The problem with ACME thread profiles is the nature of the thread, i.e., it is 28 degrees total, 14 each side, and a tap will be probably dead on, and your hand ground threading tool, unless you use an insert, will be ground to fit a gauge, and then remember, it has a "thickness" of the thread, top and bottom.
ACME is a profile typically used for applications where the thread form has a maximum exposure...meaning a lot of material to ride on, and the fit will be class 1 typically. Used for obviously, jack screws, and bar clamp screws...stiff like that.
If you need to place a gear on the end, the obvious answer is to use 2 ACME nuts, either side of the gear, and drill a set screw in as well, or cut the diameter down to say 1/2 inch, and then use a key and set screw to hold the gear if space is an issue.
Just as an added thought, most ACME taps I have ever seen are two or even three tap sets...starting, mid, and final cleanup. Dies are the same way.
Hope this helps.....I am a machinist. Or was in a past life.