Using A Spring Scale To Set Your Intermediates

Article by Rick Brethorst

For many years I had always followed the various tuning guides method for setting the intermediates.  This measurement is always presented as a crucial measurement when setting up the mast.  I struggled with how accurate a measurement I was really getting.  The measurement really depends on how much pressure you pull the upper sidestay and the intermediate.  No two people would probably get the same result and the measurement isn't very repeatable.  Did I pull more or less hard the last time I set these?  If I did this measurement 100-200 times a year I would probably get pretty good at it, but I don't and even then it still isn't 100% repeatable.

I heard of several guys using a scale to make this measurement.  After discussing with them I felt that I knew I was on to something.  I wanted to accurately measure the intermediate settings and reproduce that exact measurement every time.  

I decided to use a fishing spring scale to to this measurement.  Various types of spring scales can be found at any fishing shop.  The one that I use and prefer can be found on our website here.  The model I use and prefer is a T shaped device (See Picture 1).  At first, using any scale will seem awkward.  After using it a few times you will get comfortable with it.

When setting you mast on the stands make sure that it is supported at the jib halyard intersection.  Failure to do so will make your measurement inaccurate.

The first step is to make a mark on the uppers and intermediates (See Picture 2).  The mark can be made either a the bearing point or the center of the hole as I have chosen.  I don't think it matters as long as you make the mark at the same place on each intermediate and upper.   I used a dremel to etch the mark in permanently.

The next steps are similar to the tuning guide.  I pull the upper with the scale and make a pencil make on the mast. (Picture 3).  I put 10 lbs on the scale when I make each of these measurements.  I chose 10lbs because it's easy to remember (1/2 of the scales total measurement) and gives the shrouds a decent tug.  I don't think the number of pounds you use matters as long as you are consistently putting on the same number of pounds on the scale.  I then take my tape measure and make a mark 74mm from the upper sidestay mark (Picture 4).  Note that I use 10cm on the tape measure for my starting point and measure 74mm  from there.  This will give you a more accurate measurement then trying to line up the front of the tape measure.  Next I pull the intermediate with 10 lbs of pressure on the scale (Picture 5).  Notice the etch in the intermediate.  I adjust my intermediate if needed until the etch lines up at 74mm with 10 lbs of pressure.  The last picture (Picture 6) is an overhead shot showing 10lbs on the scale.  Repeat the process for the upper and intermediate on the other side.  

You will need to have two people to do this when you first start.  One to hold the scale and one to make the pencil mark.  Once you get comfortable holding the scale you will be able to do both.  If you have any questions on this article or feedback on your experience please post them on the stargear.net forum.