# [EVDL] Better Emergency Brake



## EVDL List (Jul 27, 2007)

Hello Mark,

That is why I have drum brakes on the rear and disc on the front. The =

problem with a EV with a manual transmission, there is no compression you =

have with a engine where you can have the transmission in 1st or reversed =

which may hold the vehicle on a small slope and a 2nd back up using a =

emergency brake.

With a EV, you have only one parking brake option, so when I am on a steepe=
r =

sloped, I put out a set of wheel chocks which I made out of a piece of 4 by =

4 inch wood that is cut 4 inches long that the face is cut at a 45 degree =

angle. Attach one of those heavy 14 grit adhesive back sand paper that is =

use for floor sanding.

Roland


----- Original Message ----- =

From: "Mark Hanson" <[email protected]>
To: <[email protected]>
Sent: Thursday, August 09, 2007 11:52 AM
Subject: [EVDL] Better Emergency Brake


> Hi,
>
> With the usual problemn of an EV gaining weight and still wanting braking
> safety, I'm curious if there is a good way to get better emergency =

> braking.
> It seams like on a rear disc brake, the emergency brake handle just slows
> the vehicle down. This is what happens on my E-Porsche and our diesel
> Beetle with rear disc brakes. I remember with my Electro-Metro which had
> *drum* rear brakes, I could lock up the rear wheels with the emergency =

> brake
> handle.
>
> Is there a way to improve emergency braking if the main brakes fail? Or =

> is
> that just an inherent problem with rear disc brakes?
>
> have a renewable energy day,
> Mark
>
> _________________________________________________________________
> Messenger Caf=E9 - open for fun 24/7. Hot games, cool activities served =

> daily.
> Visit now. http://cafemessenger.com?ocid=3DTXT_TAGHM_AugHMtagline
>
> > _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev =


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## EVDL List (Jul 27, 2007)

Do you tie anything to wheel chocks?
I have run over them sometimes. =




> --- Roland Wiench <[email protected]> wrote:
> 
> > Hello Mark,
> > =
> ...


----------



## EVDL List (Jul 27, 2007)

Hello Mike,

Tied a big rope to a pole, just kidding.

No, the wheels chocks are not tie. Could never roll over them. Do not pus=
h =

the accelerator down that much to get out of a parking spot.

The accelerator has a very soft start mode.

Roland


----- Original Message ----- =

From: "mike golub" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Thursday, August 09, 2007 1:21 PM
Subject: Re: [EVDL] Better Emergency Brake


Do you tie anything to wheel chocks?
I have run over them sometimes.



> --- Roland Wiench <[email protected]> wrote:
> 
> > Hello Mark,
> >
> ...


----------



## EVDL List (Jul 27, 2007)

Hi, Mark. I think the problem is that disc calipers take a bunch of pressu=
re to actuate, so the parking brake cable only works so-so. It is also thi=
s way on my Fiero. We'll have to wait and see how well the wilwood brakes =
John W. is going to use work.

If you are looking to upgrade, check out the rear disc brakes from a late 8=
0's-early 90'2 daytona or laser. They had a small drum brake on the back j=
ust for the parking brake, and a main disc that only activated under the hy=
draulic pressure.
=





David Brandt


----- Original Message ----
From: Mark Hanson <[email protected]>
To: [email protected]
Sent: Thursday, August 9, 2007 1:52:15 PM
Subject: [EVDL] Better Emergency Brake


Hi,

With the usual problemn of an EV gaining weight and still wanting braking =

safety, I'm curious if there is a good way to get better emergency braking.=
=

It seams like on a rear disc brake, the emergency brake handle just slows =

the vehicle down. This is what happens on my E-Porsche and our diesel =

Beetle with rear disc brakes. I remember with my Electro-Metro which had =

*drum* rear brakes, I could lock up the rear wheels with the emergency brak=
e =

handle.

Is there a way to improve emergency braking if the main brakes fail? Or is =

that just an inherent problem with rear disc brakes?

have a renewable energy day,
Mark

_________________________________________________________________
Messenger Caf=E9 =97 open for fun 24/7. Hot games, cool activities served d=
aily. =

Visit now. http://cafemessenger.com?ocid=3DTXT_TAGHM_AugHMtagline


=

___________________________________________________________________________=
_________
Building a website is a piece of cake. Yahoo! Small Business gives you all =
the tools to get online.
http://smallbusiness.yahoo.com/webhosting =


_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

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## EVDL List (Jul 27, 2007)

The standard thing to do is to turn the front wheels so that the car can
hopefully lock into the curb if it starts to roll. Not sure if that would
be enough if you had a soft curb or an especially steep incline.

-----Original Message-----
Hi,

With the usual problemn of an EV gaining weight and still wanting braking 
safety, I'm curious if there is a good way to get better emergency braking.

It seams like on a rear disc brake, the emergency brake handle just slows 
the vehicle down. This is what happens on my E-Porsche and our diesel 
Beetle with rear disc brakes. I remember with my Electro-Metro which had 
*drum* rear brakes, I could lock up the rear wheels with the emergency brake

handle.

Is there a way to improve emergency braking if the main brakes fail? Or is 
that just an inherent problem with rear disc brakes?


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----------



## EVDL List (Jul 27, 2007)

> David Wilker wrote:
> > You have the emergency brake on the front brakes? I have never seen that before.
> 
> Some Subarus and all Citroens with Hydropneumatic suspension brake the
> ...


----------



## EVDL List (Jul 27, 2007)

You could have another taperlock adapter made for the front of a motor and =
use a disc brake caliper setup for a lawn tractor. They are about 5 inches=
in diameter and clamp using a cable. I have also seen instances where peo=
ple modify a disc brake to mount on the snout of the axle pinion and actuat=
e with a cable. =


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behal=
f Of David Brandt
Sent: Thursday, August 09, 2007 18:44
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Better Emergency Brake

Hi, Mark. I think the problem is that disc calipers take a bunch of pressu=
re to actuate, so the parking brake cable only works so-so. It is also thi=
s way on my Fiero. We'll have to wait and see how well the wilwood brakes =
John W. is going to use work.

If you are looking to upgrade, check out the rear disc brakes from a late 8=
0's-early 90'2 daytona or laser. They had a small drum brake on the back j=
ust for the parking brake, and a main disc that only activated under the hy=
draulic pressure.
=





David Brandt


----- Original Message ----
From: Mark Hanson <[email protected]>
To: [email protected]
Sent: Thursday, August 9, 2007 1:52:15 PM
Subject: [EVDL] Better Emergency Brake


Hi,

With the usual problemn of an EV gaining weight and still wanting braking s=
afety, I'm curious if there is a good way to get better emergency braking. =

It seams like on a rear disc brake, the emergency brake handle just slows t=
he vehicle down. This is what happens on my E-Porsche and our diesel Beetl=
e with rear disc brakes. I remember with my Electro-Metro which had
*drum* rear brakes, I could lock up the rear wheels with the emergency brak=
e handle.

Is there a way to improve emergency braking if the main brakes fail? Or is=
that just an inherent problem with rear disc brakes?

have a renewable energy day,
Mark

_________________________________________________________________
Messenger Caf=E9 - open for fun 24/7. Hot games, cool activities served dai=
ly. =

Visit now. http://cafemessenger.com?ocid=3DTXT_TAGHM_AugHMtagline


=

___________________________________________________________________________=
_________
Building a website is a piece of cake. Yahoo! Small Business gives you all =
the tools to get online.
http://smallbusiness.yahoo.com/webhosting =


_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev

_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev


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## EVDL List (Jul 27, 2007)

Don't forget, any brake on the motor or drive shaft is not safe if there is=
a differential between
the brake and the tires. If one wheel looses traction (resting on sand, ice=
, etc.) the vehicle can
roll. =


Dave Cover



> --- "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[email protected]> wrote:
> 
> > You could have another taperlock adapter made for the front of a motor an=
> d use a disc brake
> ...


----------



## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

Not necessarily. That theory definitely holds true if the differential is =
an open carrier. If it is a locker or a posi then it will hold just fine. =
You also get the added benefit of a pinion brake of the multiplication the=
ring and pinion assembly provides. Pinion brakes are much more powerful t=
han a drum brake assembly. That is why you see them used a lot in the mons=
ter truck world. =


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behal=
f Of Dave Cover
Sent: Friday, August 10, 2007 9:46
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Better Emergency Brake

Don't forget, any brake on the motor or drive shaft is not safe if there is=
a differential between the brake and the tires. If one wheel looses tracti=
on (resting on sand, ice, etc.) the vehicle can roll. =


Dave Cover



> --- "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[email protected]> wrote:
> 
> > You could have another taperlock adapter made for the front of a motor =
> 
> ...


----------



## EVDL List (Jul 27, 2007)

Don't lockup differentials rely on the power delivered to lock up. I know i=
f I have a rear wheel
off the ground with my truck, I can spin it by hand, and it does have a loc=
king differential. Same
with my 944. Relying on a lock up differential to hold your car doesn't see=
m safe. And how many
vehicles have this feature? Probably less than you think.



> --- "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[email protected]> wrote:
> 
> > Not necessarily. That theory definitely holds true if the differential i=
> s an open carrier. If
> ...


----------



## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

I guess it depends on the vehicle. my 300zx won't move if i forget to
release the emergancy brake. (288V zilla 1k warp 9) 
it will pick up the back end about 3 inches if I try. LOL

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## EVDL List (Jul 27, 2007)

In my "ultimate" design, on the gear reducer is an adapted parking pawl.
The parking pawl was created to handle this exact problem.

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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

Maybe we are going about this wrong. Semi truck trailers have a
solution. Air brakes.
These are spring applied air released emergency brakes for the trailers
so that when disconnected the brakes are applied.

Perhaps a small vacuum operated version for an EV, you just release the
remaining vacuum when you park (probably would need a really good vacuum
pump, but it would also keep you from driving without vacuum for the
power brakes. 

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## EVDL List (Jul 27, 2007)

That's a good ideal. I will ask my master mechanical who also works on 
semi-trucks to how a air brake can be modified to brake using vacuum. Can 
be done, because I have converted many vacuum devices to work on pressure.

The problem would be to find one small enough to fit under a EV. These 
units are large and uses a large pressure tank which you would have to use a 
large vacuum canister for a vacuum system. You will have to use a large 
diesel truck type of vacuum pump they use for some transmissions, which I 
already run in my EV. Also you have to have a drain system to drain out 
the water that builds up in these unit.

When its very cold, truckers have to check this braking systems every hour, 
even if the lines are triple insulated.

Roland


----- Original Message ----- 
From: "Jeff Shanab" <[email protected]>
To: <[email protected]>
Sent: Sunday, August 12, 2007 7:18 AM
Subject: Re: [EVDL] Better Emergency Brake


> Maybe we are going about this wrong. Semi truck trailers have a
> solution. Air brakes.
> These are spring applied air released emergency brakes for the trailers
> so that when disconnected the brakes are applied.
>
> Perhaps a small vacuum operated version for an EV, you just release the
> remaining vacuum when you park (probably would need a really good vacuum
> pump, but it would also keep you from driving without vacuum for the
> power brakes. 
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
> 

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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

Actually. I have switched over a vacuum brake booster to air once myself
and it worked great. Thatas what gave me the idea of switching it to
vacuum, since we already have it (or we could go the other way,
regulated 14.7psi for the brake booster and 50-60 psi for the brakes and
on board tire inflation. Gimme a storage tank and a small electric
compressor for those times when the regen compressor(ac clutch on crank
shaft driving under hood air compressor) isn't sufficient. 

With vacuum we wouldn't have the condensation issue of a pressure based
system. The problem is vacuum is practically limited to 14.7 psi, it may
make the piston diameter to large.

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## EVDL List (Jul 27, 2007)

Most positraction type differentials use clutches, cones, or gears to lock =
the wheels together. If you lift only one tire off the ground yes it will =
let it move. The differential is tuned to link the axle only when both whe=
els are going at the same speed. Depending on the model you select there w=
ill be different strengths at which they will "lock up." Detroit locker di=
fferentials actually "click" when they lock and unlock. With a pinion brak=
e you will always have one side that holds the car. If one tire slips, the=
other will still be holding. If you don't like that kind of setup you can=
always use the cable operated calipers off of a camaro or Imapala SS. =


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behal=
f Of Dave Cover
Sent: Friday, August 10, 2007 13:27
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Better Emergency Brake

Don't lockup differentials rely on the power delivered to lock up. I know i=
f I have a rear wheel off the ground with my truck, I can spin it by hand, =
and it does have a locking differential. Same with my 944. Relying on a loc=
k up differential to hold your car doesn't seem safe. And how many vehicles=
have this feature? Probably less than you think.



> --- "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[email protected]> wrote:
> 
> > Not necessarily. That theory definitely holds true if the =
> 
> ...


----------



## EVDL List (Jul 27, 2007)

Of course, my theory goes to hell when you consider how almost any automati=
c transmission car
parks. The parking pawl is very effective at keeping a car in place even th=
ough there is a
downstream differential. Haven't heard of too many minivans rolling down th=
e hill lately. So I
guess a single point brake, such as on the drive shaft, should work pretty =
good.

Dave Cover



> --- "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[email protected]> wrote:
> 
> > Most positraction type differentials use clutches, cones, or gears to loc=
> k the wheels together. =
> ...


----------



## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

[No message]


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## EVDL List (Jul 27, 2007)

but don't forget the system you are talking about uses the pressure (converted to vacuum) to release the brakes not to engage them they are engaged by springs so getting the needed pulloff should be pretty easy even if you do it through mechanical advantage,

> Date: Sun, 12 Aug 2007 13:37:07 -0700
> From: [email protected]
> To: [email protected]
> Subject: Re: [EVDL] Better Emergency Brake
> 
> Actually. I have switched over a vacuum brake booster to air once myself
> and it worked great. Thatas what gave me the idea of switching it to
> vacuum, since we already have it (or we could go the other way,
> regulated 14.7psi for the brake booster and 50-60 psi for the brakes and
> on board tire inflation. Gimme a storage tank and a small electric
> compressor for those times when the regen compressor(ac clutch on crank
> shaft driving under hood air compressor) isn't sufficient. 
> 
> With vacuum we wouldn't have the condensation issue of a pressure based
> system. The problem is vacuum is practically limited to 14.7 psi, it may
> make the piston diameter to large.
> 
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