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Re: [EVDL] Basic drivetrain questions, was Re: Looking for a Conversion Kit for a 19

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Re: [EVDL] Basic drivetrain questions, was Re: Looking for a Conversion Kit for a 19

Jack Murray wrote:
> Greg, thanks for pointing out my efforts.
> The Comet CVT does change the gearing as the RPM changes, it seems to
> me this does just what you want, although this is just unmeasured
> observation, the motor tends to stay at about the same RPM and the
> gearing changes as the torque and vehicle speed changes.

I had been thinking that ideally one would have more control - for
example, at highway speeds, most of the time you want the gearing set
for efficiency. If you jam on the acceleration, though, that means you
need torque (I don't know where you live, but here changing lanes is a
contact sport). So a system where the CVT and the motor were controlled
separately, and where acceleration depended on increased motor output
and possibly even decreased gearing, yet when speed stabilized the CVT
and motor would rebalance for efficiency.

I'm a computer scientist. I have trouble with working solutions like
yours when the option of screwing up a more complex one exists ;>.
Having said that, I'm keeping your original post in my folder for
reference because it does sound darn good.

> The "soft start" of the belt drive is useful, and in fact, I've been
> thinking this may make a contactor controller work very well in
> conjunction with this CVT. This would allow building a very
> inexpensive lightweight EV.

Does that imply that the normal drawback to a contactor controller is
abrupt start?

I was also looking at minibike CVTs, like this:

I'm wondering how that'd work for a <1500lb vehicle.

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