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  1. dirty_d

    Electric Hydrofoil/E-Foil

    I think this is a common misconception. Rewinding a motor doesn't change its mechanical characteristics, that is, it's torque/speed relationship at a given output power. A motor's mechanical characteristics are determined by it's size, shape, magnet strength, and copper fill percentage. Changing...
  2. dirty_d

    Electric Hydrofoil/E-Foil

    I guess this is a good first step. I think I'll worry about learning how to ride behind a boat before I start thinking too hard of about the electric propulsion.
  3. dirty_d

    Electric Hydrofoil/E-Foil

    I think if you really wanted to try this with the torqeedo prop, you could by flashing a custom firmware to the ESC. It's definitely possible to run a motor sensorless like that. The ESC by default just isn't expecting the motor to accelerate so slowly.
  4. dirty_d

    Electric Hydrofoil/E-Foil

    Is this one of you? https://www.youtube.com/watch?v=D-zdHYI_ZkI I have that same motor just laying around unused, hmm...
  5. dirty_d

    EDF kiteboarding?

    https://www.youtube.com/watch?v=uSudkID3zJM :lol: :lol: :lol:
  6. dirty_d

    Electric Hydrofoil/E-Foil

    NolaDoogie, they almost certainly do based on the size of the propeller compared to the size of the motor housing. I really think the best way of doing this is the same as pacificmiester did. An inrunner and inline gearbox gives you a slender drive that minimizes drag, and it lets you use a...
  7. dirty_d

    Electric Hydrofoil/E-Foil

    I like the idea of using something like this https://www.mhz-watercraft.com/shop/en/motors/449/motor-sss-56104?c=110 direct drive to something like one of those 52mm impellers https://www.mhz-watercraft.com/shop/en/jets/504/spare-impeller-jet-52-52mm-diameter-spare-part?c=110. Cooling an...
  8. dirty_d

    Electric Hydrofoil/E-Foil

    I've been toying with the idea of making one of these. I've ordered a kit from http://www.clearwaterfoils.com/ already. I'm going to just use it as a wake foil behind a boat for now. The thing that's holding me back from making an electric one is the gearbox. Even the one that pacificmeister...
  9. dirty_d

    DIY 6FET Controller help

    As far as your current limiting goes, it might be more complicated than it needs to be and not react fast enough to save the FETs from frying. Its ok to have the shunt between ground and the low side fets, because while the average voltage across it will be the average battery current, not motor...
  10. dirty_d

    My big(15 lb) quadcopter project

    I was working on a flight controller a while back. It used an STM32 Arm microcontroller eval board. I was having stability problems the last time I was working on it, so I just ended up getting the KK so I could finally just fly the damn thing :) I admit it is kinda intimidating to fly knowing...
  11. dirty_d

    Quadcopter Build

    I did some research and ended up getting the ImmersionRC Uno5800, the 600mW transmitter, and cloverleaf antennas. I found some tests online that measured the actual power output at around 750mW. I was stuck between that and the Boscam TS352 or TS353 with the RC832 receiver. Those both tested...
  12. dirty_d

    My big(15 lb) quadcopter project

    Testing out how it flies with a load, maybe 4 pounds. Nowhere near the full payload capacity. I have the KK2.1 throttle scaled to 75% and was hovering at around 50% throttle on the transmitter. It's a lot more stable than I thought it would be...
  13. dirty_d

    My big(15 lb) quadcopter project

    It felt really stable, maybe because of the size. I've never flown a quadcopter before, and I didn't even realize that auto-level was off the entire time. What is 42Hz filtered? The output to the ESCs?
  14. dirty_d

    My big(15 lb) quadcopter project

    I finally got around to flashing the simonk firmware to the ESCs, I went ahead and bought a KK2.1 controller as well. It works pretty damn well. https://www.youtube.com/watch?v=XlMyax9dP8E https://www.youtube.com/watch?v=wzRT8luIYk4
  15. dirty_d

    My big(15 lb) quadcopter project

    I've been real lazy since getting back from Vegas. I need to get this thing outside one of these days and get it tuned right.
  16. dirty_d

    D-drive a unique transmission system

    I saw that thing before. It doesn't solve anything. You end up needing a 2nd motor with its own cvt/ivt to drive the secondary input of this device. Just someone trying to make money.
  17. dirty_d

    My big(15 lb) quadcopter project

    Well I think i have the PID code all fixed now. I could tell with my indoor test that the -D term is definitely kicking in now. I set it way too high though. Just the vibrations alone were amplified and apparent on the motor output which made it shaky and took 75% throttle to hover, it did seem...
  18. dirty_d

    My big(15 lb) quadcopter project

    While working on the C++ simulation I noticed that I made a mistake in my PID code on the micro-controller. The statement for calculating the D term was basically: d_term = (pv - last_pv) * dt Where it should have been: d_term = (pv - last_pv) / dt * d_weight Sure enough after changing the...
  19. dirty_d

    My big(15 lb) quadcopter project

    Hmm i just read that, it said to reduce -D to reduce oscillations in stable mode. That's strange to me. Unless by reduce they mean make it more negative, but they say reduce it by -0.5, so id think they mean increase it towards 0. I'm going to try to alter my simulation a bit to try and simulate...
  20. dirty_d

    My big(15 lb) quadcopter project

    You used only PI on a quadcopter or some other project? I wrote a pretty accurate simulation in c++ before I began building anything and i was unable to get the thing to stabilize without a D term. the quad would oscillate itself out of control and flip over, with a D term it was rock solid...
  21. dirty_d

    My big(15 lb) quadcopter project

    No, it doesn't respond to the input signal at the same 400Hz that its given. There is a digital impulse response low-pass filter in the ESC. But The filter is designed to work with a 50Hz input signal. When you feed it 400Hz it shifts the cutoff point upward because its based on the time between...
  22. dirty_d

    Flying Dutchman - is this fake?

    I think it is, I don't see any motors or anything on it.
  23. dirty_d

    My big(15 lb) quadcopter project

    Yea its uncontrollable right now. I had it up about a foot off of video for a couple seconds and it started oscillating back and forth very fast. From the physics simulation I wrote before building it, I can tell that that's either from too much P, or an ok amount of P and not enough -D. The...
  24. dirty_d

    My big(15 lb) quadcopter project

    Thanks. I tried my first flight today, I think I need to adjust my PID, lol. The payload should be somewhere around 15 pounds, I planned for 20 but i don't think its going to do it. Right now it weighs about 15, and it hovers at about 40% throttle. Video: http://www.youtube.com/watch?v=cBCbTRqPMTY
  25. dirty_d

    My big(15 lb) quadcopter project

    I haven't been on this forum In a couple years but I thought I'd share a project I've been working on for a couple months. Its pretty much finished it last night and did a quick 1 or 2 second hover test in the living room :shock: here are the specs: 4x 5055 size 1600W 700kv motors 4x 60-70A...
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