We use snap rings on our 1/2" hex axles as well. Here's a photo.
Tips:
- Turn down the ends of the shafts so the clips go into the grooves. The clips can't stretch over the hex.
- For applications with any sort of significant side load, use heavy duty snap rings. (McMaster Carr 98585A109) Otherwise, normal ones are fine.
- We highly recommend these snap ring pliers from McMaster Carr: 5449A81
- If a snap ring has any signs of being stretched out, throw it away and use a new one.
- In the heat of competition servicing, don't hesitate to destroy a clip to get it off quickly.
- Don't use the pliers for 3/8" snap rings for 1/2" heavy duty rings. The tips will break off. Hide the 3/8" ones from newbies, or label very plainly. We have ruined two tools in two years from this.
- For most jobs, the straight pliers are easier to use, but every so often the 90 degree ones come in very handy.
- When making the grooves, use a go/no-go gauge (we made our own) to get the diameter of the rings right.
- When turning the ends of the shaft, be sure there is still a tiny bit of black anodize left visible. If not, the ends are too small, and the snap rings may pop off under side load. (like while turning during a match) Most years, your bumpers will keep the wheel from completely falling off, but this year this may not be the case.
- After turning the ends, put a chamfer on the end of the shaft. That knocks off the burr left from parting to length.
- After cutting the grooves, use abrasive paper to knock off the burrs on all six faces of both ends of the shaft. Nothing will slow you down when assembling like burrs.