I would like to know how 254/973/1323 connect the dog to the moving shaft inside the output axle (roll pin, bolt or something else).
Our team used the
WCP dual speed gearbox for this season, but a few days before ship date, the 4-40 bolt (threaded all the way) snapped. In the same week, the same thing happened to our two years old
AM SuperShifter as well. We didn't want to have this problem on the field, so we drilled through the thread with an 1/8'' drill and punched a roll pin in. Our very old
AM Shifter have the the roll pin setup and never failed on us. AndyMark now improved the dog design by custom making a bolt with threads only at the end (
am-1272).
After 4 events (BMR, CRR, Champs, Indiana State) and weeks of testing for IRI, the modified dog gear finally failed, just 6 days before IRI. By that time the hole was enlarged by the shifting motion, causing the dog to break. We rush ordered the dog from WCP and thankfully, it came in time for us to complete the repair on IRI load in day. On the new dog, we drilled only halfway through the threaded part, leaving more materials on that side. I handed the partly drilled dog to Team 20, and they tried to repair it with the 4-40 bolt. There wasn't enough thread left for the bolt, so they went with the roll pin method. Unfortunately they used a bit that is to large, and when we went up against The Rocketeers, the second dog shattered.
I hope this never happen to any team ever again.
Some suggestions for improvement:
- Make the OD of the dog larger, there is plenty of room before interfering with the 45t gear.
- Use roll pin or solid body 4-40, the current bolt will snap when inexperienced programmers attempt to write an auto-shift code.
- Thicken the thin part of the dog if there is room
-Josh