Metric vs SAE hardware

[asid61]

SAE is really handy because hardware stores stock it.
However, if you are able to order everything online, metric is generally cheaper for screws, bearings, etc.
So if you have the money to order everything and have enough machine tools to avoid AndyMark and Vex, go to metric.
If you have fewer than the maximum available resources and want to use Vex and Andymark parts, go SAE. Most likely SAE is better for you, especially if you live in SF.