Having done a water test with the Trainstar floatplane I've been researching techniques on launching floatplanes. In the process I came across more detailed sketches of floatplane configuration which caused some concern regarding how I'd installed the floats.
While I'd got the basic setup correct, with CoG in front of the step and the front of the floats ahead of the spinner, the proportions weren't right, with the CoG being too far ahead of the step (around 45mm) when it should be about 10mm, and the tip of the floats was about 25mm ahead of the spinner when ideally it should be greater than this.
The setup and installation of the floats is quite fiddly and awkward so I wasn't really keen to repeat the experience, and additionally moving the floats would mean a set of open holes in the floats which wasn't desirable.
However the rationale behind the setup criteria were quite compelling; having the CoG too far ahead of the step means rotation during takeoff is harder, and having the floats extending further forward reduces the risk of the plane capsizing which, despite having invested in a rescue craft, is a highly desirable feature. Finally, and perhaps the deciding reason, was that the Trainstar's CoG was in fact a little far back, which would be corrected by moving the floats forward without needing ballast, something I absolutely don't want to do.
So I bit the bullet and uninstalled the floats. I'm still in the process of attaching them about 30mm forward, however this position has adjusted the CoG perfectly in terms of the step and the floatplane as a whole.
So, I just need to finish off the screws and the seal around the mounts, and do a bit of sealing of the unused holes and a cosmetic touch-up. The weather has been terrible lately, so I might just pop down to the local pond again and do another water test, this time perhaps trying to get the Trainstar planing more and, perhaps, even airborne for a few feet to give myself a bit more confidence...
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