crossbreak
1 MW
this looks a lot like the planetry gear reduction of a geared hub motor, fixvid. I build quite a few bikes with such a gear reduction with success, there is a very long thread linked in my signature.
My RC Mid Drive with Single Stage Reduction
- Thread starter FZBob
- Start date
Have you considered a plastic chain?
https://www.rollerchain4less.com/35p-acetal-plastic-roller-chain-10ft
Silent, self-lubricating, and seems rated for what you desire. Lighter as well, obviously.
Can be combined with a 3d printed plastic sprocket I presume.
If I knew about existence of such chains before I've ordered a planetary gear reducer, I think I'll be using one instead.
https://www.rollerchain4less.com/35p-acetal-plastic-roller-chain-10ft
Silent, self-lubricating, and seems rated for what you desire. Lighter as well, obviously.
Can be combined with a 3d printed plastic sprocket I presume.
If I knew about existence of such chains before I've ordered a planetary gear reducer, I think I'll be using one instead.
aCeMadMod
1 kW
Hi they shit chians plastic.only hold 3 times has less steel chian
I broken steel chian h25# before
It use less use for this app.
You can get 2 chians in one.
Not wight saveing.
Good luck all
I broken steel chian h25# before
It use less use for this app.
You can get 2 chians in one.
Not wight saveing.
Good luck all
We just need to compare peak chain tension with rated tension, leave a healthy margin and see results.
Since this is a low-power ASSIST, not 3+wk beasts, and with a single stage reduction, it should theoretically suffice, there are precedents with using PURELY plastic chains in first stage reduction, and this one (steel sideplastes/pins) is rated for FAR more than that.
Btw, all 'crank drives' are technically two-stage reduction
Since this is a low-power ASSIST, not 3+wk beasts, and with a single stage reduction, it should theoretically suffice, there are precedents with using PURELY plastic chains in first stage reduction, and this one (steel sideplastes/pins) is rated for FAR more than that.
Btw, all 'crank drives' are technically two-stage reduction
New toy time:
This puppy with chinese pedigree is very close in size to the orange D5035 but it's much heavier(~+250g) and at half the price! I wonder if it's more copper in there.. I didn't test it yet cuz i had a hell of a time enlarging the 8mm ID of 11t sprocket to 10mm as this motor's shaft.
This puppy with chinese pedigree is very close in size to the orange D5035 but it's much heavier(~+250g) and at half the price! I wonder if it's more copper in there.. I didn't test it yet cuz i had a hell of a time enlarging the 8mm ID of 11t sprocket to 10mm as this motor's shaft.
thepronghorn
1 kW
fixvid said:
5035 is probably the stator dimensions of the orange motor - 50mm diameter, 35mm length. Going by that, this motor looks like it has 15mm more stator which should give it 15/35=43% more torque capability for the same heat dissipation. While you have it open, would you measure the lamination thickness?
These motors are also often referred to by their outer dimension aka 6384=63mm diameter, 84mm length. The orange motor is a 6355. The 6384 should have much more torque than a 6355.
fixvid said:
Nice find! Compared to the Turnigy 6374 130Kv I've been using for a while, it looks like it's only 5% (48gm) heavier and it has about 22% more stator volume. 120KV is a bonus. Did you get it off EBAY?
By the way, https://electricscooterparts.com/sprockets25chain-motor.html has a selection of #25 sprockets with 10mm bores.
Looking forward to hearing your results!
Whoah i think we are going too far with the numbers here.. this motor is just a little bit longer than D5035. I expect it to be a little more torquier but i don't think it's stronger than Turnigy 6374. It would be too good to be true at half the price of Turnigy motors.
Still, i do think that a motor like this could be a good choice for cheap and light crank drive because it compensates for the lack of reduction.
I dont think i could measure realiably the lamination thickness, any tip ?
..and because you we're asking nicely:
https://www.aliexpress.com/item/33011400738.html?spm=a2g0s.9042311.0.0.27424c4ddB5VRX
Still, i do think that a motor like this could be a good choice for cheap and light crank drive because it compensates for the lack of reduction.
I dont think i could measure realiably the lamination thickness, any tip ?
..and because you we're asking nicely:
https://www.aliexpress.com/item/33011400738.html?spm=a2g0s.9042311.0.0.27424c4ddB5VRX
I borrowed some pics of the Turnigy 6374 from the eSk8 website just for comparison.fixvid said:
I think stator volume is probably a reasonable metric to compare motors (assuming other parameters are similar). Here are some rough stator dimensions from my motor spreadsheet. I didn't measure them myself, but I think they are in the ballpark. The Power (watts) numbers are the max burst (a few seconds) I have seen from my Turnigy wattmeter from all my rides. Note that I only use high power for short bursts (a few seconds), as I don't want to cook anything.
Turnigy 6354_________Dia: 50 Length: 25.6 Vol: 50 Pwr: 430
Turnigy D5035 Orange_Dia: 50 Length: 35.6 Vol: 70 Pwr: 557
Turnigy 6374_________Dia: 50 Length: 45.9 Vol: 90 Pwr: 655
Mystery 6384_________Dia: 53 Length: 50.5 Vol:111 Pwr: ???
The Turnigy motors all have internal fans, and some dust shielding. I think they may be more reliable/durable long term, and "may" cool better, at the expense of some weight and volume. The Mystery motor seems to pack a lot of stator into a small volume. I would bet that the Mystery motor could put out close to 750 watts (burst) if the VESC doesn't fry...
Might be interesting to pair up with a VESC 6 which I believe will handle more power...
All that being said, I like the color, and the price at your link is amazing, so I just ordered one. Merry Christmas to me!
FZBob said:
And you din't even wait for my review .. may Aliexpress fulfill your wish :lol:
This motor has really the biggest stator of all with the outside dimension being roughly equal to D5035. There is a catch .. the rotor is not suported on both ends of the axis as Turnigy ones.. and sometimes when i spin the motor with my hand i hear something inside, like something is trapped between the rotor and stator. In normal use it was all right.
https://imgbb.com/
So i enlarged my 8 mm slot to 10mm and mounted the new motor. Spinning it without chain at a specific rpm the whole frame resonated. I thought that's a balance problem and probably i will feel it while pedaling. Boy i was wrong.. for inexplicable reasons this motor is sooooo much smoother then the Turnigy one that i couldnt believe: belt like experience. Even the sound is much better and more quiet too.
The only difference is that i use 11t sprocket instead of 10t, but i remember using the same on D5035 and it wasnt even close. I tested it sensorless and with the same phase current of 30A. I would say that in this unfair configuration it's a little bit behind D5035 but very close in terms of torque (because of the bigger sprocket). So it seems that it's a little more efficient. I didn't test it with higher phase current but i suppose it has to better otherwise i see no reason for the bigger stator.
Until now i managed to get away without supporting the end of the shaft because it's a little more thicker at 10mm. I will test at 50A phase current and get back with some results.
BalorNG said:
I was playing with it on VESC application and with a 14v power supply it was showing a power of ~3w. I didn't hook up a power meter but 1.5A seems too much for no load current. Maybe you were using more input volts, i'm not sure.
I see metal chips sticking to the rotor, but Turnigy was also leaking some magnetic field. I'm just worried because of the venting holes on the bottom, something will get inside and will frock up the very tight tolerance between rotor and stator. I will print a plastic cup and at least seal that part. There is another ~0.5mm gap between rotor and stator at the top, but that one is much harder to seal because one is turning, the other not. From this point of view Turnigys are better sealed and i would say splash proof. Not this one.
Don't trust the VESC, it also 'told' me something like 6 watts, while my wattmeter showed ~35.
I've used 25v, btw, but as I understand, it will draw same amps at FULL speed no-load on any voltage, because no-load speed losses (hysteresis and eddy currents) are linear with speed, and more volts - more speed.
If you use throttle to vary speed, current draw vary accordingly... please test no-load current using a wattmeter, I'm interested whether I 'overpaid' 50$
I've used 25v, btw, but as I understand, it will draw same amps at FULL speed no-load on any voltage, because no-load speed losses (hysteresis and eddy currents) are linear with speed, and more volts - more speed.
If you use throttle to vary speed, current draw vary accordingly... please test no-load current using a wattmeter, I'm interested whether I 'overpaid' 50$
thepronghorn
1 kW
fixvid said:
The 5035 and 6384 have very similar kVs at 120 and 125, so one would expect very similar torque at the same current. The 6384 probably has much lower phase resistance though, so it should be much more more efficient at the same torque. Would you be able to measure and report the phase-phase resistances of each motor?
Thanks!
FZBob said:
No keyway -> D-shaped shaft. I have 3 grub screws holding on it. No problems until now.
BalorNG said:
I will put at least a clamp meter on the wires and check for current.
thepronghorn said:
Im not sure about this one, you mean the 3 coil resistance of the stator ?
It's possible to measure the coil resistance with Vesc Tool (FOC Detection).
I think the shown resistance value is for one coil in star/wye connection,
so phase to phase resistance it's twice this value.
Here are some example values for higher KV motors:
https://vesc-project.com/node/811#comment-form
I think the shown resistance value is for one coil in star/wye connection,
so phase to phase resistance it's twice this value.
Here are some example values for higher KV motors:
https://vesc-project.com/node/811#comment-form
BalorNG said:
Hi Balor
I managed to measure the no load current of this chinese 6384. At 14.5v supply i got 0.8A current consumption.
I still think this motor beats everything in this price range. It has enough torque, sounds good and is cheap. Wouldn't go back to turnigy in this setup.
FZBob
Did you get the motor? What are your impressions ?
BalorNG said:
Unfortunately i don't have access to a dynamometric stand, but i feel that it has a little more torque at same phase amps than turnigy d5035. I guess it can't be that bad then.
What's more to like about this motor is that it runs cooler than D5035. I remember that turnigy was warming up easily when i was running it hard, but not this one.
I tried a very very steep incline without any leg assist and at 50A phase current it was pulling me up that nasty mountain albeit at very slow speed. It wasn't really cogging only at too low rpms. At 40A phase current there wasn't any cogging at all. At ~15v supply the ESC was pulling around ~25A from the battery but it felt very inneficient because of the low rpms.
I wonder do the cogging disappear with high RPMs and high supply voltage ?
I received the Mystery 6384 motor a while ago. It took about 6 weeks to ship from China. I have 5 rides on it since the end of January.fixvid said:
Power:
I originally ran the D5035 (orange) motor. I switched to the Turnigy 6374 motor mid last year. The 6374 was a bit stronger (and heavier). The new Mystery 6384 seems a bit stronger still. I used the same current limits as the Turnigy 6374, since I worry about cooking the VESC. Also, the same gearing (11T sprocket). I really like the power!
Weight:
Not much heavier than the big Turnigy 6374...
Dust Protection:
Turnigy motors - Appear to be well thought out, designed for skateboards. I don't worry about dust.
Mystery 6384 (and all my other "open" motors) - None! There is ZERO dust protection. Rocks and large bugs can wander into the motor. I put electrical tape over the end holes, and made a sleeve out of plastic from a 2 liter pop bottle, which overlaps the gap between the rotor and stator.
Noise:
All my Turnigy motors (I have 4 now), have a pleasant, quiet whir. If silence is a 10, and a metal shop full of grinders is a zero, the turnigy motors are a 9 to my ears.
The Mystery 6384 has a fairly harsh and somewhat louder sound in comparison. I give it a 4. Tolerable to slightly annoying. All the other open motors I tried had a similar characteristic.
Thermal:
I'm not a power user, so my motors don't really get hot. I typically climb at 100-200 watts, with occasional 1-2 second bursts of 400-650 watts to boost me over obstacles.
No load current/drag:
On the workstand, it takes about 10 watts to drive the back wheel (in low gear), maybe a watt or 2 more than my other motors. It may take just a tiny bit more effort to pedal without assist, but I'm not sure. I'm riding in totally different terrain right now (more technical/loose rocks & gravel), and my chains are filthy...
Cost: Half!
Am I going to change back to the Turnigy 6374? Meh - not right now...
Overall I like this motor. I just wish it was a bit quieter & more pleasant sounding. However, for the price it's a bargain. I pay more for a tire!
FZBob said:
Why worry ? just set the MOSFET temperature start and limit values and power will be gradually reduced from start to end limit tempeature. I would say 60C to 70C is pretty safe.
FZBob said:
That's an interesting point because for me this motor had a more satisfying 'brushless' sound with a characteristic whirl and high pitched sound. Although at a specific RPM it resonates but it's not very problematic. When i turn by hand both motors the turnigy is indeed smoother but somehow in my application Mystery had a better sound and the transmission was smoother too. The shaft of the motor is 10mm thick which is a BIG plus because i have no longer have to support the end of the shaft - D5035 was bending like crazy at high loads causing all sorts of chain problems.
FZBob said:
Don't overpay for tyres. Buy Continental and Schwalbe tyres from www.bike24.com
Their top tyres are between 30E and 40E. I don't know if you have to pay import taxes, if any, because they are from Germany. For a speedy rear tyre i use Conti Race King 2.2 or if i want more grip and cushion than Schwalbe Rocket Ron 2.6. For front tyres with more grip i use Schwalbe Rocket Ron 2.2 - 2.8 or Conti CrossKing 2.4.
These tyres are lightweight and if you are agressive or ride in harsh environment chose the Protection(Conti) or SnakeSkin(Schwalbe) carcass or go with their more agressive pattern tyres which are more robust (Conti Mountain King, Schwalbe Knobby Nic, etc).
