I have been attempting to measure the bend of some of my masts using the guide from Sailworks http://www.sailworks.com/pdfs/MCS_test.pdf.

I was finding I was getting different results after repeating the test on the same mast.
Aside from the jig I was using to measure at 1/4, 1/2 & 3/4 points, I found the mast would move once I placed the 30kg load on it. The base would move away from the wall (its reference point) more than the top would move away from its corresponding reference point, I don't think this is correct.
I assume under load, the overhang over the suspension points should be the same at each end?
OR
Does base get fixed @ 50mm overhang and the top moves when the mast is bent under load?

I have included some pics which may help show what I mean.