Pardon a digression from the more broadly interesting subjects we’ve been visiting lately. Purely for those who build professionally and juggle spoke lengths, I carry and discuss the allegedly World’s Best spoke cutter and threader. Okay, I’m dangerously biased.
Many people buy the Morizumi for its most superficial feature, the rarity of spokes jamming during threading. When it comes to livability, this trait means a lot. But how does the machine manage to jam rarely (never for many).
Rolling is how the vast majority of threads are put on round fasteners. First, it is net material – none is removed as in cutting. At today’s prices, we can’t afford to use only 50% of a rod to make a screw, and merely recycle the rest. Second, rolling (like forging) rearranges the crystal structure of the metal. This realignment is superior to the interruption of cutting. The threads are stronger.
Rolling succeeds the world around but it has one strict rule: work must enter the rolling dies at an exact perpendicular angle. Otherwise, much metal tearing, heat, damage, and usually the whole tool seizes. In manufacturing, this is prohibitive. Production lines cannot be halted by jams. Mr. Morizumi hails from a spoke making career so it was obvious to him that spokes enter the dies at the correct angle every time. His machine provides a guide block and spring loaded plate to guarantee accurate entry.
Trick: when you pull down the sprung plate to insert a spoke, let it go with a bang rather than gently releasing. This tends to ensure the spoke is lying fully in the guide block groove. If it reaches the groove but is a tiny bit crooked, there’s a chance for jamming.
Jamming can also be caused by running too-large wire (2.0mm when it’s set for 1.8mm). Obvious but possible. In that case, change the gauge switch. I’ve known at least one operator to go crazy and hang from the cutting lever trying to get it to move in spite of the miss fit. Another used a sledge hammer to force his machine. Both needed some repair but both are in service today.
Special Method to Exit a Jam
When a spoke makes a crooked entry for whatever reason (earthquake, bent wire, hiccup, etc.) the operator feels additional resistance. Always be monitoring your threading effort so a change is easy to detect. Stop your downward stroke, reverse direction and lift the lever as far as it will go. This is not enough to eject the spoke, it’s simply when the threading lever is vertical again.
Now pull the lever towards you until you can press in the small red button (force return pin) on the thread lever linkage. It will reach a hole when you’re in the right spot.
With the button engaged, the threading linkage is locked and as you raise the lever back towards vertical, the spoke will be forced lower, closer to ejection.
Before you reach the actual start, release the button, reverse and begin another downward stroke, just as if it were the beginning a a fresh threading. Watch as the machine self aligns the spoke. 100% of the time, it will roll through perfectly. The machine lines up the spoke on the return stroke. Step 4 is a normal downward threading action.
The uninformed observer does not even notice a jam since an experienced operator makes such a subtle correction. Don’t lose spokes or time to bad threads. The machine is self clearing and self realigning. Very important feature. Better than music and booze for preventing threading headaches.