Grinding and cutting jig for Skelestruder 5mm shaft

Jig and support to help with cutting to length and grinding flats on the [5mm rod](http://s.click.aliexpress.com/e/N2L8FGpi) used in the
[Skelestruder](https://www.thingiverse.com/thing:2845416)

* do check the depth of the flats and location outside the guide
* flat widths are 5 mm (instructions say flat width should be 4mm or greater)
* the saw should be flush with the edge of slot towards the middle of the jig, this slot is 3mm wide


**2019-03-07 Update**
* I uploaded a lower jig t