I didn’t try the 3 blade FR prop without the duct.
However, when using the 2 blade folding prop without duct I noticed a reduction in thrust at slow speeds which makes since (less blade area), but once the wing was flying it felt like more thrust. Maybe it’s just the reduction of drag.
I really like the folding prop. I couldn’t stay on foil with the motor off and blades folded. I think I need to re-trim the rear wing and test it on a “down winder”. I hope to be able to foil with the prop folded when surfing and running with a downwind swell.
Yes. These tests have been with the FR motor. My 65161 motor is currently waiting to be mounted on my second board. But, I will try to get it mounted on a mast soon so I can do some more side by side tests. So far I have been impressed with the performance of the 65161 motor compared to the FR motor.
Don’t you also have both motors @Jezza? Have you compiled data comparing these two motors yet?
I’ve made some progress on my second propulsion unit. Got the 65161 motor mounted to the slingshot mast. Converted my Chinese carbon fiber wing to fit the slingshot mast. Printed a prop duct. Ran the internal wires and water cooling. Just need to solder on some plugs and I’ll go test it out. Thankfully efoiling is surfing and Hawaii isn’t about to ban surfing!
Managed to fit the flier ESC, a BEC, and the maytech receiver. The external antenna wire is a bit short, but I’m waiting on a longer one to arrive.
As usual I added corrosionX to the box before sealing it up. Filled it about 1/2" deep. Mainly for corrosion protection, but will also help with cooling.
The wires are 6AWG. And my battery is 14s. I haven’t had any issues. I did the math. Less then 2% voltage drop at 150 amp load. I think the guys who have problems are running smaller gauge wire, and or a 12s battery, and or Lipo cells that struggle with the load.
If you don’t mind, could you please explain further?
Amps, voltage, watts. The ESC pulls less Amps at higher voltages in order to supply the needed watts. If wires are too long, or not large enough in size the Voltage at the ESC will drop causing a spike in Amps, loss in power, and extra heat.
Long wires of large gauge can provide the same values of short wires of smaller gauge. If mathed out to be equal. Capacitors at the ESC are basically batteries to help regulate the spikes, and lulls as load varies quickly correct?
I agree the goal is to have as short of wires as possible. Which I think I have for all practical purposes I have achieved.
The battery I built is 14s14p, all 6awg quality copper wire. It can supply 280 amps continuous draw, I don’t have the same voltage drop / spike issues others might run into.
I am open to learning and improving my build. I appreciate your feedback.
I have an electronics background so I can relate to this WIKI.
It can be complex but I remember the first thing that was thought to me about electronics was “OHM’s Law” Than all other to follow could make sense.
Something to consider. Wire size affects resistance, frequency can affect inductance and capacitance. Capacitance and induction is kinda on the opposite scale but can affect overall impedance (virtual resistance in a circuit). The right combos will lead to efficiency, and a bad mismatch leads to inefficiency and danger.
I tested the 65161 motor on the Chinese carbon fiber wing with the Flier ESC. It worked well. Full throttle was just over 20 mph. Needed over 10 mph to foil. Not sure what the limiting factor is. I suspect the wing. I plan to test the FR motor with the same wing and see what speed / performance differences are.
All of these things have been explained if you read the posts.
I post these things to help the community. I don’t mind explaining things. But, come on guys… Please read the thread before asking questions about stuff I just explained! Your killing me!
The aluminum box with the copper tubing wrapped on the outside houses the 75/300 VESC. The build details are shown earlier in this thread. This VESC is designed for air cooling, so I had to get creative. The VESC aluminum heatsink is attached to the aluminum box, so the whole box is the heatsink, then the copper tube cools it. It works well. The box is just warm to he touch after a 1h20m 17 mile long ride.
The larger aluminum box houses the Flier 400a ESC. I am building two boards. I posted pictures of the inside of this box earlier in my thread as well. There is not copper tube because this ESC has water cooling.
The BEC is inside the aluminum box. Yes.
If you look at the extended receiver antenna you can see that the maytech receiver is inside the Flier ESC aluminum box, thus eliminating the small plastic box. I also discussed this if you read my thread. I am waiting for longer external antenna to arrive, then I will be moving the other maytech receiver to inside the aluminum box with the VESC.
As explained in the thread…I don’t use a water pump. Just ram water pressure. Water pump is not needed. I have also posted pictures of how I did the water cooling.
I attempted to do a full throttle speed run on the FR motor with slingshot infinity 76 wing. I got up to 70% throttle before I ate shit at 26mph (41.8kph)! Got rag dolled!
26mph is pretty fast. I need smoother water and more practice to get to 100% throttle. Feels like there is quite a bit more speed if I could only hold it together!
I am using a VESC with the FR motor setup but I haven’t bothered to figure out how to data log yet. I know if I have my phone connected to the VESC it can data log, but I’m under the impression the logging stops if the phone screen is off.
I need to look into this. I’d like to be able to connect my phone to the APP, start the logging, then dim / lock the screen and leave the phone in the board compartment.
