I want to replace my brushed lynch motor - target 35kW/18kg?

[c_a]

Hello!

Last year I used a lynch D127 in my www.epo-bike.de, we used the motor at ~100V (28s Lipo) and ~380Amps. We got 34 real HP at the rear wheel. Total efficiency only 65%.

I am searching for a brushless motor with a maximum weight of 18kg including the controller.

When we started with building our bike we used 4kWh headway cells, the total weight was 124kg. Then we used polyquest lipo and the total weight with 5kWh was 113kg (topspeed 100mph). Now with new 8% lighter batteries and some over improvements we are at 95kg and 5,2kWh. Lynch motor and Kellycontroller have a total weight of 14kg.

A total of under 100kg would be fine.

What for a motor can I use to get a high efficient drive train?

Thanks!
Best regards
Christian

 

[Bluefang]

Have you looked at Agni motors that everyone seems to talk about. http://endless-sphere.com/forums/viewtopic.php?f=10&t=12480 is a build using 2 of them, but thats only 30kw peak from what has been said. Otherwise your talking big money it seems to get motors any bigger. Or using multiples. Best bet is to read thru the motorbike forum for ideas. The Colossus motor which could probably do what you want still seems to be in testing atm.

I am thinking the best way to get a high powered light weight system with out breaking the bank might be to link up a bunch of Turnigy 80-100 motors that have new bearings and been rewound per Thuds DIY thread. They weigh about 2kg each 4 would be able to handle peaks of 35kw running at a high voltage. If you setup a 12fet controller to run 120V it should be able to pump out the required amps to run each motor. This setup would even be alot cheaper then the others, $400 for the motors, $100 for bearings and wire to rewind, $800 for the controllers(getting someone on the forum to mod them up should be possible). I think a even better approach would be to then link these motors to a gearbox, either a Thud special or a CVT drive from a large scooter(250~500cc) will handle the power. 300% gear range and no shifting = Godlike

 

[c_a]

Hi,

a twin setup is at least 30kg. I have not enough room in the bike.

I already tought about four or six turnigy motors, but I found no good controller (4 or 6 controllers...)

 

[joec]

I'm not sure about controllers, or if these are even suitable or shipping as a product, but the specs are impressive:

http://www.jobymotors.com/public/views/pages/products.php

A pair of those at 4kg each and 20kw peak would leave 10kg for the controller and supporting hardware.

 

[Bluefang]

Lyen builds something that would work, may need to put some braided wire along the traces but its a solid start.
http://endless-sphere.com/forums/viewtopic.php?f=31&t=18214&hilit=150V

Steveo is building controllers with 4110 Mosfets that would limit you to 100V max, you may be able to ask him to build afew for you with 4115 mosfets or similar. His controllers are slightly more hardcore then Lyens as he has done extra work with building the traces with braided wire etc so his controller i would think will cost abit more. But would almost be a plug and play controller for max power.
http://endless-sphere.com/forums/viewtopic.php?f=31&t=29107

The next bit i would look at getting is one of burties timing tools for each motor/controller. Probably the best improvement in recent times for these high speed RC motors and E-bike controllers.
http://endless-sphere.com/forums/viewtopic.php?f=31&t=26068

 

[Doctorbass]

Go with the AC15 motor. This motor is a ral beast and can be overvolted alot more than the brushed motor.!!


Doc

 

[liveforphysics]

Go with the AC15 motor. This motor is a ral beast and can be overvolted alot more than the brushed motor.!!


Doc

We put an AC50 in our previous TTXGP bike. Huge heavy overheating inefficient pile of sh*t motor. Big fans blowing through it, heatsinks bolted on it, running it at only 45hp, and it just disappoints you with its soggy performance before it overheats and shuts down.


A pair of Agni 95R motors would be the right choice. Highest system efficiency, and when setup correctly its a beast of a setup.

 

[Doctorbass]

Well.. every opinion exist :lol:

I have read that some replaced their AGNI for brushless motor like the AC serie and got better performances.. ... on the other hand i also read comments like yours Luke...

Doc

 

[liveforphysics]

Well.. every opinion exist :lol:

I have read that some replaced their AGNI for brushless motor like the AC serie and got better performances.. ... on the other hand i also read comments like yours Luke...

Doc

It works OK for about 2 minutes of aggressive riding. On the street, you just spurt up to speed and cruise at speed (which requires very little power), and it would likely work very well. On the racetrack, it heats up in about 2mins and just becomes a giant heavy chunk of iron and copper that doesn't cool off worth a damn, and we even had the ends drilled with fans blowing through it and on it and around it and heatsinks etc. If somebody gave me another to work with, I would sink it as a boat anchor.

 

[c_a]

As already said, a twin agni system is to heavy. I will buy a emrax in two months and then we will see...

 

[TylerDurden]

Any advertisement you see on this site can infect your computer. DO NOT CLICK ON ANY ADS
http://endless-sphere.com/forums/viewtopic.php?f=1&t=30462&p=440222#p440222

Well.. every opinion exist :lol:
I have read that some replaced their AGNI for brushless motor like the AC serie and got better performances.. ... on the other hand i also read comments like yours Luke...

It works OK for about 2 minutes of aggressive riding. On the street, you just spurt up to speed and cruise at speed (which requires very little power), and it would likely work very well. On the racetrack, it heats up in about 2mins and just becomes a giant heavy chunk of iron and copper that doesn't cool off worth a damn, and we even had the ends drilled with fans blowing through it and on it and around it and heatsinks etc. If somebody gave me another to work with, I would sink it as a boat anchor.

From the TTXGP:

Before:

After: