THREAD MILLING DEVICE!

[Frank S]

Machining 4 all; The only bad ideas are the ones in which an injury to a person occurs, everything else is and has a variable amount of usefulness.
Just because there is already machine which is capable of doing something doesn't necessarily mean everyone owns one or wants to buy one.
That being said I have a couple of questions about your device.
#1 do you have an indexing feature on it? I noticed in the photo of the job you are incorporating it on has multiple starts for the helix groves.
#2 Do you change the thread pitch by swapping out gear combinations?
#3 what would be the minimum useful TPI or MM per thread reasonably achievable?
#4 By the way I like your idea for the device