I have never heard of trapezoidal thread before.

Just had a quick look on eBay the trapezoidal threaded rod prices seem good, but there seems to be only one person sellings the trapezoidal nuts, the ones he is selling are made from bronze, and to me seem quite pricey being £40 for three 12x3, I don't know if that is the going rate.

Besides eBay does anyone know any websites for where I can buy trapezoidal threaded rod & nuts?

The PCB drill bits i use are 40mm long from end to end, and the working end is 10mm long.

I went for 150mm of travel on the Z-Axis as I did not want to have to rebuild it again if I needed to work on a bigger job.

I know irving2008 keeps saying 75mm or there abouts for the z-axis travel, so how about going to 100mm of travel sound?