80100 direct cooling


Before buying the propeller, i tried designing one, but i postponed it :

  • This is a very big motor (80 mm diameter)
  • The drag will significantly increase with every mm i add to the diameter.
  • To get the blades strong enough, i’d need to increase significantly the diameter.
  • and that solas prop seemed quite adapted to the power and RPM … and i might have gotten a bit lazy :slight_smile:
  • as i wasn’t sure of the rest of the system, i stuck to a known working solution.

But for sure once everything is stable and i get some time, the prop will be revisited.
Even just a smoother reduction of diameter between the motor and the prop hub would help, but first i need logging capability …

Regarding corrosion, CorrosionX HD is magic, i barely rinse the motor with clean water after getting out of the salty bay where i test, and no corrosion issues so far :slight_smile:


From what I understand, the propeller will dictate a lot about the system, such as the efficiency, current draw, and total power output. You might want to make it a larger priority.


that’s why i need to be able to log current and voltage first :slight_smile:


@Mat, did you submerge the windings in Corosion X HD or spray?



i’m using the spray…
But first the windings are covered with a few coats of Epoxy, i trust it more to protect them in case something hard enter the motor, and it’s not too thick, so i don’t think it affects cooling too much.
CorrosionX is more to protect the bearings and the exposed metal part…


Did you paint on the epoxy or did you dip the core? Thanks for answering these questions, this is the next step in my build once I get the remote wrapped up.


Can you tell me what the dimensions of the bearings are (ID, OD)? I would like to look for ceramic bearings while I wait for my motor. Thanks!


we discussed the bearing sizes in another thread… but be careful, there might be different versions of that motor out there…

And again, Ceramic might not be the best choice as those bearing have to handle the axial load too…
please let us know if you try!


I brushed it on, masking the bearings surfaces and i applied a few layers.
Be careful how the resin interfaces with the waterproofing of the leads… epoxy is usually not very flexible…


You are probably right, but the price alone is a reason to avoid them.

Next question that comes to my mind is bearing clearance. Judged by the price of your bearings you probably have CN, I wonder if the 30-40% higher price of C3 bearings is worth it, since the load is pretty high and a quick temperature increase after starting is likely. I would guess that the standard bearings of the motor are also C3 (can someone confirm that?) and it normally isn’t a good idea to go lower than stock.


I agree about ceramic not being an option, $65 per bearing is to much for me!

Do you think its better to have sealed or unsealed Stainless steel bearings?

Ive got sealed stainless steel 316 bearings for my Direct Drive setup, haven’t installed them yet.

From what I gather, with the seals on, eventually the grease would all leave and the balls would be permanently submerged in water, this could increase the chance of corrosion. Maybe taking off the seals and having the balls exposed could help them see air and keep the oxide layer on the outside of the steel built up?

What do you think?


I have no idea… ebay sellers don’t have the best documentation… i’ll check if they have any marking on them tonight (see below)
I remember the original ones being a Japanese brand, i’ll try to get a clean picture of the marking.
For the temperature increase, it can’t be that bad as they run submerged in water.

below are the original bearing: not much markings : Japan, NSK, and the size with a Z at the end.


For now i’m running the completely open ones for that exact reason: sealed one would eventually fail and it will become a perfect trap for the salty water. At least with open ones, i can easily flood them with Corrosion X.


I just ordered a APS C80100 80kv and may somewhat base my build of the propulsion unit on your files, will see.
Could you give me some insight on how you epoxyed your stator? For the rotor I plan to print a cylinder using water-soluble PVA that relatively tightly fits the rotor ID and just fill the gaps with epoxy. For the stator I currently plan to avoid using vacuuming and think of either as well printing a temporary casing and filling it up or applying epoxy manually on the windings. When using a cylinder casing I guess cooling would be bad and I don’t know if I can print the casing to go inside the gaps between the individual poles to leave the gaps free. Any insight would be appreciated, thanks!


For the stator, I applied the epoxy with a brush, i’m using regular surfboard epoxy (resin research CE).
I did it in several coats to get it thick enough (a couple mm i think).
The epoxy is very liquid, so bubbles don’t really stay trapped in and as long as you don’t introduce too much air when mixing, it should be ok…
To make sure the wires are waterproof, i cut them first, tinned the ends, then applied the epoxy on the stator and and got it slightly up the wires too, where they were not supposed to bend. Then i applied liquid tape from where the epoxy ends up to the tinned part, and finally i covered the whole with adhesive lined shrink tubing.

For the rotor, your solution should work, i used a piece of Plexiglas tube (leftover from my previous build), the OD was slightly over the ID of the magnets so i did 1 cut lengthwise to the tube and forced it in. I sealed the bottom with clay and fill with epoxy between each magnets.
I waxed the tubes before to make sure i could get it out.
The magnets didn’t end up completely covered, but the gaps were filled. So i sanded the inside smooth and apply a few coats of clear coat just to avoid the rust.


Thank you very much! Very helpful.

As for the Fusion files (that I would like to use and/or modify), I only seem to find a model of the motor itself (80100 direct cooling) and the plate you added between motor and prop (80100 direct cooling). Can I find the motor and mast mount somewhere? If not, would you be so kind to share it? :slight_smile:


Really neat setup here !
Have you managed to get the datas working since last test ?
Also, regarding your ESC and batteries box, I’ve done pretty much the same thing with a transparent plexiglas sheet on top, screw onto the board. But I’m having some issues with the waterproofing. I’ve bought several different seals but so far, after 2-3 times putting it on and off, it starts leaking again.
What kind of seals are you currently uusing ?


that’s strange, there should be the mount instead of the motor… i might have played with the file on my computer… but that was the old mast anyway (orange liquid force foil fish)

this is the new one for the black liquid force mast (i think there’s only one model now)


no data yet… 350A TK15 got some water drops on it and burnt a bit at the first run… i though i re-soldered the pins properly, but when i connected the battery, it made a big flame and got my smoke detectors screaming… :slight_smile:
so i’m now waiting for a elogger V4… i’m wondering what color will be that flame :thinking:

For the waterproofing, i used 2 rows side by side of “JVCC SCF-02 Single Coated PVC Foam Tape [medium density] / Size: 1/8 in. thick foam x 1/2 in. x 75 ft.”
And i glued the corners with some silicon.


Thanks !
The water drops on the TK15 data looger happend with the 2 rows of PVC tape you mentioned ?

I’m going for a 100A Vesc and a metr app for recording (awesome app !).I’ll let you know if it actually handles the 100A continuous. Some say it does but I want to find out by myself =)

So for you are still using your solad prop ?