The battery holder above is designed to hold two D cell Alkaline batteries and provide center-tapped ground, Vdd, and Vcc. I noticed that the D cells provide a full 2V unloaded when new so they are not really 1.5V cells and as such they are sufficient to drive opamp dual supplies and logic single supplies when operated in a pair like this. Even as the voltage drops to 1.5V or so, we still have enough voltage to run modern parts. And, well, I have four D cells so there!

This is all part of my new motivation to get back to basics before continuing. You see, some folks have offered excellent advice to me like "use motors designed for the task" and "get store bought propellers" and such things that cost money. I'll have money for that in a few months but for now I don't so why not spend my time now using what I have - NOT to build a working project, BUT to build the pieces of that project that I can build with what I have.

To that End I thought I'd take one of my last remaining breadboards and make a nice battery holder for it. See above, obviously it grips the battery (or I hope it will) by being slightly over half-round and the three horizontal segments with spherical holes in the bottom are designed to wrap about six inches (150mm) of wire around each piece there to make battery contacts. I left 2mm on each side as play for that (4mm per battery) and the wall thickness is 2mm for reference, so that should work out fine.

I'll keep you posted and thanks many times over for all your great advice, I do appreciate it!

Les