What kind of machine will do stainless steel or brass engraving

[Jonathan]

Brass is easy to engrave with a CNC router, however stainless steel is much more challenging since the cutting forces are greater. The machines on eBay from China would be fine for engraving brass, but would struggle with stainless steel due to their high spindle speed and poor rigidity, so you would need to make some upgrades. That may still work out cheaper than making the whole machine yourself, so I would compare the price of the components to find which is the best option. With the right tools the spindle being limited to relatively high speeds may not be a problem.