EDIT: ABOVE SCHEMATIC UPDATED with the overvoltage crowbar. Using the standard circuit with an SCR (cost around $1, package TO220), found no real alternative.
I will put this into the PCB machine now.
Welcome to CPF, Eddy !
If you want something right now, take a look at
the thread over there.
The PCB discussed in this thread here is just being made and not yet available.
Once it is, the PCB will be 1" wide and as long as needed by the components. Electrolytics will be off the PCB to keep it small and independent of the capacitor size (which depends on dynamo type and user preference).
I will place the components very closely (violate keep-outs) because this project will be hand-built, no automatic insertion machine to care for.
Surface mount is not meant to be done at home. The chip components require a reflow oven, following a well-defined temperature profile. Anything else potentially cracks capacitors, resistors and ferrite beads. I seen it before, more than once, over 1%.
So by the time I make this SMT, either a nice factory owner from Shenzhen has offered to help or SMT will be restricted to transistors, ICs, diodes, wire-wound inductors, tantalum caps, LEDs.
Component availability is something else to be aware of. People can't easily buy SMT parts at typical hobby shops so they may need to place multiple orders with distributors that have a high MOQ and shipping charge.
And yes, I will include multi-footprints where applicable.
I like the idea of the Collie, should give you some extra pull and fully compensate for the dynamo. What lights are on the Collie ?