Hubmonster 94% efficient 7kw NO LONGER FOR SALE

[hillzofvalp]

argghhhhhhhh jealousy

 

[gensem]

Dont be HoV... I dont have money for batteries atm...
max I ll be able to do is stare at it for a couple months, odd but true... hehe

argghhhhhhhh jealousy

 

[hillzofvalp]

could I borrow it?

But seriously take a caliper to that thing to confirm the dimensions. I want to have my swingarm modified whenever I have the moment. ANd verify the axle flats are not coincident.

 

[gensem]

Will do!

As far as my previous inspection on the borg frame went, I wont have to do alot of mods to the get the tire/motor fitted in. I ll probably just extended the swing arm 100mm using 20mm thick steel and add clamping on bought sides using m8 bolts. That way I ll have a wheelbase of 1.40m.

Does anyone know if 1.4m is enough to control the wheelies?

Whats your wheelbase on the super V John?

could I borrow it?

But seriously take a caliper to that thing to confirm the dimensions. I want to have my swingarm modified whenever I have the moment. ANd verify the axle flats are not coincident.

 

[John in CR]

SuperV's wheelbase is right at 1.4m . I find putting weight on a pedal to be the most critical part of keeping the nose down.

I don't think calling it double is a fair comparison, since the area in the magnetic gap isn't significantly different. For an apples/apples comparison you'd have to put the other one in the same diameter wheel and feed it with 1.7X higher voltage and about .6X the current fed to HubmonsterHE. The problem is that we haven't even scratched the surface of high voltage exploration with the beast, but we already know what happens at high voltage with the 51 slot 48 magnet motors. You try to push to and past 1krpm and the high frequency causes too much iron losses resulting in burned up motors. While I can explain till I'm blue in the face, Bluefang already proved the high voltage potential using his Mini-Monster at 2krpm+ with a 1.3A no load current at 127V. Same quality lamination steel and similar pole count means we can expect similar rpm potential from HubmonsterHE without bumping into prohibitive iron losses. We may have to ventilate despite the great efficiency, but that's to be expected with 30-40hp or greater peak input.

That puts any comparison back to not being fair, since Hubmonster can gulp down much higher current at much higher voltage, and do it more efficiently. The fact that sales of Monster motors didn't spike when Bluefang posted his no-load current results at high voltage, tells me either people didn't see it, or the magnitude of a hubmotor with such a low current draw at 2krpm isn't broadly understood. The high Kv means thicker copper in the windings, so it can handle higher current. Since high voltage isn't a problem either, then power potential gets extreme in a hurry. This is why I tell customers who want extreme power to go with the smallest wheel they can live with, so they can go to a higher voltage for a given speed. That's what's pushing me toward mid-drives, because speeds get unrealistic without extreme aero.

Did I mention that it's the quietest hubmotor around too?

John

 

[hillzofvalp]

Shit you scared me when you said 1.4meter wheelbase. The mb-5 stock wheel base is 1.21m. I had planned to extend it 60-90mm. Think ill be okay with all the 70lb battery weight up front? At 20kW?

 

[John in CR]

Shit you scared me when you said 1.4meter wheelbase. The mb-5 stock wheel base is 1.21m. I had planned to extend it 60-90mm. Think ill be okay with all the 70lb battery weight up front? At 20kW?

It's not just wheelbase. You have to factor in CG and mass. The meat of my saddle is 35cm in front of the rear wheel contact patch, and only 80cm above the ground (actually about 75 after suspension sag). 10ah of battery is in the swingarm at near axle height, and the other 10a is mounted to the fork in front of the headset. Don't forget I'm 120+kg and when I put weight on the pedal it's well forward of your pegs and closer to the ground.

The CA3 and its current throttle control will be the route to optimum control for a bargain price, and Justin has some great features coming down the pipe that will make it a must have. With good control concerns about flipping go away. If you're talking about bicycles though, you really have to take "wheelie machine" statements with a grain of salt with their saddles so high and rearward, so with no motor just a slight push on the cranks and soft pull on the handlebars and you're on one wheel. :? You need to make dropouts anyway, and it looks a bit short in stock form, so personally I'd add some wheelbase while I'm at it. Then you can program in harder acceleration to your throttle settings. It costs almost nothing in terms of efficiency as long as cruising speed is the same, so why not?

John

 

[gensem]

Wrote quite alot of things about cromotor and the new hubmotor... lost it by accident and im tired to do it again now.
summing it up
Cromotor is amazing strong to be a bicycle hub
but the kv is just too low to show its true face
Either way I think the bigger scooter hub motor is capable to output twice as much power at least...
Cromotor can handle a lot of power for free sprints... but get a stop and go flooded trafic in summer and you can burn it really fast with 10kw.
I didnt burn any of my cromotors but i did feel the lose of power due to the high temperature inside the motor alot the times when i was pushing the envelope without venting holes.

 

[gensem]

John... im used to put my chest over the handlebar and hope for the best...

 

[John in CR]

but get a stop and go flooded trafic in summer...

High repetition full stop starts can be deadly even at moderate power with any system. That's because they all start at 0% efficiency. I got a Mini-Monster hot that way, and I was riding conservatively thru downtown with a controller pushing only 6kw peak. My mistake was not shifting the windings to low speed. Now that I have it ventilated I need to repeat the same torture test. It was flat terrain, so going to low didn't cross my mind, but that ride really pounded home how dangerous stop n go can be. The thermistor tripped just before I reached my destination, and the stators on these motors are so full of metal that it takes forever to cool down.

That was running as a mid-drive and trimmed down for a lot less surface area than HubmonsterHE. Plus it's bolted to an alloy rim and has more mass in the stator, so it will take a lot more to get it hot. If you do a lot of heavy traffic stop-n-go riding be sure to connect the thermistor switch to some kind light or audio alarm, and if you ever trip it, then consider swapping out that thermistor for one that can give you temperature. I agree with the factory placement on the stator steel about 1cm away from the windings, and if you stay with that go a bit more conservative and consider 90°C as being a hot motor vs the 95° factory thermistor trip point. You probably won't need it, but just in case your solutions are simple with the wires already in place.

Based on the condition of that hot motor lesson with the Mini, I have no doubt whatsoever that ventilation would have prevented it. I might no help much with repetitive hard launches from a full stop only to 15mph, but in normal stop-n-go riding it would certainly allow a large amount of that heat to rise right out of the motor. I've never had a vented motor get hot, but even when they're warm I've clearly felt warm air rise out of the topmost exhaust holes when I stop. That's another example of how holes at the extreme perimeter is better than the holes in the pizza pan approach....Hot air rises upward, not sideways.

Just to summarize and repeat, because it's important and not well known. While bogging a motor down to a stop or very low speed on a hill is the worst thing you can do to a motor, it's quite obvious when you do it and easy to avoid. Hill climbing itself is quite easy, and as long as you aren't already pushing the stator into saturation, then all you have to do is know the minimum speed you need to be able to maintain. I've found that to be about half of top speed on flat terrain. The close 2nd hardest thing on a motor is repetitive full stop starts, and it doesn't have to be hard launches.

John

 

[teklektik]

If you do a lot of heavy traffic stop-n-go riding be sure to connect the thermistor switch to some kind light or audio alarm, and if you ever trip it, then consider swapping out that thermistor for one that can give you temperature.
...
While bogging a motor down to a stop or very low speed on a hill is the worst thing you can do to a motor, it's quite obvious when you do it and easy to avoid. Hill climbing itself is quite easy, and as long as you aren't already pushing the stator into saturation, then all you have to do is know the minimum speed you need to be able to maintain.

Here the CA V3 can help you out - upgrading to a thermistor hooked to the V3 will allow the V3 to increase current limiting with increasing temperature to prevent Bad Things from happening... As you say - it's best to avoid having things get to the point where this feature would cut in, but...

 

[John in CR]

If you do a lot of heavy traffic stop-n-go riding be sure to connect the thermistor switch to some kind light or audio alarm, and if you ever trip it, then consider swapping out that thermistor for one that can give you temperature.
...
While bogging a motor down to a stop or very low speed on a hill is the worst thing you can do to a motor, it's quite obvious when you do it and easy to avoid. Hill climbing itself is quite easy, and as long as you aren't already pushing the stator into saturation, then all you have to do is know the minimum speed you need to be able to maintain.

Here the CA V3 can help you out - upgrading to a thermistor hooked to the V3 will allow the V3 to increase current limiting with increasing temperature to prevent Bad Things from happening... As you say - it's best to avoid having things get to the point where this feature would cut in, but...

Good point, the CA3 has a number of new useful features with more to come. In 6 months of riding I've never gotten mine remotely hot, including plenty of miles long steep climbs and riding in substantial traffic, so I don't see the strong thermal control as necessary. I'm not one to unnecessarily open motors, but others who ride in higher ambient temps or extremely heavy traffic or to pick their way more slowly up steep climbs may find it necessary. We need the CA3's advanced throttle control anyway to be able to use very economical controllers, so the temp monitoring is there for the taking. I'm not a gadget type, but those who are into all that stuff go for it.

John

 

[gensem]

John do you think you would be able to get the motor parameters from the manufacter so we can play with ebikecalc simulator?

Im asking because the simulator is telling me that I ll reach 90kmh in under 4 seconds (19" wheel using 24s lifepo4 and 160 amps) is that close to real?

 

[John in CR]

John do you think you would be able to get the motor parameters from the manufacter so we can play with ebikecalc simulator?

Im asking because the simulator is telling me that I ll reach 90kmh in under 4 seconds (19" wheel using 24s lifepo4 and 160 amps) is that close to real?

Easier said than done with everything treated like a state secret on that side of the ocean. While they make motors, they aren't a motor manufacturer per se. I don't think there are technical people there doing R&D on new motor designs. They make scooters and the motors to power them. I think the people with the info we'd like are in Japan.

Tell me all the parameters we need and I can try. Most are probably on my list of open questions with them.

Regarding your 4 second result, what does it predict with an all up load of 175kg?

John

 

[gensem]

Haha... i found what was wrong... (the results were too good to be truth).
I filled the weight like It was kilograms not lbs..


Right values now:

for 275lbs it predicts 0-90km/h in 6.5sec
for 385lbs it predicts 0-90km/h in 9,4sec


I think we only need motor resistance and no load current to have a somehow accurate result.

 

[Arlo1]

Haha... i found what was wrong... (the results were too good to be truth).
I filled the weight like It was kilograms not lbs..


Right values now:

for 275lbs it predicts 0-90km/h in 6.5sec
for 385lbs it predicts 0-90km/h in 9,4sec


I think we only need motor resistance and no load current to have a somehow accurate result.

Are you making sure to include losses? What do you have for efficiency of the motor at those power levels. If its 94% at 7kw then its WAY less then 94 at 20kw
Did you add wind resistance?
Im excited to see this motor ripping and I have a feeling its going to be fast but I would like to see more building and less bench racing. I know Im one to talk but Im to buisy/pour to order this motor.

 

[xenodius]

Haha... i found what was wrong... (the results were too good to be truth).
I filled the weight like It was kilograms not lbs..


Right values now:

for 275lbs it predicts 0-90km/h in 6.5sec
for 385lbs it predicts 0-90km/h in 9,4sec


I think we only need motor resistance and no load current to have a somehow accurate result.

I feel like a fool, but we are talking about the ebikes.ca calculator, right? There's no way to add a custom motor to it... is there? Because I spent some time doing hand calculations for the Minimonster and I still don't trust those values especially since they're not far from yours, gensem. I think I figured 10.5 seconds for 380lbs to hit 60mph, quite similar. I don't think there's really any motor on there that's comparable to the HubmonsterHE, is there? Or really, any 'Monster'?

For some reason I was unsatisfied with the results and I figured them again, running the MiniMonster at 8kw peak (90 amps battery); with an aero recumbent and typical cruising speeds the average draw will be around 3kw or less-- the 8kw draw would be only for a second or two, only while accelerating and impressing the cars around me. Hopefully a sinusoidal controller will improve starting torque and efficiency so the peak draw is less important.

According to http://www.recumbents.com/wisil/simul/HPV_Simul.asp , even an unfaired recumbent could achieve incredible acceleration with the HubmonsterHE. Barring of course, all the errors encountered when misusing such a calculator... not the least of which is traction. I came up with about 1.5 seconds to 60mph In reality I think it's 1.5 seconds to repeating Luke's infamous BMX flip.

EDIT: thanks gensem, I see you used swbluto calc. Hubmonster is looking good!

 

[gensem]

Haha... i found what was wrong... (the results were too good to be truth).
I filled the weight like It was kilograms not lbs..


Right values now:

for 275lbs it predicts 0-90km/h in 6.5sec
for 385lbs it predicts 0-90km/h in 9,4sec


I think we only need motor resistance and no load current to have a somehow accurate result.

Are you making sure to include losses? What do you have for efficiency of the motor at those power levels. If its 94% at 7kw then its WAY less then 94 at 20kw
Did you add wind resistance?
Im excited to see this motor ripping and I have a feeling its going to be fast but I would like to see more building and less bench racing. I know Im one to talk but Im to buisy/pour to order this motor.

Arlo im also short on Money... thats why im trying to predicting stuff and not doing the actual build.
Im only pumping 12kw on the simulator (swbluto ebikecalc) so the effiency should be still good.
Efficiency should be close to 90% in the simulator and motor resistance was set to .06

 

[John in CR]

Haha... i found what was wrong... (the results were too good to be truth).
I filled the weight like It was kilograms not lbs..

Right values now:

for 275lbs it predicts 0-90km/h in 6.5sec
for 385lbs it predicts 0-90km/h in 9,4sec

I think we only need motor resistance and no load current to have a somehow accurate result.

Those times seem high to me, though I am pushing 210A peak. Almost a 3 second difference for 50kg . Smoking is finally out of the way permanently, so I need to get to work on this ridiculous weight. I think my other SuperV, which is still stock, needs a 500W geared hubbie in the front wheel and do some some spinning. I've been wanting to do a hubmotor installation on a 20mm axle fork anyway. One I get in some semblance of shape maybe I'll go motorless for exercise.

I weighed the bike recently and it's 122lbs (55.5kg) in it's current form. I just got on the scale (1st time this year) to get the bad news, and including my backpack empty except the chain I carry, it's an unacceptable 278lb (126kg) . That's an all up normal load leaving the right now house of 400lbs (182kg). I'll confirm that the CA is well calibrated, and maybe add a stand alone speedometer. I'll bring my GPS too, though I think they're really only accurate over long distances. Mount the GoPro at the CA and speedometer and get you guys some actual number. The hardest part will be finding a flat good road that isn't wind aided or hindered, but I've got a few candidates, and I'll do both directions for a good average. I'm not going to put too much effort into it, because what I say is often doubted around here, because it seems too good to be true. That's why I posted the cash prizes offer, to reward those who show faith early and share their results, and prove that I haven't stretched the truth or overstate expectations.

John

edit- chain wasn't in my pack, so I updated the weights

 

[xenodius]

I'm not going to put too much effort into it, because what I say is often doubted around here, because it seems too good to be true. That's why I posted the cash prizes offer, to reward those who show faith early and share their results, and prove that I haven't stretched the truth or overstate expectations.

John

I think that if I do end up using a sinusoidal controller like I hope to, Minimonster will live up to it's name and more. A well built motor and a smart controller is a great recipe for efficiency-- and power!

 

[gensem]

I'm not going to put too much effort into it, because what I say is often doubted around here, because it seems too good to be true. That's why I posted the cash prizes offer, to reward those who show faith early and share their results, and prove that I haven't stretched the truth or overstate expectations.

John

I think that if I do end up using a sinusoidal controller like I hope to, Minimonster will live up to it's name and more. A well built motor and a smart controller is a great recipe for efficiency-- and power!

Btw we are not using ebikes.ca simulator... we are talking about swbluto ebikecalc.

 

[gensem]

Had to come home and a take a snap... it looks so tinny near my older wheel.

I think it ll look awesome in mate black.

 

[John in CR]

I'm not sure 90kph is a good one for quoting acceleration times at 20s. At that voltage I think 90 is too far on the downside of power curve with acceleration tapering off. I always issue my challenges to 80kph, which is also a nice round 50mph.

I did get in 3 flat road launches from 0 while I was out. Traffic wasn't cooperative so I got only to a count of 5 once and 6 twice before I had to let off the throttle. The speeds were 45.4mph, 46.5mph, and 47.2mph. These controllers are set to medium start, so I may need to accelerate up a hill to get full current, since I current peaked right around 180A on each run.
I did test my count before and after several times with the stopwatch on my cell phone, and I'm pretty confident they're within .5 second with the first being the least accurate of the bunch and long. I think 6sec to 46mph with 400lbs all up and 180A peak is reasonably conservative and accurate, especially considering the fairly slow current ramp up.

Tomorrow I'll try an early am run and do some 9sec WOT launches. I can feel the suggishness of the extra tonnage over the last couple of months, so the time will fall rapidly as that weight melts away.

John

 

[John in CR]

Had to come home and a take a snap... it looks so tinny near my older wheel.
I think it ll look awesome in mate black.

It won't feel tiny.

Black for looks, but if your bike parks in the sun, then it starts with a hot shell. If it's for hours then the motor starts quite a few degrees warmer.

 

[John in CR]

mmmmm that is the one. Should I vent it before running it at 20kW with a 180lb bike 195lb rider?

So much depends upon how you ride and the voltage you run, that I would wait for the motor for either the thermistor to trip or the shell to get to 60-65°C before considering cracking the factory seal on the motor. That's me. I don't like opening motors unless necessary. Since you'll have a big battery pack, you can afford to ride hard all the time, so if you plan to ride at the limits, then I would. When I'm ready to run one as a mid-drive, then I'll ventilate it for 2 reasons:
1. I will be planning extreme power on a frame that can handle it.
2. The motor will be more shielded from direct air flow (and water and debris) and will need the more direct heat dissipation of good ventilation.
The exception would be inside a velo, in-wheel or out. I'd try to make a sealed one work first, because sound is such an issue in a velo. Also, I doubt a velo has the handling to take advantage of the true power potential of the motor....high speed maybe, but not extreme acceleration except in straight lines....much like I ride now. ie Humpty Dumpty on a longer SuperV with small tires. :lol:

John