I am putting together a clamping device for my lathe to make horizontal bores (see attached). The acme thread is both left and right threaded and arranged to close the clamp when the crank is turned clockwise. I've priced end bearing supports by Nook Industries and was just a little shocked to find a ~$700.00 price tag for 12mm fixed and simple supports. Are there some reliable end supports that will do for less?