Blackjack 26, time for an upgrade

[JackBlack26]

not like the sharp bend shown above

I assume you're talking about the picture I posted. The bend may look sharp but its not. This boat has very little deck height so a gradual bend is not possible without making the stuffing tube in to an "S", which is how the stock tube actually comes, or cutting a very oblonged hole for the stuffing tube to come through the bottom of the hull. But you wouldn't know that without actually have built one of these boats. It also has a Teflon liner so wearing out the stuffing tube is not an issue when you factor in that it will be well greased. And lastly, this isn't my first build. The App, Geico, and Segad have way more space to make a gradual bend than this boat does. I have owned all except the later.

[JIM MARCUM]

some what. My Apparition Pro & Segad have enough room to park my Kia Soul in. However, I don't understand the concern of making an oblong slot for the stuffing tube to pass thru. Every FE catamaran I've seen - except bare hulls - have a slotted hull for a gently curving stuffing tube. Some use S shaped stuffing tubes, and some argue that an S tube has slightly less friction on the flex shaft than a gentle curve. But I don't think you will find much support from experienced FE builders that a sharp bend in the stuffing tube won't cause the stuffing tube excess wear & put unecessary drag on the flex drive. Friction is your enemy.

Oval slots ane easy to make and make bending & aligning a new tube far easier. For a scratch build: drill hole in hull, form slot with a round rat tail file. If replacing a stock tube, it's probably already slotted.

As to using teflon liners or no liner, I've heard from people with 30 years of RC boating experience - including several FE SAW record holders - on both sides of that issue. My preference is no liner.

Because running w/o a liner, it will prematurely wear out thin brass tubes. I use seamless Stainless Steel stuffing tubes on my builds, and when replacing a worn/dammaged stock brass tube. In my experience, for full sized or model boats, Stainless Steel beats brass anytime. Maybe I just like shiny things. JIM

[JackBlack26]

For a sport build this works just fine. I'm not trying to break any SAW records, lol.

Good idea on running stainless on your builds. I like running Teflon because it's easier to swap out the liner rather than having to replace a tube.

As for the bend, whether it be 1, 30* bend or 2, 15* bends in an "S" bend, its still the same amount of friction. You cant escape physics. I know one long slit across the bottom of the boat would have fixed that but I didn't feel like cutting a 2 inch slit when I can just run the liner and call it good.