that looks really awesome david!! nice work! how do you get them attached to the rotor?
Hummie, keep up the good work! It will be interesting to see what type of tooling is required for processing the EPDM rubber. It is indeed high temp stuff and is an interesting option. You know the fascinating thing about your project journey is when you are using materials and techniques for one application (human powered skateboards) and then adapt them for a new one, itās at that point you find the limitations of what has always just been. The heat generated from the motors is one of those variables that shows how assumptions in product development are dangerous. In reality, you are very far along the process and imagine if you had paid thousands in tooling to some skate-wheel company to find the heat generated from hub-motors is too much for standard methods. Iāll be out riding my board some more in the next coming days to check heat, climb performance, and wheel wear. Iām running 10S and am using the faster cure urethane, FYI.
Itās still the same mechanism as used by Hummie, no changes there and it seems to be a tight fit. Getting it to be as round as it should be was the main challenge. Iām not worried about the temperature, itās not that hot on the can side. Weāll see how it performs the next days.
but hummies stator has all these āchannelsā, so how is a round milled cylinder within the wheel going to work for the torque transfer? or did you mill all the required ābumpsā as well?
I think that is where the milling comes in: first get the inner diameter right with a lathe and then use the milling machine for all the āchannelsā
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Pylonflyer works at bjb enterprises and is a rubber guru. Hot pour polyurethane and a hard polyurethane core could possibly work he said as it will have a bit higher temp ability but Iām not going to try that first, first is going to be epdm butIām really syched for car tire rubber wheels Iām going to try! That stuff can take anything. Getting some of each of these made and the mold will be intended for hot pressing so I could try other stuff as well.
I was looking at onboard or maybe it was staryās site. They have the same temp issues. No surprise. They use n45sh magnets good for 300f and claim to have an air cooling system that is 40% better than not.
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@Maxid, thatās exacty what Iām doing, but there are other ways too, like a punch form containing those channels to be used with a folding machine with some tons of pressure.
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that would be nice. It sounds like it COULD be really easy. a metal sleeve to hold the wheel and then how to do the cutting blade? Cad mill. Or wait and the polyurethane rubber is curing as I write. REally excited for the very likely future car tire rubber.
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How much do your stators weigh wound? Just the lams and copper?
i dont know as the stators come permanently attached to the stator tube. Thereās definitely room for more copper and a bit more stator though next time. I know the turns and gauge of the wire but thatās it.
I finally got to go for a longer ride over the weekend to get some Data. Overall I am super impressed with what I see and the Hummie motors were a pleasure to ride. On the flats there is plenty of speed (for me) and hill climbing was good. I found that if I carry a little speed into a hill climb they would just keep chugging along at a good clip. This Data is on 10S so I canāt compare to others riding on 12S. Iāll let the video explain the restā¦
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Nice!
I think keeping up to at least half speed, where u have more power, keeps u cooler.
Butā¦but I dont do secrets and am getting different motors made. Tell me what u think about this idea as Iām full in and still excited:
Getting very similar motors made, all steel, two fat bearings now instead of one big and one small, same diameter at 80mmmatching kegel 80mm diameter, but twice as long!!! I can get 3 times as long a stator in there so 150% as powerful with one motor as the two now with a double long. Why bother making motors if theyāre all underpowered and u need two at least! This will make things cheeeepā¦one motor and one esc.
I think itās going to look reaaly good somehow with one extra long wheel out the side and the three regulars but those of us who have strong symmetrical needs will ā¦need to get two or if ur really in that boat four. I wonāt bother as at 155lbs with the single Iām sure Iāll be good.
Handling ā¦surely the one powered wheel wonāt effect handling but being slightly longer on one sideā¦Iām looking forward to feeling it and really doubt it will be a drawback.
If these longer motors are your bag tell me and ā¦being constantly poor need to round up one or two more people interested in spending with me on the prototypes to get made.
I think one longer hub motor sticking off the sideā¦this will be the cheapest build possible and can still do a drop/drop unobstructed and rideā¦almost inconspicuous. Canāt wait to see the confusion in bystanders eyes
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I am interested in this new steel hub motor. If it has a water sealed cover, I am going to save up fast 
Ifmotor is made waterproof with epoxy on the steel stator and if also the connections between the windings and the motor leads are fully sealed the motor can run in the water no problem. Can run under water. Bearings donāt like it though.
Getting better rubber made folks. If ur riding around pushing ur motors hard the heat isnāt good for polyurethane and they will lose their tight fit long before they wear down. Iām getting the mold done for Epdm rubber and others to try so hold on and stay cool
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I know that brushless motor are waterproof by nature as there are no electronics in the inside except if you implement the hall sensor. However dust and particles can get in and ruin everything after a long run. These all adds up together and occasionally need to be cleaned up. Itās not a big problem if the motor is detachable for regular maintenance, but if itās locked up with a loctite, then its hard to do maintenance.
Btw is the hub motor you provide can be delivered with a kegel hub wheels? Iād be even more interested if it is.
The cost of sending stuff to u from here is a lot. Maybe itās cheaper for me to send u the kegels as well but I doubt it. Iāve been riding for a couple hundred miles on a new set of motors, steel, and just opened them up 3 days ago. Not a scratch to the magnets. The motors have filtering screens on on side and adding them in the other side is possible too. The bearings will eventually need replacing but thatās doable. (The smaller one easily the larger more work involved) With the steel motors being steel I donāt feel they NEED to have the bearings fixed with retaining fluid and i could send them without so the motor wouldnāt need to be pressed apart for maintainence. Up to u. they will rattle a bit similar but less than a regular skate wheel without my fixing-down the bearings. Itās really minor but I like the silence. U could get ur own retaining fluid
Just a thought, would it be cheaper to ship a bulk order to someone in Europe and Aus then distribute locally? Kinda like a group buy sort of haha
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