DN NA Class

Interested in building the dial Indicator Runner aligner as described in Think Ice.Any one have more info as like what type of Dial Indicator?What do you use as Spud? how do you attach it? any info would be appreciated.

I have one I built Ill forward some pictures
I used a piece of electrical conduit and glued wood dowels  in the conduit I drilled the wood and installed bolts for  adjustment and mounting the dial indicator
and teflon slides for indicator end
I used a standard dial indticator that had a  tab on the back for mounting to bolt

Thanks Bob

here are photos

http://groups.yahoo.com/group/iceflyer/photos/album/376728347/pic/1493915189/view?picmode=&mode=tn&order=ordinal&start=1&count=20&dir=asc

Rolley: you need to be a Yahoo! member to see the photos...

Here is another aligner build.  This one uses an 8 foot section of aluminum tube and plastic rods with grooves for engaging the runner edge itself  One end is fixed, with corse adjustment to keep the dial indicator in range.  The other has the plastic rod sliding inside the tube with the groove exposed through a window to engage the other runner.  A second rod is drilled to accept the dial indicator, with a thumbscrew to hold it in position.  The end of the sliding rod has a hexbolt to provide a hard surface for the indicator plunger.  The indicator has an internal spring so it stays in contact as you arc the rod back and forth to find the minimum distance between runners.

With this set up I can set alignment to within a couple thousandths of an inch.  Far better than needed, since a light push with a finger can move a runner .020 inches.

Works best in a shop with plank upside down. Kind of fussy on the ice.
 Note that runners must be parallel and at the same angle to the plank as when sailing with sheet tensioned.

missing photo

Nice idea,probably a dumb question but why the hook rods?

For rubber bands to hold the jig against the runner when the plank is right-side up (ex. on the ice).

That makes sence,thanks Geoff.I guess that means they are optional.
BTW great job qualifying for Gold Fleet Geoff.

Geoff got it right. The hooks are for when it is runneredge down.  Not really very useful since the horses are in the way, but I leave them on and it helps to guide the edge into the notch in the plastic.

  I have two of these assemblies and did some experiments with plank load and alignment.  I zeroed both to the same length, strapped them underneath the edges parallel with the boat when set up on horses and runners snug in the chocks.  Plank deflection did not contribute to misalignment as long as the runner edges were parallel to the plank flat sides.    So when we hear that plank deflection twists the runners out of alignment, that is not technically correct.   If your boat is set up so the runners are not very near perpendicular in sailing trim and load, AND the plank is pitched fore and aft a bit (meaning not level with respect to ice) when in that condition, then you can see some misalignment when the plank is deflected.

Now understanding this, I am going to be certain that my plank/hull joint is such that my plank ends are horizontal fore/aft when loaded with my weight and sheet is tensioned.

And add my congrats to you too, Geoff!

Re alignment and plank deflection

What was said is true with two conditions:
 1.  Plank is symmetric fore and aft
 2. You are only measuring the flat portion of a runner.

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 (http://www.idniyra.org/articles/liners.htm)).

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 (https://ice.idniyra.org/Articles/Runners/Iceboat-Runner-Blades-3-Steps-to-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?