An experiment would be cool, I’d love to see a side by side real world comparison. I think it’s hard to predict whether the benefits would be worth the extra cost since it’s quite a lot of wire. IMO it’s worth a try at least as a one off since heat build up is one of the last major disadvantages facing hubs, but I think I might feel differently if I was the one buying all the wire haha
The density of silver is higher than copper too, so the windings would be heavier, but I doubt that would have much impact really. There’s a lot of variables
i’ll write and see how much it is for like 30 feet (two motors worth) of 17 awg silver wire. especially with a hub motor its almost all copper losses (silver losses!) and at full speed of just over 30mph the iron losses are only about two amps or 20 watts.
with I squared R…lets say a single motor gets 25 amps at full tilt and resistant of .057 miliohms with copper wire…im awful at math but get 37 watts while with silver at maybe resistance of .052 that’s about 32 watts lost and turned to heat. maybe that’s not right. and beyond that the heat would be staying lower with the silver and further reducing the resistance in the wire because of that, and it’s got that better thermal conductance helping with that. i’d like to compare it. it would be very fair comparision as I can fix every other variable.
and I want a set too.
relevant is the comparison of the 9 and 10mm magnets I did on the bldc tool. f at full speed of 82000 erpm with the 10mm magnets at about 15.3 volts theres 20 watts needed, and that would be core losses, largely the huge grease filled and sealed bearings that are new but the rest being switching losses from magnetic stray losses and not an ideal coupling of magnetism,… but the 9mm magnets hit maybe 25 watts when going full speed, so more core losses there, another couple watts, yet same stator and bearings, so they seem not as good in the core losses department, but that is at a full speed of 8000 erpm so they have VERY IRRONICALLY a lower kv. very strange with the smaller magnets doing that and must be the shape of the bell or something, will be testing other ones today, so lower kv is higher kt and they get more torque per amp, so if I were to bring the kv back up to what the 10mm magnets produce, I could omit one turn of wire, so the wire could be thicker, and have less electrical resistance for the same kv slash kt and have lower copper losses which are a greater loss in this slow turning and low core loss motor (I think the percent of the iron losses that are true eddy current or switching losses, magnetic, is really small and it’s misleading the results I get with these bearings…the number dropped after 5 min of full throttle down 5 watts in both tests as the bearings loosen up.) its really a toss up and theyre both pretty close but rather do the 9mm
everyone asks that but its hard to answer because the question is vague. for peak wattage it would be what torque can be produced just before stator magnetic saturation and also at top speed multiplied. I don’t know but considering what the little motors were capable of these will no longer crush Boosted but you wont even see Boosted boards anymore. The continuous power rating is also hard to say definitively since what is “continuous”? 20 minutes or an hour. I will do continuous output testing and see what power output is sustainable for 30 minutes and be under 150f at the end of that. seems a reasonable and very very conservative continuous rating since I know of at least one person who would cook the old motors to 260f daily putting out huge power and also because the magnets are n48sh and good to 300f before they lose magnetic strength permanently. a long answer but unavoidable. and going over 140f is considered poor form as the resistance will increase and more inefficient.
since no one has come up with a standardized test for “continuous power output” i’ll do that.
peak power would maybe better be decided based on math and the amount of steel in the stator maybe as it would be the limit…once you put in more amps than will bring the steel over around 1.7 tesla magnetic field strength the ratio of amps to torque is no longer linear and it turns really inefficient. be hard to do a realworld test as the electrical power the vesc shows wouldn’t be making it to the road once it gets to that point.
I’m skipping work these days up at 11 to stay up till 1am and on the job. motors are decided and proven and we’re gunna kick out a bunch today. the wheels are in the works and undecided but materials to work with galore aind in the oven now trying different stuff. fit is good just getting the details on how to pour bubble-free. ramble ramble.
I talked to a place that has the 17 awg in silver with the only choice being a 240c resistant enamel. very high temp but really the cost isn’t there and its the silver, and its the only enamel choice with what’s already available or else you have to get like 1000 ft. I can get small quantities for a few motors but adding up at 18$ a foot and its 42ft of wire needed for all three phases of a single motor…that’s about 750$ for just the wire for one motor! damn. would be nice but I’m not doing it for myself at that cost. if it were half that maybe, a third that for sure.
Seriously guys for 750€ you could improve every other component and still have spare. Make the parts from titanium or slap in some SKF bearings. Heck why not fill the board with helium to save some weight.
Hey I just had a thought about something that would look great with your hubs! On your hub motors, you have in the outer side a purple plate to cover the motor, and it looks great, but then if it’s just a 2WD, the front wheels don’t match. So perhaps it would be possible to offer a set of cover plates that can be mounted on the front wheels so all the wheels match?! I think that would look fantastic, and would definitely order a set if they were offered.
Like this board, just make a set that will fit in the front wheels and they will all match!
I was wondering about that too, I think it can I’ve read some threads on efoil builds where people waterproof their motors and they basically do that in one of the steps.
I was looking at current price for silver and the weight of wire in each motor and it should be like $65 per motor and raw silver value @ 130 grams… I have been looking and found some much cheaper wire, going to call around once the weekend is over.
Just wanted to update everyone. We are ramping up production. The first motors were spun a few days ago, hummies been winding like crazy, and a small batch of bells was done a few days ago also. We are waiting for some more magnets to finish the bells off, but I can glue a bell in about 30 minutes. The limiting factor is the winding, as it’s hard on the hands and takes about an hour each to wind. But hummie is working hard knocking them out. Should have the first batch of 4 running by tomorrow, and probably a few more also.
If all goes well, we should be shipping by mid April. Still putting together wheels so we want to do about a month of wheel testing before we ship, even though we’ll have motors ready for shipping with in the next 2 weeks.
Thank you everyone for your patience. We really wanted to make sure we get everything as good as possible now, so we can ship a highly refined product instead of a beta product. We’ve tested different winds and different magnets to find the best combo and we have all of the details optimized now and the assembly process as been refined, so it’s just assembly now. Will post more photos soon!
8 motors wound and pressed successfully. Just need to be dipped, baked, add phased wires, and assembled. The most difficult and time consuming part of motor building is done for these ones. Going at an about 4 a day pace right now.
I’ve seen silver wire for a lot cheaper too, AliExpress could bring the raw wire down to about those levels and even if the purity is off 1% it would matter little, the gains appear real, would be a great option.
What type of stainless is used for the bells? Wondering if there is material advantages there in terms of weight and heat transfer?
It would be cool to see what an elite hub motor design could bring against the D/D and belt systems, maybe a mistake on my part of understanding a brushless motor but the core and bell do not necessarily need to be made of metals with a magnetic property, titanium? Chrome-moly etc
That would be great, I’d really like to see this tested. Could really make a substantial difference in some motors where heat keeps being an issue. Could potentially lead to a whole new innovation in how motors are made…
