[X1/9jm]

It is my understanding that DC motors are not very good candidates for regen braking. This being the case, seems disengaging the motor entirely while going downhill would help in coasting situations, letting gravity do the work. Instead of pushing in the clutch pedal to coast, has anyone tried a centrifigul clutch in conjunction with the trans clutch? For the brief moments on a rolling hills road, the load would be reduced through slippage maybe extending battery life.

Also would the use of performance lightweight flywheels be much help in EV setups?

 

[Coley]

"Freewheeling", with the clutch pushed down or the car in neutral is against the law in most states. Back in the 1930s, GM, I believe, actually had a free wheeling setup, but it was soon dropped.

Our cars don't have much drag from the motor, but they are still "in gear" so we are not breaking a law.

A lightened flywheel will help the synchros in the trans live longer and help acceleration (which eats a lot of amps).

 

[X1/9jm]

I have never heard that allowing a car to freewheel down a hill was illegal in all my life. Thanks, I'll have to look into that. My son just finished driver's ed. and there was nothing about that. I knew it was not recommended due to the possibility of re-engaging the wrong gear but never illegal.

 

[onesojourner]

I am also going to need some proof on that. I always take it out of gear and cost down hills.

 

[trabant601]

I am still in the planning stages of my project to EV a Trabant. The Trabant has freewheeling in 4th gear. I have wondered why on earth I should take out the clutch when it seems easier just to leave it in.
I often pop the car out of gear to coast without using the clutch in 1st, 2nd, or 3rd. In 4th I can coast in 4th almost to a stop.
Can someone explain to me why I should remove the clutch to "keep it simple", because I do want to keep it simple? Thank you.

 

[Coley]

Removing the clutch unit and the flywheel that goes with it, will take 25 or more pounds off your car.

It is also easier (simpler) to connect the motor without the clutch.

Shifting has to be done a little slower, but you get used to it really quickly.

It is also one more thing to NOT have wear out!

3 of us in the area, did without the clutch and don't miss it....

 

[DVR]

I've also read somewhere that 1 pound of rotational mass removed, gives the same performance increase as removing 10 pounds of dead weight. So then, "theoretically" that 25 pounds you save could be like putting your car on a 250 pound diet

Theoretically anyway

 

[trabant601]

The car empty weight is 620- 660 kg (1366.9 – 1455 lb.).
It is originally 26 hp at 594 cc. The whole transmission probably weighs 25 lb.
I do understand what I have been told above and will put it to my friends who will assist me (they know way more than I do about such things.)
The clutch will probably go.
Thanks

 

[Manntis]

Removing the clutch unit and the flywheel that goes with it, will take 25 or more pounds off your car.

It is also easier (simpler) to connect the motor without the clutch.

Shifting has to be done a little slower, but you get used to it really quickly.

It is also one more thing to NOT have wear out!

3 of us in the area, did without the clutch and don't miss it....

In the first AC motor I installed, we drilled out the motor shaft and used it as the pilot bearing for the transmission input shaft. A simple spline adapter locked the two together. This enabled us to move the motor closer to the trasnmission than any coupler/clutch design, not only eliminating the weight of the clutch, flywheel, and hydraulic clutch assist but moving the engine mass closer to the center of the car for better handling

 

[mattW]

Cough ***there is no wiki yet on clutch vs clutchless*** cough =P

 

[KiwiEV]

As some of you may have already seen, on one of my videos there's a good example of clutchless "How to" and "How not to" gear changing on an EV:
http://nz.youtube.com/watch?v=rFrmjhKcAws
At 3:24 you can see someone changing gear in a hurry on my clutchless EV, and,
at 8:55 you can see how it's supposed to be done.

I'm not for or against clutchless vs clutched. What ever you're comfortable with.
The big benefit of keeping the clutch is easy, fast gear changes when you need them.
The big benefit of losing the clutch is simplicity and weight and possibly cost.

 

[onesojourner]

Is there potential to get more range with a clutch? it seems like you could fine tune your gear shifts easier.

 

[rebenergy]

It is also easier (simpler) to connect the motor without the clutch.

Shifting has to be done a little slower, but you get used to it really quickly.

It is also one more thing to NOT have wear out!

3 of us in the area, did without the clutch and don't miss it....

I recently bought a motor transmission set coupled with a love joy coupler. I was thinking of using a different transmission with clutch until reading this post. If what you say is correct, and I could shift gears without damage to this transmission, it would cut my building time considerably. I did think that low resistance from the traction motor would enable sifting without a clutch, but it seems too good to be true.
I will follow this pose and watch your links.

 

[rebenergy]

As some of you may have already seen, on one of my videos there's a good example of clutchless "How to" and "How not to" gear changing on an EV:
http://nz.youtube.com/watch?v=rFrmjhKcAws
At 3:24 you can see someone changing gear in a hurry on my clutchless EV, and,
at 8:55 you can see how it's supposed to be done.



Sorry for my inept knowledge of U-Tube, but I could not find that info on U-Tube. I’ll keep searching.

 

[mattW]

just click on the link

 

[Coley]

To check it out a bit, try shifting your ICE car with a clutch, without using it.

Upshifting is usually easier but downshifting can be done as well.

Just don't force the shift. As your synchros in the trans try to equate the speed of the engine, you can feel resistane to the lever going into gear.

This is normal, as the synchros are working.

Don't force it at this point, just keep a slight pressure and it will slip in.

My firends S-10 actually shifts better without the clutch than before.

 

[michaeljayclark]

I am also going to need some proof on that. I always take it out of gear and cost down hills.

it is illegal in vermont under chapter 25.

http://www.leg.state.vt.us/statutes/fullchapter.cfm?Title=23&Chapter=025

I drove a commercial vehicle and during the driving test you had to have it in gear at all times or you failed.

Im sure it will fall under the law that you have to have control of the vehicle at all times. they give people tickets for spinning tires because they do not have control of the vehicle. coasting you do not have control even with brakes. the extra weight of the vehicle puts more pressure on the brakes then what they were designed to do, therefore you do not have control.

With all the laws on the books it menas NOONE can drive legally. It is impossible to follow every single law there is. If there were cameras recording every thing you did and mailed you a ticket for doing anything illegal everyone would be driving illegally and have their licenses suspended for points within a few days.

its just stupid. This goes to show if anyone makes an EV that works and coasts at any time guarantee that the manufacturers will have it shut down asap under the anti-coasting law.

so with this in mind to be legal you would have to have engine braking which is easily done with an AC motor. The DC motors that disengage when the accelerator pedal is not depressed is actually illegal.

 

[Coley]

A DC motor doesn't "disengage" it just hasn't a huge amount of drag.

In the Saginaw overdrive unit that a lot of car manufactures used in the 50s and 60s, when you were not in overdrive, the trans would freewheel.

Since most of the time, the overdrive was used, there was no penalty because the trans was still in gear.

I would not think that our DC motors would be operating in a non-legal manner, as long as the trans was engaged.

 

[X1/9jm]

Still can't find anywhere is says it's illgeal to caost out of gear.

 

[X1/9jm]

Still can't find anywhere is says it's illegal to coast out of gear.