Optimize 63100 outrunner motor for wet cooling and direct drive

Lets start a new thread, to optimize a new to be specified motor based on the existing

Compared to the 6384PG we gain some wealthy stator length, it grows from 56 to 66mm, so the torque and power of the electro and magnetic system grow by 17.8%. The weight grows from 955 to 1090g, 14.1%. The specified power grows from 4000W to 4500W, which is a little underestimated, but perfect for our use.

I want to start discussion about a new specification for the 63100, to set up a kind of open source standard owned by the public to which some people can contribute and others could offer products aligning to this standard more or less. Following points i have in mind:

  1. Kv, shall it be 100 instead of 140 as now? Reduce the windings thickness to enable better cooling of inner windings.

  2. Rod shall be made of stainless steel and reduced length, so it does not stick out at any end.

  3. Bearings? Bearings!

  4. Circlip shall be stainless.

  5. Some openings in the bell, maybe few than for the air cooled motors.

  6. Drill patterns.

  7. Leads and electrical interface.

  8. Streamlining the inside of the rotor, glueing of magnets, protection against corrosion and abrasion.

  9. Protection of the stator and windings against corrosion and abrasion.

The product shall not be kept in water endless time, but only for time of usage.
It is clear that the bearings need to be swapped from time to time, especially when used in salt water. This implies, the motor is disassembled, the circlip is unmounted to take off the rotor and reach the bearings. The electrical interface shall support this, so (waterproof) plugs are needed.


Looking forward to seeing a guide or such a marinized motor available on the shelf.
I am no expert and satisfied with this spec but, if it does not evolve, say, by the 14th July (post publication date = 2nd June + 6 weeks), does it mean you are going to call for a small batch production (with or without survey aiming at evaluating the number of potential buyers) ?

It is not an economical problem at all, if we know what we exactly want. APS and its manufacturers are waiting for a reply from me to start discussion about production.
I just wanted your input about technical aspects, so we do not forget something important. Is there anything that sucks with the 63 series? How about bearings and life time, i heard of some bad simulation results.
How is your experience with the electric interface? How long shall the leads be ending in a plug? I found it extremely difficult to solder the enameled winding wires. How do you, from your “good” experience want the electrical interface to be?

The bearings and all other parts need to be replaced to SS. Will the motor and the magnets already coated with Epoxy? The shaft can be shortened. Threads need to be inserted the the front cap.

Also the setscrew to fix the shaft is jammed that tight that it is almost impossible to scew it out without damaging the hexagon socket.

Hello everyone, I have been testing the 63100 this year, and also 6384,6374…
I did a slick epoxy work on the can and the winding.
Total replacement of bearings with stainless steel.

This motor could reach me to 33kmh top speed gps, cruising at 20kmh the consumption is good about 25a, I’m 67kg,

the only drawback I see is the consumption at startup, I am using a vesc, and sometimes I was triggering a fault at startup or klinking motor… I put absolute max at 150a and solve the problem but still had clinking issues (I am not vesc expert)
Second problem are vibrations, the can is aluminium and really long, only maintained by the back.
I had issue of the can vibrating on the 2x 63 motors I tested ( the first one accidentally felt, and the second one was carefully processed )
After testing 80100 and 8085 motor I prefer them, they are more robust and they can handle the high torque at startup better than any 63 motors.
I tested 80100 80kv and 100kv both work great, I have a preference for 100kv as you can use props with reasonable pith diameter ratio (5”5 6” )

the perfect out runner for this would be a 7080 :slight_smile:

Right now with my company I am developing an direct inrunner drive with a motor engineer, we are testing the first batch’s in 1 month, this will be a 71130 inrunner size, with an efficiency of 93% in the 1.5-2kw region (power needed for approx 25kmh fouling speed ) with such motor it will be possible to foil more than 1 hour with 30 ah battery.

like Peter, lamination is really expensive, but we hope provide this motor around 500€ vat ex.


Thanks for these informations being very helpful!
So another requirement is, to balance the rotor after all the finish for the rotor is done.
I believe the rotor is not too long to generate vibration by its own elasticity, but of course it is generating lots of vibrations if the motor shaft is swapped by a stainless steel shaft and it is harder to maintain the tolerances. If we get a motor with SS long shaft sticking out on both sides of the motor it can be easily cut without disassembling anything.
The Vesc 4, Vesc 6 have the problem of too high shunt resistance already for the 6384 to develop full power, so they always kick into the ABS_HW_Current issue at around 150-160A because this is the rail of the possible measurement. Also with FOC you get much higher current peaks. If it is not the abs_hw_current, it will be temperature which limits the usability.
The Vesc issue is best discussed here: Any interest in a custom e-foil ESC? - #147 by PowerGlider - Electronics (ESC, remote, batteries) - FOIL.zone

The 80 series has only little benefit in torque, the effective magnetic volume and thereby torque of the 63100 has outstanding ratio for both front area and weight and volume, so it is very promising. Your data with 25A (12s?) at 20km/h is very good for such a cheap and simple motor. As i already reach 32-35kg bollard thrust with 6384PG 100Kv i see no need for a larger diameter at the moment. The actual 63100 has 130Kv (but we want 100Kv for the optimized one), so you cannot compare to the 80100 100Kv if you use the same Vesc with same current capability.

I expect the price at 150-200$ for 63100 optimized.


Hi pg
I was unclear about vibration, the vibration does not comes from balance problem but from a misaligned can, I will make a video.
I bought a lot of 63 motors (around 10 models) the 63100 is the only with this issue.

Regarding the power of the 63100, if I increase the pitch of my props, the motor pushes a lot more amperes at startup, not seeing better top speed, but I will make more tests.

Regarding kv i had better results with 120kv than 80kv or 100kv.
I could reach 27kmh with a quickly prepared cheap 6384 (50usd motor) with 120kv, stock bearing :rofl:

I also tried 60kv but the wires were really thin and the total power admissible really lower

I expect the end user not to remove the set screw. The rotor and stator will be coated and streamlined already. The shaft shall be SS with long ends, 30-50mm on both sides, so the end user can cut it off, so it is more versatile. Removing the setscrew is a risky task, same goes for pressing the shaft out and in again. I do not want the end user to have this risk at all.
The only maintainance is to renew the bearings, for this the electric interface needs to be opened and the circlip removed to pull the rotor from the stator.
New bearings can be easily pressed in with some long M10 threaded rod, nuts and washers. Or simply with a large vice and old bearings to support as press in tool.
All the mentioned process go for other sizes as well.
I do not think the perfect outrunner is larger in diameter, if there is a chance to build a 50150 with double bearings and rotating shield, i would be fine, but it really drives cost, complexity and in the end you have less power per cost, complexity, weight, drag, etc. So this altogether is a rather simple thing, why lose so many words at all? :wink:

Each time the “SS” or “stainless” term is used (circlips, rod, …) it should be precised “316 SS” or “A4 SS”, Otherwise, you will certainly get the cheaper 304 (or A2) SS grade that rusts in salt water.


Good point, please continue. We should point out we want it to be proof against seawater at least for some time. But i am sceptic about permanent usage in seawater. The circlip side can easily be protected by a glued rubber cap. So the water does not flow through the bearing and shaft.

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How about cable lengths of around 1.3m? This way all connections could be in the waterproof enclosure.

Good point. Length could be 1.5m to be safe.

…and the bill of 316L materials (bearing, shaft, C Clip, washer) to achieve that result (120CNY = 15EUR = 17USD), key post from @alan_wong
Alan, would you have a 63100 outrunner to recommend or a comment about the process described in post 1 of this thread ?

still searching other motor which is good value for money


The Neodymium magnet corrosion being the main issue in case of wet cooling, this is what wiki says to address this problem.

Sintered Nd2Fe14B tends to be vulnerable to corrosion, especially along grain boundaries of a sintered magnet. This type of corrosion can cause serious deterioration, including crumbling of a magnet into a powder of small magnetic particles, or spalling of a surface layer.

This vulnerability is addressed in many commercial products by adding a protective coating to prevent exposure to the atmosphere. Nickel plating or two-layered copper-nickel plating are the standard methods, although plating with other metals, or polymer and lacquer protective coatings are also in use.

What does the above Corrosion of Nd-Fe-B permanent magnets paper say ?
Design/methodology/approach: Corrosion tests were made in two corrosive environments in water [=fresh water Redact note] and in 5% NaCl solution [= salt water Redact note]
Findings: It was found that the bonded magnets with the polymer matrix demonstrate better corrosion resistance than the sintered magnets.

[…] Employment of the protective coatings on the Nd-Fe-B bonded magnets surfaces may
feature the effective protection of the substrate material from the corrosive action of the aggressive agent.

I built several motors using Copper Nickel coated magnets, some of them lasting for ten years already. A plastic coating could be added to glue and hold the magnets in position additionally. I also had to remove the coating sometimes to match the circumference in outrunners due to bad tolerances but after epoxying them it never turned out to be a problem. Anyhow, the rotors inside needs to be filled with some plastic to make it streamlined. If you leave this away the rotor causes a lot of friction.

Hey @kotnascher, congratulations for your very nice project (not so dirty :wink:).
where you have demonstrated that a marinized APS 63100 with the proper prop ( @foiledagain 156mm reduced by 0.78 = 121mm here) was a nice match with very nice consumption data.
Could you summarise your own experience (with picts hopefully) with an emphasis on what is missing in this thread ? Do you have a list of materials ?

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Maybe this one is same like APS 63100?

This one has already holes for mounting the Prop


Hey @SoEFoil, i somehow just read your comment today. Like in my build i just did those 4 things

  • Cut the overhanging shaft
  • Coating the inside with epoxy
  • Drilling three M4-threads in the back as a prop mount
  • Replace the standart bearings, circlips and washers with stainless steel ones

I’m sorry but there is nothing I could add to this topic right now. I’m foiling for months now multible times a week with up to 120A and i am satisfied with this decision.:blush:

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