by PegLeg » Fri Jun 22, 2007 8:21 am
To get an inexpensive, compact and dual purpose mast centering device (triangle / divider for athwartship centering) just purchase an old fashioned wooden folding carpenter ruler and make the following modifications:
1. notch each end of the wooden fold outs on oposite sides. Notching about 3/8 in deep for half the width retains tip strength against breakage.
2 MAKE SURE that the notches oppose each other so that when fully unfolded and pivioted at the 3 ft mark the notches provide a lip to locate against the deck shear.
3. also make sure that the depth of the notches are as equal as you can make them.
4 unfold the rule and find the 3 ft junction. Then sand or grind away the joined tips to make a point when the legs are spread about 10-->12 inches apart.
To use the device as a centering tool
1 unfold the rule to have equal legs
2 spread the legs to allow the notch to locate on the deck shear (tip on the outside) with the pointy end up.
3 using the point (or fold joint) allign the mast to the center.
Note first allign the mast using only the lowers (uppers not even attached). Then add the uppers and straighten the mast with the boat on its side, sails close hauled. Finally recheck the center with the device and make any necessary minor adjustments.
The advantages of using a folding ruler for mast centering are
1 compact - will fit most back pockets or tool kits
2 simple to make and use
3 handy for taking measurements of competitors boats for comparison to yours.
If anyone wants pics I'd be pleased to send them on individual request.