I find it hard to accept the situation where superwing mast tipweights can range from 7.8 kg to over 10 kg (your claim Valtteri) when fully fitted. That would imply that one particular ready to sail superwing mast may be just short of 5 kg heavier then another with all of them coming from the same die.

That is a huge variation in extrusion weights (30%).

The default weight of a 8.575 mtr long F16 superwing is theoretically 14.5 kg. Even with a 10% up or down variation in crossections the range of tipweights should be running from 7.4 kg to 8.8 kg with its center at 8.1 kg.

My mast at 8.3 kg, Hans's mast at 8.8 kg and Frank's mast at 7.8 kg are all in that range. Yours at 10+ kg is well out of the range.

But I think the best lesson here is to check the masts before shipping them out. Even if that particular superwing mast was so heavy that it had to result in a 10+kg tipweight then that section should have been scrapped and replaced by a lighter one. This is no great expense. Afterall, the variations are random and therefore all weights from light to heavy will be in a single batch.

I'm not allowed to disclose the costs per mast but rest assured that 33% of a batch can easily be disguarded without significant cost increases per mast. An expense that I'm sure we are all more then willing to pay for a (worse case) 1.5 kg tipweight reduction.

Therefore any F16 builder will be smart to measure all masts and simply scrap the heavy 33% of a given batch. There is no need to use the heavy outliers.

This should result in tip weights below 8.6 kg when fully rigged. Even less when using lightweight spreader arms instead of the (heavy) proctor arms.

Wouter