What is the proper nomenclature for this?

[Bat Rastard]

I’m trying to find one of these with a different size adapter. Me not knowing its proper name makes searching difficult.
It’s the mounting plate on the top of a construction tripod.
What’s it called?

 

[JPB3]

on an old Hart rest it used to be called a mariners wheel..

Probably different on that but worth a try.

 

[FNSafari]

can you make or have made an adapter for the screw on the wheel? May be your quickest solution.

 

[Murray Brook]

Other diagrams call it the head mounting plate.

 

[BoydAllen]

Here you go.

Google Search

 

[jxb]

You don't need a different plate if you simply need to change thread sizes, you can get an adapter. Of course assuming you want a standardized size. Like if you want to take that 3/8" to 1/4".
Search: 3/8 to 1/4 camera mount adapter
you'll find soup to nuts for types.

example: https://www.amazon.com/JJC-Threaded-Converter-Adapter-Mounting/dp/B073XLH9T3/?tag=accuratescom-20

 

[WayneShaw]

You will never find a more stable tripod for a spotting scope or any other device than that surveyor's tripod, known as legs in that trade. That one you have has the hollow hand screw, which is typical, and is 5/8" if I recall. Ideally those legs have the adjustable kind instead of solid.