The mower just stopped working, it has an good 80V lithium battery, a
PCB which is on a substantial heat sink and covered in resin but I can
make out what look like 7 IGBTs, a few capacitors and a relay. No
apparent overheated or bulging components.

There is no movement when the control is squeezed and it gives out a
double bleep when activated.

The 80V brushless motor cogs as one would expect, has 8 permanent
magnets on the rotor and probably 7 pars of coils on the stator.

A replacement PCB is listed at over half the cost of a replacement mower
at £340.

I think the motor is probably alright but cannot think of a way of
testing it, It has 3 power wires and a ribbon of 7 control wires.

The Q code on the motor shows:

GGP Code:;Power:1500W;Voltage:80V;RPM min:3000;RPM max:4000;Order
number:5010009578;Q.ty pcs of order:1098;Serial
number:151225-U10;Supplier Code:30001334;.

I wonder if there is any chance of finding a cheap generic motor control PCB

Stiga-Mountfield-Greenworks say return to dealer (out of warranty) and
dealer says it is unserviceable.

I guess I can use it as a wind generator if I can find a propeller :-)

ajh <news@loampitsfarm.co.uk> wrote:
> The mower just stopped working, it has an good 80V lithium battery, a
> PCB which is on a substantial heat sink and covered in resin but I can
> make out what look like 7 IGBTs, a few capacitors and a relay. No
> apparent overheated or bulging components.

Is there a microcontroller?

> There is no movement when the control is squeezed and it gives out a
> double bleep when activated.

Any documentation to say what that means?

Have you removed the battery for a few hours/days and tried again?

> The 80V brushless motor cogs as one would expect, has 8 permanent
> magnets on the rotor and probably 7 pars of coils on the stator.
>
> A replacement PCB is listed at over half the cost of a replacement mower
> at £340.
>
> I think the motor is probably alright but cannot think of a way of
> testing it, It has 3 power wires and a ribbon of 7 control wires.

Measure resistance between each pair of power wires. Should be fairly low
and roughly the same. I imagine the control wires are for the hall sensors
to feed back the motor position. As the shaft spins different combinations
are activated:
https://www.motioncontroltips.com/faq-what-are-hall-effect-sensors-and-what-is-their-role-in-dc-motors/

It is unclear whether those are analogue (give out positive and negative
voltages when it spins) or digital (require being powered up before they are
energised, or even has some electronics inside the motor). Probing with a
multimeter on voltage mode while spinning might be instructive.

Is it possible to take the motor apart and see where the control wires go?

> The Q code on the motor shows:
>
> GGP Code:;Power:1500W;Voltage:80V;RPM min:3000;RPM max:4000;Order
> number:5010009578;Q.ty pcs of order:1098;Serial
> number:151225-U10;Supplier Code:30001334;.

I wonder who makes the motor? Any indications?

(digging around Alibaba for something similar-looking might be worth a shot)

> I wonder if there is any chance of finding a cheap generic motor control PCB

Brushless DC motor controllers (BLDC) are all over ebay, Aliexpress etc.
They are quite common for ebikes for example. The main issue is working out
relations between the three phases and the hall sensors.

(with an ebike controller there might be a 'speed limit' due to ebike laws,
but it may be possible to derestrict it)

> I guess I can use it as a wind generator if I can find a propeller :-)

The mower blade is a good start :-)

Theo

On 18/10/2022 13:04, ajh wrote:
> The mower just stopped working, it has an  good 80V lithium battery, a
> PCB which is on a substantial heat sink and covered in resin but I can
> make out what look like 7 IGBTs, a few capacitors and a relay. No
> apparent overheated or bulging components.
>
> There is no movement when the control is squeezed and it gives out a
> double bleep when activated.
>
> The 80V brushless motor cogs as one would expect, has 8 permanent
> magnets on the rotor and probably 7 pars of coils on the stator.
>
> A replacement PCB is listed at over half the cost of a replacement mower
> at £340.
>
> I think the motor is probably alright but cannot think of a way of
> testing it, It has 3 power wires and a ribbon of 7 control wires.
>
> The Q code on the motor shows:
>
> GGP Code:;Power:1500W;Voltage:80V;RPM min:3000;RPM max:4000;Order
> number:5010009578;Q.ty pcs of order:1098;Serial
> number:151225-U10;Supplier Code:30001334;.
>
> I wonder if there is any chance of finding a cheap generic motor control
> PCB
>
> Stiga-Mountfield-Greenworks say return to dealer (out of warranty) and
> dealer says it is unserviceable.
>
> I guess I can use it as a wind generator if I can find a propeller :-)

From model plane experience you probably have a blown controller.
Motors don't usually let go without letting out a lot of magic smoke...

Are there just three fat wires into the motor?
If so a model plane controller might work...

...ish there would be no sane RPM stabilisation though.

Almost certainly (some of) the MOSFETS are blown...
--
Future generations will wonder in bemused amazement that the early
twenty-first century’s developed world went into hysterical panic over a
globally average temperature increase of a few tenths of a degree, and,
on the basis of gross exaggerations of highly uncertain computer
projections combined into implausible chains of inference, proceeded to
contemplate a rollback of the industrial age.

Richard Lindzen

Theo wrote:

> with an ebike controller there might be a 'speed limit' due to ebike laws,
> but it may be possible to derestrict it

A 15.5mph lawnmower might be quite exciting

(yes, yes, i know).

On 18/10/2022 13:37, Theo wrote:
> ajh <news@loampitsfarm.co.uk> wrote:
>> The mower just stopped working, it has an good 80V lithium battery, a
>> PCB which is on a substantial heat sink and covered in resin but I can
>> make out what look like 7 IGBTs, a few capacitors and a relay. No
>> apparent overheated or bulging components.
>
> Is there a microcontroller?
>
>> There is no movement when the control is squeezed and it gives out a
>> double bleep when activated.
>
> Any documentation to say what that means?
>
> Have you removed the battery for a few hours/days and tried again?
>
>> The 80V brushless motor cogs as one would expect, has 8 permanent
>> magnets on the rotor and probably 7 pars of coils on the stator.
>>
>> A replacement PCB is listed at over half the cost of a replacement mower
>> at £340.
>>
>> I think the motor is probably alright but cannot think of a way of
>> testing it, It has 3 power wires and a ribbon of 7 control wires.
>
> Measure resistance between each pair of power wires. Should be fairly low
> and roughly the same. I imagine the control wires are for the hall sensors
> to feed back the motor position. As the shaft spins different combinations
> are activated:
> https://www.motioncontroltips.com/faq-what-are-hall-effect-sensors-and-what-is-their-role-in-dc-motors/
>
> It is unclear whether those are analogue (give out positive and negative
> voltages when it spins) or digital (require being powered up before they are
> energised, or even has some electronics inside the motor). Probing with a
> multimeter on voltage mode while spinning might be instructive.
>
> Is it possible to take the motor apart and see where the control wires go?

Not yet for fear of breaking it
>
>> The Q code on the motor shows:
>>
>> GGP Code:;Power:1500W;Voltage:80V;RPM min:3000;RPM max:4000;Order
>> number:5010009578;Q.ty pcs of order:1098;Serial
>> number:151225-U10;Supplier Code:30001334;.
>
> I wonder who makes the motor? Any indications?

It has:
Globe 9940
381011299
80V DC
151224-U2

but a search doesn't yield much other than a site that has been hacked

>
> Brushless DC motor controllers (BLDC) are all over ebay, Aliexpress etc.
> They are quite common for ebikes for example. The main issue is working out
> relations between the three phases and the hall sensors.

Far too complicated for me, I have already fouled up the brushed motor
controller for the ebike I was attempting to repair.

>
>> I guess I can use it as a wind generator if I can find a propeller :-)
>
> The mower blade is a good start :-)

I don't think so, the cogging is quite strong so will need a bit of
torque to overcome, then it would need to reach 3000rpm (rated speed as
a motor)

On 18/10/2022 15:01, The Natural Philosopher wrote:
r if I can find a propeller :-)
>
> From model plane experience you probably have a blown controller.
> Motors don't usually let go without letting out a lot of magic smoke...

That is what I am hoping
>
> Are there just three  fat wires into the motor?

Yes

> If so a model plane controller might work...
>
> ..ish there would be no sane RPM stabilisation though.
>
> Almost certainly (some of) the MOSFETS are blown...

I can probably scrape off the resin on theit three connections but can
they be checked when still in circuit? The opposite side of the PCB is
totally embedded.

I have now measured the resistance between all three power leads, about
0.5V.

Also the open circuit voltage when spun up about 2k rpm is near enough
the same 26V between each pair.

On 18/10/2022 16:28, ajh wrote:
> I  have now measured the resistance between all three power leads, about
> 0.5V.

0.5Ohms
>
> Also the open circuit voltage when spun up about 2k rpm is near enough
> the same 26V between each pair.

ajh <news@loampitsfarm.co.uk> wrote:
> I have now measured the resistance between all three power leads, about
> 0.5V.
>
I hope you mean 0.5 ohms! :-)

--
Chris Green
·

On 18/10/2022 17:04, Chris Green wrote:
> ajh <news@loampitsfarm.co.uk> wrote:
>> I have now measured the resistance between all three power leads, about
>> 0.5V.
>>
> I hope you mean 0.5 ohms! :-)
>
Yes corrected that after I posted

On 18/10/2022 15:58, ajh wrote:
> On 18/10/2022 15:01, The Natural Philosopher wrote:
> r if I can find a propeller :-)
>>
>>  From model plane experience you probably have a blown controller.
>> Motors don't usually let go without letting out a lot of magic smoke...
>
> That is what I am hoping
>>
>> Are there just three  fat wires into the motor?
>
> Yes
>
But I rechecked and you said there were 4 thin ones as well? Think it
was 4...

>> If so a model plane controller might work...
>>
>> ..ish there would be no sane RPM stabilisation though.
>>
>> Almost certainly (some of) the MOSFETS are blown...
>
> I can probably scrape off the resin on theit three connections but can
> they be checked when still in circuit? The opposite side of the PCB is
> totally embedded.
>
I suspect that the way its constructed its gonna be a new PCB assembly.

The are reasons to encapsulate - like it still works after being rained
on - that will preclude it being fixable

All in all, don't buy another mower like this as it is patently
non-reparable at economic costs

--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

On 18/10/2022 17:06, ajh wrote:
> On 18/10/2022 16:28, ajh wrote:
>> I  have now measured the resistance between all three power leads,
>> about 0.5V.
>
> 0.5Ohms
Very high. Probably the resistance of the test wire. I have expected
0.05 ohms more like for a motor in that class.

>>
>> Also the open circuit voltage when spun up about 2k rpm is near enough
>> the same 26V between each pair.
>

I think its clear that its the controller is blown, unfortunately it
seems to be a sensored one

--
Ideas are more powerful than guns. We would not let our enemies have
guns, why should we let them have ideas?

Josef Stalin

I used to use hall effect sensors many years ago to make cassette auto stops
work better. Most relied on some kind of rotating switch from the take up
spool, but these wore out, and basically a tiny read relay operated by a
hall effect sensor and a small magnet glued to the clutch made them more
reliable. You listening Akai!

Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"ajh" <news@loampitsfarm.co.uk> wrote in message
news:jr7t20FfvdkU1@mid.individual.net...
> On 18/10/2022 13:37, Theo wrote:
>> ajh <news@loampitsfarm.co.uk> wrote:
>>> The mower just stopped working, it has an good 80V lithium battery, a
>>> PCB which is on a substantial heat sink and covered in resin but I can
>>> make out what look like 7 IGBTs, a few capacitors and a relay. No
>>> apparent overheated or bulging components.
>>
>> Is there a microcontroller?
>>
>>> There is no movement when the control is squeezed and it gives out a
>>> double bleep when activated.
>>
>> Any documentation to say what that means?
>>
>> Have you removed the battery for a few hours/days and tried again?
>>
>>> The 80V brushless motor cogs as one would expect, has 8 permanent
>>> magnets on the rotor and probably 7 pars of coils on the stator.
>>>
>>> A replacement PCB is listed at over half the cost of a replacement mower
>>> at �340.
>>>
>>> I think the motor is probably alright but cannot think of a way of
>>> testing it, It has 3 power wires and a ribbon of 7 control wires.
>>
>> Measure resistance between each pair of power wires. Should be fairly
>> low
>> and roughly the same. I imagine the control wires are for the hall
>> sensors
>> to feed back the motor position. As the shaft spins different
>> combinations
>> are activated:
>> https://www.motioncontroltips.com/faq-what-are-hall-effect-sensors-and-what-is-their-role-in-dc-motors/
>>
>> It is unclear whether those are analogue (give out positive and negative
>> voltages when it spins) or digital (require being powered up before they
>> are
>> energised, or even has some electronics inside the motor). Probing with
>> a
>> multimeter on voltage mode while spinning might be instructive.
>>
>> Is it possible to take the motor apart and see where the control wires
>> go?
>
> Not yet for fear of breaking it
>>
>>> The Q code on the motor shows:
>>>
>>> GGP Code:;Power:1500W;Voltage:80V;RPM min:3000;RPM max:4000;Order
>>> number:5010009578;Q.ty pcs of order:1098;Serial
>>> number:151225-U10;Supplier Code:30001334;.
>>
>> I wonder who makes the motor? Any indications?
>
> It has:
> Globe 9940
> 381011299
> 80V DC
> 151224-U2
>
> but a search doesn't yield much other than a site that has been hacked
>
>>
>> Brushless DC motor controllers (BLDC) are all over ebay, Aliexpress etc.
>> They are quite common for ebikes for example. The main issue is working
>> out
>> relations between the three phases and the hall sensors.
>
> Far too complicated for me, I have already fouled up the brushed motor
> controller for the ebike I was attempting to repair.
>
>>
>>> I guess I can use it as a wind generator if I can find a propeller :-)
>>
>> The mower blade is a good start :-)
>
> I don't think so, the cogging is quite strong so will need a bit of torque
> to overcome, then it would need to reach 3000rpm (rated speed as a motor)
>

ajh <news@loampitsfarm.co.uk> wrote:
> I have now measured the resistance between all three power leads, about
> 0.5V.
>
> Also the open circuit voltage when spun up about 2k rpm is near enough
> the same 26V between each pair.

OK, so it sounds like the motor coils are OK. It's possible the hall
sensors are broken, which would prevent it being able to sense motor
position.

Are there any other mechanical components? eg I had an ebike motor that
went into a similar sulk and had a similar potted control board. It turned
out it had a torque sensor which was just a pot with a spring. The pot had
worn its carbon track and wasn't reading correctly. It was easy to replace
(once I'd got the part from Japan). Anything like that?

Theo

On 19/10/2022 10:19, Theo wrote:
> ajh <news@loampitsfarm.co.uk> wrote:
>> I have now measured the resistance between all three power leads, about
>> 0.5V.
>>
>> Also the open circuit voltage when spun up about 2k rpm is near enough
>> the same 26V between each pair.
>
> OK, so it sounds like the motor coils are OK. It's possible the hall
> sensors are broken, which would prevent it being able to sense motor
> position.
>
> Are there any other mechanical components? eg I had an ebike motor that
> went into a similar sulk and had a similar potted control board. It turned
> out it had a torque sensor which was just a pot with a spring. The pot had
> worn its carbon track and wasn't reading correctly. It was easy to replace
> (once I'd got the part from Japan). Anything like that?
>
> Theo
>

Nothing else that I can see, the pricing of the controller makes the
mower un repairable. No loss to me but something to be wary of if one
is in the market for a cordless mower but it is 6 years old.

On 19/10/2022 08:22, The Natural Philosopher wrote:
> On 18/10/2022 15:58, ajh wrote:
>> On 18/10/2022 15:01, The Natural Philosopher wrote:
>> r if I can find a propeller :-)
>>>
>>>  From model plane experience you probably have a blown controller.
>>> Motors don't usually let go without letting out a lot of magic smoke...
>>
>> That is what I am hoping
>>>
>>> Are there just three  fat wires into the motor?
>>
>> Yes
>>
> But I rechecked and you said there were 4 thin ones as well? Think it
> was 4...

Yes, sorry I missed the "only"there are three power wires plus a ribbon
of thinner ones. I have re checked and the ribbon has 5 wires

>
> All in all, don't buy another mower like this as it is patently
> non-reparable at economic costs
>
>

That's right, it is such a shame as the rest is in very good condition.
I might see if I can take the honda engine out of another one that has a
rotten deck and fit that.

OR

Mount the motor and deck upside down under the honda engine and make a
generator

On Tuesday, 18 October 2022 at 15:55:02 UTC+1, ajh wrote:
> On 18/10/2022 13:37, Theo wrote:
> > ajh <ne...@loampitsfarm.co.uk> wrote:
> >> The mower just stopped working, it has an good 80V lithium battery, a
> >> PCB which is on a substantial heat sink and covered in resin but I can
> >> make out what look like 7 IGBTs, a few capacitors and a relay. No
> >> apparent overheated or bulging components.
> >
> > Is there a microcontroller?
> >
> >> There is no movement when the control is squeezed and it gives out a
> >> double bleep when activated.
> >
> > Any documentation to say what that means?
> >
> > Have you removed the battery for a few hours/days and tried again?
> >
> >> The 80V brushless motor cogs as one would expect, has 8 permanent
> >> magnets on the rotor and probably 7 pars of coils on the stator.
> >>
> >> A replacement PCB is listed at over half the cost of a replacement mower
> >> at £340.
> >>
> >> I think the motor is probably alright but cannot think of a way of
> >> testing it, It has 3 power wires and a ribbon of 7 control wires.
> >
> > Measure resistance between each pair of power wires. Should be fairly low
> > and roughly the same. I imagine the control wires are for the hall sensors
> > to feed back the motor position. As the shaft spins different combinations
> > are activated:
> > https://www.motioncontroltips.com/faq-what-are-hall-effect-sensors-and-what-is-their-role-in-dc-motors/
> >
> > It is unclear whether those are analogue (give out positive and negative
> > voltages when it spins) or digital (require being powered up before they are
> > energised, or even has some electronics inside the motor). Probing with a
> > multimeter on voltage mode while spinning might be instructive.
> >
> > Is it possible to take the motor apart and see where the control wires go?
> Not yet for fear of breaking it
> >
> >> The Q code on the motor shows:
> >>
> >> GGP Code:;Power:1500W;Voltage:80V;RPM min:3000;RPM max:4000;Order
> >> number:5010009578;Q.ty pcs of order:1098;Serial
> >> number:151225-U10;Supplier Code:30001334;.
> >
> > I wonder who makes the motor? Any indications?
> It has:
> Globe 9940
> 381011299
> 80V DC
> 151224-U2
>
> but a search doesn't yield much other than a site that has been hacked
> >
> > Brushless DC motor controllers (BLDC) are all over ebay, Aliexpress etc..
> > They are quite common for ebikes for example. The main issue is working out
> > relations between the three phases and the hall sensors.
> Far too complicated for me, I have already fouled up the brushed motor
> controller for the ebike I was attempting to repair.
> >
> >> I guess I can use it as a wind generator if I can find a propeller :-)
> >
> > The mower blade is a good start :-)
> I don't think so, the cogging is quite strong so will need a bit of
> torque to overcome, then it would need to reach 3000rpm (rated speed as
> a motor)

Strong cogging is a deathblow for motors for wind generation. They need to get going easily.

On Wednesday, 19 October 2022 at 18:31:33 UTC+1, ajh wrote:
> On 19/10/2022 10:19, Theo wrote:
> > ajh <ne...@loampitsfarm.co.uk> wrote:
> >> I have now measured the resistance between all three power leads, about
> >> 0.5V.
> >>
> >> Also the open circuit voltage when spun up about 2k rpm is near enough
> >> the same 26V between each pair.
> >
> > OK, so it sounds like the motor coils are OK. It's possible the hall
> > sensors are broken, which would prevent it being able to sense motor
> > position.
> >
> > Are there any other mechanical components? eg I had an ebike motor that
> > went into a similar sulk and had a similar potted control board. It turned
> > out it had a torque sensor which was just a pot with a spring. The pot had
> > worn its carbon track and wasn't reading correctly. It was easy to replace
> > (once I'd got the part from Japan). Anything like that?
> >
> > Theo
> >
> Nothing else that I can see, the pricing of the controller makes the
> mower un repairable. No loss to me but something to be wary of if one
> is in the market for a cordless mower but it is 6 years old.

You can't find a used one on ebay?
And one last long shot: replacing the motor with a 240v brushed jobbie, no controller.