Very nice build! 1.5 hours efoiling on flat is incredible. It makes me wonder where are the inefficiencies in my build.
I only get 15-20 minutes of efoiling with a 12s2p P45b pack, and the only major difference I see is the motor and prop (I use a cheap ali 6384 and a 3d printed 2 blades folding prop). I have to set my remote on H to get on foil with a mid aspect 1600 cm front wing. Still loving it tough.
Wow that is a big difference. I’m not straight efoiling the entire time, sorry if I misrepresented that. I’d say I’m 70-80% efoil and riding waves in off power. So still about an hour of e-foiling. I was using my 1800 naish glider pump foil with an aspect ratio of 9.8. Today I took out my 1400 naish glider and still got an hour and 15 mins. I’m also stopping at 10% battery remaining. A lot of it has to do how you ride. I e-foil right above stall speed I’m at 55-65% throttle on low power mode. Try not to get the propeller out of the water. My motor is setup at 25cm down the mast since it’s a foil assist and I ride waves off power. I didn’t notice a dramatic improvement in runtimes between different props, just much easier to handle when the prop comes out of the water. Maybe only 10-15 more mins runtime max. Hope that info helps you.
To compare efficiency, best is to look at wh/km. The less takeoffs the better the average. Takes some time to get to the point you takeoff once and stay on foil until the battery is empty. Consumption also depends on the average speed. I consider a good value around 60Wh/km@25km/h average speed.
That is a great way to compare. So yesterday I rode 10.7 miles = 17.22km and I would say my average speed was about 15-16mph which is right at 25km/h. That would mean my efficiency is 38.12wh/km, however I realized I am riding waves so it’s not 100% e-foil maybe just 70%. So I took 70% of my 17.22km which would be 12.04km and that calculation comes to 53.82km/h much closer to your number. I’ll have to test it just flat water and get a true calculation.
One advantage of a Vesc based esc is you can record data from the esc to calculate wh/km at a more granular level, then easily review it with vetr.at. There are also external modules that can do the same thing, but not sure if they work with Flycolor esc’s.
It’s fun to look at the data a bit, but gets boring after a while, so you’re not missing out on too much.
S_Roger - I just bought a Flipsky 75200 VESC so that will come in handy thanks! I wanted the capability to display the battery life on the remote controller. I think I’m going to attempt another build after this success where I integrate the box into the board. Once i get that set I will calculate the wh/km from the VESC with the foil drive prop vs other props. Will be interesting to see results.
I had another run today for an hour session. Still had 30% battery left. I noticed at 100% battery on low power mode on the remote this setup has more power than my foil drive. at 50% power it has about the same power as the foil drive setup. Usually at that point I put the remote into medium power mode and get right back to where I was at when the battery was 100%. The motor was getting loud I thought it maybe due to my prop but I think it was actually due to me not lubricating the rear bearing enough. I am using lanolin oil and was spraying the outer bearings well, but didn’t get it all the way back to the rear bearing. I lubricated that last night and today the motor was whisper quiet again.
Once again very happy with the setup lots of power and seems to be holding up. I want to test how it does with my 1040cm wing (foil drive struggled to foil even at 100%). I also have a 840cm wing if that does well.
Also as a final note I noticed a drop in power with my foil drive props close together, so I made a hub that spaces them a little further apart. This seems to work quite well for better power and still doesn’t drop out if you get the prop out of the water. Here is the STL. This converts flipsky 6384 waterproof motor to foil drive props. Bolts used are 2 - m4 x 30mm hex socket head cap screw and the 2 - M3 bolts from the foil drive hub for the props.
One more update. Today I finally got my 1040cm foil out for a test ride. It was onshore and choppy but I was able to get 58 min of runtime out of it. I was mostly e-foiling I’d say 85% motor 15% wave riding. Very impressed with motor power. I’m 185lbs (84kg) and on the foil drive assist plus with the 1040cm it was 90-100% power the entire time. With my new setup I’m at medium power on the remote and 50% throttle. Even on takeoff I’m between 70-80% throttle. I think the next test will be to see how it does with my 840cm which I’ve never attempted as foil drive was maxed out on 1040! One interesting thing was going from my Naish pump wings 1800/1400 to the 1040 the lift totally changed. 1800/1400 I’m mostly back foot when riding under power, with the 1040 it was a lot more front foot under power.