ok, I can't help myself, I have to weigh-in on this one.
I've measured runner alignment a few times over the years, using many different methods. I've watched other people measure alignment using even more methods. Some of these are simple, some are complex, many provide good results.
I am a huge fan of the "triangle plate" jigs like Ron Sherry uses. Ron and I were introduced to this method at the Cartwright's on Cass Lake. I believe it provides the best overall accuracy, and is usable on the ice as well as in the shop. I think it is by far the best method to align runners on the race course. One thing the triangle plate does that a dial indicator stick can't is insure the runners are square to the plank. The triangle plate can even check alignment dynamically (while the plank is being deflected). The oldest example I know of was made by Clifford Cartwright Sr. in the early '50s, and is still extremely accurate. Elmer Millenbach also used this type of setup, and was pretty much untouchable in the Renegade class (see Elmer's article on the "old" IDNIYRA website for instruction on how to build a set
RUNNER LINERS).
I also use a tape measure or wood stick to check alignment in the shop when I can't set a whole boat up. I do not have a dial indicator rig of the type that has been discussed above. I have used them and they can do a very good job, but I think the triangle plate is a more versatile system.
Here is a list of some of the measuring systems that I have seen, knowing these different methods can save your a** is a pinch:
- Measuring tape used to measure distance between edges. I've used this method very successfully in a pinch. Works best in the shop with two people, plank upside down.
- Wood stick (3/4" square x ~9ft long) with grooves (created by whacking the stick with your fist while it is sitting on the runner edges). Wood stick moved along runners to check alignment. This was demonstrated during a plank repair by one of my mentors (Jan Gougeon) - who went on to win the World Championship using the resulting alignment.
- Rifle scope with grooved adapter, lining up to marks on a wall, or to a distant single point. Plank must be upside down. Work Ok in the shop but pretty much useless on the ice. However - I have seen this done on the ice on a complete boat without mast (upside down on sawhorses).
- Laser sight with grooved adapter, otherwise same as using a rifle scope.
- Rod with dial indicator, direct measurement on runner edge (as shown in the pictures above). Works best in the shop, plank upside down.
- Rod with dial indicator, measuring against grooved plates under the runners. This can be used on the ice, but it is difficult to get really good accuracy because of movement of the boat/plank. Any vertical movement of the boat changes the distance between runners.
- "Angle plate" with string. This is the system Ron Sherry and most of the Detroit fleet uses.
- Pushing a loaded boat through light snow on the ice, adjusting runners to make minimal "groove" in the snow.
- Pushing a loaded boat on glass ice and watching for ice chips (and listening for the "scritch, scritch, scritch" sound), adjusting runners for least damage to ice.
- Two mirrors, each against the inside face of opposite chocks. One mirror has a hole, sight through hole. If chocks are not in perfect alignment, an infinite cascade of images is created. Requires perfect runner edge to runner body alignment.
- Giant "triangle jig" used to align chocks during epoxy bonding, I use this system. See Jans's article on the IDNIYRA website Iceboat Runner Blades - 3 steps to help you get the most out of yours this season for more info. Requires perfect runner edge to runner body alignment.
- Massive fixed jig to hold chocks in perfect alignment (all planes) while chocks are epoxy bonded (Jan Gougeon). Requires perfect runner edge to runner body alignment.
Any other state-of-the-art, historical, or just comical runner alignment methods out there?