prima bike

[mr.electric]

This is my prima bike with the full fairing removed. It originally has a pedelec controller set up.

 

[mr.electric]

The SLA pack is very low capacity

 

[mr.electric]

The prima is unusual because it is made in Italy . It also had typical euro ebike controls with eco and power settings and a generator light set up. It has a Sachs brand 5 speed internal hub with a drum brake that I have not seen before.
The frame is made of a few cast aluminum parts that are bolted together.

 

[mr.electric]

Bike pics coming

 

[mr.electric]

This is what it looks like.

 

[StudEbiker]

Did you keep the original motor?? Was there something wrong with it? See my sig. to see the Prima I'm working on.

 

[mr.electric]

It is an unusual 4 wire sensorless motor. Another thing strange about the motor is you have to take off all the spokes to seperate the two halves of the case.

 

[olaf-lampe]

Yes I stll have the original motor. It is an unusual 4 wire sensorless motor.

It seems to be a geared double DC brushed motor hub. My father has such a hub in a german brand bike. The two motors are Mabuchi 540/Johnson 600 style. The gears become very noisy over time and efficiency is getting lower and lower.
-Olaf

 

[mr.electric]

Good info. I will try powering the wires to see if it spins and test if it a double motor brushed .

 

[olaf-lampe]

On another subject, If I switch my brushless hubmotor from 36v to 48 v will the bike obtain a higher top speed or accelerate more agressively or both?

Both,but it can trigger the over current limit of the controller and the 48V battery must be able to handle the higher current peaks too.
-Olaf

 

[mr.electric]

I went on a good ride today. This bike is perfect for going to the coffee shop. It has nice frame geometry and commuter style parts.

 

[chvidgov.bc.ca]

Is it just my imagination or is this torque arm on backwards? Shouldn't it be on the other side of the dropout? The hose clamp currently is pulling in the same direction as the torque, which is opposite to the rotation of the wheel?

 

[olaf-lampe]

Is it just my imagination or is this torque arm on backwards? Shouldn't it be on the other side of the dropout? The hose clamp currently is pulling in the same direction as the torque, which is opposite to the rotation of the wheel?

It looks a bit odd to me too. I feel it is pretty useless, because the horizontal arm can move a lot in both directions...
Just my 2 cent...
-Olaf

 

[skeetab5780]

ya it looks backwards to me also. it would be spinning the opposite direction of the wheels normal drive

 

[skeetab5780]

very nice progress by the way. clean looking and unique

 

[ambroseliao]

That's a great looking ebike. I love the look of it with the fairing.

As for the torque arm. The ones on your eBikeKit.com motor are the older style. I would check with them to get the newer adjustable torque arm.

http://www.e-bikekit.com/shop/index.php?p=product&id=31&parent=5

Ambrose

 

[mr.electric]

It looks like the torque arm can move but it is quite solid. I used a high quality clamp. The bike looks good.

 

[mr.electric]

My build is done except for an on status light. I cannot find anything that will work simply and easily to give me an LEd when the controller is on to remind me if the bike has been left on.
I see chips like this one
http://www.allelectronics.com/make-a-store/item/LM317LZ/ADJ.-VOLTAGE-REGULATOR/-/1.html

but I wonder if there is something inside the e-bike kit controller already at 5v that I could use. I know the throttle gets 5v.

I used this head light on/off switch for the power switch. It gives a satisfying clunck noise when pulled. These are cheap heavy duty switches. I want to mount the on status lamp right next to the switch.

 

[mr.electric]

I was bothered by the low quality chinese plugs so I decided to hardwire the connections. This is before.

 

[mr.electric]

This is after. I used a seemless barrel type crimp connector covered with glue lined heat shrink for all the connections.

 

[mr.electric]

I am an auto electrical mechanic by trade and I spend several hours a month trouble shooting bad connectors in cars. I had a feeling these low quality plugs would eventually be a problem. (Edit) I am impressed with the quality of the e-bike kit parts for the money. I would say it is the best sub $500 all included system.

 

[mr.electric]

Finally I installed a charge jack.

 

[Geebee]

Why not hang a LED with the appropriate resistor (plenty of calcs online) between the switch output and the Negative on the battery.
Cheap and reliable.

 

[mr.electric]

I did this on a previous build. I thought the resistor would slowly generate heat and eventually get very hot. It was the correct sized resistor as recommended by Fechter. Does this sound right? I cannot remember clearly if it eventually ( after being on for over an hour) got very hot.

 

[mr.electric]

I found some left over parts from a previous build that may work to give me a power on status light.
I have some red LEDs with black plastic mounting sleeves with integral resistors designed to operate at 12v. I also have a few large 3.9k ohm resistors at least 3 watts but maybe higher wattage. I also have a few 2.7k ohm 3 watt resistors. I have the 12v integral resistor led and the 3.9k resistor connected to 48v now. The LED is dropping 8 volts the resistor 40 volts. I will leave it on for a few hours and see if it gets hot. If I solve for the current draw I get I=E/R 40v/3.9kohms = 10ma
If I use the other resistor I get 40v/2.7kohms=15ma. Either option sounds good but I thought you had to consider the wattage of the resistor in the equation.