Slow electro magnetic brake

[faico_26]

Hi,
In my Sunrise Quickie Q300R the electromagnetic brake I found it very slow to release. I explain: when I move the joystick the click sounds and the chair starts running normally, no lag or delay, and then when I release the joystick the brakes activate again in a normal way, but then when I move the joystick again there is like a second or more time to unlock again the brakes. This could look like a non sense complain, but this lag between click and click it’s very annoying. When for example I am opening a door and I have to move the chair with one hand and the other hand on the door knob and the click brake activates and I have to release the brake again it’s not comfortable. For example, in my old Invacare Mirage there was no lag between click and click.
Is there any way to solve this delay?
Many thanks,

[Burgerman]

Hi,
In my Sunrise Quickie Q300R the electromagnetic brake I found it very slow to release. I explain: when I move the joystick the click sounds and the chair starts running normally, no lag or delay, and then when I release the joystick the brakes activate again in a normal way,

OK...

but then when I move the joystick again there is like a second or more time to unlock again the brakes.

There is no difference as far as the control system is concerned between the first description and the second one that has a delay. You move the stick, it releases as soon as it sees a voltage at the motor cable.

This could look like a non sense complain, but this lag between click and click it’s very annoying. When for example I am opening a door and I have to move the chair with one hand and the other hand on the door knob and the click brake activates and I have to release the brake again it’s not comfortable. For example, in my old Invacare Mirage there was no lag between click and click.

There is no actual difference. There is no delay between the brake being on, and it releasing the moment it sees a voltage at the motor. There IS a delay between the voltage reaching zero and the brake being applied but its in the order of 1/60th of a second. A FIXED delay to prevent it chattering, a kind of inbuilt hysterisis.

Is there any way to solve this delay?
Many thanks,

You can minimise it greatly by setting the control system properly. So it doesent waste a week slowly ramping up power or down power as you touch the joystic.
Set TURN ACCELERATION 100
Set TURN DECELERATION 100
Set MINIMUM TURN ACCELERATION 100
Set MINIMUM TURN DECELERATION 100
Set TURN SPEED to a lower settng that is comfortable for you.
Set MINIMUM TURN SPEED to a speed that is comfortable for you.
Set compensation correctly. Typically a little higher than stock.

wHY? Because the "delay" you are experiencing is NOT the brake. Its the control system ignoring your stick commands and delayed control. It S L O W L Y ramps up power. And it cant do that until it slowly ramps down power first. It does that long after you release the joystick.

[faico_26]

It’s not a programming issue. I have the chair programmed as you indicate. It’s just slower than the brakes of the Invacare Mirage. I’m used to a more fast response between click and click. I guess I’m too sensitive to these things.
Adapting to a different chair is not easy taking into account I’ve been using the Mirage model for the last 20 years.

[Burgerman]

Try and explain what click and click means?

Clearly. Makes no sense to me. Does the chair DO as you request, respond in its movements to the joystick properly? If so whats the problem? If not then its programming.

It’s just slower than the brakes of the Invacare Mirage.

Heres how it works.
The brake STAYS OFF for a short period after you stop. Theres is a delay. This does not affect how the chair moves in any way.
It releases the brake instantly as you decide to move. if the chairs accelerations are set so that the chair moves instantly. Theres no delay.

If you set that delay to zero then the brakes would be clicking on and off many times a second as you sTart and stop. If that delay was set to 1 week then the brake with click OFF when you first use the chair. It wont click again, stopped or otherwise for a week.
Non of that makes any difference to how the chair moves. Unless on a steep slope.

[faico_26]

Try and explain what click and click means?

Clearly. Makes no sense to me. Does the chair DO as you request, respond in its movements to the joystick properly? If so whats the problem? If not then it’s programming.

When the brakes activate there’s actually 2 click sounds. And even if I move the joystick the brakes don’t release until the second click sounds. So when I’m moving in small movements like opening a door or parking the chair in a tiny space where I need to make sma movements and stop the chair and move it again, it’s always annoying because the response between brakes on and off take like a second or more.

[Burgerman]

Theres 2 brakes. Each makes a click. Both are powered TOGETHER simultaniously in every case. And so you should hear a single click coming from BOTH motors at the same time or a brake is faulty/sticking.

As you move a chair from stationary the brakes should release instantly. As you stop moving they may take some time. That time should be around 0.6 seconds from when a wheel actually stops. If you move again before this .6s time the brake(s) will just stay off, no click.

[emilevirus]

No, I have that issue too. Don't have that with Pilot+. If you release the joystick, wait until it clicks. If you happen to push the joystick WHILE they're clicking. You'll have a 2s delay. Test it, you'll see.

[Burgerman]

I just have. For 5 mins solid.
The BRAKE delay never prevents a motor moving. If you are having to wait then theres a problem with programming (turn or forward/backward slow acceleration rates).

The logic is to always apply power to release brakes anytime it sees voltage on a brake wire. That can mean waiting for motor compensation to ramp up or down too if your settings are too low. But then the chair wouldnt be moving anyway.

Theres never any time where you have to wait for a brake to release before a chair can move. On Pilot Plus, R-Net, VR2, or any brand of control system inc roboteq.

There IS a settable delay on the roboteq, but again it ALWAYS releases with no delay. The only delay that can ever happen is reapplying the brake.

[emilevirus]

You don't get it. Acceleration has nothing to do with that.
Go forwards, release joystick, wait until it's ABOUT to apply brakes then go forwards again, brake will still apply even tho you ask it to go forwards then takes 1-2s to remove the brakes and start rolling. I have everything set to 100% and still does it.
It's kinda hard to reproduce but it happens. Looks like a firmware bug.

[Burgerman]

Well I certainly cant reproduce it.
Do a video demo?

So the power starts and the brake "holds it" for 2 seconds, so it will start with a lurch?
Video...

You don't get it. Acceleration has nothing to do with that.
IGo forwards, release joystick, wait until it's ABOUT to apply brakes then go forwards again, brake will still apply even tho you ask it to go forwards

Yes it does. You are not understanding what is going on under the surface.

That delay is because the acceleration and deceleration is affected by the time it takes for voltage to hit zero. Even though your chair stopped its not yet at 0V. The chairs turn or / and forward movement does not go to zero when you centre the joystick. It smoothly declines. And the curve is rounded. And it takes a second or so. So the brake applies a second or so AFTER you release the stick. This IS affected by acceleration/deceleration rates, and also by the amount of motor compensation that may also have a large input at this time also applied. All this IS affected by forward and turn (and the minimum turn DECELARATION) settings as well as compensation. So the brake cannot apply the moment you stop, but the moment the motor output reaches a true zero.
The exact same applies when you try to move again. It has to wait for the voltage to reach zero even if you are actually stopped. And only then it ramps up to start to move after this point and the brake releases.
Pushing the stick forwards does nothing until the previous movement motor output reaches a true 0.0V which is dependent on acceleration/deceleraion settings+ a tiny time delay. You can adjust this behaviour in the ENGINEERING/CONTROL/SPEED section. And its not easy! The best compromise already exists. The help file explains what does what. How it affects the smoothing of transitions between speeds as you stop etc. It needs to behave properly on steep slopes, under load, under no load or downhil on ramps etc and be smooth and controlled too. All of these are intereactive.

[faico_26]

Yes, a video would help a lot to show what I am explaining, but I think emilevirus has the same issue than me. Maybe it’s NOT an issue, but VR2 with my motors work like that. What I can assure 100% is that my old Invacare Mirage’s is almost instantaneous when I move the joystick after the click brake sounds, and with the Sunrise Quickie Q300R is slower to release the brake with another click.
So basically what I complain about is the time between click (brake on) and click (brake off).
Stupid question: could I install a different electric brake from another chair?

[emilevirus]

If it's decelerating why are brakes already applied? You mean it's still decelerating when brakes are applied?

So the power starts and the brake "holds it" for 2 seconds, so it will start with a lurch?

No, nothing starts, it waits 2s then remove brakes and starts normally.
It goes like this:
You release joystick
It decelerates
You push the joystick again
You hear the click so it's DONE decelerating. IT cannot be decelerating. Brakes are on!
Then it waits 2s and removes the brake and starts moving.

Stupid question: could I install a different electric brake from another chair?

It's not a hardware issue. Looks like a protection or something. It's just voltage being applied to the coil. There can't be any delay here.

[Burgerman]

If it's decelerating why are brakes already applied? You mean it's still decelerating when brakes are applied?

The brake is NEVER applied unless the joystick is CENTRAL, and the motors are no longer turning.

No, nothing starts, it waits 2s then remove brakes and starts normally.
It goes like this:
You release joystick
It decelerates

So you are still moving? NO BRAKES ARE APPLIED.
So you actually STOP? Brake then applied. A brake is not used to slow a chair.

You push the joystick again
You hear the click so it's DONE decelerating. IT cannot be decelerating. Brakes are on!
Then it waits 2s and removes the brake and starts moving.

Well if the brake is on. The joystick must be central. And the chair has to be stopped. If you now move the joystick the brake will instantly release.
Or I am going to need to see a video.

Stupid question: could I install a different electric brake from another chair?

Since the brake is applied BY THE CONTROLLER and released by the same controller what possible difference do you think that will have?

Understand this.
A brake DOES NOT SLOW A CHAIR. It can/WILL only apply a brake if the following 2 things are true.
!. CHAIR STATIONARY. This is determined by motor voltage. ***
2. JOYSTICK CENTRAL.

*** IF rolling and your joystick is central then it sees the motor generated voltage. The compensation sees this and will add opposite "power" if set high enough. That then results in the chair stopping rolling, and THEN the brake is applied. The same happens on a ramp. Or if you RELEASE the joystick while rolling at speed. The system sees a centralised joystick and wants to apply the brake. It CANNOT do so until it also sees zero volts on the motors. So it will slow down, and as you wait it will eventually stop and THEN the brake goes on. This can be delayed on a ramp as the chair doesent naturally come to a stop so no zero volts situation happens. But compensation forces it to stop, and so THEN you get a click. Remember that just because the chair has stopped there may be 1 or 2 volts still at the motors as compensation is holding the chair against some movement from the casters or the ramp etc.

It's not a hardware issue. Looks like a protection or something. It's just voltage being applied to the coil. There can't be any delay here.

emilevirus

There isnt.
There can be a delay in APLYING THE BRAKE after you stop. A brake will not be applied while moving or if it sees a voltage. Those can be different things. Remember there can be voltage holding you stationary during this time if a caster is pushing sideways or a ramp or something is loading a motor.
Theres NEVER a delay RELEASING the brake if you apply power (move the joystick away from centre.)

If you think there is I am going to need a video of the joystick moved away from centre and a 2 second wait... That makes zero sense.