Well, I'm a great fan of making my own stuff, if I can. If I wanted one, that's what I would do, make my own; that way you get to save money, and customize it to your specific wants/needs. Found this out there, and seems to be as good as any, and possibly better than most. Guy is using it for banjo making.
My Homemade Copy Carver or Duplicarver to aid in Banjo Construction - YouTube And, I would say you should be able to make a working version out of wood/plywood if you cared to - but I would think the welded tubing would hold up better for long term.
And that reminds me, I've got a banjo about half finished out in the shop, need to start putting in some work time on that. Then I can learn how to play it. :haha:
Mine will have some unknown hard-as-a-rock pallet wood; and from my property, courtesy of a hurricane years ago, dogwood, hickory, oak, holly, probably pine; plywood; two brass screws; and possibly a bit of door skin.