I had a mortiser hold-down and wanted it to fit my needs with the table saw carriage. Very handy mortiser accessory this one would probably be on the carriage. The vertical rod slides into a recess of the mortiser table and a screw locks it. I just had to build a base.

I made the 12 mm rod in diameter bored and threaded by a friend having a lathe. He also gave me an aluminium bar 45mm in diameter by 50 tall and 13 drilled. I screwed a 95x46x5mm metal pate underneath the bar and locked a pin at the other end then masked screws with a stuck smooth plastic pad. This last would help the sliding and prevent from scratching the anodised aluminium carriage. I also made a threaded rod welded on a metal bevelled strip where screwing the 12mm rod locks the hold-down.

For one time on the mortiser table I use it five times on the carriage. If I had know I would have built earlier. Mind the rip fence replacing the over blade guard, here in the way.