Sponson tube fillets, turnfin L-mount and turnfin(s)!
KEP's T2 .21 Presentation
KEP's T2 .21 Freebie
KEP's T2 .21 Build Series #1
KEP's T2 .21 Build Series #2
KEP's T2 .21 Build Series #3
KEP's T2 .21 "Inspirational" Article
KEP's T2 .21 Build Series #4
KEP's T2 .21 Build Series #5
KEP's T2 .21 Build Series #6
KEP's T2 .21 Build Series #7
KEP's T2 .21 Build Series #8
KEP's T2 .21 Build Series #9
Continue to do the rest of the pin holes in the tub part.
Note, the top picture is just for reference showing the tube being pulled out and the pin is shown semi-through the carbon tube. The bottom picture shows the 2 mm pin pushed through and locking the two tubes together. When you are doing the final set-up and assembly of your ready painted T2-21you will only need a small amount of electrical tape over this joint to secure the pin from falling out.
When all of the holes have been drilled, and all pins pushed in place (in total 8 pins), you can feel that the locking pins makes a rigid and secure way of locking the sponsons in place. It's a system that also is quite easy to fix when you have hit a buoy etc. The carbon tubes wont be crushed either as will happen if you would use a screw system. Me like. :)
The length-wise alignment of the turn-fin mount L-bracket is that the edge of it should be 55 mm from the vertical sponson step.
Of course you can choose and drill these holes perfectly straight in the sponson but then you will need to make the 3 holes oval later on as you will most likely need to add some toe to the turn-fin. You might still need to adjust this (make the 3 holes oval) even though you add the toe to begin with but it's the way I do it. :)
Note, in this picture you can easily see that the front hole will pretty much be centered with the sponson tube! That means you need to pay attention when drilling that hole. I drill it so the drill bit touches the aluminum but not through of course.
When the epoxy has set over-night you can start sanding the protruding inserts parts flush with the sponson. Take your time as the sanding will crate some heat in the aluminum insert and you don't want it to get too hot.
FYI: The included (in the original pdf's) std T2-21 turn-fin is based on the JAE 21 fin but modified as the T2 fin is mounted differently and it's shorter then the std JAE fin also. We for sure will test more fins in 2013! I'll keep you posted on how the testing goes. :) If you want to try any of these development fins you can download the A4 sized pdf with them HERE. The std T2 fin is included also in that pdf.
Note, at this time don't make the sharpened leading edge too "sharp". Leave a flat spot of a few tenths of mm. If you make it too sharp it will be too fragile (at least at this stage).
Done for now - the next build-series article will be in about two weeks. :)
Next: KEP's T2 .21 Build Series #11