Fitting a CellMan DD hub to 10yo 'Strong' ebike....

[monkeychops]

The "crab walk" thing has got me a bit worried now.
The rear wheel is slightly over to the left so that the disc brake fits into the caliper.
I did go for a very short test ride (no power yet) yesterday and it *seemed* ok.
So how do I know if I have a crab walk problem? It's probably out of alignment by 10mm.

Maybe I can drill some air vents in the sandwich box if it gets hot.

Burtie - I am ignoring the spark issue for the moment. I guess the spark will happen inside the 'ignition' switch. Come to think of it, recalling the 'ignition on' noise it made when turning the switch sounded a bit like a spark. Ho hum. Maybe my ignition switch is robust enough to cope.

[Brentis]

The "crab walk" thing has got me a bit worried now.
The rear wheel is slightly over to the left so that the disc brake fits into the caliper.
I did go for a very short test ride (no power yet) yesterday and it *seemed* ok.
So how do I know if I have a crab walk problem? It's probably out of alignment by 10mm.

Maybe I can drill some air vents in the sandwich box if it gets hot.

Burtie - I am ignoring the spark issue for the moment. I guess the spark will happen inside the 'ignition' switch. Come to think of it, recalling the 'ignition on' noise it made when turning the switch sounded a bit like a spark. Ho hum. Maybe my ignition switch is robust enough to cope.

Be weary.
There is a big difference in the "feel" from straight line under pedal power to leaned over in a corner under DD hub power.
To be truthful, I am unaware off the correct alignment process.
To my mind & what I've experienced, you want the rear & front wheels in central alignment with headset center line.
Adjust your brakes & derailleur from there.
10mm out, seems to me to be on the high side.
I hope someone can jump in with better Alignment tech.

Drilling holes in the container will let it vent some heat.
Just monitor in the beginning/after big hills WOT.
I'm sure it will be fine.

I think the Ign. switch is fairly robust, that said it will still wear/blacken eventually.
Pre-charge resistor is really nice.
I have one on the Cell_man pack, they come standard.(Nice touch Paul)
Ive not seen a spark yet.*That wasn't operator error*

Good luck Monkey, get that thing centered, ride safe.

[mushymelon]

That switch wasn't good enough for the original 36v setup, I would swap it out.

[monkeychops]

Thanks for the advice guys.

I'm reluctant to change the ignition switch. It works. I hear what you are saying though. It may die, I have to be prepared for that.

Just to qualify things a bit: I am very much a beginner here, not particularly mechanically minded and (brace yourselves) have *not* really been into bikes before. Thus far, this project has been somewhat of a struggle. Just about every little thing I have had to learn from scratch.

So I can't immediately think how to move the brake caliper over any more. More spacers won't fit on the bolts holding the caliper on. More spacers could push the disc out a bit. So maybe keep the caliper where it is and add more disc spacers? is that going to be mechanically safe with nearly 20mm of spacers on the disc and long-ish bolts holding the disc in? Adding spacers is something I *can* do.

The bike is nearly rideable now. I am a cautious rider. The motor won't take me over 25mph under power. I never liked leaning over on it around corners so I just go slow around them. Did I say I was over 40 years old?

[monkeychops]

Shifted the brake disc out a bit. The wheel lines up better now. Centre enough for me.
Increased the number of spacer washers from 6 to 10 on the disc. Had to glue them together to get them in, my fingers not being small enough.

Brake side

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Freewheel side

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[monkeychops]

Got it all working, wired up, controller successfully boxed.
Went for a test ride.
Such a difference to the old brushed hub motor. Everything I expected it to be: more powerful, faster, quieter.
Top flat powered speed is about 23 mph. Fast enough for me. Already I feel the need to get a freewheel with fewer teeth on it.
Massive difference up hills. Slowest speed up the steepest hill dropped briefly to 14 mph. This is a hill I would be doing 6 mph and sweating hard on with no motor.
Anyway, some photos.

Checking cells are balanced during bulk charging. Battery case top pops off easily enough. The charger is quite noisey and sucks up about 380W of AC power.

Bulk charging

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Not too hot after a 47 minute ride (air temperature is 11 degrees).

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Handlebar stats

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Final pack voltage = 44.95V
17.7 mph moving average.
One 7 minute stop in the middle.
0.43 Ah/mile.
Very similar stats to when I last did that ride with the brushed hub motor. But a much better experience this time

[Brentis]

Looks real good Monkeychops
The thermometer on controller case is a nice touch.
I really like your dash set up. I thinks I shall investigate GPS dash type units.

How did it handle alignment wise?

Keep us posted/pic'd as you put some mileage on it.

Take care

[Samd]

I see you have one of the cellmonitors (with red LEd readout) in the pics. I have bought a few off ebay that were hideously inaccurate when compared to the charger. They were consistently over or under on each cell at least.

Anyone else found this? Or it might be that they ended up on ebay because they were rejected from good stock anyways...

Sam.

[monkeychops]

Brentis:
Thanks. Thermometer now inside the case. Since it's a clear case I can still read it. Looks like the lack of ventilation isn't going to be a problem, but will keep an eye on it.
The GPS is meant for a car. Battery only lasts about 1.5 hours now so I have to make sure it's charged before every ride, which is a pain. It works though.

Samd:
I have found that the cellmonitors are roughly ok. One of them matches the charger, but the other one doesn't. Having said that, my IMax B6 charger doesn't match my (reliable) multimeter. I think as long as you don't use them to try to charge right up to 4.2V on each cell then they are a good general guide to how balanced the cells are. I've seen a lot of discussions on how balanced the lipo cells should be. I reckon the cellmonitors are fine for checking the cells are balanced enough, but not good enough if you want pinpoint accuracy.

Minor update:
Weather improving.
Looking forward to my first ride to work. A 15 mile journey. 0.75 miles over a grass field.
In the meantime, new rear disc (rotator) on it's way, plus a cheapo handlebar mirror.

[psycholist]

Congrats on the build monkeychops!
".43A/mile" Is this motor power only? How hard were you pedalling?
Is this the slow wind motor?
I use a handheld gps on my bike. Batteries last ~15-18 hrs.

[Brentis]

Brentis:
...
The GPS is meant for a car. Battery only lasts about 1.5 hours now so I have to make sure it's charged before every ride, which is a pain. It works though.

... plus a cheapo handlebar mirror.

Does the GPS have a 12 input then? Maybe a DC/DC converter & plug? Or strictly battery op?

I use a couple of $8 cheapo bar end mirrors. I liked them.
Plastic, ie cheap mirrors will almost always move on ya.
You are on a FS bike & @ relatively slow speed though,
so that should surely help over my "Ghetto" build application.

Keep us posted

[monkeychops]

physolist:
Good idea about the handheld gps. More money though. Would need a good mount too. It is nice to know your speed and distance travelled. Hmm, decisions.
Don't know if it's slow or fast wind. There were no choices when purchasing from cellman. He did say it should reach 25mph. I'm fine with 23. I usually do gentle pedalling these days. My gearing is such that after 20 mph my feet are going round too fast so I've been cycling at about 18-19 in order to be able to pedal gently.

brentis:
Yep, could rig up 12V to the GPS. More wiring though. Another component to fail. Tempting though. At the moment I'm going with the 'do nothing' approach.

Cycled to and from work yesterday. Weather not really quite warm/dry enough yet.
Battery capacity not quite large enough for the journey yet. Cells down too low when I got home. 2 more 4Ah lipos being fitted soon.
Front light bracket broken off on the way home (the stock one). Now replaced.
Bulk charger was noticed at work - the fan is loud. The little cardboard box I've made for it with the polystyrene corners worked ok, but the polystyrene isn't quite strong enough.

Photo of bulk charger transport box (before slight polystyrene crushing):

Box

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Anyone any (simple) ideas for the box?

[psycholist]

Thanks for the info monkeychops. The reason I asked is because I have the exact same motor and was curious as to the performance I can expect (still in the building stage). Judging by your top speed your motor is slow-wind. I like your idea using the lock-n-lock container with the thermometer mounted inside (protected and still visible through the translucent plastic). Where'd you get the thermometer? Did you glue it to the container? Also curious what gear ratio your using? Is it the typical 44/13?

[monkeychops]

Wired in 2 more lipos.
Top speed now slightly more (I think) at 24 mph. This is possibly due to the voltage sag being less with the extra lipos.
I think the smallest cog has 14 or 15 teeth on it.
Been looking more at the 11T TNC ones. £20 plus £10 delivery from the US is all I can find at the moment.
The thermometer was from dealextreme.com. http://www.dealextreme.com/p/1-5-lcd-car-home-outdoor-digital-thermometer-black-2-x-lr44-105647
I should glue it but it's currently loose.
Cheapo mirror turned up. It's rubbish. Poor field of view. Bought one for £15 bar end one that looks better. Not tested it yet.

Other things:
Rear disc brake rotator changed. Much better now, still nowhere near as effective as front brake but I think that's just how it's going to be.
Battery case now contains 6 x 4Ah Turnigy 6S 20C lipos. Effective range 20 miles with lots of throttle.
Charger polystyrene padding not tough enough. Have bought a large sandwich box and will pad it with bits of carpet.
I hadn't noticed, but one of the spokes on the rear hub was *really* loose. now tightened.

Sorry about the lack of photos. Not much to see right now. Will be back with photos shortly.

[monkeychops]

Update:

Upgraded charger box

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Upgraded charger box

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Mirror. Essential to stop me turning my head every 5 seconds to check for cars.

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Stock front light back on with new bracket.

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Showing the broken old bracket on the tyre. The stock light isn't great. A pretty weak bulb. But it works straight off the 48V power. And I'm not planning to ride in the dark so will rarely use it.

11T DNP freewheel on its way from the US.

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[monkeychops]

Updates:

The charger broke. It didn't like being transported around, even in the padded box.
I have stripped out all the unnecessary gubbins (lights, horn, 'ignition').
I have moved the power analyser onto the frame to reduce wire length.
I have replaced the throughout with 12AWG wire.
The mirror fell off and was replaced by a better fitting one.
I bought 2 more lipos (total=8, 16Ah).

Sorry, no pics.

I now want a tiny bit more speed. Greedy I know.