I need to make a test fixture, that's going to look a whole lot like either part of an ink-jet printer or a really lightly loaded CNC axis.
Basically, I'm making a measuring instrument for a client that -- from the user's perspective -- involves putting a magnet on a board and getting a length measurement. The test fixture is to verify the design and later, to calibrate units in the manufacturing process.
For testing and calibration, I'd like to make a fixture that moves a carriage up and down, horizontally, over about a meter's stroke, and drops or lifts the magnet. The magnet is 10mm x 6mm; that, an RC servo (or whatever) and a carriage to hold it all is the extent of the "load" the machine needs to carry.
It needs to be accurate to about +/- 0.1mm. Repeatability is less important -- if I could reliably stop the carriage at as much as +/- 0.5mm that would be OK, but more accuracy is always better.
I'm looking for suggestions for how to do this using parts that are available in quantities of 1ea -- I know how to do it if I was going to be making 100 a year for ten years, but not for just one or two.
I started with a vague plan of using bits and bobs from the hobby CNC market, but those are all pretty heavy-duty for what I want to do. I had the notion of trying to get a 1 meter long, 6mm lead screw, but it looks like long precision lead screws are hard to find. Some sort of motor driving a long toothed belt attached to the carriage would probably work, if I could measure the position of the carriage along the stroke.
So -- comments and suggestions are welcome, particularly if they come with part numbers and company names from whom to order.
TIA.