Does anyone know where I can get a decent price on stationary rollers--the kind that go under your loco's drivers so it can run in place? I know Aristocraft sells them for around $55 but are there any cheaper ones?
There’s nothing cheaper than my locomotive test stands. Glue a piece of 1 1/4 x 3/4 inch pine to a piece of hardboard. Slip it under the motor block(s) and the wheels are raised just high enough to let them turn freely.
Note the Annie block has a groove sanded in it with a sanding drum to clear the gearbox bulge.
Supporting the electric motor block is okay if the axle/wheel suspension is rigid with the block. With a Live Steam loco (or even an electric with side rods that are not very loosely attached) and some sort of active suspension then letting the wheels/axles "dangle" will cause binding and with Live Steam affect the valve adjustments.
Edit: BTW, non-working wheels (tender and lead and trailing trucks) do not need rollers, they can either be left dangling (unless support is needed to get the weight on the drivers correct) or they can sit on rails (or boards, or whatever).