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

monkeychops

monkeychops

100 W
Joined
Oct 17, 2011
Messages
160
Location
Wiltshire, United Kingdom
.... or confessions of an impatient newbie bodger.

I have this:
View attachment 1

which I'm told is Chinese in origin and they were imported into Canada under the name 'Strong GT', or Strong GT-S210. I bought mine from a little shop in London 10 years ago and they called it a 'Tornado'. Just recently I've switched from a 16Kg SLA battery pack to lipos (about 3Kg). Anyway, the brushed motor is noisy and slow and underpowered.

So this has just arrived from cellman (http://www.emissions-free.com/catalog/i14.html)
P1070542.JPG

I will add more photos as I go along, mistakes and all.
 
Thanks for the support. I guess one of my first questions is where to put the controller. It's too big to put in the little box where the stock one goes.

In the meantime, some more pics.

20120227_194715.jpg
View attachment 1


New axle looks much more suited to anti-torque measures than old one. Unfortunately I can't see an easy way to fit the Dr Bass torque plates I've bought. Fortunately my existing torque plate and wrench torque arm will be more effective on this axle.
 
monkeychops said:
Thanks for the support. I guess one of my first questions is where to put the controller. It's too big to put in the little box where the stock one goes.


New axle looks much more suited to anti-torque measures than old one. Unfortunately I can't see an easy way to fit the Dr Bass torque plates I've bought. Fortunately my existing torque plate and wrench torque arm will be more effective on this axle.
Click to expand...

What are the dimensions of the controller?
I may go downtube.
It could go on the seat to side frame rails, or in the swingarm area, as well.

Options.

Ditch the stock torque arm crap.
Then Epoxy Dr.Bass' plates on the inside of the swingarm.
There is lots of space. Too much.
You will soon find. That old motor was wide
175mm. You are going to need washers to space things out, for alignment sake.
:mrgreen:

*edit*
I had a difficult time getting the alignment just right with the Hx3540.
It felt good on the Strong frame, but a 40kph it had a crabwalk wobble.
The scooter motor I am using instead, aligns like it was meant to be :wink:
 
monkeychops said:
Some good advice there, thanks Brentis.

A pic showing how much space there is:


Space for fat torque place plus additional spacer(s) required to secure the wheel.
Click to expand...

Also consider front to rear wheel alignment.
The spacing issues I found to be two fold.
1. 175mm worth of space for a motor designed for 135mm.
2. To get the proper wheel alignment. So it wont "crabwalk" as it did with my Hx3540 tests.
the derailleur did not function as intended. I could only use, low or is it high?, 11 tooth cog.
& the proper wheel alignment requires a brake caliper & or disc spacer to make it work.
These issues are fairly easy to overcome.
Do you have regen brake on that controller. Thats the simplest solution.
If I can help, post a ?, I'm following this thread now.
Good luck
:mrgreen:
 
I've ordered a few washers to act as spacers to get the disc brake caliper and disc aligned.
I only realised about the gear issue when you mentioned it. I guess there is no way around it? I can probably live with it.
The 175mm of space can be compressed to 165mm as the steel bends a bit. But still too much space. I have ordered some 14mm washers for spacers. I will use the Dr Bass torque plate(s) too.
No regen brake on the controller.
Controller dimensions are 140mm x 80mm x 43mm.
Current favourite location for the controller is lying flat between the rear pannier rack and the seat post, resting on the pannier supports and junction of mudguard/seat post.
 
monkeychops said:
I've ordered a few washers to act as spacers to get the disc brake caliper and disc aligned.
I only realised about the gear issue when you mentioned it. I guess there is no way around it? I can probably live with it.
The 175mm of space can be compressed to 165mm as the steel bends a bit. But still too much space. I have ordered some 14mm washers for spacers. I will use the Dr Bass torque plate(s) too.
No regen brake on the controller.
Controller dimensions are 140mm x 80mm x 43mm.
Current favourite location for the controller is lying flat between the rear pannier rack and the seat post, resting on the pannier supports and junction of mudguard/seat post.
Click to expand...


That's pretty small.
I was going to suggest that controller position as well.
Lots of room down your seat post to. Yours is quite high.

+1 on the Dr.Bass plates.

*Edit*
With doc's plates on the inside of the swingarm. You may be able to MacGyver the derailleur in closer using more gears.
*edit*

I only ever used the smallest cog anyways. No loss for me gear wise :wink:
In fact with the scooter hub I will have a single speed freewheel & will run it as such.

Keep us posted.
:mrgreen:
 
+1 subscribed to your new thread. You've come a long way monkeychops!
 
Trying to drill a hole through Dr Bass torque plate:

20120301_073701.jpg

2 broken drill bits. I will keep going tonight. The hole is about 1/5 of the way through.

<edit>heat = bad when drilling a hole, I will use oil to help cool the drill bit</edit>
 
I agree, a drill press will avoid a lot of frustration. For hard steel, I would start by drilling a 5/32"- 3\16" pilot hole at ~250rpm. A smaller bit will just burn out immediately. You also need to apply the correct pressure in order to maintain a sharp bit. Too little pressure and the bit just rubs against the metal and becomes dull.Too much pressure and the bit succombs under fatigue, dulls and breaks. Try and maintain feed just at the pressure point where the bit has a definite bite and you can see the resulting shavings. Only drill for about 5-7 second intervals, relieving the pressure and reoiling at each interval, allowing the bit to cool. Higher quality bits (I use Dormer) definitely help but may not be econonically feasable, unless you have sharpening skills. Just get some good quality bits and consider them dispoable.
Hope this helps.
 
These did the job:
20120301_211955.jpg
I drilled slowly and used oil and they worked fine. Took about 10 minutes.

I bought a stand!
20120301_230850.jpg
£38 delivered on eBay.

I found that Dr Bass's torque plates make great spacers:
20120301_230639.jpg
and
20120301_230711.jpg

The steel bends more than I thought. The drop outs are closer together by about 15 - 20mm when the axle nuts are tightened up compared to their positions when the wheel is off.

made a bit of a cock up with the hole I drilled in one of the torque plates. The hole is too close to the main axle nut. So I will probably end up gluing the torque plate on anyway. I just feel better about bolting things.
 
Is that hub motor geared? I always thought gearless were such a large diameter, thinner width...
 
:oops: Ok, confession time. :oops:

The 3 times I've connected up the batteries to the controller to test things, there is a flash and a bang :shock: and some blackening of the connectors.
The first time it was small and reminded me of when I used to connect up the batteries to the IMAX B6 charger without turning the charger on first.
But the last one was a bigger flash. I thought: no more, this can't be right, confess all to the good people on E-S, they can probably help?

:?:
 
sure. you need a preload resistor or some more sofisticated solution with a mosfet.
google for it on E-S.
the sparks happen because there are caps in the controller which are "loaded". as caps take a lot of power in a very short time, connecting the battery to the controller is close to shortening it. so there is high current running there for a very short time - this causes a spark.
 
Ok, thanks for that.
Is one of these preload resistors actually needed then?
There is a switch with a key on the bike which I will be using.
I don't know if this will help prevent a spark anywhere, but under normal use I don't think I'll be able to see if it it does spark.
20120304_123130.jpg
 
an 'ignition' key has nothing to do with that. as soon as you connect the battery to the controller there will be a spark. so if you connect two plugs or turn a key (which connects the battery to the controller) is the very same thing. you still need a preload resistor to not destroy the contacts over time - burned contacts are bad in two ways - first resistance raises due to the burned surface, and finally the contact will be totally burned and there will be no contact at all - of course depending on how big sparks are). or you use a mosfet which will act as a switch controlled by the current running through it with the only difference that it slowly (for sparks we are talking milli-seconds ;) charging. so voltage raises from zero volt to full volt within some tenth of a second, which loads the capacitors slowly - so no spark :)

i hope i explained that in a way everyone can follow
 
Learn to love the spark. It gets addictive....

Another few months of it and you will have superhero like powers. Honest.
 
Got the wheel secured on. Quite a fiddle. Lots of different sized washers needed.
As Brentis pointed out, spacers for both the disc and caliper were required.
Needed to file a few nuts and bolts down a bit too as the main axle nut and bolt were snagging against the torque plate nut/bolt (the c0ck up from earlier).
Also got the controller (in sandwich box) secured on. I admit, it's not a great look but I wanted to weather proof the controller and connectors as well as having easy access to it.
Anyway, the photos:

View attachment 3
20120306_081328.jpg
20120306_081512.jpg
20120306_081559.jpg

Not all wired up yet and I need to make an sizable exit hole for the controller wires.
 
Wait till ya test ride it & have to fiddle 2-3 more times.
"Crabwalk" miss-alignment is very dangerous.
Leaned over in a corner, Bam, you hit the ground.
It will toss you.

As for the "sandwich case" controller protection.
Consider spray painting the inside black. That will make it look like it was designed for such a use. :wink:
But, if you start running higher power that controller will heat up.
It needs airflow for cooling.
Monitor for awhile see if it heats up.
My controller @1500 w has never gotten so much as warm.
I think it would do fine in such an environment.

Good luck to you.
Hope it doesn't take you as many tries. :lol:
The bike is coming along nicely.
 
Thread about adding pre-charge resistors, to avoid that spark....

http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=37213&p=541150&hilit=precharge#p541101
 
You must log in or register to reply here.
Back
Top