My first attempt at a tow boogie turned out pretty good but it does have a few drawbacks. Running along with larger waves it has a tendency to bury its bow into the wave. Running against wind chop it bounces around a lot and the propeller often catches air. It would also be nice to ride some waves when the wind is on here in Stockholm. Unfortunately my current tow boogie would never work for that and is mostly a tool for having fun on flat water. When @ludwig_bre released support for differential thrust I started thinking about how I could build a tow boogie that would handle the chop and also steer straight for a few hundred meters while I was having fun on the waves. Talking to Ludwig he told me there’s actually an IMU on the receiver board of the BREmote. Basically all that’s needed to program an autopilot in a dual motor tow boogie. This is still very much a work in progress but at the moment I’m looking at a catamaran tow boogie with wave piercing hulls. This will hopefully handle chop more gracefully and with two counter rotating motors any prop torque issues will be eliminated.
I’m planning on using the same Peli 1400 case but increase the battery capacity to 10S12P with Samsung INR21700-50S cells. This will leave no room for a VESC in the case so I’m planing on moving them to a separate box aft of the case. Motor mast and mounts will be 3D-printed as well as the propellers (might modify and use the toroidal prop designed by @Waisted). I’m looking to use dual 6374 motors and Flipsky 75100 VESC’s. Having a little problem deciding on a motor. Has anyone used the waterproofed Saite 6374 130kv motor?
Only every foildrive customer…
But I’d use dual 6384. Marginal weight gain but better torque.
For wave piercing designs look into other small craft like surfskis etc. Catemerans track way worse in chop than monohulls and if one hull buries while the other is out it will twist.
Hmm, a surfski like design might be better. A lot easier to build as well.
I use the cheapest 6384 120kv motors I can find on AliExpress for my dual motor tow boogie, put ceramic bearings in, corrosion x and enjoy.
I have mine setup on a slightly larger 5’ 8” soft top surfboard, but it definitely jumps around in chop like crazy, but I haven’t had a lot of nosediving issues.
I am definitely interested in the autopilot concept. That was my plan for the next iteration!
Maybe have a look at this hull design?
Rough first draft of a single hull version. Will be a lot easier to build and might even be able to right itself if it capsizes. It’s 1.3 meters long or in imperial measurements about 4.3 feet.
looks nice, but why not take it one step further, and put a wing underneath it
And a nice deck pad so you can stand on it!
Two small angled wings to make it a stable foil vessel like some boats would reduce the drag nicely.
The masts are located too close to the stern, the board will go under water at the start. In my opinion, the optimal shape for a tow boogie is a fairly thin board and a voluminous nose.
And also, if you implement halyard control, then the wider the motors are, the harder it will be to turn.
Why not since chop is an issue. Inverted foil section (negative lift) as on cruise-ship sides would maintain the TB bottom stuck to the water surface.
Damien leroy posted a YT video about towing with a lift efoil. I think he mounted the foil upside down. Could be a thing to try out
I tried it and it sucks. It is necessary to tie the leash too close to the fuselage and dangerously close to the propeller. It handles and turn poorly.
I was going to try it this weekend
anyone have a 3-d model for printing 2 props going the opposite ways for the Flipsky 7070 Motor that is not an outrunner?
You only need one—just mirror it!
oh yeah! does anyone have a good model for the prop then on a motor like this that is a bit smaller then the single motor?