works...)

Some questions:

1) The web interface defaults to a 0.063 thick board. Should I go  
thicker/thinner? What's cheapest?

2) The web interface defaults to "hot air solder leveling," but  
there's other more exotic versions available. Any compelling reason to  
go with a different technique?

3) It asks about copper weight, and defaults to "1 oz" but 2, 3, and 4  
oz are available. Thoughts?

4) It asks for minimum tracing/spacing, minimum annular ring, smallest  
holes, and number of holes. How do I ask Eagle to tell me what these  
are for my different layouts? (I know I can set a design rule check to  
check if a minimum of something is exceeded, but it may be that I  
naturally didn't go anywhere that minimum and hence there's no reason  
to pay for a more detailed process.)

#4 is my main concern.

- Aaron