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Discussion Starter #1
As I reported earlier, I put a CVT belt drive on my Aspire,
a Comet 94C,
http://www.hoffcocomet.com/comet/aftermarket-torque-converters.asp#94c
It has a variable gearing from 3.49:1 to .78:1. When I connected it
directly to the rear wheel in the aspire, it didn't have enough torque
to get the car moving from a stop, the belt just slipped. No surprise
really, it would have been nice if it worked, so I gave it a try.

To fix it, I built a 3.27:1 planetary gear setup for the driven pulley,
http://www.nimblemotorsports.com/planetary.jpg
This weighs only 32lbs.
So now the car starts off with a 12.9:1 gear and a seamless transition
to a 2.55:1 gearing.
I took it for a test drive today, and it works great, no problem at all
from a start.
If my calculations are correct, the motor at 5000 rpm could transition
from 27mph to 140mph through the gear ratio.
I don't have a tach on the motor yet, but the calcs show at 25mph the
motor at 2500rpm with the belt drive at mid-point, and that is about
what it looked like today.

A remaining issue is running the car with ICE power. The electric motor
does still spin, the belt mostly slipping, however a couple times it
would get engaged in the motor and spin up to speed, in which case, it
would create momentum to keep the car moving when lifting the ICE
throttle. Not sure if that is a bug or a feature, but it didn't happen
every time. More testing to do, but I'm quite pleased with the results
so far.

Jack
 

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Discussion Starter #2
Jack - that is outstanding work. Way to go. What drive setup are you using i.e. how much power? There's lots of lightweight vehicles that might benefit from this type of setup.



----- Original Message ----
From: Jack Murray <[email protected]>
To: [email protected]
Sent: Wednesday, August 1, 2007 12:43:34 AM
Subject: CVT results update

As I reported earlier, I put a CVT belt drive on my Aspire,
a Comet 94C,
http://www.hoffcocomet.com/comet/aftermarket-torque-converters.asp#94c
It has a variable gearing from 3.49:1 to .78:1. When I connected it
directly to the rear wheel in the aspire, it didn't have enough torque
to get the car moving from a stop, the belt just slipped. No surprise
really, it would have been nice if it worked, so I gave it a try.

To fix it, I built a 3.27:1 planetary gear setup for the driven pulley,
http://www.nimblemotorsports.com/planetary.jpg
This weighs only 32lbs.
So now the car starts off with a 12.9:1 gear and a seamless transition
to a 2.55:1 gearing.
I took it for a test drive today, and it works great, no problem at all
from a start.
If my calculations are correct, the motor at 5000 rpm could transition
from 27mph to 140mph through the gear ratio.
I don't have a tach on the motor yet, but the calcs show at 25mph the
motor at 2500rpm with the belt drive at mid-point, and that is about
what it looked like today.

A remaining issue is running the car with ICE power. The electric motor
does still spin, the belt mostly slipping, however a couple times it
would get engaged in the motor and spin up to speed, in which case, it
would create momentum to keep the car moving when lifting the ICE
throttle. Not sure if that is a bug or a feature, but it didn't happen
every time. More testing to do, but I'm quite pleased with the results
so far.

Jack







____________________________________________________________________________________
Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games.
http://get.games.yahoo.com/proddesc?gamekey=monopolyherenow
 

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Discussion Starter #3
Jack,

Do you have pictures of your setup? I would love to see it.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Jack Murray
Sent: Wednesday, August 01, 2007 0:44
To: [email protected]
Subject: CVT results update

As I reported earlier, I put a CVT belt drive on my Aspire, a Comet 94C,
http://www.hoffcocomet.com/comet/aftermarket-torque-converters.asp#94c
It has a variable gearing from 3.49:1 to .78:1. When I connected it
directly to the rear wheel in the aspire, it didn't have enough torque
to get the car moving from a stop, the belt just slipped. No surprise
really, it would have been nice if it worked, so I gave it a try.

To fix it, I built a 3.27:1 planetary gear setup for the driven pulley,
http://www.nimblemotorsports.com/planetary.jpg
This weighs only 32lbs.
So now the car starts off with a 12.9:1 gear and a seamless transition
to a 2.55:1 gearing.
I took it for a test drive today, and it works great, no problem at all
from a start.
If my calculations are correct, the motor at 5000 rpm could transition
from 27mph to 140mph through the gear ratio.
I don't have a tach on the motor yet, but the calcs show at 25mph the
motor at 2500rpm with the belt drive at mid-point, and that is about
what it looked like today.

A remaining issue is running the car with ICE power. The electric motor
does still spin, the belt mostly slipping, however a couple times it
would get engaged in the motor and spin up to speed, in which case, it
would create momentum to keep the car moving when lifting the ICE
throttle. Not sure if that is a bug or a feature, but it didn't happen
every time. More testing to do, but I'm quite pleased with the results
so far.

Jack
 

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Discussion Starter #4
Jack Murray wrote:
> As I reported earlier, I put a CVT belt drive on my Aspire,
> a Comet 94C,
> http://www.hoffcocomet.com/comet/aftermarket-torque-converters.asp#94c
> It has a variable gearing from 3.49:1 to .78:1.

Do you recall how much this puppy weighs offhand? And around how much
your Aspire weighs?
 

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Discussion Starter #5
http://www.rqriley.com/u-car.html

Jack, I'd like one day to build an electric Urba Car - with 'your' CVT.

I know the current frame isn't anywhere near able to handle lots of
batteries, but it could be done.
Thoughts anyone?

(of course, I've got to finish my current project, the 1986 Mazda.....)

Since its 4-wheel base makes it an 'automobile' - I have concerns with
licensing.
Would I be better to go with the Doran, TriMagnum, or XR3 model, since
they're 'motorcycles' - and have less restrictions on design?

There's no way I could afford to put airbags and whatnot in it...

Ed Cooley






Greg Owen <[email protected]>
Sent by: [email protected]
08/01/2007 12:09
Please respond to
[email protected]


To
[email protected]
cc

Subject
Re: CVT results update






Jack Murray wrote:
> As I reported earlier, I put a CVT belt drive on my Aspire,
> a Comet 94C,
> http://www.hoffcocomet.com/comet/aftermarket-torque-converters.asp#94c
> It has a variable gearing from 3.49:1 to .78:1.

Do you recall how much this puppy weighs offhand? And around how much
your Aspire weighs?
 

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Discussion Starter #6
Hi, thanks.
The motor is a ADC 8", I posted the pic earlier that shows the setup
with the planetary, http://www.nimblemotorsports.com/NiMHybridCVT.jpg,
and the rear axle converted to a driven wheel,
http://nimblemotorsports.com/drivenwheel.jpg (this was with the 5:1
chain drive, which worked, but was REALLY LOUD)
Jack

Frank John wrote:
> Jack - that is outstanding work. Way to go. What drive setup are you using i.e. how much power? There's lots of lightweight vehicles that might benefit from this type of setup.
>
>
>
> ----- Original Message ----
> From: Jack Murray <[email protected]>
> To: [email protected]
> Sent: Wednesday, August 1, 2007 12:43:34 AM
> Subject: CVT results update
>
> As I reported earlier, I put a CVT belt drive on my Aspire,
> a Comet 94C,
> http://www.hoffcocomet.com/comet/aftermarket-torque-converters.asp#94c
> It has a variable gearing from 3.49:1 to .78:1. When I connected it
> directly to the rear wheel in the aspire, it didn't have enough torque
> to get the car moving from a stop, the belt just slipped. No surprise
> really, it would have been nice if it worked, so I gave it a try.
>
> To fix it, I built a 3.27:1 planetary gear setup for the driven pulley,
> http://www.nimblemotorsports.com/planetary.jpg
> This weighs only 32lbs.
> So now the car starts off with a 12.9:1 gear and a seamless transition
> to a 2.55:1 gearing.
> I took it for a test drive today, and it works great, no problem at all
> from a start.
> If my calculations are correct, the motor at 5000 rpm could transition
> from 27mph to 140mph through the gear ratio.
> I don't have a tach on the motor yet, but the calcs show at 25mph the
> motor at 2500rpm with the belt drive at mid-point, and that is about
> what it looked like today.
>
> A remaining issue is running the car with ICE power. The electric motor
> does still spin, the belt mostly slipping, however a couple times it
> would get engaged in the motor and spin up to speed, in which case, it
> would create momentum to keep the car moving when lifting the ICE
> throttle. Not sure if that is a bug or a feature, but it didn't happen
> every time. More testing to do, but I'm quite pleased with the results
> so far.
>
> Jack
>
>
>
>
>
>
>
> ____________________________________________________________________________________
> Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games.
> http://get.games.yahoo.com/proddesc?gamekey=monopolyherenow
>
>
 

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Discussion Starter #7
I would guess the CVT itself is 10-15lbs.
The Aspire weighs about 2000-lbs from the factory, my car still has its
complete ICE drivetrain, its a parallel hybrid prototype.
I don't know what it weighs now, at least 300-500lbs more than stock.
Jack

Greg Owen wrote:
> Jack Murray wrote:
>
>>As I reported earlier, I put a CVT belt drive on my Aspire,
>>a Comet 94C,
>>http://www.hoffcocomet.com/comet/aftermarket-torque-converters.asp#94c
>>It has a variable gearing from 3.49:1 to .78:1.
>
>
> Do you recall how much this puppy weighs offhand? And around how much
> your Aspire weighs?
>
>
 
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