Starting a Build From Scratch - Looking for Input

Discussions related to motors other than hub motors.
This includes R/C motors, botttom bracket, roller and geared drives.
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mclovin   100 W

100 W
Posts: 184
Joined: Apr 04 2009 1:19pm
Location: Seattle

Starting a Build From Scratch - Looking for Input

Post by mclovin » Dec 18 2011 10:19pm

Hi All,
I'm planning a <1000W mid-drive build from scratch. What I have right now is a concept and a basic design (more of a cartoon, really). Have a look:

Image

Image

To date my plan is:

BLDC from Golden Motor - rated at 500W. Specs show max power at 750+W (@48V). I'm not set on this motor. I'd like to find something rated at 800W or so.
Operating voltage is 48V. The motor will go through a single stage reduction to a jack shaft. As shown, I plan to mount the motor through the frame. I may need and internal structure to maintin rigidity but I'll wait until I run an FEA analysis before I do that.

Planning on a Ping battery 48V, 15AH but that could change. I want to mount it in a gas tank position/method with the idea being i will dismount the batts when the bike is locked up on the street. I'm not trying to resemble a motor cycle on purpose...when balancing my design considerations it just worked out that way.

I'm not dead set on any particular controller but I have a Lyen controller at the moment. I plan to mount it internally just above the bottom bracket. I'll see how well this works out.

I've choosen 20" wheels because i like the form factor and some of my motor/power clacs work out well with a 20" wheel. I'd like to use solid wheels but all I can find are plastic ones. So, maybe I'll lace the wheels and use Matt's 47mm rims I have.

I am planning on a 45" wheel base for better stability (moving in a straight line) and more room to "package" the drive system.

Frame will be formed sheet metal (like a monocoque) using 6061-T6 AL, welded for the "main" section. The rear stays will likely be formed AL tubing but again that could change after I do some FEA.

I plan on running the cables and wire internally to make it look as clean as possible.

After I feel better about the electrical choices I've made I proceed and do the actual mechanical engineering and mechanical design work on this.

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gtadmin   10 kW

10 kW
Posts: 744
Joined: Aug 07 2009 7:46am
Location: Whyalla South Australia

Re: Starting a Build From Scratch - Looking for Input

Post by gtadmin » Dec 19 2011 6:54am

Hi All,
I'm planning a <1000W mid-drive build from scratch. What I have right now is a concept and a basic design (more of a cartoon, really). Have a look:
...
To date my plan is:

BLDC from Golden Motor - rated at 500W. Specs show max power at 750+W (@48V). I'm not set on this motor. I'd like to find something rated at 800W or so.
Operating voltage is 48V. The motor will go through a single stage reduction to a jack shaft. As shown, I plan to mount the motor through the frame. I may need and internal structure to maintin rigidity but I'll wait until I run an FEA analysis before I do that.

Planning on a Ping battery 48V, 15AH but that could change. I want to mount it in a gas tank position/method with the idea being i will dismount the batts when the bike is locked up on the street. I'm not trying to resemble a motor cycle on purpose...when balancing my design considerations it just worked out that way.

I'm not dead set on any particular controller but I have a Lyen controller at the moment. I plan to mount it internally just above the bottom bracket. I'll see how well this works out.

I've choosen 20" wheels because i like the form factor and some of my motor/power clacs work out well with a 20" wheel. I'd like to use solid wheels but all I can find are plastic ones. So, maybe I'll lace the wheels and use Matt's 47mm rims I have.

I am planning on a 45" wheel base for better stability (moving in a straight line) and more room to "package" the drive system.

Frame will be formed sheet metal (like a monocoque) using 6061-T6 AL, welded for the "main" section. The rear stays will likely be formed AL tubing but again that could change after I do some FEA.

I plan on running the cables and wire internally to make it look as clean as possible.

After I feel better about the electrical choices I've made I proceed and do the actual mechanical engineering and mechanical design work on this.
Excellent, as I'm planning a similar thing but you're at least 2 sketches in front of me (but I have all my parts either ordered from CRC or already in the shed :D ). Watching with interest & good luck 8)

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