Plenty of powerhouses aren't done early. Numerous perennial Einstein competitors have traditionally had slow first goings (71, 233, and 177 have had their share), but they never cease improving.
I also want to underscore that while it is important not to start cutting metal until you know what you want to build, there comes a time when (as JVN puts it)
you have to shoot the engineer and just build the thing. (Hopefully nobody takes that literally
).
In my experience, it is important to be realistic about when this must occur for your team's manufacturing situation. Remember when you read JVN's build journal that 148 has an amazing resource in IFI's sheet metal shop - they can have precision-made parts available the day after drawing them. Most teams do not share this luxury. Necessarily, there might be times where you really must start building even if you don't know *exactly* what manipulator X is going to look like. Just build what you know won't change, leave room for the things that might change, and KEEP PROTOTYPING (in parallel to build) until you arrive at the solution that meets your specifications.