liveforphysics
100 TW
Holy shit! That bionix motor looks awesome! Do you have specs on it?
Ultimate lightweight wheel-motor concept
- Thread starter speedmd
- Start date
flathill said:
'bout 15-16 pounds.
Aluminum side covers.
The stator looks pretty weight optimized - it has these giant thin spokes.
It's about the weight of a crystalyte HS35xx.
I experimented with a magic pie in a 20" wheel and a HS3548 in a 20" wheel and the HS3548 seemed just as powerful, but watts seemed to just disappear into the ether at a higher rate.
Could be that i had the HS3548 on a cargo bike with much worse aerodynamics than my mountain bike i had the 'pie on.
thats cool
I did miss that bionx motor
didnt you work for tidalforce?
They were working on yasa style bicycle hub motors at one point
tidalforce was awesome, but the timing was off
maybe we wont make it that much better
we are not trying to reinvent the wheel
maybe just better materials
with more optionality
would be fun to do an open source kit
if it doesnt end up being stupid expensive
big if
I did miss that bionx motor
didnt you work for tidalforce?
They were working on yasa style bicycle hub motors at one point
tidalforce was awesome, but the timing was off
maybe we wont make it that much better
we are not trying to reinvent the wheel
maybe just better materials
with more optionality
would be fun to do an open source kit
if it doesnt end up being stupid expensive
big if
With the introduction of the D-Series motor, BionX has implemented four new technical features:
ITS (Increased Tangential Speed):
By increasing the motor diameter, the tangential speed of the magnetic components increases as well.
MCR (Magnetic Component Reduction):
By increasing the diameter of the motor, less electrical force is needed to produce torque. This enables BionX to build a lighter motor. Both ITS and MCR are major contributors to the 250% increase in power output at steady state.
NSC (Non Structural Cover):
An extra lightweight construction due to non-structural motor covers and a super slim profile reduces the weight to only 3.9 kg.
STC (Spoke To Center):
The spokes of the D-Series motor are attached to the centre of the motor, enabling the wheel to flex more in the vertical direction. This results in more comfort, more grip and more traction on the trail for the sport oriented rider.
At a peak torque of 50Nm and a steady state torque of 25Nm, the D-Series is aimed at the sporty on-road and off-road rider, who wants high performance and modern design in one product.
The new D-Series motor will have its world premiere at Eurobike 2013. It will be offered on certain OEM bicycles powered by BionX™ in the coming 2014 model year, starting with WHEELER as the official launch partner.
ITS (Increased Tangential Speed):
By increasing the motor diameter, the tangential speed of the magnetic components increases as well.
MCR (Magnetic Component Reduction):
By increasing the diameter of the motor, less electrical force is needed to produce torque. This enables BionX to build a lighter motor. Both ITS and MCR are major contributors to the 250% increase in power output at steady state.
NSC (Non Structural Cover):
An extra lightweight construction due to non-structural motor covers and a super slim profile reduces the weight to only 3.9 kg.
STC (Spoke To Center):
The spokes of the D-Series motor are attached to the centre of the motor, enabling the wheel to flex more in the vertical direction. This results in more comfort, more grip and more traction on the trail for the sport oriented rider.
At a peak torque of 50Nm and a steady state torque of 25Nm, the D-Series is aimed at the sporty on-road and off-road rider, who wants high performance and modern design in one product.
The new D-Series motor will have its world premiere at Eurobike 2013. It will be offered on certain OEM bicycles powered by BionX™ in the coming 2014 model year, starting with WHEELER as the official launch partner.
liveforphysics
100 TW
Thats fantastic! That alone solves many issues with hubmotors.
Now we simply need to make it much less weight.
Now we simply need to make it much less weight.
good eye.
after Magna bought the remains of WaveCrest & a few of it's engineers along for the ride i wasn't surprised seeing it sport a Bix badge.
that's all there is by way of specs.
and some utube's from the bike show.
after Magna bought the remains of WaveCrest & a few of it's engineers along for the ride i wasn't surprised seeing it sport a Bix badge.
that's all there is by way of specs.
and some utube's from the bike show.
yes non structural side covers make so much sense
if you dont make the motor the same size as the wheel
But on second thought
it may even be superior in most all cases really
as the spoke guard against shock damage from potholes
much cheaper to replace a bent rim than a bent rim-stator
very exciting
if you dont make the motor the same size as the wheel
But on second thought
it may even be superior in most all cases really
as the spoke guard against shock damage from potholes
much cheaper to replace a bent rim than a bent rim-stator
very exciting
JennyB
1 kW
This may be mad, but seeing there are so many lightweight disc-brake road bikes around these days... IF the motor could be made an effective rear brake... build it as a direct replacement for a six-bolt rotor. Then you can use whatever superlight disc-compatible hub you like, and your superlightweight frame is already built to deal with the torque. 
speedmd
10 MW
Some great ideas coming. A bolt up motor! Wow.
Absolutely. Not even much of a challenge given what is commercially available and the talent pool of this group of skilled enthusiasts. Tons of PhD's coming up with better ideas every day just to be told that there is no market for it, or it would not hit a arbitrary price point. Nothing like the stings of the bean counters and business owners/boards killing any change at venturing into avantgard thinking and experimentation. Regardless, you are breaking every rule in brainstorming. No idea is a bad one. Even the one that are!
Lots of ways to better the status quo. May not be as pretty, have marketing budgets or ever make a dime, but better toward our goals, for certain. It is obvious that you have experience, and could contribute, but if not able to do it within the basic rules of the process, please stay out of this.
Absolutely. Not even much of a challenge given what is commercially available and the talent pool of this group of skilled enthusiasts. Tons of PhD's coming up with better ideas every day just to be told that there is no market for it, or it would not hit a arbitrary price point. Nothing like the stings of the bean counters and business owners/boards killing any change at venturing into avantgard thinking and experimentation. Regardless, you are breaking every rule in brainstorming. No idea is a bad one. Even the one that are!
Lots of ways to better the status quo. May not be as pretty, have marketing budgets or ever make a dime, but better toward our goals, for certain. It is obvious that you have experience, and could contribute, but if not able to do it within the basic rules of the process, please stay out of this.
Punx0r said:
the single press release already posted, that's it to date.Toorbough ULL-Zeveigh said:
oh, if only i could.speedmd said:
remember the ending to '12 monkeys' ?
i'm in insurance.
Permanent magnet motor rotor having magnetic permeable material for enhanced flux distribution
https://www.researchgate.net/public...and_Hybrid_Electric_Vehicle_Propulsion_System
MitchJi
10 MW
Hi,
I think that a rough maximum price should be an agreed upon parameter. I'm sure that with a very high price you can easily come up with an excellent motor. It's a bigger challenge, with a much more useful result, to design a motor, and figure out affordable production techniques, for a motor that at least 10-50 members can afford to buy.
I think integrating the motor with the rim is an impractical idea because it limits the wheel size for every motor produced to one wheel size. That would make it much harder to ramp up production enough to even produce 10-50 motors at an affordable price.
I don't fully understand the implications of the 400 rpm design parameter. One of the desired goals is to have a design that can be scaled from something like 8mm width to 80mm width if more power is required. At a width of 80mm will the 400rpm become less than 50 rpm at the same voltage?
I think that a rough maximum price should be an agreed upon parameter. I'm sure that with a very high price you can easily come up with an excellent motor. It's a bigger challenge, with a much more useful result, to design a motor, and figure out affordable production techniques, for a motor that at least 10-50 members can afford to buy.
I think integrating the motor with the rim is an impractical idea because it limits the wheel size for every motor produced to one wheel size. That would make it much harder to ramp up production enough to even produce 10-50 motors at an affordable price.
I don't fully understand the implications of the 400 rpm design parameter. One of the desired goals is to have a design that can be scaled from something like 8mm width to 80mm width if more power is required. At a width of 80mm will the 400rpm become less than 50 rpm at the same voltage?
speedmd
10 MW
Hi MitchJi
Good point. I was thinking well under 2 thousand dollars should be possible for a complete wheel/conventional motor build. Most likely we will experiment in several different directions and spend more on a few of them. I am reasonably confident we can do it for half that by taking cost trade offs as they become more clear and the learning curve kicks in. Too early to say for me as I have many questions still in my head on possibilities of a dual rotor axial motor design as well as hub design and spoke vs spokeless configurations. Much would depend on quality / costs of the selected components such as steel choices, magnet and wire types as well as complexity / machining costs for small quantities. Maybe we can value the weight savings of various designs and components in dollars per pound or dollars per gram. The lighter we go, most likely, the more expensive it will get per gram of savings.
liveforphysics
100 TW
I was expecting around ~$2k as well.
If we design it to be modular with respect to width, the user could elect to use exotic cobalt alloys or not, and simply make the rotor wider to still make the power if they aren't willing to spend a few hundred on exotic lam materials.
I've got a neat concept for a pair of spoke flange/bearing holder side plates. Thinking a 4" flange, and sized to work correctly with proper sized thin strong bicycle spokes. We can do a FEA stress model optimized cutout webbing pattern between the bearing pocket and spoke nipple flange stress points. In the webbing will be a few fastener locations for attaching the bearing/spoke-flange sides to the carbon side plates that mount to the back iron flux ring. To keep the flux ring very thin, I'm thinking laser cut carbon fiber rings that slip on around the outside of the flux ring and get a bead of epoxy around them to stiffen it up just enough to not have magnet/stator crashes, but that assembly doesn't need to be any stronger than that. The majority of the stresses are just passed through the little bearing pocket/spoke flange plates.
If we design it to be modular with respect to width, the user could elect to use exotic cobalt alloys or not, and simply make the rotor wider to still make the power if they aren't willing to spend a few hundred on exotic lam materials.
I've got a neat concept for a pair of spoke flange/bearing holder side plates. Thinking a 4" flange, and sized to work correctly with proper sized thin strong bicycle spokes. We can do a FEA stress model optimized cutout webbing pattern between the bearing pocket and spoke nipple flange stress points. In the webbing will be a few fastener locations for attaching the bearing/spoke-flange sides to the carbon side plates that mount to the back iron flux ring. To keep the flux ring very thin, I'm thinking laser cut carbon fiber rings that slip on around the outside of the flux ring and get a bead of epoxy around them to stiffen it up just enough to not have magnet/stator crashes, but that assembly doesn't need to be any stronger than that. The majority of the stresses are just passed through the little bearing pocket/spoke flange plates.
I do like the idea of having a regular-sized spoke hub, like the Bionix motor and Luke suggested before that
I could be wrong, but I believe growing the stator width will simply mean more torque, with KV staying about the same. Anyway, I imagine several winding configurations may be possible to let people change KV and KT.
Taking the extreme mention, the power of a 400mm x 80mm motor would be crazy
I could be wrong, but I believe growing the stator width will simply mean more torque, with KV staying about the same. Anyway, I imagine several winding configurations may be possible to let people change KV and KT.
Taking the extreme mention, the power of a 400mm x 80mm motor would be crazy
speedmd
10 MW
I can take a stab at modeling individual flanges and do some optimization scenarios in SW. Sketch out what your general concepts are and I should have some time next week to play around with it. I was considering plain flanges for bonding spun aluminum side walls for disc wheel construction strong enough to support the magnet ring. We can share the same flange design and add / bond a spoke ring to it for optional spoke designs. Standard axle diameters and drive side configuration? Is there enough room in them for the current we are looking at. If so, something like the Mavic axle sizes and drive config. so we can adapt a simple light standard freehub. Center barrell can be much larger to resolve added stator torque and add axle support .
speedmd
10 MW
Yes it would. Super bike territory.Taking the extreme mention, the power of a 400mm x 80mm motor would be crazy
You would need accelerometers on board to keep from doing back flips.No, Kt will increase, pretty much proporionately, with the stator width, if the turn count is kept constant.Punx0r said:
To answer Mitch's question: It's helpful to know the nominal speed when you choose the number of poles to use.....
liveforphysics
100 TW
Spoke flange concept sketched during dinner tonight.
Still need a lightweight axle solution, but I think we can get the side bearing-holder/spoke-flange plates and CF sides to support the flux ring easily <0.5lbs (<225g).
Anyone have some brilliant super light axle/stator center solution aside from just FEA optimized aluminum webbing/spoke patterns made as thin as possible and pressed around a rather conventional axle?
Seems like to be as light as possible, we want a very thin wall section axle with a lot of radius, but it's also gotta fit into bicycle drop-outs. Someone have a clever solution? Maybe insertable axle stubs that mate into female splines in the stator assembly at a large-ish diameter, and also provide the wire pass-through area, and one spoke flange uses the thin-section bearing for the non-axle wire outlet setup used on a few nice hubmotors. Seems like it might work, but it's not screaming DIY friendly nor very Zen in design.
Still need a lightweight axle solution, but I think we can get the side bearing-holder/spoke-flange plates and CF sides to support the flux ring easily <0.5lbs (<225g).
Anyone have some brilliant super light axle/stator center solution aside from just FEA optimized aluminum webbing/spoke patterns made as thin as possible and pressed around a rather conventional axle?
Seems like to be as light as possible, we want a very thin wall section axle with a lot of radius, but it's also gotta fit into bicycle drop-outs. Someone have a clever solution? Maybe insertable axle stubs that mate into female splines in the stator assembly at a large-ish diameter, and also provide the wire pass-through area, and one spoke flange uses the thin-section bearing for the non-axle wire outlet setup used on a few nice hubmotors. Seems like it might work, but it's not screaming DIY friendly nor very Zen in design.
speedmd
10 MW
Hi LFP
Like it. Do not see yet best way to share a mounting (for bonding) flange with the spoke mounts on the same part. For larger diameter spoke flanges, my new favorite design is the 2012 campy shamal. Special spokes also. Something like the concept can be made to accept more spoke angle variation, but still a major issue on the rim side with the larger diameter we are looking at and smaller rims folks will want to use also.
Axle is a problem still for me also. I do not see a light weight solution without stepping it down in diameter (Boring out the center or making it in several parts) to get through the smaller size bearings. I am thinking we may need to go to a more conventional hub motor design in the hub with larger bearings to take advantage of lighter materials and still be able to resolve the 25nm of torque reliably over time. I have a few days playing in the snow with the kids to think it through a bit more.
Like it. Do not see yet best way to share a mounting (for bonding) flange with the spoke mounts on the same part. For larger diameter spoke flanges, my new favorite design is the 2012 campy shamal. Special spokes also. Something like the concept can be made to accept more spoke angle variation, but still a major issue on the rim side with the larger diameter we are looking at and smaller rims folks will want to use also.
Axle is a problem still for me also. I do not see a light weight solution without stepping it down in diameter (Boring out the center or making it in several parts) to get through the smaller size bearings. I am thinking we may need to go to a more conventional hub motor design in the hub with larger bearings to take advantage of lighter materials and still be able to resolve the 25nm of torque reliably over time. I have a few days playing in the snow with the kids to think it through a bit more.
