GRUNZ was asking about axle blanks & set-up wheel blanks to use on a honeycomb block.
I use hobby shop aluminum tubing as axle blanks.
You can solder away without fear of making the axles a permanent attachment to the chassis.
Also doesn't create much of a heat sink, so soldering is quicker & flows better.
I use off-fall 3/64 brass rod from prior built chassis as pins.
I pin down some hobby shop balsa strips on each side to locate axle height to motor pinion.
I have old crown gear hubs to use as a pinion to axle distances.
I Use an assortment of cast off junk as various shims to adjust heights wherever needed.