I wanted to get my Starrett combination square and my double square out of my toolbox and somewhere more accessible. So I took inspiration from a set of holders I found from mkegadgets and changed a couple of things. First, I made a holder for the combination head that sits perpendicular to the wall rather than parallel. Then I adjusted the angle finder head and protractor head with cutouts that can handle the heads inserted in either direction, rather than just one way, as in the original. The protractor holder, for instance, has grooves in case the rule is left in the horizontal position and also cutouts in case the rule is in the vertical position. Same for the center finder head.
Tested to fit the following:
I think all Starret heads are the same dimensions, but I haven't tested anything but what is listed here. Note that the #9 set comes with a single-sided protractor head that will not fit this holder (though I own one and intend to make a separate holder for it). I left a cutout at the back end to accommodate the scriber that comes with the combination square, but mine is missing, so I don't know if it's big enough because I can't test it. Leave a comment if it doesn't fit.
My PEC Combination Square head fits the holder Starrett perfectly without modification. My set is old enough that it's still black (before PEC switched to all blue). Haven't tested the protractor or center head yet.
Mounting holes are designed to clear a #6 screw, a common wood, deck, or drywall screw size.
I own a single-sided protractor head and also a similar Precision Engineering Corporation (PEC) combination square set that I plan on adding holders for. I also want to redesign the center finder and protractor head to also sit perpendicular to the wall. But I intend to do a lot of things I never get around to, so I wouldn't count on it.
The author remixed this model.