Problem in the Left Engine.

[martin007]

I have a problem in the left engine.
The left engine don´t turn.
I believe that the sinus brake does not work.
The right motor works and the batteries have voltage.

I´m in a manual wheelchair ...
What do you think?

[Burgerman]

Nobody can know without taking it apart and checking it out.

I do remember that when I said I swapped motors every couple of years and rebult everything as new and no expense spared you (or maybe elryko?) said I was mad. Trust me, you NEED a reliable backup chair. And thats not adequate alone because that may fail. I have about 5 chairs. 4 in fully 100 percent ready to go state. Because its important that you do.

Your motor problem?
Gearbox failed, motor armature, bearing, magnet break up or unstuck, brake seized and not releasing, motor coupling rubber failed and jammed the motor. Are a few of my favorite catastrophies, and I had them all.

[martin007]

The engine worked perfectly and suddenly stopped working.
I'm going to try to dismantle it.

Your motor problem?
Gearbox failed, motor armature, bearing, magnet break up or unstuck, brake seized and not releasing, motor coupling rubber failed and jammed the motor. Are a few of my favorite catastrophies, and I had them all.

I bet for: brake seized and not releasing, motor coupling rubber failed and jammed the motor.

[Dan]

I would check to see if it had power going to it before doing anything else.

[martin007]

I would check to see if it had power going to it before doing anything else.

I don´t understand you.
What do you mean?

[Dan]

Sorry I now see your saying its jammed. I guess you have already released the break and tried manually to spin the wheel.

[martin007]

Yes...

[LROBBINS]

Before tearing things apart, do try to do some diagnosis from outside. For example, does the brake click when you try to drive it and click again when you let go of the joystick? If it doesn't click, check the resistance of the brake coil - should be less than 100 ohms but neither open nor shorted. Is voltage arriving on the brake connections when you move the joystick (12V or 24V depending on the chair)? If you put it in free-wheel and disable the no-brake interlock microswitch (e.g. by shorting the two terminals on the microswitch), will the motor turn? Even if you have to dismount the motor, you might want to physically remove the brake (that's usually not too hard) and see if the motor then turns. In other words, try to do everything you can to distinguish between an electrical problem, a brake problem and a motor/gearcase problem before digging into the guts.

[martin007]

does the brake click when you try to drive it and click again when you let go of the joystick?

> No.

Si no hace clic, compruebe la resistencia de la bobina del freno: debe ser inferior a 100 ohmios, pero no debe abrirse ni entrar en cortocircuito.

> How do I do that?

[martin007]

Sorry.

does the brake click when you try to drive it and click again when you let go of the joystick?

> No.

If it doesn't click, check the resistance of the brake coil - should be less than 100 ohms but neither open nor shorted.

> How do I do that?

[Burgerman]

Does the right brake click?
Are your joystick lights normal?

If so, then disconnect the left motor from the power module, and look at the plug. Set your multimeter to resistance, and measure the two smaller connections. What does it say?

Do the same with the right motor.

[martin007]

Are your joystick lights normal?

> Yes.

[Burgerman]

Does the right brake click?
Are your joystick lights normal?

If so, then disconnect the left motor from the power module, and look at the plug. Set your multimeter to resistance, and measure the two smaller connections. What does it say?

Do the same with the right motor.

[martin007]

Where do I place the tips of the Fluke?
The engine has 4 connections.

[Burgerman]

The two small wires work the brake. Those are the ones.

The two large ones wont tell you very much, they connect to the motors. Measure those too, to compare each side. Those will be very low...

[martin007]

Sorry...

Something I should not do with the multimeter when measuring resistance?
I'm a rookie and I do not want to ruin the Fluke.

[martin007]

Right motor (works) > 59,5 Ω

Left engine > 61,9 Ω

[LROBBINS]

The absence of the brake click tells you that the brake isn't releasing. That could be because it is burnt out, or because it is stuck, or because it isn't getting electricity from the controller. Measuring resistance will tell you if the brake coil is bad. Measure resistance with the chair turned off. When you look at the cable going to the motor and brake there is one connector coming from the power module and its mating connector on the motor/brake side. Disconnect them and measure the resistance on the connector on the motor/brake side - it's the two smaller pins that feed the brake.

If the coil is OK, you next need to check whether the brake is getting electricity or if it is stuck. But, one thing at a time. Check the coil, tell us the result, and we'll try to guide you to the next steps.

You are going to be living with basic electric circuits for the rest of your life. It would be a good idea to find a very basic text on electricity and circuits so that you understand what and how you measure things with that fancy meter.

[martin007]

Right motor (works) > 59,5 Ω

Left engine > 61,9 Ω

[Burgerman]

Thats normal. No fault.

So are you SURE that theres no click? On left motor? And on right motor? And no error lights?

If so then the fault is either the power module, (not sending power to the brake (you can measure this) or the mechanical brake is stuck, or theres a motor or gearbox or cush drive failure. Can you turn a wheel by hand if the brake is off (add 12v to the two small wires). If not then its a failed motor/gearbox. Which is why I change them before I get stuck miles from home.

[martin007]

And no error lights?

> No.

So are you SURE that theres no click? On left motor?

> No.

And on right motor?

> The right motor clicks and works perfectly.

Can you turn a wheel by hand if the brake is off

> The wheel turns when the chair is turned into manual.

[martin007]

(add 12v to the two small wires).

I don´t understand.

[Dan]

Here is a video of a motor being taken apart.

He works the break with a battery at 11:20

youtu.be/taua7C8HqCM

[Burgerman]

Very good video.

Motor looks like a Linix (chinese) 2 pole, which are extremely common on smaller or cheaper chairs. And while a longer armature and magnet increases torque a little, it also means that 2 brushes then have more Amps passing through them, so heating them up and wearing them out faster... So 4 pole always better. And he seems surprised to find that they use nylon/ptfe/delrin gears.

I took lots apart. All the ones that use worm drive, single stage gear, and theres lots, use a non metal gear. Because the diameter means that less pressure is required for a given level of torque. And so it doesent fail. (I remember mark on the junkie site going on about his new high tech single stage high efficiency motor on the Edge 2, which was just a cheap 2 pole like these... As a new marketing advance! Been around for 20 years that I know of).

Off all my motor failures, its never been the plastic gear that dies on decent motors. They use this material because it allows a very tight zero clearance or (close to it) fit. Since theres some flexibility. So no backlash, and because of the material is quieter running with less losses due to friction. And they dont wear fast like metals. And lighter. They dont need a running clearance as in a metal gear. And his roller bearing was a ball bearing. But other than that a very good clear vid.

[martin007]

Are there any spare parts for the sinusoidal brake on the market?

[Burgerman]

Sinusoidal? The brake is a simple DC electromagnet. You already tested that. Its working as expected. If it was burned or shorted it would have read lower resistance. If it was open circuit it would have read very high impedance. So your magnetic coil is fine.

It can be:

A lack of voltage from the power module. We can test that later.
A seized or broken motor, bearing failure, magnet collapsed and broken destroying and jamming the motor, gearbox broken, cush drive motor coupling broken and jamming the motor from turning, etc etc. The brake MAY be seized but very unlikely.

[martin007]

A lack of voltage from the power module. We can test that later.

The energy reaches the engine ...

Tomorrow plus...

https://www.youtube.com/watch?v=59DNyGYkW3A

[steves1977uk]

Power chair motors are called motors, not engines Never heard them being called engines before! Although I see why Martin calls them engines

Steve

[martin007]

Power chair motors are called motors, not engines Never heard them being called engines before! Although I see why Martin calls them engines

Steve

I don't understand what you say.
I'm going to sleep.

[Burgerman]

The brake? Or the "engine"?

I dont think your problem has anything to do with the brake.