fechter said:
Do you know the standard diameter and pitch of spoke threads?
I just now measured the pitch at 50 threads/inch. I don't know the depth--I guess I could attempt to measure it. The correct depth seems to be near the final, fully tight, adjustment setting of the die head--when the adjuster nut is nearly flush with the end of the die threads on the collet. (This is pretty much my tool):
http://www.yellowjersey.org/SPOKROLL.JPG
The die is near the "fully loose" position in the above photo.
Tightening the adjuster nut to the opposite end of the threads, for a final setting, matches the threads cut at the Sapim factory--at least on my Sapim "12 ga" threads, which are nearly the same diameter and the spokes that shipped with my Crystalyte wheel. I've been rolling my threads in three stages. Two stages would be possible, except it's difficult to "take a big bite" on the 2nd stage right ofter cutting the spoke and get the die to follow the light threads smoothly and get started. I've heard the die wears quickly if you try to force it onto the end of the spoke so I do three threading steps:
1. Thread lightly to the final 165mm "threaded section width" point, or close to it.
2. Cut/dress the spoke to final length.
3. Tighten the die head only slightly so it may easily get past the freshly cut spoke end and follow the light threads over the full and final threaded region of the spoke.
4. Tighten the die head to the final setting and thread a 3rd time along the entire threaded section of the spoke (~12mm or so from the end of spoke).
The above technique puts a few more "threading miles" on the die when cutting a 184mm down to 165, but it has the benefit of always having threads on the tip of the spoke to guide the die onto the spoke for each threading step. This would not be the case, if I'd cut the spokes to the final 165mm length before doing any threading. All in all, I believe the above technique results in the lowest die wear, despite the extra "threading miles."
After rolling the threads, I measure the thread diameter at nearly 0.114" vs. 0.102" for the non-threaded section of the spoke.
I bought 80 black 12 ga Sapim spokes from Danscomp.com. Despite what the website implies, they won't / can't cut them for customers That's why I bought a Cyclus die head and Cyclo tool from http://www.biketoolsetc.com. They had a great deal on the 12 ga Cyclus head so the entire setup "only" cost me $111 but I had to extend the flat on the shaft slightly with a file to make the Cyclus head compatable with the Cyclo tool.
I read various online reports of difficulties with this sort of tool (Hozan tool, etc.) but I have to say, my setup has worked great for me. It's very time consuming, of course, and patience may be real problem other users have experienced with these tools. (Or a lack of "wrench savvy

).
I've finished 13 spokes but the rest of a batch of 40 are in process (not cut yet, but lightly threaded to the 165mm spoke point). That leaves 40 spokes I've not touched yet. How many do you need and at what length? The Danscomp spokes are 184mm and I'm cutting my spokes to 165mm. One of the ways I justified spending money on the tool was to consider making it available to loan to some other needy e-bike enthusiast.

It's hard to say how many spokes are in the life of the expensive die, but biketoolsetc thought maybe 200-300, depending on technique.
I see you live in CA and I know you're "wrench-savvy." PM me, if you'd be interested in borrowing the tool. It would be cheap to UPS it to CA. I'm using Phil oil on every "run" and a metal reinforced cutoff wheel on a Dremel tool to cut and lightly dress the ends of the spokes before final threading. I can provide further details.
-Cal