RXV Brakes

[Helirich]

My son recently bought a RXV cart. I didn't even get to see it when he damaged the motor and brought it back to the place he got it for repair. Anyways, I'll probably get to see it this weekend at a family get together.

On this forum, I've seen several times where people said that the RXV uses regen braking exclusively. I just want to confirm this to be true. There is no other brake on one? Not even some kind of emergency brake?

Assuming you guys confirm this, is the motor brake a "fail safe" system? When I say "fail safe", I mean if you lose power by any number of ways, do the brakes come on? What if a stick pokes up rips the cables off the motor? Hard to believe they could make a cart like that unless it was fail safe. (lability)

[Volt_Ampere]

No cart can stop completely with regen braking.

[mjroman20]

There is an EM brake on the back end of the motor. Putting it in tow mode releases the break on power up and if for some reason the controller is not functional there are two pairs of plugs that can be switched around to manually disengage it.

http://www.manualslib.com/manual/762...r.html?page=27

[kernal]

So, the RXV doesn't have conventional brakes on the wheels. There is a "brake" on the end of the motor used for parking. I'm given to understand that this brake will also engage if brake pedal is floored and will lock the wheels. Not recommended unless for emergency stop and doing it often will damage the brake.

Under normal operation, when cart is brought to a stop the parking brake engages automatically and you just step off the cart. To go again you just hit the gas. I love that feature.

My experience is when you let of the gas (coast) regen braking brings the cart to a stop, even going down a hill. Using the brake pedal significantly hastens this process. I find the brake is very effective even at speed 20mph+. All regen.

The cart tests the parking brake during "post" (ignition on) and won't run if brake test fails. I've heard this called a twist test. There are other electrical failures that will engage the parking brake also but I don't know the details. There are forum members that know.

FWIW: I have a cartsunlimited digital meter installed directly to the batteries. Typically when "coasting" the voltage rises into the 52-53 range and I have seen 56+ under braking.

[mjroman20]

I don't have much intel on the Danaher version but with the Curits there is an RPM threshold for the EM brake. It wont lock it down unless the RPM is below that speed. It will regen brake until it gets under that. Applying the brake pedal increases the % of regen braking. Certain these parameters could be adjusted to a point where it isn't healthy for the brake, however.

[mjroman20]

Adjustable with low level handsets.

[Helirich]

Originally Posted by mjroman20

There is an EM brake on the back end of the motor. Putting it in tow mode releases the break on power up and if for some reason the controller is not functional there are two pairs of plugs that can be switched around to manually disengage it.

http://www.manualslib.com/manual/762...r.html?page=27

I went to your link and it does appear to be fail safe. It says if there's no power, you have to release the parking brake manually to tow it. So I assume the brake is spring loaded "on". It must have power to release. I bet if the cable were to be cut some how, that motor brake would be quite an eye opener. LOL.

Thanks for the info.

[mjroman20]

Yes, 'brakes on' with no power is the standard for EM brakes. If it were the other way there would be nothing to stop the vehicle in the event of power loss or severe fault conditions.

The controller will also check for the presence of the brake coil, if it is damaged or removed the vehicle will not operate.

[Isaac-1]

On my 2010 RXV with the Danaher controller which has been set to 19.5mph top speed it will coast a considerable distance before coming to a stop with no feet on the pedals, I tested it out going down hill on a moderate hill (35-40 feet of drop over about 1,000 feet), accelerated up to full speed let off the accellerator and coasted about another 500-600 feet before rolling to a stop 150 feet or so from the base of the hill. I don't know if it is adjustable, or different on the Curtis controller RXV's but on mine as set it takes considerable pedal travel to do much breaking, it seems 75% of the braking is done in the last 25% of pedal travel, which makes it easy to hit the parking brake lock point in normal driving.

[cgtech]

Originally Posted by Volt_Ampere

No cart can stop completely with regen braking.

this is a totally untrue statement when speaking of the 3-phase AC motor (like used in every RXV). the controller & motor Does bring the vehicle to a Complete stop, then hands over the duties of holding the cart still to the motor brake. the motor brake is normally never used when the cart is in motion at all. the only time the motor brake would be activated while in motion is in an emergency panic stop (brake pedal jammed all the way to the floor), or a complete electrical system failure.