The last mechanical component I need to source for my z-axis is a 72tooth HTD 5mm pitch by 25mm wide, preferrably in alloy.

HPC do them at £££, RS only stock Gates (Gates use Cast Iron at that size), and I can't remember the name of the company usually recommended by the model engineering lot.

I also need a belt and a 24t for the motor, but they're easy enough to source.

Any suggestions?