Hubmonster 94% efficient 7kw NO LONGER FOR SALE

[xenodius]

I hope it makes a big difference. Imagine how efficient they might get...maybe over 100% . But seriously, any efficiency increase is always welcome, and coming with even less noise is a plus too.

And more torque. I know you said these 6-phase motors start quite smoothly already, but with a sinusoidal controller they should have perfectly and truly silent starts.

I know I'm hating on great technology, and I know it's more than a controller-- but andreym's controller/electronics set is pricey. $800 plus shipping from Russia. I suppose if you subtract a BMS and a cycle-analyst it's not so bad, but... who knows what the software will be like? The TFT LCD is a point off from me, but continuous regen is a point up... =) Still, there's no way I'm buying two of those to run a 6-phase motor for a few percent extra efficiency... I'll just get another couple Kwh of lifepo4. I know it's less elegant, but it'll get me a lot farther than that 3%, and I don't think I'd ever overheat even MidMonster, especially with CA temperature rollback.

I know nothing about sinusoidal controllers that other ES members are working on, other than comments I've heard about Arlo and Zombiesss. If they made a simple, reasonably priced ($300? $350? Maybe $400 with the right specs) CA compatible sinusoidal controller I would leap with joy! But I like the support and design of the CA, and I want a separate BMS so I don't have to remove my controller if I want to remove and charge my pack.

 

[jansevr]

gensem, the bike is starting to look like a beast! I am excited to see it completed! i have done a few minor changes in the model of my bike and also a few more renders. i decided to add a clamping dropout. also i changed the body a bit and lowered the suspension - just because i thought it might look cool and i think it does. More of a low rider/chopper or drag bike.

 

[EvoBikeShop]

gensem, the bike is starting to look like a beast! I am excited to see it completed! i have done a few minor changes in the model of my bike and also a few more renders. i decided to add a clamping dropout. also i changed the body a bit and lowered the suspension - just because i thought it might look cool and i think it does. More of a low rider/chopper or drag bike.

Very interesting. Just one question, I take it that those forks are suspension forks and those are the controllers (or batteries) mounted on the downtube. If so, you may have clearence issues if your suspension compresses with the wheel turned either way. Its looking good but I just felt that i needed to point that out.


EBS

 

[jansevr]

the batteries are on the downtube, but the front suspension is pretty much as low as it can go so it wouldn't be a problem. i don't exactly know if it is even plausible with this fork to lower it like this but its just an idea

 

[xenodius]

the batteries are on the downtube, but the front suspension is pretty much as low as it can go so it wouldn't be a problem. i don't exactly know if it is even plausible with this fork to lower it like this but its just an idea

You might consider welding up a thick-walled battery box to replace the downtube, protect your cells, and help keep everything compact. Just an idea.

 

[jansevr]

ive considered it..but think that it will be more work than it is worth. also i hate to cut up such a beautiful frame! it might make more sense to build a complete custom frame rather than cutting one up.

 

[xenodius]

ive considered it..but think that it will be more work than it is worth. also i hate to cut up such a beautiful frame! it might make more sense to build a complete custom frame rather than cutting one up.

Yikes, I get not wanting to cut up an already-made frame. I thought you were going to do a custom frame! You probably have about the best approach there. I spent hours trying to figure out the best way to fit a bunch of Headway cells onto a DH bike a while back... it's not easy.

 

[hillzofvalp]

You know, 94% efficiency really does permit 30kW usage. Especially ventilated. I would love to make a bike that showed up a 500cc bike to 50mph. Is this possible at 400lbs net weight at 28S life?

 

[John in CR]

You know, 94% efficiency really does permit 30kW usage. Especially ventilated. I would love to make a bike that showed up a 500cc bike to 50mph. Is this possible at 400lbs net weight at 28S life?

Setting expectations so high can only lead to disappointment, but let's examine the details. 30kw is a realistic peak output for a 500cc engine, so lets look at the electric. With an electric motor the absolute max power for a given voltage occurs at full stator saturation and efficiency is 50% at that point, and since we're measuring what comes out of the battery, you can probably take off another 5% for the controllers.

Let's start with the battery. Voltage sag to 3V/cell under load seems like pretty good estimate with your A123's, so at 28s that's 84V. I've been running mine since July at 210A peak battery current from the 2 controllers combined. That's with the motor in sealed form, and since I've had no heat issues we know that can't be anywhere near saturation. I have no problem going on the hook to say we'll be safe at 300A with a good ventilation design, but that does count on saturation not being a point we suddenly reach without signs of lower efficiency well before it's reached. We don't know where saturation occurs. The controllers on the way from Zombies will help me confirm my expectations, because this will be the first time I run it with programmable controllers.

You don't have to worry about phase current in this analysis, because we're looking at peak power. Rpm will be up around half of no-load speed and BEMF pushes the controllers toward full duty, so phase current will be roughly the same as battery current. 300A X 84V = 25kw Don't forget that's power input, not output, so worst case the stator is saturated, that's about 11kw output after factoring controller losses in too. I'll take the liberty of a guess educated only because I've pumped over 30kw into a similar weight hubbie before and call it 15kw out.

Can 15kw peak electric geared to about 70mph top speed pushing an all up load of 400lb beat a 30kw peak gasser pushing an all up load probably over 600lbs to 50mph? My knee jerk reaction when I first read your post was that's biting off more than you can chew, but based on 8 months with a similar load and about 16kw peak input, I'd say it depends on the rules. The difference in torque curves and the gasser having a gear shift or 2 make them impossible to compare on paper.

John

 

[hillzofvalp]

Very well put. But what about.. a double wide hubmonsterHE. 8)

 

[John in CR]

Very well put. But what about.. a double wide hubmonsterHE. 8)

What would you do, instead of a sidecar put a passenger seat on the front to keep the front down?

 

[xenodius]

Very well put. But what about.. a double wide hubmonsterHE. 8)

What would you do, instead of a sidecar put a passenger seat on the front to keep the front down?

*chanting* TRIKE, TRIKE, TRIKE, TRIKE!

A delta trike would be far, far less wheelie-prone than an upright bike, what with it's low COG. And it would probably be more zippy-zip, what with aero and all

 

[EvoBikeShop]

Very well put. But what about.. a double wide hubmonsterHE. 8)

What would you do, instead of a sidecar put a passenger seat on the front to keep the front down?

*chanting* TRIKE, TRIKE, TRIKE, TRIKE!

A delta trike would be far, far less wheelie-prone than an upright bike, what with it's low COG. And it would probably be more zippy-zip, what with aero and all

Hmm a pedal t-rex, now that would be cool!

Also if you could take a tadpole trike and make it 3 wheel drive, it could be capeable of some serious acceleration.

 

[EvoBikeShop]

An electric version of this would be awesome.

.

Oh wait, its already been done.

http://www.wired.com/autopia/2010/04/optamotive-e-rex/


EBS

 

[xenodius]

That's an awesome looking vehicle =D E-rex is appropriate. I may someday build an EV for two, but for now, I can't justify the added expense, insurance, and all the other details.

I'm planning on building an electric recumbent trike using the ingenious and exacting design of the "Jetrike" rear end, which uses the weight of the rider (and in my case, 28x 60ah Sinopoly cells at 4lb each) to create a self-centering effect. Essentially, when you lean your height above ground remains constant instead of decreasing along an arc as in a linear track vehicle-- therefore, equilibrium brings the trike back to a vertical position when you aren't deliberately leaning. It is also extremely simple to add rear suspension, which I wanted anyway-- so it's like having almost no extra weight cost, and none of the disadvantages of a leaning trike with all the advantages. I might widen the track, though.

For my front end, I plan on running a MidMonster and a fixed boom/BB with a serial hybrid setup. I can't wait to start, I just need some space to do everything in...

 

[John in CR]

That white one is awesome. I'd need two though, an enclosed one like in the pic, and one open air for the full visceral experience. I worry about rear wheel traction the way I'd want to drive them though, so if not a leaner then I'd lean more toward something like an electric Ariel Atom.

What disadvantages of a leaner? A lean lock for when stopped is all I can think of. Since first seeing it I've been unable to shake the road rocket potential of an electric version of Bram Smit Kanteltrike http://www.fastfwd.nl/index.php?id=13 or his Munzo TT http://www.fastfwd.nl/index.php?id=56. The elegance of simplicity really attracts me.

I can't wait to see the stuff you guys come up with, because I'm just a hacker with a few ideas. 8)

John

 

[xenodius]

That white one is awesome. I'd need two though, an enclosed one like in the pic, and one open air for the full visceral experience. I worry about rear wheel traction the way I'd want to drive them though, so if not a leaner then I'd lean more toward something like an electric Ariel Atom.

What disadvantages of a leaner? A lean lock for when stopped is all I can think of. Since first seeing it I've been unable to shake the road rocket potential of an electric version of Bram Smit Kanteltrike http://www.fastfwd.nl/index.php?id=13 or his Munzo TT http://www.fastfwd.nl/index.php?id=56. The elegance of simplicity really attracts me.

I can't wait to see the stuff you guys come up with, because I'm just a hacker with a few ideas. 8)

John

Pretty much just the lean lock, for us-- for those relying only on human power, additional weight and complexity are also concerns. Regeneration largely eliminates the negative effects of towing more weight uphill in round-trips. I think, given the speed and power output that may be expected with the HubMonster or Midmonster, a leaner is the only way to go. Bram Smit's trike is gorgeous and elegant, but unfortunately the rear geometry makes it more unstable than a linear track vehicle. Not much, but I'd rather have geometry working for me than against me-- or, limit the title angle.

There's a lot of considerations but it's definitely the most promising approach! =)

 

[John in CR]

Bram Smit's trike is gorgeous and elegant, but unfortunately the rear geometry makes it more unstable than a linear track vehicle. Not much, but I'd rather have geometry working for me than against me-- or, limit the title angle.

I need help understanding that. The rear wheels are always exactly parallel with the line of the trike aren't they, so where does the instability come from? You're not talking about the fact that the CG height lowers as it leans are you, because a bike "falls" to either side too without affecting stability? I want mine to be as much like a bike as possible, ie a 3 wheel bike is exactly what I want in a leaning delta.

John

 

[xenodius]

I need help understanding that. The rear wheels are always exactly parallel with the line of the trike aren't they, so where does the instability come from? You're not talking about the fact that the CG height lowers as it leans are you, because a bike "falls" to either side too without affecting stability? I want mine to be as much like a bike as possible, ie a 3 wheel bike is exactly what I want in a leaning delta.

John

If the swing-arms are parallel to the ground the vehicle will perform much more like a bike than at the ~30 degree angle on Smit's trike. Because of this angle, the rear wheels actually move MORE than the seat/front wheel/frame as you lean. So this trike will "fall" to the side more than a linear track vehicle would at the same angle. What you want is a leaning trike whose swingarms are parallel to the ground plane. The reason that this angle is important is because the wheel moves in an arc from the point at which it is fixed on the frame. So if you're already at an angle like 30, by the time you tilt 30 degrees left, your right wheel is at 60 and your left is at 0. But degree for degree, your left wheel lowers you less between 0-30 than the right wheel raises you between 30-60. Think of a sine function-- rate of change is greatest at 45 degrees, the average angle for the right wheel in this example. I believe Bram Smit's trike may be the least stable design possible.

While it's not the end of the world, you might as well build a trike that's easy to balance. Based on estimations from his photos (Thankyou photoshop), leaning 30 degrees to one side results in about an inch of surplus travel from what would otherwise be perfectly parallel wheel-to-ground contact. It may not sound like much but based on reports from those who've ridden it, it's all but impossible to start moving from a stop without using the tilt-lock; many other tilting-trike designs don't even use tilt-locks because they are "neutral", so I think it's a significant difference. I plan on building a trike quite similar to his. My only change would be to make the swingarms parallel to the ground plane. There are some other geometry tricks that Henry Thomas detailed on Jetrike.com; I used his simulations as a model to confirm the geometry of both Bram Smit's trike and Jetrike and I'm sure that he's got it all right.

I'm no engineer, I'm a biologist, so I would *never* have understood any of it if I hadn't have read this page: http://www.jetrike.com/geometry.html
Bram Smit's trike would be the "other trapezoidal geometry" on the figure further down the page.

A final thought. This effect is increased or decreased directly based on the load on the rear wheels. That's why one of the significant modifications from Jetrike's original design is the simple shortening of the rear swingarms. Bringing the wheels closer to the COG decreased the turn radius and increased the self-centering effect. With a fixed BB and hubbie, zero-point turns would be practical from a stop.

 

[jansevr]

ive always been intrigued by trikes as well. the combination of the cornering abilities with some consideration of aero would make for an excellent electric vehicle. leaning trikes are obviously even more intriguing for their cornering capabilities. however...i do question the (relitevely more) complex nature of a leaning trike as well as the lack of examples of them. maybe i just prefer bikes because of their simplicity and i the fact that they are narrow enoguh to fit between cars

john, ive seen the Kanteltrike before and thought that it was awesome! i hadn't seen the Munzo TT before but it looks well built and like it would be a lot of fun.

xenodius, thanks for the jetrike link! after reading around on there for a bit i realize that he and you both make a great point about the geometry. the jetrike seems like the ideal trike. now someone needs to build an electric one!



tell me if you guys are getting sick of me posting renders or if this is not the right place for them...

i did a bit more work on the rear swingarm extension (completely new - minus the clamping dropout) as well modeled some new battery boxes. each one would have a removable side cover as well as a transparent (although the renders don't show it well) side portion and top (for battery voltages) each box is large enough for 6 6s 5000mah lipo. 100v 30ah total

as always, the renders didn't turn out quite as expected...mainly not sure why the fork is the way it is but it does like kind of cool?

and looking at the first picture now i realize either the handlebars or the fairing will need to be adjusted a few inches for proper steering.

 

[John in CR]

Jansevr,

I love it even naked. One thing from a practical standpoint is the long swingarm. I had no choice but go that route on my SuperV, but it's hard to control all that weight on the end a long arm. I also means the arm will have to be built much stronger to be sufficiently rigid. You'll find you can fit more batteries down there too, which is the ideal location for keeping the bike light feeling and nimble. With the ability to have vertical supports for the saddle area you'll be able to save weight while making it more rigid and strong.

Also be sure to make your saddle nice and comfy, because with feet forward pedals you can't let you feet bear the weight and take a lot of load off your rear like on a regular bike.

Going industrial looking like that with your axle clamp on the flats is a good idea, especially for the wire side of the axle. Then a large piece of angle iron like that can extend beyond the end of the axle, so it protects the wiring harness from damage in case the bike falls on it's side. Have the harness bend 90° and exit from between the angle at the rear, and then go down and to the front, so your drip loop is covered too.

A sleek and low Hubmonster powered ebike like that will make an incredible cruiser and a real attention getter from both a visual and performance standpoint. I can't wait to see once you bring your vision to life.

John

 

[full-throttle]

i did a bit more work on the rear swingarm extension

Whoa!
What is the compression ratio on the rear shock - 6:1 or something?
Combined with a heavy wheel don't expect it to be practical.
Also chainring would work much better on the inside of the crankarm.
..and the steering angle is a little bit too steep..
Nice rendering though..

 

[jansevr]

i agree with you about the naked look, i especially like it with only the front battery pack. the swingarm might still be a bit long, but the length is partly based off the angles from the bike's swingarm. similar to your's i feel like this is the best way to extend mine. it should be sufficiently strong for anything i can throw at it. i understand why more weight lower would be ideal, but is adding weight to the swingarm the right idea? if it is already to long/heavy wouldn't it be best to not have anything added? the seat will definitely be comfortable, i was thinking a big/wide seat to support/distribute the most weight. kind of like a dirt bike maybe? the seat might need more support, but i like the almost floating look without the rear battery pack. if i did add some supports it would have to be a pretty angled to attach to the frame, as swingarm below it is all moving.

i model and render mainly for fun and eventually, (and i stress eventually) this bike will live in the flesh. i don't mean to get yours or anyone else hopes up. haha although i have the bike and an idea it will be a few months before i have the time and money for a project like this. hopefully by then i will have most of the design work done =)

and thanks again for your help and comments on the design

 

[jansevr]

haha the compression ratio would be quite high the way it is now. john is the only person that is running a similar setup. my swingarm might be a bit longer but would weigh less if i don't have batteries in mine. also i only weight about 170 so a bit less as well. if i need to i can get a stiffer shock...or possibly make the swingarm a bit shorter. i still want to extend it at least 8 inches, i don't think that would be pushing it too much. i hear what you're saying about the chainring. it is a bit unconventional and probably doesn't make much sense. this was a result of using pedals from an old model, trying to keep the drive line in line and keeping the pedals narrow so the pedaling with the fairing isn't an issue or so the fairing isn't too wide. although i don't have all the proper dimensions modeled, the main problem is that the chain (or possibly belt? ) is very wide at the motor and results in being wide at the crank as well. the steering angle is based off of dimensions of the bike from the manufacture website but it is possible i messed up by a degree or two.

 

[John in CR]

I forgot you were starting with a bike. Mine is 67cm pivot to motor axle, 20cm pivot to shock attachment, with a 140cm wheelbase. I've got 10ah 20s lipo rigidly attached to a piece of 16mm plywood which is rigidly attached to form the bottom of the battery area in the angle iron swingarm. The entire swingarm assembly probably weighs about 70lbs. Of course the little Fox Float air shock can't dampen that load, but in regular road use it works surprisingly well. A single bump or hole isn't a big deal, but bumpy sections require care. If I could raise the shock attachment point further from the pivot and fit a stronger shock, I'm sure I could tune it far better. On good road all that weight is virtually unnoticeable due to where it is placed.

As long as your rear wheel doesn't go airborne the lower and closer to the rear wheel you can place weight, the more light and nimble and bicycle-like it will feel. In the swingarm as unsprung weight is no good on the bumps, but the 12lbs or so of battery centered forward of the midpoint is almost immaterial compared to the total weight. I'd never recommend it to someone just due to the vibration on the battery, I have certainty that mine is 100% secure and well compressed, so no banging around or cell deformation is possible.

Battery space is our biggest premium, and you'll want a big battery for good range when you take advantage of performance. If you have good quality roads, you should consider going hardtail. On smooth roads nothing handles like a hardtail. You do have to take extra care about unexpected bumps or holes, but a suspended seat may be an answer, and still get exactly the lines you want without suspension sag changing the look. That also simplifies attachment of your tailbox, and of course gives total freedom to pack a lot of batteries in front of the rear wheel, especially with width no real concern due to feet forward pedals.

Here's my 4yo cargo bike Blue, that actually started life as a steel dual sus MTB. I turned it into a hardtail. It has 1.4kwh of A123 M1's in that box, but I could easily double that capacity.


Another option would be to move the pivot point reward and make a short swingarm to match the motor. You only want a few inches of travel, so a low pivot-to-axle/pivot-to-shock ratio makes the big motor wheel weight far easier for a bike shock to control. That would free up a lot of space below the seat for batts.

I'm with Full-Throttle on the head tube angle. It seems too steep, which seems to get more problematic with longer wheelbase bikes. Blue's was too steep when I first built it, and I had to hack it off and put it on at a more slack angle. I ended up with 4.5" of trail if I remember correctly, and it's a bit long for very low speeds like under 5mph, but even at 60mph it tracks like on rails.

John