Hello, looking for a small desktop machine capable of engraving on top of standard coins. The material is either Silver, copper or Copper/nickel alloy. Most of the small desktop machines say they will not engrave on metal. I am wondering however, since these metals are fairly soft non-ferrous metals is there an inexpensive option. The bed itself can be small. Thanks for the help. I did search the forum before posting, but did not find anything related.