Voicecoil's red, fully rigid commuter

[voicecoils]

Updates:

Motor's in a wheel, a 36h Rhyno Lite Pinned wheel. I'm using 216mm spokes with a 1 cross lace, but they are a tad long. I would suggest anyone else with the same hubmotor & rim combo go for 214mm as suggested by johnrobbinholmes. I've put some zefal cloth rimtape on and hope it will be all good. I'll also have the wheel trued up at a bike shop even though it's reasonably true and tight already.

I've mounted my Cycle Analyst to the handle bars, but have 2 concerns: The mount seems a bit flimsy and I'm not convinced it's waterproof. Two things to look into.

My 20 mhz crystal resonators came from farnell.com and I soldered one on with no problems. the 72v 28A ecrazyman controller is now happily blinking faster. I've done fetcher's LVC mod by putting a 24k ohm resistor across R3. The LVC now trips at 47-48v which would mean 2.0v cell voltage for my 72v pack. Tripping the LVC at 2.1 per cell would probably be a bit safer.

I also bought a bunch of 45a powerpole connectors in the same farnell order and will be using them to connect the stand alone Cycle Analyst in line with the controller and batteries and for a bunch of other connections. They're smaller then I expected! I might use them for the phase sensors too In general, I think the quality of the connectors on the ecrazyman is pretty low. I hope to change most of them to more reliable and watertight connections.

pics soon 8)

 

[recumbent]

I noticed you started another bike on a seperate thread, do you have this bike going yet?

 

[voicecoils]

I noticed you started another bike on a seperate thread, do you have this bike going yet?

Nope. I'm waiting on the batteries. I suppose I could use my powersupply and a long extension cord

I've got two 36v 10ah battery packs coming. Building an ebike part by part is SLOW especially when 90% of the electrifying parts must be shipped in from overseas. I'll be using the same battery packs on both bikes. Due to the fabrication involved, the DH team bike will likely be an even slower build.

I hope to have the red bike running within a month.

 

[voicecoils]

Photos from my previous update, and

Bafang PMGR in the Sun Rhyno Lite rim. (maybe I should bring my seat up a bit more 8) )
View attachment 4

Lots of wiring to manage. I've started crimping & soldering on my anderson powerpole 45a connectors. Farnell didn't have any red or white ones in stock, but I'll manage with these. Cycle Analyst is also visible.


Here's the cockpit (from left to right): front brake, thumb throttle, cycle analyst, rear brake, 8spd twist grip for rear internal hub.


This was a pain, despite having two throttle types, and hub shifters (rapid fire and twist) very few combinations would actually fit, with room to reach everything. My ideal setup would have had brake thumb throttle and rapid fire shifter all on the right hand. Ah well...



Last one, pretty bafang :wink: (the speed sensor pickup is also visible, for the stand alone CA)

It'll have to do as my avatar for now.

 

[voicecoils]

My CETMArack front rack finally came, but as is it won't fit on the red bike. The legs of the rack can't bolt onto the hub axle because of the shape of the fork dropouts. I either need to make a little adapter that bolts onto the axle to give a mount point for the rack further out, or have some tabs welded onto the lower fronts of the fork legs.

For now I've put it on another bike:

Still handles well with the extra weight, and when I load it up.

 

[electraflyit]

Good thread Voicecoil,

I had just PM a couple of other Aussies here to find out where they where sourcing their parts before I found this thread. But this thread has answered a lot of those questions.
I bought a cheap ebay steel frame DS bike, just ordered a 48v 1000v Golden Motor kit and now looking at all the other bits as money allows.
Torque arms, CA, Circuit Breaker/Switch, Connectors, Wiring, maybe heavy duty spokes. Battery is the last thing, probably a 'ping' 48v 20a when I can afford it (ealry next year maybe). Just looking at getting eveything else set up on the bike first. Anything else you can add would be great.
Maybe we should do a thread for Aussie builders on sourcing parts.

Eddie (Toowoomba QLD)

 

[voicecoils]

Maybe we should do a thread for Aussie builders on sourcing parts.

Eddie (Toowoomba QLD)

Hi Eddie,

As you've probably noticed, much has been sourced from overseas. As for local stuff...

Torque arms: maybe brett @ solarbbq? http://www.users.bigpond.com/solarbbq/torquearmsandwashers.htm and http://www.e-mtb.com.au (email and ask)
CA: http://www.e-mtb.com.au
circuit breakers, switches, fuses, connectors, wiring: Jaycar.com.au, au.farnell.com & others
Spokes: ebay.com.au for crap quality spokes, local bike shops for quality DT or Sapim spokes.

 

[voicecoils]

small updates:

* I've zip tied and electrical taped as much wiring as possible so for, things are looking reasonably neat and organised now 8)

* I've had the hubmotor wheel trued and tensioned by the bikeshop, spins dead straight now. I put a second rim strip on (cloth rim tape first, vinyl type band rim strip second).

* Batteries have arrived in Australia! They should reach me any day now As soon as I get them I'll start planning my battery enclosure.

* I've got a 46t front sprocket (haven't put it on yet) so I'll be able to high a higher top speed while peddling.

 

[voicecoils]

Batteries arrived !!! both packs at 40.2 volts exactly. So that's 3.35v per cell

Will put them on the 3a chargers once I've fit 45a powerpoles to the packs and charger leads.

Time to start making an enclosure.

 

[dontsendbubbamail]

What is that white thingy that the power strip is plugged into?

Bubba

 

[Ben]

What is that white thingy that the power strip is plugged into?

That'd be the Kill-A-Watt Meter.

Lookin' good voicecoils.

 

[voicecoils]

More crap "CAD" incoming. My Bafang PMGR is mounted in the wheel with torque washers, which sits in my cromo rigid fork. However, there are three issues with the setup that are lacking which I'd like to rectify:

* No way to mount a disc brake caliper (no disc mount on the motor either)
* No mount for a torque arm on the fork (and no torque arm)
* No mount for my front rack, shown a few posts back

Here's my idea for a single device to address these issues. A two piece metal collar which can bolt together onto the fork (similar to what Mark_A_W had made for his bike). On one side of the collar would be a mount for the torque arm and the front rack. On the opposite side would be a mount for the disc brake. The second set would not need a disc mount as I would only need one front disc brake.

Here's the rough idea:


(a torque arm is shown but not the front rack arm or disc caliper).

 

[Mark_A_W]

What size tube would you need? How would you hold the tubes on the forks? Hose clamps?

Even with Cro-mo forks, better to be safe than sorry (that's coming from Mr Break-a-frame!).

 

[voicecoils]

What size tube would you need? How would you hold the tubes on the forks? Hose clamps?

Even with Cro-mo forks, better to be safe than sorry (that's coming from Mr Break-a-frame!).

Yes, I'm after a safe and reliable setup for sure.

The forks are ~28.65mm-29mm towards the bottom (they taper down slightly from top crown to dropouts).

Ideally, where they are split in half, there'd be a flange that could be bolted together on each side. I'm more or less just thinking out loud here. There may well be better/easier ways to address the 3 things above. (btw the google sketchUP's are not dimensionally correct, just a method of visualising)

Probably easier to just weld to the fork, now that I'm looking at it...

 

[voicecoils]

Here's a photo I found of your lower supports:

Awesome stuff

 

[voicecoils]

small update:

spent $100 at powerwerx.com on more 45a powerpoles, a crimper, contact remover tool, and some more 45a contacts.

I wasn't completely happy with the "solder & squeeze" job I did to some of my powerpoles. Getting all wire strands wetted and soldered to the contact, without using too much solder making it impossible to crimp into a small enough size to fit into the connector was quite tricky.

I think I'll feel more confident with the result using the proper tool. The quality of the wires used on the battery packs seems low and the gauge is rather high but at least the length is quite short. I'll be happier with a better connection to them.

What's the maximum wire gauge you guys have squeezed into a 45a powerpole?

also, I've bought spare Bafang gears from knuckles along with a sensorless module, some resistors to lower R1 & R3 on my older pic based ecrazyman, and a few hall sensors. When they arrive, I should be pretty well set for any problem that may arise from running the motor at 72v. As long as I don't melt the varnish on the windings I can replace halls, wiring, gears, or go sensorless to keep me on the road.

No battery box, torque arms, rack mount, or disc mount yet...

Also not much new work will be happening for a bit: http://endless-sphere.com/forums/viewtopic.php?f=6&t=6475&st=0&sk=t&sd=a&start=90#p103924

 

[voicecoils]

package from knuckles arrived. good stuff. Fush came by and dropped off my new plug in cycle analyst with current limit switch.

anyone know how to wire the plug in CA to the old ecrazyman 72v pic based controller? I've got a connector, and a separate magnet/sensor pickup from an old bike computer.

Backpack testing has started, but I've been frustrated by the hall wire connector. I've changed to a molex type 6pin one, but it was too late to get back out and test. Hopefully I can spend a bit more time on the bike tomorrow afternoon.

For now, just some pictures...
View attachment 2

 

[voicecoils]

[youtube]Ok44T8AAIEo[/youtube]

motor is making a strange sound when it freewheels and winds down. Not so confidence inspiring sound wise. I will do more testing tomorrow hopefully.

 

[Mathurin]

Oh, man that sucks about the CETMA, gonna make it work? This sounds like a good pretext to whip up some kinda torque arm while you're at it.

Otherwise there's those front racks that make canti braze ons feel self-actualized, they're about sized for a 6 pack. Thing is, one could possibly do a pretty fair job of dissimulating a controller under these if it's painted black... Though they don't seem all that very useful to actually carry stuff, guess they could hold a bag/basket/briefcase if it was bungeed to the handlebars.



Also Wald has some front baskets that would allow carrying groceries and stuff while avoiding the fork end issue.
http://www.waldsports.com/index.cfm/baskets.html


And hey you mentioned you intended to weigh the motor when you'd get it - did you?


Oh and this cycleanalist placement:


I think looks better like this, though IRL it would probably sit further onwards due to the stem and the way the CA's mount is made. It would also likely sit higher then it's current placement, but I figure that won't look jackass cause the risers you're rocking ought to make up for it. Just a thought.

 

[voicecoils]

Oh, man that sucks about the CETMA, gonna make it work? This sounds like a good pretext to whip up some kinda torque arm while you're at it.

I've bought some 5mm stainless plate, just waiting for it to arrive. I'll try to file/drill/saw a pair of torque arms that the CETMA rack supports can bolt on to. Then I either need to hose clamp it to the fork, pay someone to weld it on or make a 'collar' that would clamp to the fork which the torque arm could mount to. I'll make it work somehow.

Plan is to mount the CA on the CETMA rack, there's a perfect place for it. Controller in the battery box hopefully.

Otherwise there's those front racks that make canti braze ons feel self-actualized, they're about sized for a 6 pack. Thing is, one could possibly do a pretty fair job of dissimulating a controller under these if it's painted black... Though they don't seem all that very useful to actually carry stuff, guess they could hold a bag/basket/briefcase if it was bungeed to the handlebars.View attachment 2

That does look nice and simple, probably cheap too! I really like the size of my 5-rail. Any smaller and it would not be that useful. With mine, I can remove the fence and carry even wider things. I'm using it on another bike at the moment and it is great

Also Wald has some front baskets that would allow carrying groceries and stuff while avoiding the fork end issue.
http://www.waldsports.com/index.cfm/baskets.html

They look nice too. I'd like to have everything bolted down though and my ride is mostly with traffic mostly signposted at 60kph (ranges from 40-70kph).

And hey you mentioned you intended to weigh the motor when you'd get it - did you?

Yes I did, I need to find the bit of paper I wrote the weight down on, from memory it was 3.2kg (bit over claimed weight).

Also, I read you're looking to reduce weight on it. Don't bother, the weight is in two areas: things that can't be changed as they're necessary (like windings, magnets, gears) and things that are the result of manufacturing and material selection (like the outer housing, inner motor housing, axle).

You could do small modifications but the gains would be insignificant. Most of us are using the Bafang beyond it's designed uses (36v, 10a, ~350W) so IMHO weight reduction is asking for trouble.

My suggestions would be: use high quality 14ga spokes (sapim or DT Swiss) and have your hubmotor built into the nicest (strong/light) rim for your particular intended use. Then run light weight tubes and tires. If you plan to run disc brakes, get a disc specific rim, they don't waste weight on having a machined braking surface.

 

[Mathurin]

Oh, how disappointing, would have hoped it was slightly under 3Kg. Oh well.

Thing is I'm dreaming of a bike that, excluding backpack battery, would weigh < 10Kg complete with full fenders, a usable rack, lights & reflectors, bottle cages, minimal exposed mechanisms (hub motor, SS drive line) and for it to seem a bit ratty/not worth stealing. I don't think this is possible, but 12-15Kg would be fine too I guess. In any case it clearly isn't within my current means, but I'm sure I can reach an approximation of success over the next few years. It's just that I'm gonna have to pay attention to details, such as how weight could be removed from the Bafang motor if I end up using it.

For what concerns brakes, I figure: Disks would mean 150 to 350 extra grams over rim brakes and the heaviest (well, first step up from disposable bike grade) cantis are about as light as the lightest V's. So that's pretty much settled. If my legs weren't all messed up the plan would be to go fixed so I could nuke the rear brake & braze-ons, also save on freewheel vs cog + lock ring weight.

 

[voicecoils]

Oh, how disappointing, would have hoped it was slightly under 3Kg.

10 kg is a BIG ask. My road bike (with carbon fork & rearstays & Campag 10 spd) weights ~8.3kg. It's to fragile to use as an everyday bike and has no fenders/rack/light/reflectors The only way I can see you getting motorized with that weight budget is to us an RC motor and friction drive. The motor+controller+friction/freewheel mechanism might weigh 2kg with wiring.

You would think that singlespeed/fixed gear = light weight but that's not the case. Track components are not that light, the 1/2" chain alone is pretty porky.

Otherwise you need to make your own carbon fibre & kevlar hubmotor with ceramic bearings and a titanium axle.

 

[Mathurin]

Yep! Nearly impossible, hence 10Kg as dream weight. If I had real deep pockets I'd get me a Moots made with shoddy looking welds and supercycle decals on it. I can't even imagine how seriously awesome such a bike would be. But it's also why 12-15Kg would be fine too.

Trouble with RC motors is that exposed mechanisms degrade fast, need frequent maintenance and occasionally end up frozen in winter usage, so a hub motor seems a better choice. And for the SS drive line, you know I was thinking 3/8 stuff and nothing close to NJS-legal.

But anyways I'll stop derailing your thread now, wishing you the best in getting that freewheeling sound issue worked out so you can enjoy your ride again!

 

[voicecoils]

PEANUT BUTTER !!!

Long story in this post, short version below.

After my first quick night test, I sorted out the hall connectors, now everything is tightly connected. No problems there. Next morning I went out again.

3min 12seconds of fun, according to the cycle analyst.

I have peanut butter gears. No catastrophic failure sounds, but a grinding noise and loss of power to the ground.

My cycle analyst reported max amps at 31.71A (I have a 30A 12v blade
fuse on the battery +) so I don't think I was pulling 30+ A for many
seconds.

Eased the throttle on to full throttle going down a gentle hill and
kept the throttle wide open as I hit the bottom and started heading up
a gentle hill again. The grinding started as I was heading up hill.
Max reported speed was only 22.3 mph so nothing crazy! Was definitely
not using the brakes and throttle at the same time either.

Spend about 2 hours getting the munched gears out and replacing with new ones. It's quite straightforward (after knuckles gave me some guidance and explanation) but getting the gears off their posts is a major pain. It's doable but not fun.

With new gears, I took the bike out again last night. (see the graphs)

The second set of gears lasted almost 6km and nearly 15min. Not as
badly mangled but not usable.

I was very gentle on the throttle this time, max amps 17.75A, min voltage 67.7V.
Max speed 47.8 kph. (GPS, see attached)
Did not hit the throttle till I was already peddling and moving.
Rolled the power on very slowly to try to engage the gears smoothly.
The motor/controller does make a few jumps with the throttle, especially towards WOT. ie rolling the throttle on smoothly doesn't correspond with a completely linear increase in speed/power. "jumpyness" seems dangerous for these gears.

I need a solution. Even a bucket of nylon gears would not be suitable
as changing them is a chore. Unless there is a bigger problem with my motor, the gears are just a MAJOR weak link in the system.

It's an awesome little motor otherwise. The ride only warmed it up a
bit and it rides great on the flat. I need to be able to use the full
30A so I get get some assistance up hills though. A metal or
composite gear setup is the only thing I can think would work.

 

[voicecoils]

I've killed two sets of gears now.

At this rate, my first ride cost me $10/min, and my second ride cost me $5/ kilometer. Petrol is starting to look cheap!

Running 72v nominal, 30A fuse on the battery, ~28A controller.

I'd love suggestions on how to get back on the road. Metal or composite gears? Magic gear lubricant? Is voltage or current the bigger problem?

The gears certainly don't LOOK like they'd last long under any decent power, and they seem to behave that way for me to. Others have been running the Bafang motor without any problems. I'd like to join that group