Voicecoil's red, fully rigid commuter

[voicecoils]

Crikey. At 60v nominal and 30amps, I do 15Wh per kilometer.

Ah, the Wh/km meter on the CA is not accurate because when the motor freewheels it doesn't record distance traveled.

More accurate would be 790Wh /~ 35km = 22.57 Wh/km. I may have actually rode a bit farther. Anyways, with proper pedaling 15 Wh/km should be about what I'll get too.

 

[Mark_A_W]

Crikey. At 60v nominal and 30amps, I do 15Wh per kilometer.

Ah, the Wh/km meter on the CA is not accurate because when the motor freewheels it doesn't record distance traveled.

More accurate would be 790Wh /~ 35km = 22.57 Wh/km. I may have actually rode a bit farther. Anyways, with proper pedaling 15 Wh/km should be about what I'll get too.

Ah...that wouldn't happen to me as I have a standalone CA with a separate magnet sensors. Can you add a magnet sensor to yours? It's inaccurate without it..

 

[voicecoils]

[youtube]clItn95l02A[/youtube]
http://www.youtube.com/watch?v=clItn95l02A&fmt=18 <--- Higher quality

(not sure why anyone would want to watch the above video. I was just messing around with a place to mount the camera. It's obviously not the best place since my leg is in the way most of the time. Anyways you guys can hear what the bafang sounds like and try to guess where it is being ridden).


P.s. Mark, I have a stand alone CA as well. The only thing I lose with the direct plug in CA is total distance and Wh/km. Since I have the GPS bike computer on next to it it doesn't really matter. Guess it might be fun to accumulate km's on it but first the ebike (and chargers!) have to work long enough to get soem serious road time.

 

[Toshi]

Crikey. At 60v nominal and 30amps, I do 15Wh per kilometer.

Ah, the Wh/km meter on the CA is not accurate because when the motor freewheels it doesn't record distance traveled.

More accurate would be 790Wh /~ 35km = 22.57 Wh/km. I may have actually rode a bit farther. Anyways, with proper pedaling 15 Wh/km should be about what I'll get too.

for comparison purposes here's my usage over time with a 48V nominal LiFePO4 pack, Crystalyte 407 in a 26" wheel, hilly terrain with many stop signs and lights, and a cruising speed once moving along of 20-25 mph with light pedaling. note Wh/mi vs. Wh/km.

 

[voicecoils]

[youtube]8vhUOOE5JlM[/youtube]
:?

 

[Mark_A_W]

What is the clunk clunk noise?

 

[voicecoils]

What is the clunk clunk noise?

That's what I want to find out. I'm starting to get a tad pissed off with the bafang.

At 72v nominal and ~14A current limited it gives me very good performance for commuting. Good starting torque for skirting through traffic, accelerating off the line (with pedaling), and blasting up hills. It raises my level ground speed considerably with a good reduction in pedaling effort, allows me to hold higher speed going up hills, and 'assists' me downhills up to almost 60kph which is quite useful for some stretches of my regular route.

The conundrum is that I want a lightweight hubmotor with this performance but true reliability. I don't know that the Bafang has the build quality to satisfy this. Furthermore, I think heat dissipation may be a serious limiting factor with the small enclosed motor having no passive or active cooling to shed heat with it's relatively low copper mass.

The clunking has me worried. I was convinced it was mechanical, perhaps the freewheel clutch but then I took the motor core out and ran it in the truing stand. It still doesn't sound smooth. I should post a video of that too... Also, I should build a little hall tester gizmo to make that side of things easy to diagnose. Maybe there is some problem with the magnets or how they're attached to the outer motor housing. Perhaps they've even started to demagnitise due to heat. I really don't know.

 

[Mark_A_W]

You're running a 36v motor at 72v.

You can't blame it for failing.

 

[voicecoils]

Mini update:

New parts:
two torque arms from ebike.ca (nice tight fit!)
mini-xlr connector for the bafang hall wires


battery boxes:
The red rocket is with the Engine Whisperer (http://www.enginewhisperer.com) who will be making an accessible battery enclosure. There's plenty of room in the frame, might even get the controller mounted to an aluminium side of the box for water protection but maintaining heat dissipation. It won't be open to direct airflow then but might be still worth doing.

 

[voicecoils]

a new hall sensor has been glued into the spot where the misbehaving one was first silicone'd then epoxied in place. I'll hopefully wire it up tonight.

Planning for the possibility that my bafang cannot be saved, I've purchased a 9 continents hubmotor from ebay. I don't know it's exact characteristics yet, other then that it's in a 26" wheel. I will post more when it arrives.

 

[voicecoils]

see photo comment

 

[voicecoils]

see image comments


View attachment 1

 

[voicecoils]

My 9 Continents hubmotor has arrived. According to the sticker on it, I have the FH154 or 7x9 model.
A French guy on E-S a few days ago made a post saying the FH154 is 7 wires with 9 turns each and
has a 48v loaded speed of 420 RPM. I'll try to verify this myself.

 

[voicecoils]

Weights:

9 continents in the 26" rim weighs ~6.7kg (I will update this when I get the tyre and tube mounted)

My bafang in a rhyno lite 26" rim with tube and tyres weighs ~4.8kg

 

[voicecoils]

First 9cont no-load test results with the x'lyte 35-40A analogue 24-72v controller.

At 37v it draws 0.9A and spins at 290 RPM (36.5 kph in a 26" rim w/ 1.5" tyre)

My controller is jumpered to reverse for operation with my bafang so the 9cont spins backwards on the phase/hall arrangement suggested to me by Methods:

HALLS
9 cont ---------- x'lyte controller
red ---------- red
black ---------- black
blue ---------- green
green ---------- blue
yellow ---------- yellow

PHASE
blue ---------- green
green ---------- blue
yellow ---------- yellow

I'll try to find a combo that runs forward smoothly.

 

[Rassy]

voicecoils wrote:

I'll try to find a combo that runs forward smoothly

Since it's a front wheel, you could possibly just flip the whole wheel, so the wire would come out on the other side of the fork. Good luck.

 

[Mark_A_W]

I think it's the same winding as mine Abraham.

66v gives me 43kmh, no pedalling. No load speed is 56kmh.

 

[Mark_A_W]

Oh, can you try the rear bafang while you are fiddling? Please?

 

[voicecoils]

Oh, can you try the rear bafang while you are fiddling? Please?

Yep the silver bafang is up next I'll only be able to run the motor core as I've taken some of the circlips out and put them in the black bafang. Without the circlips the planetary gears make contact with the motor core. Should not affect no-load speed much if at all though.

Back in 15min...

 

[voicecoils]

Oh, can you try the rear bafang while you are fiddling? Please?

Silver Bafang at 37V:

draws 0.57A. Core motor spins at 990-1000 RPM. Hub spins at 220-225 RPM (worked OK without the circlip). I used a bike speedo set to wheel size 1666mm which gives RPM/10. Double checked with the direct plug in CA which read 28.4 kph in a 26" wheel with 1.5" wide tyre (works out to 225.4 RPM).

In my experience the bafang no-load speed is 25% higher then on-road speed on level ground. I think it needs to be run at 72v to be useful but with serious current limiting to prevent gear failure and thermal destruction.

 

[Mark_A_W]

Oh, can you try the rear bafang while you are fiddling? Please?

Silver Bafang at 37V:

draws 0.57A. Core motor spins at 990-1000 RPM. Hub spins at 220-225 RPM (worked OK without the circlip). I used a bike speedo set to wheel size 1666mm which gives RPM/10. Double checked with the direct plug in CA which read 28.4 kph in a 26" wheel with 1.5" wide tyre (works out to 225.4 RPM).

In my experience the bafang no-load speed is 25% higher then on-road speed on level ground. I think it needs to be run at 72v to be useful but with serious current limiting to prevent gear failure and thermal destruction.

Actually, that's not far off what we got.

At 30.0v, we got 3hz. Which is about 21kmh I think.

Scaling your 28kmh at 37v down you get 22.7kmh - not too far off, considering we did a rough test.

I'll connect a cycle computer (the motor is at work in the lab), as it's much easier to calibrate than an opto and a frequency counter - it's designed for the job.


Is it any different to you front bafang?

Thanks heaps for testing it!!!!!

Mark

 

[voicecoils]

Actually, that's not far off what we got.

At 30.0v, we got 3hz. Which is about 21kmh I think.
Scaling your 28kmh at 37v down you get 22.7kmh - not too far off, considering we did a rough test.
I'll connect a cycle computer (the motor is at work in the lab), as it's much easier to calibrate than an opto and a frequency counter - it's designed for the job.

Is it any different to you front bafang? Thanks heaps for testing it!!!!! Mark

No worries. Tomorrow I'll get my 4th SLA battery back so I can test at 48v. That will give us another data point and if yours then falls on the trendline of my two points then we can be quite sure.

I'll try the black bafang too tomorrow.

 

[voicecoils]

OK More tests:

Black Bafang:
@37.6V
250 RPM (magnet speedo)
31.5 kph (calculated for 26" rim 1.5" wide tyre)
31.3 kph (CA direct)

@49.7V
335 RPM (magnet speedo)
42.2 (calculated for 26" rim 1.5" wide tyre)
41.5 kph (CA direct)

Silver Bafang
@50.5V
300 RPM (magnet speedo)
37.8 kph (calculated for 26" rim 1.5" wide tyre)
38.3 kph (CA direct)

9Cont
@50.5V
385-390 RPM
48.5-49 kph (calculated for 26" rim 1.5" wide tyre)
(since the 9Cont has a different number of poles then the bafangs, the CA speed readings are wrong)

 

[voicecoils]

Mark_A_W:
We have the same bafang....

 

[voicecoils]