Sturmey archer flange sprockets

[classicalgas]

I want to use a Sturmey Archer IGH as a combination jack shaft and 3spd transmission from a low power mid drive to the rear wheel (left side) SA makes a "trike" hub, for use in a similar way, with a "flange cog" bolted to the spoke flange. Problem is, I can't find them listed under spare parts anywhere. Anyone tried this, or have any ideas?

 

[amberwolf]

For the one in my SB Cruiser frame, I just took a cog off a generic multispeed freewheel,

removed the tabs from it's inner circumference, and welded it to the flange.

I'd tried bolting it on, but the tiny screws I could fit thru the spoke holes just sheared thru even with pedal power with my wimpy legs. :/
https://endless-sphere.com/forums/viewtopic.php?f=2&t=67833&p=1227692&hilit=IGh+sprocket#p1227692

I also changed the input gearing by bolting another sprocket off the freewheel to the original.

 

[Chalo]

I'd tried bolting it on, but the tiny screws I could fit thru the spoke holes just sheared thru even with pedal power with my wimpy legs. :/

It should be feasible to tap the flange holes with M4 threads after enlarging them with a 1/8" drill. Even only 9 such screws should be more than adequate, but there are 18 flange holes to work with (sometimes 20).

 

[classicalgas]

I looked at a solution like Amberwolfs, even got the sprocket to fit, but I'd like to use the factory (engineered and proven) solution. Replacing a worn sprocket would be simple, no fabrication involved. I suppose I could make a clamp ring type arrangement to attach cluster cogs to the SA flange.

Maybe there's a way to use part of a freehub, or old style cluster(or some sort of off the shelf adapter?) mounted to the SA flange.

Lots of places sell the "trike hub", but no one seems to carry the specialized sprocket .