Model is intended to be printed without supports. Sizing in the saved files is for the cheap (but in my experience quite effective) quick clamps available from time to time in Aldi Australia (I don't know if they are also in other countries). Brandname on them is “Workzone”.
Uses the screw and nut from the clamp to hold the thing together. If you are using this to increase the span of a spreader, then the screws/nuts are redundant - the process of spreading the work piece will hold it all together.
Prints without supports because there is sacrificial part in the design - ‘bridging’ to be removed after print in one place, a thin circle around the screw hole, and progressive refining of the screw hole from rectangle to circle as we move up in the top section.

In the supplied stl and amf files this relies on a 0.2mm layer height, but that can be modified in the Freecad design file.

All other parameters can also be modified in that design file - different clamps with different thicknesses etc should be able to be handled this way.

(and I have no idea why the output files for the ‘small’ version are larger in kB than the ‘large’ version equivalent. They are the “same” only physically smaller…)

(and and, the image with both sizes shown has the small version with quick n nasty self made ‘end parts’ - see [https://www.printables.com/model/1132181-clamp-end-piece](https://www.printables.com/model/1132181-clamp-end-piece))

Layer height: 0.2mm