DIY stage 3: motor testing, on fork [photos]

[daniel.weck]

Table of Contents:

http://www.pedelecs.co.uk/forum/electric-bicycles/4682-diy-stage-1-received-bafang-tongxin-kits-photos.html#post59183

http://www.pedelecs.co.uk/forum/electric-bicycles/4734-diy-stage-2-received-li-ping-lifepo4-battery-photos.html#post59988

http://www.pedelecs.co.uk/forum/electric-bicycles/4737-diy-stage-3-motor-testing-fork-photos.html#post60039

http://www.pedelecs.co.uk/forum/electric-bicycles/4747-diy-stage-4-16-wheel-lacing-building-photos.html#post60153

http://www.pedelecs.co.uk/forum/electric-bicycles/4769-diy-stage-5-prepping-fitting-electricals-photos.html#post60345

http://www.pedelecs.co.uk/forum/electric-bicycles/4778-diy-stage-6-fork-hub-torque-protection-photos.html#post60504

http://www.pedelecs.co.uk/forum/electric-bicycles/4786-diy-stage-7-first-ride.html#post60641

http://www.pedelecs.co.uk/forum/electric-bicycles/4825-diy-stage-8-continuous-improvements.html#post60991

http://www.pedelecs.co.uk/forum/electric-bicycles/6956-diy-stage-9-a123-nano-battery-pack-photos.html#post88165

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Let's pretend I'm an electronics wizard, in my ultra-sophisticated e-bike lab (aka "my kitchen")

 

[daniel.weck]

I tested the 3-speed controller...pretty useful feature indeed
(reminder: the Tongxin and and Bafang motors have the same controller hardware, but different software/firmware configuration)

I will post movies as soon as I know how

EDIT: my first YouTube videos ! (in full CD "Crap Definition"[tm])

Bafang:
YouTube - Bafang hub motor testing

Tongxin:
YouTube - Tongxin hub motor testing

 

[daniel.weck]

The Tongxin is 80mm wide, whereas the Bafang is 10mm wide. I used a single fork for testing, so I first widened* it to accommodate the Tongxin, then for the Bafang. I had to enlarge the dropouts openings to 10mm (by grinding off some steel), because the original Brompton/Merc axles are about 1mm thinner.

* To widen the fork, I used the most ancient tool of them all: muscle power. I didn't do a very neat job to be honest, but I knew it would take a few takes, thus why I am experimenting on my cheap Merc before I work more seriously on the much more expensive Brompton. I had to straighten the dropouts to re-align them (after widening, they were not parallel, they were pointing outwards). The actual act of widening is surprisingly easy, as it requires very little force. I guess this old fork uses pretty soft steel. I will build a screw rig for when I do the Brompton.

EDIT: here are photos of my high-tech fork widening/narrowing tool !

 

[Northern Irelander]

Have you tried using some M1O thread bar to widen the forks, now that the axles are 10mm wide, just slide a the thread bar with some washers and M10 nuts on the inside.

Tighten the nuts up to the inside of the forks, turn each nut a full turn, mark one of the 6 sides to keep track of orientation.

Each full turn will widen each side by 2mm.

You dont have to bend the forks just spring them out a little before cold setting.

 

[jerrysimon]

As always Daniel excellent post. Videos a little small but its great your putting all this stuff up for us to see, and funding the project for us.

The Tongxin (the clearer of the two videos) is possibly quieter though there is a lot of background noise so its hard to tell. Mine is pretty much silent when powered on.

Also hard at this stage to see what the free wheel of both motors is like.

I guess we will have to wait and see till you spoke them both up into wheels.

Love the workshop. If my missis was there she would go balistic if I used the kitchen. Guess I am lucky to have a 20 * 20 foot workshop

Regards

Jerry

 

[daniel.weck]

Love the workshop. If my missis was there she would go balistic if I used the kitchen. Guess I am lucky to have a 20 * 20 foot workshop

My wife doesn't know
...yet

 

[GT3]

Have you tried using some M1O thread bar to widen the forks, now that the axles are 10mm wide, just slide a the thread bar with some washers and M10 nuts on the inside.

Tighten the nuts up to the inside of the forks, turn each nut a full turn, mark one of the 6 sides to keep track of orientation.

Each full turn will widen each side by 2mm.

You dont have to bend the forks just spring them out a little before cold setting.

I'm no engineer, but the assumption you can move each fork independently requires the all thread to be fixed between the forks, otherwise Newton interferes?

 

[Pedalo]

Another good post Daniel - thanks for taking the time to show us what you're doing. It's very interesting for me becuase I'm thinking of doing something similar.

The 3 way switch looks like a useful addition to the standard throttle/brake arrangement.

Do you need a special controller to accomodate it or does it simply hook in to the throttle circuitry? Can you adjust the speeds?

Thanks again.

 

[didi28]

The 3 way switch looks like a useful addition to the standard throttle/brake arrangement. Do you need a special controller to accomodate it or does it simply hook in to the throttle circuitry? Can you adjust the speeds?

You need the special 3-switch-controller. The controller is programmable, so you can adjust the 3 speeds. You need a special software and connector and you have to open the controller to do the programming. If you don `t take care, you can destroy the controller, the programming is something for experts. It is safer and easier you let it be done by the dealer.

 

[daniel.weck]

The controller is programmable, so you can adjust the 3 speeds. You need a special software and connector and you have to open the controller to do the programming. If you don `t take care, you can destroy the controller, the programming is something for experts. It is safer and easier you let it be done by the dealer.

Yes, you need a special USB data cable, and a Windows software called "Parameter Designer" (note: i don't have it) to modify the firmware settings of the controller. There is a new version of the desktop software, but it is for the 116 MCU chipset that is used in hardware compatible with hall-sensor motors. The Tongxin and Bafang do not have such sensors, as the signal is fed back to the controller through the main 3 power cables (other motors have 5 extra wires for the hall-sensor).

There's a lot more info on the Endless Sphere forums:

Endless-sphere.com • Index page

Cheers, Dan

 

[jerrysimon]

My Bafang in my Alien kit must be different as it has more than the three main thick wires coming out of the hub wheel ?

Ah unless its because yours is the new Fun one ?

Regards

Jerry

 

[Northern Irelander]

I'm no engineer, but the assumption you can move each fork independently requires the all thread to be fixed between the forks, otherwise Newton interferes?

Yes, true, although I did not say each fork would move independently, the forks move apart relative to pressure exerted.

It's much better than bending it with a 2 x 2

 

[daniel.weck]

My Bafang in my Alien kit must be different as it has more than the three main thick wires coming out of the hub wheel ?

Ah unless its because yours is the new Fun one ?

Yep, the 8-Fun with side-entry cable (no hollow axle/spindle) only has 3 wires.

 

[my.motion]

fuse

Hi,

Are you planning to install fuse between controller and battery? My fuse wire is not breaking but the sides are melting. I may get the maplins fuse protector

Regards,

Motion

 

[daniel.weck]

Are you planning to install fuse between controller and battery? My fuse wire is not breaking but the sides are melting. I may get the maplins fuse protector

No, just a high-quality connector, see the photos here:

http://www.pedelecs.co.uk/forum/electric-bicycles/4682-diy-stage-1-received-bafang-tongxin-kits-photos.html#post59183

 

[daniel.weck]

Have you tried using some M1O thread bar to widen the forks, now that the axles are 10mm wide, just slide a the thread bar with some washers and M10 nuts on the inside.

Tighten the nuts up to the inside of the forks, turn each nut a full turn, mark one of the 6 sides to keep track of orientation.

Each full turn will widen each side by 2mm.

You dont have to bend the forks just spring them out a little before cold setting.

Update, see here:

http://www.pedelecs.co.uk/forum/electric-bicycles/4737-diy-stage-3-motor-testing-fork-photos.html#post60041