Mark_A_W's DH Team/MAC Shanghai/64v Headway build

[Hyena]

Curious...
Have you got another controller you can try ?

Have you had a look inside to make sure it's not a mechanical problem ? I guess the fact that it gets stuck drawing 7 amps is odd and would probably rule out that. It almost sounds hall related, but it shouldn't come and go so precisely like that even if one was loose and was vibrating around inside the motor.

If you can sort out the problem before I get mine that'll be good

 

[Mark_A_W]

Over the next fortnight full_throttle (who I work with, along with adrian_sm) will get his MAC running with a 12 FET Infineon.

Will be interesting to see how that goes.

 

[adrian_sm]

Haven't you got an old osciloscope at home? Have a look at what is coming down the phase lines would help.

I also like the idea of hooking up another controller. What wiring standard did you end up using. Can you hook it up to my crystalyte controller?

 

[Mark_A_W]

Yeah, I have a cro, but it only misbehaves under load, and I think it needs to be a dynamic load. It's not simple...

I used a wiring diagram for a crystalyte controller and a BMC motor...I forget which way around. I used a mini-xlr connector, and I don't have another and they are like hen's teeth..

 

[adrian_sm]

Sounds like we could throw the wheel on my bike in a pinch. As I have a crystalyte controller, and mini-xlr halls.

 

[Mark_A_W]

Maybe.

Guaranteed the hall wiring will be wrong.


Even if it's "right" it will probably still need to be played around with to make it work..

I'll see how full_throttle goes, I can wait a week or so, the bike is functional.

 

[fechter]

It sounds like an interaction between the motor and the current limiter in the controller.

These kind of things drive me crazy since they are difficult to analyze or fix. Tweaking the software settings for current and/or ramp up speed in the controller are your best bets. Try adjusting one parameter at a time and test. For each change, try to figure out if it gets better or worse. You may have to repeat the process many, many times to really get dialed in, since one adjustment could affect the others.

If that only gets you so far, then it may require hardware changes in the current sensing part of the controller, like finding the current signal line and filtering it. Most controllers have a current measuring shunt that goes to an amplifier before it feeds into the microprocessor. Some kind of capacitor on the amplifier feedback will slow down the oscillations.

I guess another test would be to try a different controller if you have one. I don't think the motor itself would cause that, but it's possible.

If all else fails, it may work to completely disable the current limiter in the controller and use some other method to prevent overcurrent (really long phase wires). Now that I think about it, the length (resistance) of the phase wires could have a an effect on this. You might try adding some wire to each of the 3 phase wires just for a test.

 

[Mark_A_W]

MMWHAHAHAHA!!!


Full-throttle and I reprogrammed the controller today, and FIXED IT.


With all the suggestions on board (thanks Methy, Cell-man and Fetcher), we played with the phase current;

- 30A Battery, 50A Phase = no change, still shudders.

- 30A Battery, 90A Phase = FIXED. No shudder so far. Smooth acceleration under load.


So it seems it was the Phase current limiting that was making it shudder, some interaction with the motor and freewheel system (at least it felt like it was bouncing off the clutch).


Seeing as it was fixed, I set it to 35A/100A . The 2.5x rule would give me 90A for 35A battery current, but it seems to like a little higher.

My phase wires are chopped close to the axle and I run huge big cables to the controller, but still I will check the temps.


The bike seems great so far, just looping around the carpark at work. I will ride a bit more and see how it goes...it has to get me home from work tonight...


Thank you all for your input.

Mark

 

[cell_man]

Glad you got it sorted. 55kph isn't too shabby for a single geared motor and 1500W to pull that speed doesn't sound like you're pushing it too hard either. Looking good.

 

[Hyena]

Great success!
Good to hear you got it sorted.

Any change of a 'ride by' video to check out the sound of the motor ? You have the metal gear right ?

 

[Mark_A_W]

Ok, I got home no problems....well, it has a tendency to do little wheelies if I don't keep the weight over the handlebars


It hammers now, maybe not like an X5 at 72v 60A, but it's pretty good. Way better than my old Direct Drive motor.


My power consumption on medium speed is a touch too high, I set it to 75%, from 60%. 60% was too slow. I think 70% is the go. I need enough range on medium to do 32k on one charge.
I'm using about 20wh/km so I only have about 27k range. I need to get that down to 16wh/km.


Anyway, nice issues to have compared to the performance yesterday.


The battery box is nearly done. Just a bit more finishing and then painting.


It's pretty noisy Hyena, and depending where the freewheel stops it's sometimes noisier than other times. Yes, it has a metal gear.
I'll try and get a video.

 

[full-throttle]

Took Mark's bike for a few laps of the carpark - great power and handling! Very nice build.

I didn't find it noisy, even when Mark was zooming past. Put it this way: a rusty chain or knobby tyres are noisier.

Lunchtime drag race Mark??

 

[Mark_A_W]

Yep, you're on.

Just eating now.

 

[adrian_sm]

Count me in. Drop by my desk on the way.

 

[Hyena]

Damn, I wish I worked with guys who I could duck out and have lunch time ebike drag races with!
Someone get a video on their phone!
I've built 2 ebikes for people at work but they're in their 50s so they ride responsibly. Pft!

Thanks for the feedback on the noise full throttle, it doesn't sound too bad at all.

 

[Mark_A_W]

Ok, results:

Race 1: No pedalling, standing start.


Full-throttle's 48v 25A Bafang BPM is a real go-er.

It's much faster than my MAC Shanghai 60v 35A out of the blocks ...it was carrying 40kg's less weight (30kgs of the difference being me)...then my bike starts to haul him in when the BPM tops out at around 35-40kmh, and the MAC keeps going...but..

The race was short, so I only just got going, when I had to stop, so the BPM won.


Race 2: slight rolling start, with pedalling.


With pedalling the MAC Shanghai won, I was able to keep up with the BPM in the initial acceleration, and I got to 45kmh+ by the end, and had to haul on the anchors. My extra 30kgs over Full-throttle is in my legs (not my brain...but at least not my gut..well mostly).

The MAC just needs a little leg boost from 10-20 or so (could maybe play with Phase Current), which is partially why the Bafang BPM gets me without pedalling- the other reason is it just pulls hard down low. Bafang BPM does really good wheelies. MAC goes really fast.


Adrian's 408 at 48v 35A was third, dunno how far behind, and my brother's Brett White GL2 48v 25A was last (he needs a better motor.."high torque" my arse).


The Bafang BPM was a real surprise, I knew it was good, but thought the MAC would beat it. This particular BPM is a low KV winding, and it has heaps of torque. A higher winding with a no load speed around 55 would be really sweet (but probably have less pickup).


There is some phone-camera video, but I haven't seen it yet.

 

[Hyena]

Wow that's an unexpected and impressive outcome from the bafang with less voltage and current! Is it metal geared too ? I wonder how it'd hold up with the power you're pumping into the Mac ?

I'd be interesting to swap riders from a standing start and see what effect your weight played on the bafangs performance.

 

[full-throttle]

Nah, only the sun gear is metal, the rest, incl ring gear are plastic. They're nice and beefy though.

Its prob worth mentioning that MAC is a higher winding - it gets up to 55kph, while PBM struggles to get to 40. In turns MAC got a sweet spot (max acceleration) around 30-40kph while BPM is around 20-30kph (Mark correct me if I'm wrong)

What it all comes down to:
- If your commute is mostly long stretches of relatively straight roads (flats and hills) go for the higher speed MAC.
- And if its a mix of sidestreets, bike paths and singletracks (like mine is) go for BPM - it loves corners.

Said that, I will play around with settings on the controller with MAC in my build - pretty sure its got a hidden potential.

BTW I didn't realise we were allowed to pedal in the 2nd race.

 

[Mark_A_W]

Rematch tomorrow.

And my first race start was woeful, like 3 seconds behind you.

 

[AussieJester]

psssst...Mark...build up a lil booster pack tonight and don't tellz full-throttle till you beatz him tomorrow

KiM

 

[Mark_A_W]

psssst...Mark...build up a lil booster pack tonight and don't tellz full-throttle till you beatz him tomorrow

KiM

Dependz how longz the race is.

Longer than 70m or so, the MAC wins. Less than that the BPM wins.

High KV vs Low KV.


What would be interesting is both motor wounds to about 55kmh at 48v.

 

[full-throttle]

..or Mark can just reprogram the controller - max current and 110% throttle

Why did I give him that USB programming dongle..

 

[Hyena]

What a softie that Mark is, I can see I'm going to be the first person to blow up one of these MAC motors by shoving 3000w up it's bum :lol:

 

[Mark_A_W]

Actually, I got training the next two days, it will have to be Monday.


It might be running more amps by then.

But it's not a toy. I need it functional.

 

[full-throttle]

No worries, I would actually prefer to play basketball with your brother tomorrow lunchtime and soccer on Fri lunchtime while the ground is still wet.

What was the max power output on yours again? Edit: Mine was just over 1.3kW (26.4Amax @ 49.8Vmin)