My first ebike build: custom-built KMX-based electric velomobile

[99t4]

I must say, going downhill at 30 mph and deliberately hitting deep potholes showed me that I barely feel them!

That is great news! I had similar pleasant reaction when I switched to FS.

Wish your photos weren't so hazy.

 

[uPET]

Nice!! Good to see it running with the new rear setup.

 

[adam333]

That's a good news!

Thanks for the pictures.

Yep, battery and controller positioning is always challenging.

 

[The Toecutter]

I'm hoping to have the electric drive up and running again this weekend. I need to make two new battery boxes and mounts. The batteries will temporarily be relocated at the back of the seat, hanging off of it and also attached to the seat posts. Zip ties and C-clips should do the trick. They will be more permanently affixed when I have the nacelle of the next body shell on the trike, as the rear firewall will be the intended mounting location.

The 3 kW 1.5 kWh pack of Greenways should be capable of ~50 mph with the 3T wind motor on a full charge. So similar performance to my last iteration.

The next performance upgrade will come when I get a 72V pack of NCR18650GAs put together and install the ASI BAC4000 controller, which will justify the Hubsink and ferrofluid. Looking to do at least 7 kW peak, maybe as much as 10 kW, with 250A phase current. If I get the aero right and make all the intended upgrades to the chassis, 70 mph and car-like 0-60 mph times may be possible, although there is going to be wheelspin out the ass!

If the 72V system works well, after that is going to a much higher voltage so that triple digit mph become possible.

 

[The Toecutter]

Didn't get it running this weekend. I worked on the Milan velomobile instead. I am going to need it for work this week, and unlike the trike with the shell removed, the Milan can still carry tools, hardhat, vest, work boots, hammer, stakes, water, ect.

It will probably be a while before I have a new body on it, but the next shell is going to be more efficient. Hoping to get consumption down to ~4 Wh/mile @ 30-35 mph with light pedaling.

I'm considering in the longer term my dream pack. A 24S5P pack of Molicel P45B might be the ticket. Would give me 88.8Vnom, and if I set them to 30A peak per string, max discharge would never harm them and I'd be able to dump 10 kW peak to my Leafbike 3T wind motor. The pack itself would provide about 2 kWh usable capacity and only weigh 8,016g(at least in cells alone). If the Leafbike motor can handle 10 kW peaks just fine, I may decide to try to crank things up to even 12 kW. That would be good for 0-60 mph in < 7 seconds with a top speed over 90 mph... The full charge voltage would also still be below the 103V limit of my Satiator charger, and unlike going to higher voltages than 24S, I can still find readily available and affordable BMS for that setup. Sure, it may not do triple digits like I originally dreamed about, but it would be close enough.

It will be a while before that dream pack is built, and by then, better batteries might be available, plus I need to find a higher voltage controller suited to my application, given the 72V limitation of the ASI. I wouldn't dare try it without a completed body shell and integrated roll cage, and the entire rest of the trike upgraded to handle this(wheels, tires, brakes, hubs, roll cage, ect). Even then it would be a death machine. I'll make sure that aesthetically it looks the part, like it came out of some Mad Max film. Silver Baphomet hood ornamet, rust colored paint job, sloppily-painted red anarchy sign on the left side, a real Fallout Shelter sign bolted onto the right side, pentagram wheel covers, maybe even orange LEDs in the front wheels to make them look like they are on fire when the vehicle is in motion, are all part of the plan...

Would LOVE to take such an apocalypse chariot to Wasteland Weekend and walk around wearing my cloak and plague doctor mask looking like I crawled out of some neo-Dark Age. I could carry a bucket of leeches AND a Geiger counter. Might even be able to get people to pay me money to build them one of these vehicles or something similar to it, the appeal being that it would truly be functional in the sort of energy and resource-scarce scenarios depicted in the post apocalyptic films that inspired this festival, AND would also be practical to use in the real world as it is today. Grid electricity, generator electricity, solar power, and pedal power could all run such a thing, either by themselves or as any combination thereof, and it would be extremely efficient no matter what is used to fuel it, besting a car in miles travelled per unit of energy input by 2 whole orders of magnitude and beating out a normal unmotorized bicycle by a massive margin as well when it comes to miles per food calorie. By choosing 16" moto rims, it would even be able to use 20" BMX tires/tubes in a pinch which are about the most common bicycle tire and tube size you can find in the U.S., albeit it would be suicide to do more than 35 mph on them. In SHTF scenario, it's not like you'll be able to order new DOT rubber off Amazon, and 35 mph is still better than walking! Can't go wrong there...

 

[ZeroEm]

Leafmotor should come alive with a BAC4000, I want one!

by The Toecutter » Jul 14 2022 12:27pm

I'm hoping to have the electric drive up and running again this weekend. I need to make two new battery boxes and mounts. The batteries will temporarily be relocated at the back of the seat, hanging off of it and also attached to the seat posts. Zip ties and C-clips should do the trick. They will be more permanently affixed when I have the nacelle of the next body shell on the trike, as the rear firewall will be the intended mounting location.

The 3 kW 1.5 kWh pack of Greenways should be capable of ~50 mph with the 3T wind motor on a full charge. So similar performance to my last iteration.

The next performance upgrade will come when I get a 72V pack of NCR18650GAs put together and install the ASI BAC4000 controller, which will justify the Hubsink and ferrofluid. Looking to do at least 7 kW peak, maybe as much as 10 kW, with 250A phase current. If I get the aero right and make all the intended upgrades to the chassis, 70 mph and car-like 0-60 mph times may be possible, although there is going to be wheelspin out the ass!

If the 72V system works well, after that is going to a much higher voltage so that triple digit mph become possible.

 

[The Toecutter]

I wanted a BAC2000, but they were unavailable at the time. The 4000 is really too much controller for this motor, which means more unwanted weight. No worries though, as that is not the final controller I'm going to use, because I eventually want to go over 72Vnom. This thing is going to be scary to operate at its limits, even on 72V.

Leafmotor should come alive with a BAC4000, I want one!

 

[The Toecutter]

I've sent an inquiry to Buchanon's Spoke and Rim regarding their 16x1.6" motorcycle rims. They custom drill to order. I need to get this 3T wind Leafbike motor laced to one of these with 36 spoke holes so I can throw my Mitas MC2 16x2.25" tire on it. If this works out well, I'll have them do a 32-spoke pattern for my front wheels so I can lace up a 1-cross pattern to my spare set of KMX hubs.

I am going to have a lot of fun with my "bicycle". Last year I was doing donuts in the middle of intersections with the "Bike Life" crowd. Maybe next year I'll be able to race them, and win. Here's what that crowd is all about:

https://www.youtube.com/watch?v=gjxwr9qYiJU

It's beautifully anarchic. The irony is that my vehicle complies with the law, purely on a technicality in the legal code. I need to be able to do 0-60 mph in under 6 seconds if I want to match the Ford Explorer hybrid police vehicles in acceleration. That is a long term goal, and is not going to happen on a Leafbike motor, as the best I can hope for with that in the most optimistic of scenarios(tire hooks up and I have no traction issues) is 0-60 mph in the upper 6-second range, and I'm probably not going to achieve that in the real world.

 

[ZeroEm]

May need to put a leafmotor on all three wheels and see where that gets you.

 

[The Toecutter]

May need to put a leafmotor on all three wheels and see where that gets you.

It would be almost unpedalable with the motors disabled. That being said, it could work for a 4-wheeled AWD one-seater car just fine. 0-60 mph in under 4 seconds would be possible for a vehicle that ready to ride but unladen without rider/tools, would weigh under 200 lbs.

 

[ZeroEm]

I would like two of grin's front motors and rear leaf. No would not try ride around with out power but could get home at a slow rate.
they have a feature that gives just enough power to remove the drag but will not move you down the road.
Not sure if your going to get the 0-60 times and pedal too.

 

[The Toecutter]

I would like two of grin's front motors and rear leaf. No would not try ride around with out power but could get home at a slow rate.
they have a feature that gives just enough power to remove the drag but will not move you down the road.

I'm aware of this. I want the vehicle to be ridable if the battery and/or controller and/or computer fails. The bicycle functionality is a key component of the application the vehicle is for. It's meant to be a versatile and inexpensive form of transportation that would remain functional even in the event of civilizational collapse. A post apocalyptic doom chariot that is also perfectly functional in the present day.

Not sure if your going to get the 0-60 times and pedal too.

The 0-60 time is less important than the pedalability. I'm trying to make the former as fast as possible while retaining the latter. So far, it looks like the Leafbike is the best choice for that, at least if I want regen and silent operation(especially the latter to avoid attention from law enforcement). I might try an over-powered mid drive later on running a sprocket on the non-pedal-drive side of the rear wheel, in order to keep the human power separate from the middrive output. But that's something for a later date, and by then, a better hub motor might be available and/or I might have built one. There's also something to be said for regen allowed by a hub motor, as it would allow my pedaling to recharge the battery in a pinch if electricity is unavailable and the solar panels or their electronics fail.

 

[ZeroEm]

Never have much of an issue with drag on my trike. Have road around at 17 mph without help from the motor. It all depends what kind of shape i'm in. Used to ride with a bicycle group and would not use power most of the time.

Alone is a different story would ride up to fifty miles at a time but not very often. Always considered 30 miles a good ride. Sorta out of shape at the moment.

Used to play with riding with regen but never charged much and it wore me out fast. Like going up a hill slow.

 

[The Toecutter]

Used to play with riding with regen but never charged much and it wore me out fast. Like going up a hill slow.

When I ride unpowered, I only use regen for going down hills and coasting to stops. It doesn't wear me out any faster, and over a 10 mile ride with lots of hills and stop and go, I can easily recover 20-40 Wh. In a total SHTF scenario, I could always prop the rear of the trike up on a jack stand, enable regen, and pedal to recharge it over a period of days if for some reason I need a full charge and there's neither grid electricity nor solar.

It is this sort of versatility that I'm after with this vehicle. To have as many ways as possible to keep it operational. If a gasoline, diesel, ethanol, or biodiesel fuel cell existed on the market with which to generate power, and it was sufficiently light/compact, I'd want to have one of those too so that a liquid fuel is also an option(internal combustion engines are much too heavy to consider as a component of the vehicle, but I'm not opposed to having them act as an electricity generator outside of the vehicle if there was ever a need for it). This vehicle would get literally thousands of MPG running a liquid fuel through a fuel cell.

The ability to even pedal it is a sort of last ditch means of propulsion if all else fails, without having to actually ditch the vehicle, and could keep it operational until repairs can be made. And the ability to pedal it will also supplement its range and help conserve its onboard energy storage.

 

[BalorNG]

I would like two of grin's front motors and rear leaf. No would not try ride around with out power but could get home at a slow rate.
they have a feature that gives just enough power to remove the drag but will not move you down the road.

I'm aware of this. I want the vehicle to be ridable if the battery and/or controller and/or computer fails. The bicycle functionality is a key component of the application the vehicle is for. It's meant to be a versatile and inexpensive form of transportation that would remain functional even in the event of civilizational collapse. A post apocalyptic doom chariot that is also perfectly functional in the present day.

Not sure if your going to get the 0-60 times and pedal too.

The 0-60 time is less important than the pedalability. I'm trying to make the former as fast as possible while retaining the latter. So far, it looks like the Leafbike is the best choice for that, at least if I want regen and silent operation(especially the latter to avoid attention from law enforcement). I might try an over-powered mid drive later on running a sprocket on the non-pedal-drive side of the rear wheel, in order to keep the human power separate from the middrive output. But that's something for a later date, and by then, a better hub motor might be available and/or I might have built one. There's also something to be said for regen allowed by a hub motor, as it would allow my pedaling to recharge the battery in a pinch if electricity is unavailable and the solar panels or their electronics fail.

There is no escaping the fact that the more powerful the motor, the more 'no-load drag' it has. (PM motors, that is)
Thinner laminations help, but only so far as higher speeds are concerned, hysteresis (cogging) torque will still be non-negligible for a motor powerful enough.
When the motor is running, those losses are just 'iron losses' we take for granted and almost negligible so far as 'acceleration from a stop' is concerned.

When you have a 20kw motor, 200w of loss is just one 1% (and you will have much more than that). When it comes to human power, that's like 100%

This is why there is 'virtual freewheel' for the Gmac, but losses are losses, you might not feel them but they will drain your battery all the same, and you cannot have regen with an freewheel/overruning clutch - only a manual clutch or a 'neutral gear'.

You have two solutions, both are viable:

A high-power middrive with overruning clutch designed for 'explosive accelerations' and climbing and relatively low-power (hence low no-load losses) DD motor designed for efficient cruising and scrubbing speed/regen also at high efficiency, if you want constant low-power assist and regen capability but high torque on demand...

If you want to travel *mostly* human powered, but still high torque AND regen on demand - a high-power middrive with a *manual* or centrifugal clutch (like that from a pit bike) you can engage or disengage at will.

The latter is particularly interesting because it cheap, parts are cheap and comes with gearbox, you just need an adapter.
I've wanted to create such a setup, but motor I've ordered during winter for it came defective and due to, well, 'current situation' I wasn't even able to requiest a refund, so the project is shelved for now, but barring eccelerations that are, well, 'implosive' lol, my e-board fixed gear middrive serves me just fine for now - so long as I don't try any really steep hills.

 

[ZeroEm]

Was talking about regen engaged while pedaling. Best to get some solar panels and a buck charger. Did that for a summer until the cheap charger quit. Need to get another one and more panels. Cost me more for the equipment than used in the trike. Did like the slow charge and solar power.

by The Toecutter » Aug 10 2022 10:54am

ZeroEm wrote: ↑Aug 10 2022 8:38am

Used to play with riding with regen but never charged much and it wore me out fast. Like going up a hill slow.

When I ride unpowered, I only use regen for going down hills and coasting to stops. It doesn't wear me out any faster, and over a 10 mile ride with lots of hills and stop and go, I can easily recover 20-40 Wh. In a total SHTF scenario, I could always prop the rear of the trike up on a jack stand, enable regen, and pedal to recharge it over a period of days if for some reason I need a full charge and there's neither grid electricity nor solar.

It is this sort of versatility that I'm after with this vehicle. To have as many ways as possible to keep it operational. If a gasoline, diesel, ethanol, or biodiesel fuel cell existed on the market with which to generate power, and it was sufficiently light/compact, I'd want to have one of those too so that a liquid fuel is also an option(internal combustion engines are much too heavy to consider as a component of the vehicle, but I'm not opposed to having them act as an electricity generator outside of the vehicle if there was ever a need for it). This vehicle would get literally thousands of MPG running a liquid fuel through a fuel cell.

The ability to even pedal it is a sort of last ditch means of propulsion if all else fails, without having to actually ditch the vehicle, and could keep it operational until repairs can be made. And the ability to pedal it will also supplement its range and help conserve its onboard energy storage.

 

[The Toecutter]

There is no escaping the fact that the more powerful the motor, the more 'no-load drag' it has. (PM motors, that is)
Thinner laminations help, but only so far as higher speeds are concerned, hysteresis (cogging) torque will still be non-negligible for a motor powerful enough.
When the motor is running, those losses are just 'iron losses' we take for granted and almost negligible so far as 'acceleration from a stop' is concerned.

Increasing the motor's efficiency allows it to make more power without overheating. As long as the cogging losses are kept reasonable(like a Leabike, or less), or even eliminated altogether(witched reluctance motors), then it will be acceptable. It's too bad that an off-the-shelf solution hub motor of the sort isn't available to buy.

When you have a 20kw motor, 200w of loss is just one 1% (and you will have much more than that). When it comes to human power, that's like 100%

The Leafbike 1500W can do 10 kW peak, and 've set mine up for 3 kW peak, but cogging losses when the motor is disabled are less than 50W at 30 mph. Still significant, but not they're not enough to render pedal-only mode non-viable.

This is why there is 'virtual freewheel' for the Gmac, but losses are losses, you might not feel them but they will drain your battery all the same, and you cannot have regen with an freewheel/overruning clutch - only a manual clutch or a 'neutral gear'.

I'm not a fan of the fixed clutch or all of the breakable items in this motor, or the fact that it is terrible at shedding heat. Then when unpowered, there's not only cogging torque losses, but also gear losses. The Leafbike is a much better match for my application.

A normal MAC 5T with a functioning clutch, that would be worth giving up regen to have a clutch that can decouple and kill the cogging losses. But the problem I run into is that this motor will only be good for 2 kW peak or so, if I want the clutch to last. So the acceleration I want is not doable with this.

This would be a good motor for my Milan velomobile though, were high power and car-like 0-60 mph acceleration runs would destroy it, but where a lower torque/power solution would work fine.

You have two solutions, both are viable:

A high-power middrive with overruning clutch designed for 'explosive accelerations' and climbing and relatively low-power (hence low no-load losses) DD motor designed for efficient cruising and scrubbing speed/regen also at high efficiency, if you want constant low-power assist and regen capability but high torque on demand...

If you want to travel *mostly* human powered, but still high torque AND regen on demand - a high-power middrive with a *manual* or centrifugal clutch (like that from a pit bike) you can engage or disengage at will.

The latter is particularly interesting because it cheap, parts are cheap and comes with gearbox, you just need an adapter.
I've wanted to create such a setup, but motor I've ordered during winter for it came defective and due to, well, 'current situation' I wasn't even able to requiest a refund, so the project is shelved for now, but barring eccelerations that are, well, 'implosive' lol, my e-board fixed gear middrive serves me just fine for now - so long as I don't try any really steep hills.

I'm considering the possibility of trying a high-powered mid-drive in the future. Twin Astroflight motors powering the non-pedal side of the drive wheel with the ability to freewheel when not in use would be the ticket. I could also have a very low-powered < 500W hub motor built into the rear wheel to provide regen and low-wattage assist as well. It's possible to make such a system weigh less than my current Leafbike 1500W motor, and it would be even more versatile, especially having two possible motors to propel the vehicle with each being a failure point that is independent of the other. The hub motor could be used for low-speed hill climbing when pedaling with the FOC controller matching the voltage to the operating point for best efficiency, while the mid drive system could allow 20+ kW for hauling ass). And I wouldn't even need a gearbox. I'm fine with a mid-drive being a single ratio. The major downside is added cost: two motors, and two controllers. But it is something I've been thinking about.

 

[BalorNG]

For ~500W you don't need a very expencive controller, that's for sure.

For 20KW... yea, not really, and that's the point - overall cost will be dictated by your 'most poweful' setup, but so far as efficiency is concerned 'triple parallel hybrid' setup with your power and small-ish motor to complement it and a high-powered 'vehicle mode' middrive is best I think.

 

[The Toecutter]

For ~500W you don't need a very expencive controller, that's for sure.

I do need to do research on low-powered motors. For that setup, the lowest possible cogging torque losses will be the over-riding design criterion, followed by the mass as a close second. I could run such a motor at 72V and maybe get 750W continuous, which would be plenty for the application.

For 20KW... yea, not really, and that's the point - overall cost will be dictated by your 'most poweful' setup, but so far as efficiency is concerned 'triple parallel hybrid' setup with your power and small-ish motor to complement it and a high-powered 'vehicle mode' middrive is best I think.

Money isn't an issue for this build anymore. That might change in the future, but for now, I have insufficient free time to make use of the money at my disposal, since I now make a lower-middle-class income, but still live like I'm poor.

I just need to find the right components for the job and build accordingly. Before I do that, I'm going to take this Leafbike build to its ultimate possible spec, so that may be a while off.

I've been trying to find a Hubmonster, but no one has one for sale and I haven't been able to locate any of the models of scooter that came with it. Albeit, that motor is not really suitable for my application, but it WILL give a rather nice amount of performance.

 

[99t4]

...motor I've ordered during winter for it came defective and due to, well, 'current situation' I wasn't even able to requiest a refund...

Sanctions, I'm guessing? Somebody's got to have figured a way around that by now.

 

[BalorNG]

...motor I've ordered during winter for it came defective and due to, well, 'current situation' I wasn't even able to requiest a refund...

Sanctions, I'm guessing? Somebody's got to have figured a way around that by now.

Eh, that's SWIFT and VISA/Mastercard. Getting stuff from 'chinese amazon' (aliexpress) is not exactly a problem, but when I requested a refund the money just never came back. The definition of 'force majeure' *shrugs* I think it is fixed now, yea...

Compared to everything else there is and likely will be this is nothing however... one HPV builder I know barely got away with his live from Mariupol, while an other had to immigrate to Ireland - not because he's personally threatened even, but due to his wife being Russian. A third is still being periodically bombed in Kharkiv, and that's just the tip of the iceberg I've personally observed. Some things really put things into perspective and teach one to appreciate what one has, I guess.

 

[The Toecutter]

XT150s finally arrived. Still waiting on parts for the solar system. This is going to be an awesome ride when I get the chance to put everything together. I have x5 50W panels at my disposal, and in direct sunlight with them placed in a balanced manner on the body, I might be able to get 100-150W. So possibly 500-600Wh/day on sunlight alone, which is more than I used on most days when the body shell was on it. The next shell should be more efficient. If I can only fit 150W of panels, it's not the end of the world either and I'll still get at least something in exchange for letting it sit in the sun. The charge controller can handle 400W.

If the next shell is sufficiently aerodymamic, most of its total propulsion will be from a combination of sunlight and pedaling for my current usage case. It would take a special set of circumstances for that usage case to change, but I want the bike to be capable of sustained highway speeds if circumstances necessitate, which will render both solar and pedaling a much smaller fraction of the overall energy used to propel the vehicle. But the option to have any solar at all will still be there, and is valuable to me for a variety of obvious reasons.

 

[The Toecutter]

Also, for those interested, I started photographing the local areas I ride this build and my Milan SL around in:

https://endless-sphere.com/forums/viewtopic.php?f=1&t=116801

I will get more pictures. In fact, this current build is going to get some quality hooning time when it is ready for it. The "bike life" crowd seems to like it.

 

[The Toecutter]

I dragged the KMX down into my basement bedroom so I could get some work on it done, since my job takes up all of my daylight hours.

Hydraulic brakes and ATV disc rotors are going on this weekend. Once the body design is complete, I can finally get to work building it.

 

[adam333]

No disrespect here, but I think your camera is due for an upgrade