Is this common for a brushless motor controller?

[John Doe]

https://farm1.staticflickr.com/659/21083853371_334b03da77_b.jpg

It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the power
wires come from since the stuff is encased a glob of glue.

One of those signal wires is purple, the other four are black. Is that
common? If so, what's it called so I can find some information about it.

Be happy to supply more pictures if needed.

Thanks.

 

[Tim Wescott]

On Wed, 02 Sep 2015 21:35:48 -0400, DJ Delorie wrote:

John Doe <always.look@message.header> writes:
It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the
power wires come from since the stuff is encased a glob of glue.

Brushless motors often (but not always) have either hall sensors (three
signals) or an encoder (two signals, sometimes differential pairs,
sometimes with an extra "zero position" signal). These often need power
(+5v/gnd), so three halls plus power = 5 wires makes sense.

If you watch these signals with an oscilloscope, hall sensors would show
a three-phase signal about 1x to 6x the RPMs of the motor (in sync with
the power wires), while encoders would have two quadrature signals in
the 500x to 4000x the RPMs range.

The brushless drivers that I know of that use encoders also use hall-
effect commutation for start-up, and only start using the encoder once an
index has been found.

But driving brushless motors is like skinning cats -- there's more than
one way.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Dave Platt]

In article <ms7tdp$9i4$2@dont-email.me>,
John Doe <always.look@message.header> wrote:

One of those signal wires is purple, the other four are black. Is that
common? If so, what's it called so I can find some information about it.

As someone pointed out in another thread, these are probably for a set
of Hall-effect sensors which allow the controller to monitor the
rotation of the poles, and do the switching/commutation via electronic
means.

The usual arrangement would be one wire to supply a positive voltage
to power the Hall-effect sensors, one wire for ground, and one output
signal wire per sensor.

 

[DJ Delorie]

John Doe <always.look@message.header> writes:

It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the power
wires come from since the stuff is encased a glob of glue.

Brushless motors often (but not always) have either hall sensors (three
signals) or an encoder (two signals, sometimes differential pairs,
sometimes with an extra "zero position" signal). These often need power
(+5v/gnd), so three halls plus power = 5 wires makes sense.

If you watch these signals with an oscilloscope, hall sensors would show
a three-phase signal about 1x to 6x the RPMs of the motor (in sync with
the power wires), while encoders would have two quadrature signals in
the 500x to 4000x the RPMs range.

 

[Lasse Langwadt Christense]

Den torsdag den 3. september 2015 kl. 16.37.39 UTC+2 skrev Jim Thompson:

On Thu, 03 Sep 2015 07:35:33 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Wed, 02 Sep 2015 21:35:48 -0400, DJ Delorie <dj@delorie.com> wrote:


John Doe <always.look@message.header> writes:
It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the power
wires come from since the stuff is encased a glob of glue.

Brushless motors often (but not always) have either hall sensors (three
signals) or an encoder (two signals, sometimes differential pairs,
sometimes with an extra "zero position" signal). These often need power
(+5v/gnd), so three halls plus power = 5 wires makes sense.

If you watch these signals with an oscilloscope, hall sensors would show
a three-phase signal about 1x to 6x the RPMs of the motor (in sync with
the power wires), while encoders would have two quadrature signals in
the 500x to 4000x the RPMs range.

http://www.analog-innovations.com/SED/DC_Motor_Electronically_Commutated.jpg

is three-wire, phases-only, and sensing is by observing voltages on
unconnected phases.

Bosch/Mercedes motor controller chip project (late '90's)

...Jim Thompson

Oooops! FOUR wires (you need center of wye to +12V).

only unipolar drive?

sensor less doesn't work when you need high torque at zero or very low rpm

-Lasse

 

[Jim Thompson]

On Wed, 02 Sep 2015 21:35:48 -0400, DJ Delorie <dj@delorie.com> wrote:

John Doe <always.look@message.header> writes:
It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the power
wires come from since the stuff is encased a glob of glue.

Brushless motors often (but not always) have either hall sensors (three
signals) or an encoder (two signals, sometimes differential pairs,
sometimes with an extra "zero position" signal). These often need power
(+5v/gnd), so three halls plus power = 5 wires makes sense.

If you watch these signals with an oscilloscope, hall sensors would show
a three-phase signal about 1x to 6x the RPMs of the motor (in sync with
the power wires), while encoders would have two quadrature signals in
the 500x to 4000x the RPMs range.

http://www.analog-innovations.com/SED/DC_Motor_Electronically_Commutated.jpg

is three-wire, phases-only, and sensing is by observing voltages on
unconnected phases.

Bosch/Mercedes motor controller chip project (late '90's)

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Jim Thompson]

On Thu, 03 Sep 2015 07:35:33 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Wed, 02 Sep 2015 21:35:48 -0400, DJ Delorie <dj@delorie.com> wrote:


John Doe <always.look@message.header> writes:
It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the power
wires come from since the stuff is encased a glob of glue.

Brushless motors often (but not always) have either hall sensors (three
signals) or an encoder (two signals, sometimes differential pairs,
sometimes with an extra "zero position" signal). These often need power
(+5v/gnd), so three halls plus power = 5 wires makes sense.

If you watch these signals with an oscilloscope, hall sensors would show
a three-phase signal about 1x to 6x the RPMs of the motor (in sync with
the power wires), while encoders would have two quadrature signals in
the 500x to 4000x the RPMs range.

http://www.analog-innovations.com/SED/DC_Motor_Electronically_Commutated.jpg

is three-wire, phases-only, and sensing is by observing voltages on
unconnected phases.

Bosch/Mercedes motor controller chip project (late '90's)

...Jim Thompson

Oooops! FOUR wires (you need center of wye to +12V).

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Jim Thompson]

On Thu, 3 Sep 2015 07:51:01 -0700 (PDT), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

Den torsdag den 3. september 2015 kl. 16.37.39 UTC+2 skrev Jim Thompson:
On Thu, 03 Sep 2015 07:35:33 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Wed, 02 Sep 2015 21:35:48 -0400, DJ Delorie <dj@delorie.com> wrote:


John Doe <always.look@message.header> writes:
It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the power
wires come from since the stuff is encased a glob of glue.

Brushless motors often (but not always) have either hall sensors (three
signals) or an encoder (two signals, sometimes differential pairs,
sometimes with an extra "zero position" signal). These often need power
(+5v/gnd), so three halls plus power = 5 wires makes sense.

If you watch these signals with an oscilloscope, hall sensors would show
a three-phase signal about 1x to 6x the RPMs of the motor (in sync with
the power wires), while encoders would have two quadrature signals in
the 500x to 4000x the RPMs range.

http://www.analog-innovations.com/SED/DC_Motor_Electronically_Commutated.jpg

is three-wire, phases-only, and sensing is by observing voltages on
unconnected phases.

Bosch/Mercedes motor controller chip project (late '90's)

...Jim Thompson

Oooops! FOUR wires (you need center of wye to +12V).


only unipolar drive?

sensor less doesn't work when you need high torque at zero or very low rpm

-Lasse

Built-in start oscillator (AND the hard part... sensing rotation in
wrong direction: wind driven (*) when un-powered makes it tricky to
stop the rotation and reverse direction ;-)

(*) Mercedes heater and A/C blower

I actually used a leaf blower in my lab to test the breadboard.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Tim Wescott]

On Thu, 03 Sep 2015 07:35:33 -0700, Jim Thompson wrote:

On Wed, 02 Sep 2015 21:35:48 -0400, DJ Delorie <dj@delorie.com> wrote:


John Doe <always.look@message.header> writes:
It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the
power wires come from since the stuff is encased a glob of glue.

Brushless motors often (but not always) have either hall sensors (three
signals) or an encoder (two signals, sometimes differential pairs,
sometimes with an extra "zero position" signal). These often need power
(+5v/gnd), so three halls plus power = 5 wires makes sense.

If you watch these signals with an oscilloscope, hall sensors would show
a three-phase signal about 1x to 6x the RPMs of the motor (in sync with
the power wires), while encoders would have two quadrature signals in
the 500x to 4000x the RPMs range.

http://www.analog-innovations.com/SED/
DC_Motor_Electronically_Commutated.jpg

is three-wire, phases-only, and sensing is by observing voltages on
unconnected phases.

Bosch/Mercedes motor controller chip project (late '90's)

See just about every model airplane electric motor and electronic speed
controller. It does seem to work well as long as you don't need to
deliver any torque at low speed.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[John Doe]

amdx <nojunk@knology.net> wrote in news:msa0ni$b0r$1@dont-email.me:

Why don't you look at RC vehicle motors, motor controllers and
batteries. 1000's to choose from.

I've looked at lots.

Here's a 2-1/2 hp motor for $52.00
http://www.hobbypartz.com/96m607-bigfoot110-5325-295kv.html

The rpm is high, although it's low for these kind of motors.

The max no load RPM should be no more than about 400.

> I've 'thought' about a couple of these type motors on a gokart.

There is the motor, the controller, the batteries, the charger... Then
there is attaching it to the bike. That requires low enough RPM, the
right size sprockets attached to the drill and to the bike.

Designing stuff and building stuff are two completely different things.
It's really amazing the obstacles one encounters when actually building
something. Even the simplest of ideas can be blocked.

 

[Jim Thompson]

On Thu, 03 Sep 2015 11:04:02 -0500, Tim Wescott
<seemywebsite@myfooter.really> wrote:

On Thu, 03 Sep 2015 07:35:33 -0700, Jim Thompson wrote:

On Wed, 02 Sep 2015 21:35:48 -0400, DJ Delorie <dj@delorie.com> wrote:


John Doe <always.look@message.header> writes:
It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the
power wires come from since the stuff is encased a glob of glue.

Brushless motors often (but not always) have either hall sensors (three
signals) or an encoder (two signals, sometimes differential pairs,
sometimes with an extra "zero position" signal). These often need power
(+5v/gnd), so three halls plus power = 5 wires makes sense.

If you watch these signals with an oscilloscope, hall sensors would show
a three-phase signal about 1x to 6x the RPMs of the motor (in sync with
the power wires), while encoders would have two quadrature signals in
the 500x to 4000x the RPMs range.

http://www.analog-innovations.com/SED/
DC_Motor_Electronically_Commutated.jpg

is three-wire, phases-only, and sensing is by observing voltages on
unconnected phases.

Bosch/Mercedes motor controller chip project (late '90's)

See just about every model airplane electric motor and electronic speed
controller. It does seem to work well as long as you don't need to
deliver any torque at low speed.

I utilized a start oscillator to get it going. It was a crazy
project. Controlled acceleration... no "whine" sound allowed... final
test was chief engineer sticking his head in ductwork and listening
;-)

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[amdx]

On 9/2/2015 5:32 PM, John Doe wrote:

https://farm1.staticflickr.com/659/21083853371_334b03da77_b.jpg

It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the power
wires come from since the stuff is encased a glob of glue.

One of those signal wires is purple, the other four are black. Is that
common? If so, what's it called so I can find some information about it.

Be happy to supply more pictures if needed.

Thanks.

Why don't you look at RC vehicle motors, motor controllers and
batteries. 1000's to choose from.


Here's a 2-1/2 hp motor for $52.00
> http://www.hobbypartz.com/96m607-bigfoot110-5325-295kv.html

The rpm is high, although it's low for these kind of motors.
295 RPMs per volt. 68 amp max, 55 volt.
Quick calculation, 48V battery, 14,100 rpm, 8 to 1 ratio, wheel turns
1681 RPM, 26" wheel, 30 mph. I don't know if the current would be too high.

Check my math, one time through, didn't double check.

I've 'thought' about a couple of these type motors on a gokart.



Miikek

 

[amdx]

On 9/3/2015 12:42 PM, amdx wrote:

On 9/2/2015 5:32 PM, John Doe wrote:
https://farm1.staticflickr.com/659/21083853371_334b03da77_b.jpg

It has five data/signal outputs from the controller to the motor in
addition to three heavy duty power wires. Not sure exactly where the
power
wires come from since the stuff is encased a glob of glue.

One of those signal wires is purple, the other four are black. Is that
common? If so, what's it called so I can find some information about it.

Be happy to supply more pictures if needed.

Thanks.


Why don't you look at RC vehicle motors, motor controllers and
batteries. 1000's to choose from.


Here's a 2-1/2 hp motor for $52.00
http://www.hobbypartz.com/96m607-bigfoot110-5325-295kv.html

The rpm is high, although it's low for these kind of motors.
295 RPMs per volt. 68 amp max, 55 volt.
Quick calculation, 48V battery, 14,100 rpm, 8 to 1 ratio, wheel turns
1681 RPM, 26" wheel, 30 mph. I don't know if the current would be too high.

Check my math, one time through, didn't double check.

I've 'thought' about a couple of these type motors on a gokart.



Miikek

Here's an 80 amp motor controller for $48.00.
270 amp burst.

> http://www.hobbypartz.com/ezescfor1scr.html

Mikek

 

[DJ Delorie]

Tim Wescott <seemywebsite@myfooter.really> writes:

The brushless drivers that I know of that use encoders also use hall-
effect commutation for start-up, and only start using the encoder once an
index has been found.

Yup, my driver board did exactly that: http://www.delorie.com/electronics/bldc/

But driving brushless motors is like skinning cats -- there's more than
one way.

Heh. I had that problem when I started the project. "Which of the
following seventeen or so methods do I feel like implementing THIS
time?" I think I tried five before I settled on one.

 

[Tim Williams]

"Jim Thompson" <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote in
message news:httgua1p0en1jvkbdu15ugsd1hfh978p27@4ax.com...

I utilized a start oscillator to get it going. It was a crazy
project. Controlled acceleration... no "whine" sound allowed... final
test was chief engineer sticking his head in ductwork and listening
;-)

Curious, as an automotive project, did they want you to sign away your
first-born son as collateral? Or was this kind of project far enough down
the design chain not to be so draconian? (Or did you tell their lawyers to
stuff it and come back with just the parts you approve of? ;-) )

Tim

--
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

 

[Jim Thompson]

On Thu, 3 Sep 2015 17:53:14 -0500, "Tim Williams"
<tmoranwms@charter.net> wrote:

"Jim Thompson" <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote in
message news:httgua1p0en1jvkbdu15ugsd1hfh978p27@4ax.com...
I utilized a start oscillator to get it going. It was a crazy
project. Controlled acceleration... no "whine" sound allowed... final
test was chief engineer sticking his head in ductwork and listening
;-)

Curious, as an automotive project, did they want you to sign away your
first-born son as collateral? Or was this kind of project far enough down
the design chain not to be so draconian? (Or did you tell their lawyers to
stuff it and come back with just the parts you approve of? ;-) )

Tim

Everything was quite friendly, unwanted sounds were just part of the
spec.

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Tim Williams]

"Jim Thompson" <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote in
message news3khuadqetv1afk91g4uv0ml5g66aac0ra@4ax.com...

Everything was quite friendly, unwanted sounds were just part of the
spec.

I wasn't doubting that; such would be understandable for a luxury vehicle!

On a related note, once upon a time we had some guys from LANL over; noise
was part of the spec (probably just pulled from OSHA, something like 85dB),
so one of the guys got out his iPhone and listened in.

It probably didn't help that the microphone apparently pegged at 85dB, and
we were in the middle of a noisy shop to begin with. ;o)

Tim

--
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

 

[amdx]

On 9/3/2015 3:24 PM, John Doe wrote:

amdx <nojunk@knology.net> wrote in news:msa0ni$b0r$1@dont-email.me:

Why don't you look at RC vehicle motors, motor controllers and
batteries. 1000's to choose from.

I've looked at lots.

Here's a 2-1/2 hp motor for $52.00
http://www.hobbypartz.com/96m607-bigfoot110-5325-295kv.html

The rpm is high, although it's low for these kind of motors.

The max no load RPM should be no more than about 400.

I've 'thought' about a couple of these type motors on a gokart.

There is the motor, the controller, the batteries, the charger... Then
there is attaching it to the bike. That requires low enough RPM, the
right size sprockets attached to the drill and to the bike.

Designing stuff and building stuff are two completely different things.

I made a plan (design) got a motor, a contoler, the batteries, a
charger and fabricated all the parts needed to put these on a gokart.
all was fine for about 5 years when one of my batteries failed.

https://www.youtube.com/watch?v=5MKjbXltAew
I did get 4 group 27 deep cycle batteries after I had it all working.

It's really amazing the obstacles one encounters when actually building
something. Even the simplest of ideas can be blocked.

There are many ways to get the the drive from the motor to the wheel.
What limitation have you made yourself. Is your problem uncoupling the
motor from the wheel when you just want to pedal?

Did anyone check my math, 8 to 1 seems pretty easy.

The rpm is high, although it's low for these kind of motors.
295 RPMs per volt. 68 amp max, 55 volt.
Quick calculation, 48V battery, 14,100 rpm, 8 to 1 ratio, wheel turns
1681 RPM, 26" wheel, 30 mph. I don't know if the current would be too
high.

Check my math, one time through, didn't double check.

 

[John Doe]

amdx <nojunk@knology.net> wrote:

John Doe wrote:
amdx <nojunk@knology.net> wrote:

Why don't you look at RC vehicle motors, motor controllers and
batteries. 1000's to choose from.

I've looked at lots.

Here's a 2-1/2 hp motor for $52.00
http://www.hobbypartz.com/96m607-bigfoot110-5325-295kv.html

The rpm is high, although it's low for these kind of motors.

The max no load RPM should be no more than about 400.

I've 'thought' about a couple of these type motors on a gokart.

There is the motor, the controller, the batteries, the charger...
Then there is attaching it to the bike. That requires low enough RPM,
the right size sprockets attached to the drill and to the bike.

Designing stuff and building stuff are two completely different
things.

I made a plan (design) got a motor, a contoler, the batteries, a
charger and fabricated all the parts needed to put these on a gokart.
all was fine for about 5 years when one of my batteries failed.
https://www.youtube.com/watch?v=5MKjbXltAew I did get 4 group 27 deep
cycle batteries after I had it all working.

Well done!

It's really amazing the obstacles one encounters when actually
building something. Even the simplest of ideas can be blocked.

There are many ways to get the the drive from the motor to the wheel.

Sure, if you have access to a machine shop. Or at least a metal lathe.

What limitation have you made yourself. Is your problem uncoupling the
motor from the wheel when you just want to pedal?

That's a good thought, but not my current concern.

Efficiency is everything to me. The idea is to make a reasonably
powerful bike that is easy to build from readily available components.

Besides the controller, batteries, and charger... An appropriate motor
would do the trick. A powerful and compact motor (with controller,
batteries, and charger) that is geared to no more than about 400 RPM
would make building an electric bike easy. Cordless drills/tools are the
closest I've come to satisfying that.

Or you can use a hub motor as someone else mentioned. Hub motor
technology will probably be ripe for me in the not-too-distant future.

 

[John Doe]

amdx <nojunk@knology.net> wrote in news:msd4es$cgb$1@dont-email.me:

John Doe wrote:
amdx <nojunk@knology.net> wrote:
John Doe wrote:
amdx <nojunk@knology.net> wrote:

Why don't you look at RC vehicle motors, motor controllers and
batteries. 1000's to choose from.

I've looked at lots.

Here's a 2-1/2 hp motor for $52.00
http://www.hobbypartz.com/96m607-bigfoot110-5325-295kv.html

The rpm is high, although it's low for these kind of motors.

The max no load RPM should be no more than about 400.

I've 'thought' about a couple of these type motors on a gokart.

There is the motor, the controller, the batteries, the charger...
Then there is attaching it to the bike. That requires low enough
RPM, the right size sprockets attached to the drill and to the
bike.

Designing stuff and building stuff are two completely different
things.

I made a plan (design) got a motor, a contoller, the batteries, a
charger and fabricated all the parts needed to put these on a
gokart. all was fine for about 5 years when one of my batteries
failed. https://www.youtube.com/watch?v=5MKjbXltAew I did get 4
group 27 deep cycle batteries after I had it all working.

Well done!

It's really amazing the obstacles one encounters when actually
building something. Even the simplest of ideas can be blocked.

There are many ways to get the the drive from the motor to the
wheel.

Sure, if you have access to a machine shop. Or at least a metal
lathe.

LOL, I was about to suggest, find some kid in High School and have him
do it in his shop class. Times have changed, I could have whipped up
parts in my fully equipped HS shop. 10 or 15 lathes, 5 or 6 mills, a
shaper, drill presses, foundry, tool shed. Not to mention the
woodworking shop. My son had none of this at his HS.

What limitation have you made yourself. Is your problem uncoupling
the motor from the wheel when you just want to pedal?

That's a good thought, but not my current concern.

Efficiency is everything to me. The idea is to make a reasonably
powerful bike that is easy to build from readily available
components.

I don't think you'll find the drill motors to be highly efficient
motors. The RC motors do give characteristics at the highest
efficiency.

Efficiency is a top priority in cordless drill design. That's why the
brushless versions are advertised as 57% more run time. Any cordless
device that sucks current is designed to be efficient. Cordless drills
certainly are.

Using my current electric bike (under)powered by a DeWalt DCD780... I
traveled 8 1/2 miles using one 5AH battery and one 4AH battery with a
small charge left.

Besides the controller, batteries, and charger... An appropriate
motor would do the trick. A powerful and compact motor (with
controller, batteries, and charger) that is geared to no more than
about 400 RPM would make building an electric bike easy. Cordless
drills/tools are the closest I've come to satisfying that.

What are you turning at 400 RPM? Ok, went through the math, I did make
an error in my math, didn't check where. Looks like your goal is to
turn a 26 in wheel at 400 RPM for a max speed of 30.9 MPH. The motor I
suggested would need a 35 to 1 ratio. Not impossible two 6 to 1
reductions. The idea of driving the wheel without any gear reduction
doesn't set well with me. You're putting a 13" lever on the shaft of
the motor. Hitting a bump will cause a large stress on the gears in
the drill motor.

There is no way to stress a DeWalt DCF899. Also, there is little risk of
stressing the bicycle's bottom bracket, it too is a heavy duty part. So
the connection can be sloppy without risk of damage. And the connection
is simple as sticking a 12 point socket on the impact wrench to fit the
square taper bottom bracket spindle.

I'm using a 20 inch wheel bike. Hopefully, the only werk will be
securing the drill in position against the left side of the bottom
bracket.

If only the impact wrench used gears instead of the controller for speed
regulation!

Interestingly IMO... Motor torque output is easy to apply to a bicycle
when driving the bottom bracket. Motor torque is measured in foot-pounds
(a pressure rating, formerly understood as werk). It's the twisting
force in pounds applied to the end of a 1 foot stick. So all you have to
do is visualize putting weight on the bicycle crank as if pedaling a
bicycle.