Hello Jezza,
Thanks for your feedback and questions.
Our waterproof technique is new, different from the traditional technique of fill up with very thick waterpoof glue, our thinner waterproof and anti-rust painting over the stator and rotor can better dissipate heat, you can compare it with our non-waterproof 6374 motor, inside look of stator and rotor are different, if we didnt do waterproof we dare not say that is waterproof.
Fill up with thick waterproof glue over the stator and rotor would easily cause heat and affect motor power, so we didnāt do like that.
We already have customer tried this technique waterproof motor and performance well and our customer wants to order more, please see below picture.
You can test it and see the performance.
Also since you have opened it, please be careful, do not scrat the stator and rotor, thanks.
Before producing the 6374 motor, we did some research, and found that some motor fill up with black waterproof glue, which is softer, when motor heats the glue would swell and narrow distance between stator and rotor, stator would easily touch rotor, which will shorten motor lifespan.
Our stator and wirings are all covered with transparent insulating paint, and magnets did anti-oxidation and anti-rust treatment.
A small update on the progress I have had with this motorā¦
On 8S even with a 200A ESC it will not get me up onto a 2000cm2 foil. The motor simply can not generate enough torque on 8S. RPM tops out at 2200 and battery current canāt pull higher than 115A. I have tried 2 different folding props. I top out at about 10KPH speed wise.
Things to try next will be 10S and see what happens. Lets hope it can redeem itself a bitā¦
Oooo some pics of a very average quality motorā¦
The epoxy holding the wires has melted. Really this should be a heat transferable potting epoxy. That would mean it wouldnāt crack!
Upped the battery to 10s. Maxed rpm at 2300 and absolutely can not push the motor past 3.5kw of power! After 75% throttle the motor starts desynching. Battery was at 35V (a bit of battery sag) and 100a.
Its looking like Iāll need to bring the prop blades down to 3" pitch to get the motor to a happier placeā¦
If you can pull 110 amps, you should have an adequate esc and motor. You need a different prop. Too much torque is being generated by the prop. It found out by accident, by printing and trying a smaller prop ājust for interestā that the prop I was using was too large.
GZ
I can pull a max of 3.5Kw. In theory that should provide enough to assist into a wave or with a SUP. But even with a 2000cm3 wing its not enough to get on the foil like an efoil. I need to measure the diameter and pitch of the prop I have though to see what its really sitting at.
Thanks for the update.
About the epoxy holding the wires part, we will try find another type epoxy in the future.
About the rust, it should not the ceramic bearing, it might be the shaft, we will improve to 316 stainless steel in the future.
Btw, please better not dissemble the motor frequently, that could influence the motor waterproof performance.
Thank you for your feedback and advice, we will keep improving the products.
And if you have any other advices, feel free to let us know, we will do our best to make the products better.
Further Update (I should probably start a new thread)ā¦
I hooked up the APD F3 120A ESC to the motor and gave it a shot. The only plus side is it didnāt lose synch, but it could not push more than 3.5KW through the motor. Once it was at 70% throttle (hits 3.5KW slightly earlier than ARC200) it did not speed up any more and just stayed at the same RPM at 100% throttle.
I think that the problem is not the esc but motor efficiency. You know motor torque is proportional to phase current up to saturation and if youāre reaching 3.5kW then the phase current should be high enough for efoil torque, (depends on the rpm though).
Either motor control is inefficient or motor is saturating so that the current mostly creates heat. Since you tried several esc:s now iād bet on the motor. What rpm does it reach?
Yeah the motor is definitely saturated. It just canāt take on any more current! Max rpm was 2300 which is too lowā¦ Iāve ordered a different battle hardened 6384 170kv motor from another manufacturer to see how it comparesā¦ My guess though is that it will give me the power it needs to get up on efoil.
The maytech motor would in theory assist into a wave, but I want the power to burst me onto foil first without a waveā¦
Thats the interesting partā¦ I havenāt actually measured the Maytech RPM as my RPM meter broke. But maybe that is the issue. Maybe its not really 150 and closer to 130. Time to order a new RPM meterā¦
