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  #21  
Old 11-18-2019, 07:03 PM
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1 1/8" tc isn't even difficult Comets 44C, 1190 and ar available in 1 1/8"
just not for 80 horses..

And AC or not.. shifting the motor rpm
out of the peak torque rpm is generally not exactly a smart move.

And because AC motors are common in full scale electric cars
it's very much something worth toying around with in such electric car.
(I think even the first tesla [that Lotus clone] had a 162kW 3phase AC motor)
Anywhoo...
what it did NOT have however was a clutch of course,
but yes true true... OP asked for a clutch...
luckily Randy took care of that!

The only reason I can think of a clutch making vaguely any sense is as a stalling protection.
In order to drastically remove the drawn amps at low speeds..
too high of a load slows the clutch into disengagement and thus protects from the motor drawing excessive currents..
then again not adjusting the motor rpms immediately would just boil off the clutch lining...
and you'd need a new clutch ever other time that happens ..

I'd say get a manual clutch instead if you really think you need one..
Some old sports bike dryclutch cage are easy and cheap to find and
plates are easy to replace and usually not too expensive either..
the -usually- splined cage hub can easily be cut to accept a round keyed shaft..
and an actuator pin can be made rather easily as well
(one fixed pivot on the motor case and a rocking lever essentially)

Since modern motorcycles easily exceed 80 horses,
durability of the clutch shouldn't be an issue really

it's the centrifugal part of the request that cannot easily be satisfied that way..
reversely springloaded and retrofitted with some actuators taken from a bully clutch
or an old elevator emergency brake

IDK.. if we talk vehicular motivation (which the name and gist of this forum suggests)
then there is no way I can think of a cent clutch making any sense...
Maybe on an old school two phase AC motor.. to drastically reduce the starter cap size,
but you'd need a clutch engagment speed of IDK 10 rpms? 20 perhaps..


Ah well.. Im curious let's say

'sid
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  #22  
Old 11-18-2019, 08:16 PM
Tpdingo Tpdingo is offline
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Quote:
Originally Posted by Randy H View Post
Get over yourself Boy Wonder.

I have experience with electric motors. MG sets, conveyors (like thousands of feet long) rock crushers, electric cranes,(drag line cranes). I have fond (horrific) memories of a converted diesel > electric, 300HP 3 phase 4000+ volt beast. Way before PLC control. Solenoids, ladder logic and DC motors.

The torque is instant. For example an overloaded conveyor may pull an overload if you let it cool off, the motor the starter, heaters. Things I'm going to guess you don't know anything about.

However speed is not instantaneous. A big azz squirrel cage induction motor may take seconds to get up to speed, especially under a load.

I actually support you. I would guess you have a triple digit IQ. Kudos.
Heck, it is a sort of free country. The internet is fair game for all. Doesn't change the fact that people that don't know should keep their juicy face shut.

But it's not a squirrel cage. It's 3 phase AC, and likely vector control drive(or variable frequency drive). The motor isn't waiting to get up to speed like a normal 60hz induction motor. The controller is synced to the rotor at almost every speed so you get the speed very quickly as long as the amps can supply it.
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Old 11-18-2019, 08:56 PM
Juiced Juiced is offline
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Interesting theories, deductions and information. As in most cases, this will be a application specific combination.

Think of it as "Dropping the clutch" at the launch of a drag race. It may be 100% torque, but it is still not moving at launch. It does not have to be 5000 RPM, Just enough rotation before the launch to make the vehicle hit ....hard.

I have run DC and AC motors and the AC motor still has a softer (relatively speaking) launch compared to the DC. My 60 foot times are poo poo.

I have been contemplating this change for some time and its benefits have been proven. I recently saw a AC Dragster out if California add a 10 disk from a Top fuel harley and dropped their 60 foot time from 1.7 to 1.2 sec. That is a big difference.

I would think with a lighter vehicle, I would get even better time reductions.

We will see.

Ed
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Old 11-18-2019, 09:03 PM
Randy H Randy H is offline
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Quote:
Originally Posted by Tpdingo View Post
But it's not a squirrel cage. It's 3 phase AC, and likely vector control drive(or variable frequency drive). The motor isn't waiting to get up to speed like a normal 60hz induction motor. The controller is synced to the rotor at almost every speed so you get the speed very quickly as long as the amps can supply it.
No offense, I suggest you do some research. I've been dealing with 3 phase AC squirrel cage induction motors since about 1984. Minus the last few years, because a drugged up driver ran me off the road. Poor, poor pitiful me. Lol.

You can use VFD control on a regular old 3 phase, squirrel cage, induction, AC motor. I know this, because I've done it.

Apologies to those who know, many redundancies in my previous sentence. Haha, I know I'm wasting my mad Swipe skills.
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