Its that time of year again...

My tractor mower, sometimes suffers from the cutter blades coming to a
stop due to becoming completely choked with grass. When that happens,
it slips the drive clutch, but from the driving seat, there is no
noticeable change in the noise and I carry on driving with no cutting
taking place and damaging the clutch.

I don't use a grass collector on the rear and because it tends to be
another cause of it choking up, but I can look back and see grass
cuttings being blown out the back when all is well. The drive clutch
and its pulley output to the cutting deck, is under the engine.

Ideally, I could do with a better way to be sure at a glance, that the
clutch isn't slipping and the deck is being driven round. One idea I
have is a magnet fixed to the edge of a pulley, rotating past a coil
powering an LED mounted on the tractors dash. Has anyone any other
suggestions?

"Harry Bloomfield" wrote in message ...

Its that time of year again...

My tractor mower, sometimes suffers from the cutter blades coming to a
stop due to becoming completely choked with grass. When that happens,
it slips the drive clutch, but from the driving seat, there is no
noticeable change in the noise and I carry on driving with no cutting
taking place and damaging the clutch.

I don't use a grass collector on the rear and because it tends to be
another cause of it choking up, but I can look back and see grass
cuttings being blown out the back when all is well. The drive clutch
and its pulley output to the cutting deck, is under the engine.

Ideally, I could do with a better way to be sure at a glance, that the
clutch isn't slipping and the deck is being driven round. One idea I
have is a magnet fixed to the edge of a pulley, rotating past a coil
powering an LED mounted on the tractors dash. Has anyone any other
suggestions?

Rear view mirror?

Andrew

On 18/04/2019 17:32, Harry Bloomfield wrote:
Its that time of year again...

My tractor mower, sometimes suffers from the cutter blades coming to a
stop due to becoming completely choked with grass. When that happens, it
slips the drive clutch, but from the driving seat, there is no
noticeable change in the noise and I carry on driving with no cutting
taking place and damaging the clutch.

I don't use a grass collector on the rear and because it tends to be
another cause of it choking up, but I can look back and see grass
cuttings being blown out the back when all is well. The drive clutch and
its pulley output to the cutting deck, is under the engine.

Ideally, I could do with a better way to be sure at a glance, that the
clutch isn't slipping and the deck is being driven round. One idea I
have is a magnet fixed to the edge of a pulley, rotating past a coil
powering an LED mounted on the tractors dash. Has anyone any other
suggestions?

That seems a pretty neat idea to me. My analogous problem is a 100 litre
electric sprayer that sits in the back of my all terrain vehicle,
recognising when the spray stops for any reason. I have tried a little
wireless TV camera with a monitor on the dashboard but it wasn't really
effective.

Andrew Mawson brought next idea :
Rear view mirror?

Andrew

I have already discounted that idea, because there is no place one
could be sensibly mounted, where it would allow sight of the grass
cuttings being blown out. Thanks..

On 18/04/2019 17:32, Harry Bloomfield wrote:
One idea I have is a magnet fixed to the edge of a pulley, rotating past
a coil powering an LED mounted on the tractors dash

Thats what Kirby vacuums use a magnet on the roller brush and it rotates
past the coil lighting an LED, they use it to show if the brush stops
rotating ie the belt has snapped.

On Thu, 18 Apr 2019 17:39:24 +0100
newshound wrote:

That seems a pretty neat idea to me. My analogous problem is a 100
litre electric sprayer that sits in the back of my all terrain
vehicle, recognising when the spray stops for any reason. I have
tried a little wireless TV camera with a monitor on the dashboard but
it wasn't really effective.

Fit a flow meter and monitor it with a microprocessor that can flash
LEDs at you.

On Thu, 18 Apr 2019 17:32:32 +0100
Harry Bloomfield wrote:

Ideally, I could do with a better way to be sure at a glance, that
the clutch isn't slipping and the deck is being driven round. One
idea I have is a magnet fixed to the edge of a pulley, rotating past
a coil powering an LED mounted on the tractors dash. Has anyone any
other suggestions?

Bicycle computers use a magnet and a reed switch to measure rotation,
but your mower will probably be going too fast for it to cope. An
Arduino with a Hall sensor could count your spinning magnet revolutions,
and is obviously a lot more configurable but with the overhead of having
to build the system from scratch.

Hall effect devices tend to be more reliable than mechanical things for this
purpose. I replaced a dodgy read switch in an old cassette deck autostop
with one some years back it outlasted the tape deck.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Harry Bloomfield" wrote in message
...
Its that time of year again...

My tractor mower, sometimes suffers from the cutter blades coming to a
stop due to becoming completely choked with grass. When that happens, it
slips the drive clutch, but from the driving seat, there is no noticeable
change in the noise and I carry on driving with no cutting taking place
and damaging the clutch.

I don't use a grass collector on the rear and because it tends to be
another cause of it choking up, but I can look back and see grass cuttings
being blown out the back when all is well. The drive clutch and its pulley
output to the cutting deck, is under the engine.

Ideally, I could do with a better way to be sure at a glance, that the
clutch isn't slipping and the deck is being driven round. One idea I have
is a magnet fixed to the edge of a pulley, rotating past a coil powering
an LED mounted on the tractors dash. Has anyone any other suggestions?

Tee hee.
No the magnet and hall effect sensor work well, but it would be much
cleverer to somehow link the on off pulses so that if they were not present
it cut the power.
Brian

--
----- --
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Andrew Mawson" wrote in message
...
"Harry Bloomfield" wrote in message ...

Its that time of year again...

My tractor mower, sometimes suffers from the cutter blades coming to a
stop due to becoming completely choked with grass. When that happens, it
slips the drive clutch, but from the driving seat, there is no noticeable
change in the noise and I carry on driving with no cutting taking place
and damaging the clutch.

I don't use a grass collector on the rear and because it tends to be
another cause of it choking up, but I can look back and see grass cuttings
being blown out the back when all is well. The drive clutch and its pulley
output to the cutting deck, is under the engine.

Ideally, I could do with a better way to be sure at a glance, that the
clutch isn't slipping and the deck is being driven round. One idea I have
is a magnet fixed to the edge of a pulley, rotating past a coil powering
an LED mounted on the tractors dash. Has anyone any other suggestions?

Rear view mirror?

Andrew

Rob Morley Wrote in message:
On Thu, 18 Apr 2019 17:32:32 +0100
Harry Bloomfield wrote:

Ideally, I could do with a better way to be sure at a glance, that
the clutch isn't slipping and the deck is being driven round. One
idea I have is a magnet fixed to the edge of a pulley, rotating past
a coil powering an LED mounted on the tractors dash. Has anyone any
other suggestions?

Bicycle computers use a magnet and a reed switch to measure rotation,
but your mower will probably be going too fast for it to cope.

Although you only want it to show when it has slowed/stopped
rotating, not how fast it's going when all is well...

--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

Rob Morley wrote:

On Thu, 18 Apr 2019 17:32:32 +0100
Harry Bloomfield wrote:

Ideally, I could do with a better way to be sure at a glance, that
the clutch isn't slipping and the deck is being driven round. One
idea I have is a magnet fixed to the edge of a pulley, rotating past
a coil powering an LED mounted on the tractors dash. Has anyone any
other suggestions?

Bicycle computers use a magnet and a reed switch to measure rotation,

Wrong

On 18/04/2019 23:44, Mark wrote:
Rob Morley wrote:

On Thu, 18 Apr 2019 17:32:32 +0100
Harry Bloomfield wrote:

Ideally, I could do with a better way to be sure at a glance, that
the clutch isn't slipping and the deck is being driven round. One
idea I have is a magnet fixed to the edge of a pulley, rotating past
a coil powering an LED mounted on the tractors dash. Has anyone any
other suggestions?

Bicycle computers use a magnet and a reed switch to measure rotation,

Wrong

Mine certainly does.

SteveW

On 18/04/2019 19:47, Rob Morley wrote:
On Thu, 18 Apr 2019 17:32:32 +0100
Harry Bloomfield wrote:

Ideally, I could do with a better way to be sure at a glance, that
the clutch isn't slipping and the deck is being driven round. One
idea I have is a magnet fixed to the edge of a pulley, rotating past
a coil powering an LED mounted on the tractors dash. Has anyone any
other suggestions?

Bicycle computers use a magnet and a reed switch to measure rotation,
but your mower will probably be going too fast for it to cope. An
Arduino with a Hall sensor could count your spinning magnet revolutions,
and is obviously a lot more configurable but with the overhead of having
to build the system from scratch.


A hall effect switch or reed switch could still give a false reading if
the blade stops exactly in the position where the magnet is next to the
hall effect or reed switch.

The coil would only react to changes so if the magnet doesn't move there
will be no output from the coil irrespective of where the magnet ends up
in the blade stalled position. However what is the on/off ratio going to
be? Unless the magnet energises the coil (or switch) for a substantial
time then the LED may only have a just perceivable flicker which cannot
be seen in daylight. You probably need some simple circuit, say, where
the output from the coil charges up a capacitor which in turn allows the
LED to remain on long enough to be seen at full brightness.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 19/04/2019 04:20, alan_m wrote:
On 18/04/2019 19:47, Rob Morley wrote:
On Thu, 18 Apr 2019 17:32:32 +0100
Harry Bloomfield wrote:
Ideally, I could do with a better way to be sure at a glance, that
the clutch isn't slipping and the deck is being driven round. One
idea I have is a magnet fixed to the edge of a pulley, rotating past
a coil powering an LED mounted on the tractors dash. Has anyone any
other suggestions?

Bicycle computers use a magnet and a reed switch to measure rotation,
but your mower will probably be going too fast for it to cope.Â* An
Arduino with a Hall sensor could count your spinning magnet revolutions,
and is obviously a lot more configurable but with the overhead of having
to build the system from scratch.


A hall effect switch or reed switch could still give a false reading if
the blade stops exactly in the position where the magnet is next to the
hall effect or reed switch.

The coil would only react to changes so if the magnet doesn't move there
will be no output from the coil irrespective of where the magnet ends up
in the blade stalled position. However what is the on/off ratio going to
be? Unless the magnet energises the coil (or switch) for a substantial
time then the LED may only have a just perceivable flicker which cannot
be seen in daylight. You probably need some simple circuit, say, where
the output from the coil charges up a capacitor which in turn allows the
LED to remain on long enough to be seen at full brightness.

a failing in physics understnanding, Teh avearge poutoput will be te
same capacioter or not and teh peak brightness will be higher if left
pulsing,

Most blades are close to the motor's speed anyway = appx 3000RPM or 50Hz.




--
Religion is regarded by the common people as true, by the wise as
foolish, and by the rulers as useful.

(Seneca the Younger, 65 AD)

The Natural Philosopher wrote :
Most blades are close to the motor's speed anyway = appx 3000RPM or 50Hz.

All the pulleys are approximately the same size, so yes the blades will
rotate at engine speed.

The PTO clutch is rather weird - just a metal plate trapped between
disks by spring pressure.

Brian Gaff explained on 18/04/2019 :
Tee hee.
No the magnet and hall effect sensor work well, but it would be much cleverer
to somehow link the on off pulses so that if they were not present it cut
the power.
Brian

That would involve much more complexity than it needs. It would require
some means to override it, to enable the engine to be started.

My first attempt at an indicator was a simple hinged flap on the output
of the duct. Air blown out by the cutter fan, lifted the flap, but it
was impossible to see the flap whilst driving. No air flow, meant the
deck was choked. I suppose I could fit a magnet on a flap, operating a
reed switch to turn on an LED.

On 19/04/2019 09:24, Harry Bloomfield wrote:
Brian Gaff explained on 18/04/2019 :
Tee hee.
No the magnet and hall effect sensor work well, but it would be much
cleverer toÂ* somehow link the on off pulses so that if they were not
present it cut the power.
Â*Brian

That would involve much more complexity than it needs. It would require
some means to override it, to enable the engine to be started.

My first attempt at an indicator was a simple hinged flap on the output
of the duct. Air blown out by the cutter fan, lifted the flap, but it
was impossible to see the flap whilst driving. No air flow, meant the
deck was choked. I suppose I could fit a magnet on a flap, operating a
reed switch to turn on an LED.

I think that is overblown.

All you need is something like a guitar pickup. Lots of turns round a
magnet close to where the blades are. Should be enough power to light a LED



--
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 Fri, 19 Apr 2019 00:09:11 +0100, Steve Walker
wrote:

On 18/04/2019 23:44, Mark wrote:
Rob Morley wrote:
(...)
Bicycle computers use a magnet and a reed switch to measure rotation,

Wrong

Mine certainly does.

As does mine -- wired computer, uses a reed switch and magnet.

Max speed 199 km/h or mph is usual, and wheel circumferences down to ~1200 mm
(16"). Cunning adjustment of miles/kilometers and wheel circumference might
allow it to show rpm...



Thomas Prufer

The Natural Philosopher explained :
I think that is overblown.

All you need is something like a guitar pickup. Lots of turns round a magnet
close to where the blades are. Should be enough power to light a LED

Well I tried it and although the blown flap was able to operate a
micro-switch quite easily, the flap slowed the exit air flow and
quickly choked it up.

I'm not going to try attaching anything to the blades, I have in mind a
magnet on blade pulley, above the deck. It should be fairly easy to
then make a bracket to mount a coil.

On Friday, 19 April 2019 22:06:31 UTC+1, Harry Bloomfield wrote:
The Natural Philosopher explained :

I think that is overblown.

All you need is something like a guitar pickup. Lots of turns round a magnet
close to where the blades are. Should be enough power to light a LED

Well I tried it and although the blown flap was able to operate a
micro-switch quite easily, the flap slowed the exit air flow and
quickly choked it up.

I'm not going to try attaching anything to the blades, I have in mind a
magnet on blade pulley, above the deck. It should be fairly easy to
then make a bracket to mount a coil.

easier would be a strip of polythene. When the blades turn it'll blow & flap busily. You'll notice if it's not behind you.


NT

explained on 19/04/2019 :
You'll notice if it's not behind you.

There is no way to make it visible in my line of sight. The cutter deck
is (obviously) underneath, the duct from that, carrying the fan blown
cut grass, goes below and exits at the very back.

On 20/04/2019 08:13, Harry Bloomfield wrote:
explained on 19/04/2019 :
You'll notice if it's not behind you.

There is no way to make it visible in my line of sight. The cutter deck
is (obviously) underneath, the duct from that, carrying the fan blown
cut grass, goes below and exits at the very back.

https://smile.amazon.co.uk/Digital-A.../dp/B07FLT5Y7L

On Sat, 20 Apr 2019 12:28:55 +0100, "dennis@home"
wrote:

On 20/04/2019 08:13, Harry Bloomfield wrote:
explained on 19/04/2019 :
You'll notice if it's not behind you.

There is no way to make it visible in my line of sight. The cutter deck
is (obviously) underneath, the duct from that, carrying the fan blown
cut grass, goes below and exits at the very back.

https://smile.amazon.co.uk/Digital-A.../dp/B07FLT5Y7L
£9.99, one wonders how long it would last, but for that money...bugger
diy!

On 20/04/2019 19:48, Davidm wrote:
On Sat, 20 Apr 2019 12:28:55 +0100, "dennis@home"
wrote:

On 20/04/2019 08:13, Harry Bloomfield wrote:
explained on 19/04/2019 :
You'll notice if it's not behind you.

There is no way to make it visible in my line of sight. The cutter deck
is (obviously) underneath, the duct from that, carrying the fan blown
cut grass, goes below and exits at the very back.

https://smile.amazon.co.uk/Digital-A.../dp/B07FLT5Y7L
£9.99, one wonders how long it would last, but for that money...bugger
diy!


The review here tells you how to connect it.

https://smile.amazon.co.uk/Tachomete.../dp/B01FSDT74I

Same item but from china if you want to wait.

"dennis@home" wrote in message
...
On 20/04/2019 08:13, Harry Bloomfield wrote:
explained on 19/04/2019 :
You'll notice if it's not behind you.

There is no way to make it visible in my line of sight. The cutter deck
is (obviously) underneath, the duct from that, carrying the fan blown cut
grass, goes below and exits at the very back.

https://smile.amazon.co.uk/Digital-A.../dp/B07FLT5Y7L

Unclear what the indoors word in the title means, whether its
not weatherproof or isnt bright enough to be read outdoors.

On Sun, 21 Apr 2019 09:51:43 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:


https://smile.amazon.co.uk/Digital-A.../dp/B07FLT5Y7L

Unclear what the indoors word in the title means, whether its
not weatherproof or isnt bright enough to be read outdoors.

If you don't like it, don't buy it, senile asshole.

--
Bod addressing abnormal senile quarreller Rot:
"Do you practice arguing with yourself in an empty room?"
MID:

On Fri, 19 Apr 2019 22:06:26 +0100, Harry Bloomfield wrote:

The Natural Philosopher explained :
I think that is overblown.

All you need is something like a guitar pickup. Lots of turns round a
magnet close to where the blades are. Should be enough power to light a
LED

Well I tried it and although the blown flap was able to operate a
micro-switch quite easily, the flap slowed the exit air flow and quickly
choked it up.

I'm not going to try attaching anything to the blades, I have in mind a
magnet on blade pulley, above the deck. It should be fairly easy to then
make a bracket to mount a coil.

TNP's suggestion does have the merit of not requiring any modification
to the cutter blades. This, of course, assumes they aren't made out of
non-magnetic stainless steel and assumes you can get your magnetised
pickup coil within sensing range of the cutter blades.

I suspect you might have to amplify the output if you can't get it
within a few millimetres of the cutter blades to generate enough voltage
to drive a LED directly, in which case a low pass filter may be required
to minimise the risk of false positives by interference signal pickup
from the ignition circuit.

--
Johnny B Good