Dutch Build mostly from scratch

Hello everyone! I’ve been quietly going through pretty much every thread on the site now while planning my build. Pretty amazing how much knowledge one can find.

Since I like giving myself a challenge and have the access to all necessary equipment I plan to build all parts from scratch. So Board will be CNCed core and laminated, the strut, fuselage and wings will (most likely) be printed and wrapped in carbon etc etc. I have a ton of experience in manufacturing metal parts and have been around a lot of carbon processing but never got my own hands into it (which is how the project initially started out).

First decisions already made are:
ESC: A200s V2 VESC (designed by team triforce in the UK) that I used the open source designs (with consent of course) and had manufactured for a fantastic price. Good for 18s and high current so more than powerful enough!

I will be running tests (I have a bunch of friends at the Delft solar boat team and they have kindly allowed me to use their motor test equipment) and making a waterproof casing (with water-cooling?). If I am happy with all the testing and their is interest this can be made available for the community.

Batteries: 10AH 6s hobbyking packs that I have have a bunch left from a previous venture

Board: Custom

Strut and foil: https://grabcad.com/library/kitefoil-hydrofoil-1/details?folder_id=2902073 but I will make changes so the front wing can be replaced with different ones which will also be printed and wrapped in carbon

The motor is something I am really unsure about and it determines some of the other design choices. I have made a design with a motor mounted in the deck with a shaft going down the strut and a bevel gear set. I actually have the gears on order since they were so cheap (just anglegrinder spare parts from china). This is the most hydrodynamical approach (Solarboat does the same thing and it works like a charm) but it’s really tricky to get right.

I have also modified the strut design above to include an integrated POD for a 80100 direct drive design - this seems the easy and cheapest course of action but I would like a more efficient design (keep telling myself this isn’t the best way to go). I’m also not to keen on the epoxy on a lathe procedure.

I have also considered the 70131 motor from freerchobby but there is little to no info about it and I don’t really want to take the risk.

The last is going with the SSS 56114 motor with a gearbox like a lot of successful builds here. The only spin on this is that I would use a reasonably unconventional gearbox to reduce cost. I’m looking at one from a large scale RC model which seems to have the right RPM rating just slightly lower power rating. But since the gearbox is designed with large teeth and RC cars (constantly slamming throttle from standstill) in mind I think it should be plenty robust to transfer the torque. I can’t find a picture of the gearbox fully assembled so leaving that out for now. It would require some mods but nothing I can’t fix on a CNC. Cost is roughly 35 euros for all the parts (bought as separate spares) and would need some interface parts printed/machined to be suitable. Going down this path I would consider either having a POD (like everyone else) or integrating everything into the fuselage. I still need to work up the CAD since I only recently found this option and there are no resources for the gearbox online.

The last is my preferred option since I’m interested in testing that gearbox and it seems more efficient than the outrunner.

Your input on the motor choice would definitely help out.

Since I haven’t actually built anything yet here are some of the designs I mentioned up here in CAD for those interested. The designs are a mix and match of available CAD from here and other online resources with my spin on them.

Direct drive pod:

Bevel drive torquetube:

Edit:
Found a video showing that planetary. It’s pretty similar to ones from a gearbox by the looks of things.

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First small update! The first parts of the torpedo are machined - just needs the o-ring grooves turned into them and the thread cut. That is something for next week. The design is for a jet drive heavily inspired by the pacificmeister design. Should the jet not work I can add an extra ‘module’ with my planetary reducer and just use a prop.

I also made the choice to have a go at a jet drive. I made a parametric impeller and rotor in fusion which should let me iterate different configurations really quickly. The first versions are printed and will be used for testing. Once I find a suitable combination I’ll have it printed in metal or machined.

Also the design for the board is finished and the blank can be CNCed sometime soon.

image image

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Hi, also a builder from the Netherlands here. So your planning to use a jet drive right now? I’m intrested in this as well. I made 3 geared versions and one direct drive so far.

First geared version is 420kv ss motor with 4:1 reisenauer super chief. Works realy good, top speed 37km/h with cutted down yamaha prop. But sometimes the pinion un glues from the motor.

Second one is also a geared version with 800kv ss and 6:1 reisenauer motor chief. Very fast efoil with liquid force thruster. Lots of power top speed around 50km/h.

Third one is a nema 23 planetary gear set 5:1 machined with needle bearings for high speed. Motor is ss 500kv. Not the fastest but I think realy strong. Not tested on foil yet.

Fourth one is the flipsky direct drive. I cutted a yamaha prop to 130mm for it but not tested on foil yet.

I use the swordfish x300a esc and it works realy wel with every motor that I have.

I see you have acces to nice cnc machines maybe we can help each other some times. I can make battery packs with sony vtc6 batteries that work great so far. So if your intrested let me know.

Rienk

@Rienk , yup looking at building a jet drive. I’ll keep you posted on how the development on my jet goes. If I get promising thrust figures I can share the configuration.

It sounds like you have a bunch of experience with different geared setups. What’s the reason for building a new setup every time? Not reliable or just addicted to building?

With regards to the Cnc machines, I’ll shoot you a DM.

Mostly addicted to building and also trying to find easier or cheaper ways of building. I have 2 complete working efoils and also 2 battery packs 14s11p vtc6.

Another weekend, another update. Moving along slowly with more off the shelf stuff coming in, the A200S has arrived, a backup ESC option and I spent a lazy Sunday afternoon machining inserts and a casing for the backup ESC.

Waterproof casing is in. Tight fit but should work out. Going to run 12s 24Ah.


The A200S first run hand assembled with a well priced manufacturing partner. Interested to test and see performance. Got access to a motor test stand so stress testing should be easy enough to do.

Wing Core printed and glued. Ready for laminating. Same with the strut core.

Test fitting the printed core to the CNCed bottom insert of the strut.

My backup ESC in it’s machined casing. Its an APD 200F3 with a custom water-cooling casing. These things go on huge drones and have temperature limiting, current limiting and through a flightcontroller one can log voltge, current, temperature, rpm etc etc it also exepts digital communication protocols like we use on FPV drones which is interesting. The flight controller also allows for a lot of finetuning of the throttle curve and response, failsafe behaviour, arming disarming (useful for killswitch) and much more.

Hope to be back soon with the core for the board machined, the power pack completely assembled and the first bits and pieces laminated in carbon!

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This looks very interesting, I can’t wait to see the results!

Same here! If it works I can source the machined cases for anyone who is interested. I hope to have some feedback soon :slight_smile:

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APD 200F3 looks good, im currently in the market for my esc! Any idea on the price of the housing?

Can you do a stress test with the APD 200F3 with a second current measurement?
I am curious about how accurate the current measurement by impedance is…

If you can hold off for a bit please do. I’ll run tests on the ESC first. If it’s good I think there will be more interests and I’ll do a larger order for casings. If I were to machine them one at a time as people are interested they would be much too expensive.

@Giga let me see what’s possible. I know we can do that up to a certain current limit but I can’t remember how high that was. Edit: never mind I can just run a second current measurement. I should know better than to write a response before I’ve had coffee.

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I’ll be holding off for a bit pending your results. Out of curiosity, how come you went wit the APD 200F3 as your spare instead of the Flipsky 200A which already comes with waterproof cooling housing?

Combination of things
-Being able to solder on my own cables.
-Weight and size (my current casing isn’t as efficiently packed as it could be)
-Lack of confidence in chinese products
-Great support and service from APD (as well as their track record of high end electronics projects)
-My familiarity with drone parts - I really want to use the setup, safety and arm sequence the flightcontrollers offer. If my quad doesn’t chop my hand off I trust these mechanisms to be safe on an efoil too. And the finetuneabity of the throttle curve is great too. This could be possible with pwm passthrough with a vesc too but like this I can use a digital communications protocol with all it’s benefits.
-for science/ interest

I considered the 200a vesc but decided to go with the APD.

All is soldered up by the way and it looks like we’re hooking her up on sunday.

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Do you think the APD ESC will work with a low KV Inrunner ? I’ve read that it can be quite hard for classic ESCs to control such motors.

Can’t argue with any of that!!! Look forward to the results!

We’ll have to see but my SSS 360KV is still somewhere between china and here. Generally x-class motors (that’s the crazy big quads these are usually used on) have ballpark 400kv motors so I don’t foresee to many issues. APD also mentions 300ish kv motors in their manual with prop advise so would expect it to work. The ERPM cap for these are also 750,000 ERPM so more than enough to spin a motor with a ton of poles really fast.

Edit: we’ll be testing in a very low KV pancake so should prove they work.

very interesting idee with xclass racer esc i look forward your test to

Same here, would be interested in results. I am still ordering the flipsky 200A vesc one tough cause I need to log all the data if I want to optimise the motor / prop combo. So, looking forward for your tests :slight_smile:

I really like how tiny it is and how efficient it is packed, but to what extend can you configure it? And what parameters are there? Like can you change the current limit? Are there soft limits and hard limits?
And also it doesnt state the commutation algorithm, is it using foc or bldc?

That esc looks good in your casing! Can you order these esc’s somewhere in europe? I’m happy with my swordfish esc’s but still looking for more options. If everything works well I would like to know how much your case will cost.