# RIPPERTON Electric Bicycle



## RIPPERTON (Jan 26, 2010)

This hack was my first ever Evert. Started off costing me nothing and steadily got expensive.


It started off with a Unite 24v 200W brushed DC running an on/off switch, no controller and some DeWalt solderless packs.


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## RIPPERTON (Jan 26, 2010)

Then it got LiPo's


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## RIPPERTON (Jan 26, 2010)

So I got a new bigger motor
36v 300W










And of course a bigger battery pack, $550 worth of NanoTechs 20s 2p 84v 10ah










An of course couldnt run all that grunt through a switch so got a Kelly


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## RIPPERTON (Jan 26, 2010)

Only problem now is the weak spot is now the brushes again.
I first got this latest build finished at 10pm at night after work and went around the block in the dark. Kelly's come form the factory set at 100% output and I was hearing a strange sizzling noise at anything close to half throttle, sounded like sausages but I looked down and the brushes were glowing in the dark. !! 
Ive figured the brushes are too small and they are wearing out at a very fast rate so I want to make a new brush holder with bigger brushes.

The originals are 5mm x 5.4mm but the com will allow a 10mm wide brush.
The original brushes will contact 2 com segments at once but what Im trying to figure out is can I use a thicker brush that will contact 3 segments at once ???


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## RIPPERTON (Jan 26, 2010)

with a 3 teeth pitch, 2 coils spans (white) the same width as the magnet.
3 coils are in green



















brush timing


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## major (Apr 4, 2008)

RIPPERTON said:


> Only problem now is the weak spot is now the brushes again.
> The originals are 5mm x 5.4mm but the com will allow a 10mm wide brush.


Wider in that dimension will help a lot.



> The original brushes will contact 2 com segments at once but what Im trying to figure out is can I use a thicker brush that will contact 3 segments at once ???


Thicker in this direction can have adverse affect and could make it worse. Ideally the brush would be thin. Some thickness is needed obviously. But as you expand the thickness you start commutating coils under the influence of magnet flux causing more arcing and also circulating currents on the face of the brush. 

Maybe you need a bigger (or better) motor


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## RIPPERTON (Jan 26, 2010)

major said:


> Wider in that dimension will help a lot.
> Thicker in this direction can have adverse affect and could make it worse. Ideally the brush would be thin. Some thickness is needed obviously. But as you expand the thickness you start commutating coils under the influence of magnet flux causing more arcing and also circulating currents on the face of the brush.
> Maybe you need a bigger (or better) motor


I thought so
yeah I could just go to a Motenergy but I want to first exhaust all my creative redesigning possibilities.
Motenergy is a lot heavier too.


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## Ziggythewiz (May 16, 2010)

The initial build looks a lot like one I was working on. What was the performance like?


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## RIPPERTON (Jan 26, 2010)

Ziggythewiz said:


> The initial build looks a lot like one I was working on. What was the performance like?


With the A123's (Ebay) and 200w it would get 43kmh with its 5 speed cluster.
Once did 27km on a charge but it took a few years to weed out all the dud b grade cells.
Some cells would crash every single charge and cut it short. I would charge each pack individually with a 12v lithium charger.


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## RIPPERTON (Jan 26, 2010)

just bought 8 of these for $34
6mm thick 11mm wide and 30mm long
should be able to linish them down.
have designed a new holder out of acetal
pics later


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## RIPPERTON (Jan 26, 2010)

Just in case any of you were suspecting that I was some kind of Mechanical Design Super Genius, the next few posts should put a stop that crazy talk.

I made the new brush holder out of Acetal.
Acetal melts
Brushes get very hot at 100 amps
brushes stick to the molten Acetal holder and......
you can guess the rest


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## RIPPERTON (Jan 26, 2010)

So I ripped the DC motor out of the bike in disgust and threw it in the corner and did the right thing and put a brushless hub motor in it. I had 3 new Honeywell hall sensors and thicker phase cables put in by voicecoils and I drilled the other side of the axle out, ran 2 phase cables out through the original axle drilling and the third phase cable and the hall wires out through the new axle drilling.
Does 25km on the 4 Turnigys, cruises at 45kmh and top of 70kmh.
Its going to need another 4 Turnigys and then I can crank the amps up on the Kelly.
Now it needs a new bike with dual suspension to handle the speed.


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## RIPPERTON (Jan 26, 2010)

little tip about rs232 plugs on Kelly's
I could not get my config program to boot up even if I twisted the cable plug end or held it off to one side. Could only assume the pins were loose and not contacting so I smeared some carbon grease in to the holes on the Kelly end and booted first go  make sure you clean the excess grease off well before booting


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## CrazyAl (May 9, 2011)

Thanks for sharing. That information is helpful. I'm in the process of modifying more Electric Starter Motors for my Electric Go Kart. 

I've already isolated the negative from the case, added another terminal for the other set of brushes (this makes it easier to go reverse) and will attach the sprocket to the go kart in such a way that it can turn in both directions and also not slide along the axis of the shaft.

I'm also looking to add water cooling.
I'm most likely to use the cooling system as seen on the Catavolt at the last round, but I may use a cooling system similar to yours (Ripperton) in the future.

Next time you are at Wakefield, I need to check out how you made your motor liquid cooled. I might even bring my go kart down so you can all see it.


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## Salty9 (Jul 13, 2009)

CrazyAl said:


> Thanks for sharing. That information is helpful. I'm in the process of modifying more Electric Starter Motors for my Electric Go Kart.


I was wondering about this as the duty cycle of most starters in the states is less than a minute but according to Al's blog it is not one of our starters.


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## CrazyAl (May 9, 2011)

Salty9 said:


> I was wondering about this as the duty cycle of most starters in the states is less than a minute but according to Al's blog it is not one of our starters.


I agree that the duty cycle of most starters is less than a minute. In fact, they are typically designed to run for only 10 seconds, then need a break for around a minute.

However, when put on a go kart, it does not have to turn over a gas engine, hence, why I could run mine for longer than 10 seconds.
However, the modified starter motor did get extremely hot as there are no cooling fans, fins or liquid cooling. I often had a bottle of water near by to pour on the motor when it got hot. I'm now working on cooling systems for the motor as I believe I can get more power, torque and have the motor last longer if I implement cooling on the motor.

The starter motor I modified for my Electric Go Kart is typically found on some Kohler gas engines, some John Deere equipment and some B&S gas engines.

Unlike most starter motors you find on cars & trucks, where there is a solenoid to throw the pinion out, this style of starter motor has grooves on the shaft and when the spins, the pinion is thrown out. I simply removed the springs and locked the pinion (with the welded sprocket) into position by packing washers on the shaft.

Some early model English cars also had this style of starter motor.

In the future, I am looking to modify a 24volt starter motor similar to that found on diesel trucks. This one will have a solenoid that throws the pinion out, so I will have to work out how to deal with that one.
Also, I believe a lot of those starter motors are series wound DC motors so if I want to reverse it, I will need to do more modifications. This will involve separating the field winding circuit from the armature circuit.


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## RIPPERTON (Jan 26, 2010)

I replaced the racing bike with a shocky bike for $100 off Ebay almost new.
will need a bigger shock in the back.
the seat pole tower will be cut out to make way for the battery pack an a new seat tower made from 3mm alloy coming from behind the steering head.
I have left the rear derailleur for chain tensioning but not for shifting and the front derailleur will still have its 3 speeds. All I need for keeping up with the hub.


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