What do you think about this motor for direct drive.
It s said waterproof and oxydation traitement on all parts.
http://www.maytech.cn/en/mto6374-170-ha/10339.html
Hmm, from their website:
Keep motors away from moisture, dust, scrap and small items to avoid damages.
Probably as good as any motor
I noticed a big difference between 6374 and 6384, because the stator and rotor active length is increased by 10mm.
In an alien 6374S sensored the stator is 53x40mm, 6384S is 53x50mm (+20%) and the 6384PowerGlider will have 53x55mm (another +10% torque, current capability and power instead of sensors).
The other thing is the kv or RPM/V. With 170kv and 12s you get 7000RPM, so the prop must be really small. With 100kv or less you get a much better combination.
Generally all aluminium surfaces are anodized on all motors i have seen, so nothing special.
Water proof means you can use it in the rain or mist. Nothing is said about salt on street or salt water.
The closed design is nice, on the other hand i would drill some holes into the rotor and hub to have a waterflow. Otherwise the water can get cooking hot and destroy the magnets which are mostly rated for 80°C only.
I am waiting for alien to deliver but it always gets later than promised.
In the meanwhile we could make some design approaches here for the duct, its mounting and alternatives.
I have 2 of those 170kv maytech sensord at motors at 12s on my mountain board, they work well but get quite hot. Its not actually waterproof water still gets in the motor so i suppose you will have to flush the salt waster out after each use. Never used mine in water but is already got a bit of oxydation on it so i guess it wouldnt last long in salt water lol
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Yes it was too good to be true … 
Hello,
Im just new to this forum. I like the idea of the outrunner, and to keep it as lowbudget as possible. So I will try this Rotomax motor that I had laying around. Im not sure if it will work with such a big diameter, but I wil give it a try.
I already had it inboard my surfboard, and it went ok, but now I want to foil. So I bought myself a A1 chinese Foil, still waiting for it. In the meanwhile Im trying to come up with this motor concept, just running it underwater. I don`t have experiense with running a outrunner under water. I need to maybe replace the bearings with the ceramic ones? and protect the steel magnets, and stator for corossion. Does anybody have some experience with that? is epoxy resin enough? I m planning to avoid salt water. Any Ideas would be welcome. I like al the experiments and Ideas on this formum, great work.
br,
Johannes
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I still need to downtrim the prop, because my feeling says its way to big now.
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Nice motor, what are the power specs? Is it sealed?, made for use under water I assume?
, absolutely no point changing to ceramic bearings if they never are in contact with water. If you get water inside your motor you might have a benefit running ceramic, but on the other hand having water between the stator and the rotor is not good (except maybe for cooling).
epoxy is an excellent sealing material, there are some other alternatives like plasti dip, that works well on most electronics. A combinations might be good?
if the power output is high enough(2-3 Kw) I think it will work. Even dough it produces a lot mot drag.
when it comes to drag with a big motor, it is not ideal. But if you have enough power it will work! Here is a funny example I accidently E-foiled the other day with a scarf rapped around the mast.(dont ask:stuck_out_tongue: ). Definitely increasing the drag! It worked as you can see on the pictures to the right.
Propulsion unit is the V1 unit, that several others might be using here on the forum.
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It is very nice and looking water dynamic unit as per my vision. Is it something you have @Johannes? What is current purpose and installation of it? what are parameters? KV? Power? Prop size? Looks very nice design to be underwater direct drive.
Very nice made! Perfect surfaces!
What are the dimensions of the stator iron, length and diameter?
Do you know the maximum torque?
Hello,
This motor I already had, so I will give it a try, its a turnigy rotomax 80
Spec.
Battery: 12 Cell ~ 14 Cell / 44.4V ~ 51.8V
RPM: 195kv
Max current: 150A
Watts: 6600w
No load current: 44V/4.8A
Internal resistance: 0.013 ohm
Weight: 1916g
Diameter of shaft: 10mm
Winding: 8T
Stator Pole: 24
Motor Pole: 20
Stator Diameter: 101
Lamination Tickness: 0.2mm
Suggested ESC: 200A 14S Compatible
for ESC im using: Sky rc torro beast 200A
http://www.skyrc.com/Power_System/Toro_Beast
Batteries: 8S/10S LFP 45Ah
the prop:Haswing Protruar (I down sized it by 3cm)
For the cones I used:https://hobbyking.com/en_us/catalogsearch/result/?erp_category=&q=445000152-0
Where did you get the prop and nose cone? Would you share the link?
Currently i am working at the design for the new 14cm prop. Its the same prop as before but i will cut the diameter down from 18cm to 14cm. In first design it was 17.5cm. But i think the shroud and everything is too large.
I use a fin from a windsurfboard and make some cutouts for the motor and the wires (latter not visible in sketch).
The parts for the shroud i print in PLA and glue them with UHU hart. Additional there will be bolts.
I did not use any specific profile for the shroud, but just used splines.
If someone likes to contribute to the design, i could release the drawings in fusion.
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Looks compact and nice, will you use a standard aluminium Mast, or will you you custom build the mast?
Would be really nice if it could work with no casing for the motor.
Hi @PowerGlider, Great design! Im going to build the same as a first setup with the board with 6374 sk3 140kv from hobbyking. Do you think it can be adapted to your design? I will appreciate if you can share it so I will move on from this.
So far i am not planning any mast, this is kind of a trainers board supporting windsurfing kids. If they fail to get back in changing winds we swap the boards on water and i have the job against the wind.
Maybe later i will build a custom mast. I have no experience with driving foils, but i can surely build them.
The uncased motor worked in hyeres and stockholm with different configurations of ESC and motors.
For electrical safety it is important to have no connection from the battery or ESC to the water. So i put some effort on this, e.g. watercooling of ESC is not allowed and there are no screws or any metal parts between inner and outer of battery/ESC housing. There is some failure in the interface of motor to the leads due to the construction of normal outrunners as they come out of the box. It is almost impossible to improve the situation because of the interface between stranded isolated copper and flexible leads, the soldering beeing covered by heatshrinktube somehow but not perfect. And all this sits between the aluminium hub and the stator. Hope we will overcome this issue with new 6384PowerGlider which you can disassemble. So the goal is, to have a double fault before any harm is done. Avoid the single fault by construction and design. Prove there is no single fault by checking before driving. Build an interface from battery box to motor which is proven by design and use. Isolate the motor windings and their solderings by additional measures like vacuum epoxy treatment.
I use a lot of industrial and available components to do so. I do not need to make everything myself from scratch. Like a prop, fin, mast or board or casing. And i do not have to invent everything myself.
But sometimes i need to dig into details:
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Thanks for great info! I meant to start with no hydrofoil but surf drive as you do, this is the reason I asked your motor mount design you designed in fusion to adapt it the sup fi
n to be installed on surf board.
Thanks again for your great experience sharing!
Today Aliens have delivered my 6384 PowerGlider Configuration,
and because there are no pictures available i took some for you.
The stator iron has a length of 56mm instead of 50mm, the complete motor weighs 1050g.
Tomorrow i plan some electric measurements.
In the next days i start a photo series how to apply epoxy to stator and rotor.
If you have questions about details to be photographed, please ask here.
6 Likes
Awesome. Looking forward to hearing how it works. I have been trying the 5065 running in oil and just cant get enough power out of it. Been debating whether to make the jump to a 63mm or all the way up to an 80 (which obviously has a huge form factor). How long did it take to arrive from the time you ordered it?
right now it might be available in small numbers.