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Why are motors not current limited?

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James Wilkinson Sword
Guest

Sat Apr 21, 2018 12:45 pm   



How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

I assume something like this must be done on electric cars, or instead of stalling the engine, you'd wreck the motor.

--
What's soft and warm when you go to bed, but hard and stiff when you wake up?
Vomit.

Archibald Tarquin Blenkin
Guest

Sat Apr 21, 2018 1:45 pm   



On Sat, 21 Apr 2018 13:11:10 +0100, "James Wilkinson Sword"
<imvalid_at_somewear.com> wrote:

Quote:
On Sat, 21 Apr 2018 12:54:04 +0100, Al Borland <al_at_binford-tool.edu> wrote:

On 4/21/2018 7:35 AM, James Wilkinson Sword wrote:
How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

The motor is efficiently protected by voltage, current and temperature sensors to prevent overloading. Stop buying junk and start buying Hiltis.

https://www.hilti.com/cordless-systems/cordless-drills/r6636450#technical-data

I'm not talking about little cordless drills, I mean mains powered tools of around a kilowatt. Even if they're cheap, surely these sensors are a fraction of the price of the whole tool, and you'd get so many less warranty returns.


If you have the time and around 60-00, you could buy an overload and
JB to keep it in. I think a standard 3 phase overload will work
without a contactor and there is some adjustment for FLC.

It would want two of the channels wiring in series for single phase
though.

Thermal fuses are fast acting and cheap, a none rewireable from ebay
cost me around a pound for 20, they are good although you would have
to dsimantle the tool to see if it could be placed in proximity to the
field coils.

AB

James Wilkinson Sword
Guest

Sat Apr 21, 2018 1:45 pm   



On Sat, 21 Apr 2018 13:18:28 +0100, Al Borland <al_at_binford-tool.edu> wrote:

Quote:
On 4/21/2018 8:11 AM, James Wilkinson Sword wrote:
On Sat, 21 Apr 2018 12:54:04 +0100, Al Borland <al_at_binford-tool.edu> wrote:

On 4/21/2018 7:35 AM, James Wilkinson Sword wrote:
How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

The motor is efficiently protected by voltage, current and temperature sensors to prevent overloading. Stop buying junk and start buying Hiltis.

https://www.hilti.com/cordless-systems/cordless-drills/r6636450#technical-data

I'm not talking about little cordless drills, I mean mains powered tools of around a kilowatt. Even if they're cheap, surely these sensors are a fraction of the price of the whole tool, and you'd get so many less warranty returns.

Do you think you could handle a corded Hilti?


Show me an example. I don't see why anyone (even a woman) couldn't use any power tool.

--
Birthdays are good for you. Statistics show that the people who have the most live the longest. (Rev. Larry Lorenzoni)

Al Borland
Guest

Sat Apr 21, 2018 1:45 pm   



On 4/21/2018 7:35 AM, James Wilkinson Sword wrote:
> How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

The motor is efficiently protected by voltage, current and temperature sensors to prevent overloading. Stop buying junk and start buying Hiltis.

https://www.hilti.com/cordless-systems/cordless-drills/r6636450#technical-data

Archibald Tarquin Blenkin
Guest

Sat Apr 21, 2018 1:45 pm   



On Sat, 21 Apr 2018 07:54:04 -0400, Al Borland <al_at_binford-tool.edu>
wrote:

Quote:
On 4/21/2018 7:35 AM, James Wilkinson Sword wrote:
How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

The motor is efficiently protected by voltage, current and temperature sensors to prevent overloading. Stop buying junk and start buying Hiltis.

https://www.hilti.com/cordless-systems/cordless-drills/r6636450#technical-data


Not neccessary for drills.

I had a Yellow & black device once Worx or somesuch.

I stalled it "sort of"

One's wrist forms a perfect albeit painful mechanical fuse :-(

I suppose right handed people have a slight advantage, but drilling
with the left hand on the grip ansures that the drill isn't pulled
away, it's pushed into your hand.

AB

James Wilkinson Sword
Guest

Sat Apr 21, 2018 1:45 pm   



On Sat, 21 Apr 2018 12:54:04 +0100, Al Borland <al_at_binford-tool.edu> wrote:

Quote:
On 4/21/2018 7:35 AM, James Wilkinson Sword wrote:
How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

The motor is efficiently protected by voltage, current and temperature sensors to prevent overloading. Stop buying junk and start buying Hiltis.

https://www.hilti.com/cordless-systems/cordless-drills/r6636450#technical-data


I'm not talking about little cordless drills, I mean mains powered tools of around a kilowatt. Even if they're cheap, surely these sensors are a fraction of the price of the whole tool, and you'd get so many less warranty returns.

--
"You, you, and you ... panic. The rest of you, come with me." - U.S. Marine Corp Gunnery Sgt.

Al Borland
Guest

Sat Apr 21, 2018 1:45 pm   



On 4/21/2018 8:11 AM, James Wilkinson Sword wrote:
Quote:
On Sat, 21 Apr 2018 12:54:04 +0100, Al Borland <al_at_binford-tool.edu> wrote:

On 4/21/2018 7:35 AM, James Wilkinson Sword wrote:
How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

The motor is efficiently protected by voltage, current and temperature sensors to prevent overloading. Stop buying junk and start buying Hiltis.

https://www.hilti.com/cordless-systems/cordless-drills/r6636450#technical-data

I'm not talking about little cordless drills, I mean mains powered tools of around a kilowatt. Even if they're cheap, surely these sensors are a fraction of the price of the whole tool, and you'd get so many less warranty returns.

Do you think you could handle a corded Hilti?


Colonel Edmund J. Burke
Guest

Sat Apr 21, 2018 3:45 pm   



On 4/21/2018 4:35 AM, James Wilkinson Sword wrote:
Quote:
How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

I assume something like this must be done on electric cars, or instead of stalling the engine, you'd wreck the motor.


Whatsa coil?

James Wilkinson Sword
Guest

Sat Apr 21, 2018 4:45 pm   



On Sat, 21 Apr 2018 15:29:08 +0100, Colonel Edmund J. Burke <burkesbabes_at_bigass-babes.com> wrote:

Quote:
On 4/21/2018 4:35 AM, James Wilkinson Sword wrote:
How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

I assume something like this must be done on electric cars, or instead of stalling the engine, you'd wreck the motor.


Whatsa coil?


A round thing.

--
What's meaner than a pit bull with AIDS?
The guy that gave it to him.

Jimmy Wilkinson Knife
Guest

Sat Apr 21, 2018 4:45 pm   



On Sat, 21 Apr 2018 15:43:01 +0100, <gfretwell_at_aol.com> wrote:

Quote:
On Sat, 21 Apr 2018 12:35:25 +0100, "James Wilkinson Sword"
imvalid_at_somewear.com> wrote:

How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

I assume something like this must be done on electric cars, or instead of stalling the engine, you'd wreck the motor.

Most motors that are to be used unattended do have thermal overloads
in them. I guess hand tool manufacturers assume you will stop before
you burn up the tool


P.S. one of my cats looks like she's having an orgasm rolling around in freshly cut concrete dust. That's gonna take her a while to clean out of her fur....

--
An Emergency Call Centre worker has been fired in Toronto much to the dismay of her colleagues, who were unhappy with her dismissal.
It seems that a caller dialled 911 from a cell phone stating, "I'm depressed and lying on a railway line so that when the train comes I can finally meet Allah."
To which the call centre employee replied, "Remain calm and stay on the line."

Jimmy Wilkinson Knife
Guest

Sat Apr 21, 2018 4:45 pm   



On Sat, 21 Apr 2018 15:43:01 +0100, <gfretwell_at_aol.com> wrote:

Quote:
On Sat, 21 Apr 2018 12:35:25 +0100, "James Wilkinson Sword"
imvalid_at_somewear.com> wrote:

How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

I assume something like this must be done on electric cars, or instead of stalling the engine, you'd wreck the motor.

Most motors that are to be used unattended do have thermal overloads
in them. I guess hand tool manufacturers assume you will stop before
you burn up the tool


P.S. one of my cats looks like she's having an orgasm rolling around in freshly cut concrete dust. That's gonna take her a while to clean out of her fur....

--
An Emergency Call Centre worker has been fired in Toronto much to the dismay of her colleagues, who were unhappy with her dismissal.
It seems that a caller dialled 911 from a cell phone stating, "I'm depressed and lying on a railway line so that when the train comes I can finally meet Allah."
To which the call centre employee replied, "Remain calm and stay on the line."

Andrew Gabriel
Guest

Sat Apr 21, 2018 6:45 pm   



In article <op.zhtjtbcvjs98qf_at_red.lan>,
"James Wilkinson Sword" <imvalid_at_somewear.com> writes:
> How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

You can buy professional power tools with that sort of protection,
or you can buy much cheaper DIY tools without it. My Metabo SDS
drill has it, but it cost well over 300.

> I assume something like this must be done on electric cars, or instead of stalling the engine, you'd wreck the motor.

Vastly more expensive power controller than the light dimmer used
as a speed control in DIY power tools.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Jimmy Wilkinson Knife
Guest

Sat Apr 21, 2018 6:45 pm   



On Sat, 21 Apr 2018 17:55:20 +0100, Andrew Gabriel <andrew_at_cucumber.demon.co.uk> wrote:

Quote:
In article <op.zhtjtbcvjs98qf_at_red.lan>,
"James Wilkinson Sword" <imvalid_at_somewear.com> writes:
How hard can it be to put some kind of electronic limiter on a power tool so if you over-stress it, it doesn't consume enough current to melt the coils?

You can buy professional power tools with that sort of protection,
or you can buy much cheaper DIY tools without it. My Metabo SDS
drill has it, but it cost well over 300.


But why should we have to pay 300 to get some basic electronics included?

Quote:
I assume something like this must be done on electric cars, or instead of stalling the engine, you'd wreck the motor.

Vastly more expensive power controller than the light dimmer used
as a speed control in DIY power tools.


Yes, but cars have very powerful motors. Even a washing machine has a very complex control unit.

--
"The most dangerous thing in the world is to try to leap a chasm in two jumps" -- David Lloyd George, former UK Prime Minister

rbowman
Guest

Sat Apr 21, 2018 7:45 pm   



On 04/21/2018 06:03 AM, Archibald Tarquin Blenkinsopp wrote:
Quote:
I suppose right handed people have a slight advantage, but drilling
with the left hand on the grip ansures that the drill isn't pulled
away, it's pushed into your hand.


And with any luck if there is a button to lock the trigger that gets
pushed into your hand also. I am depressed by this constant
discrimination of people of left handedness. It has to stop.

rbowman
Guest

Sat Apr 21, 2018 7:45 pm   



On 04/21/2018 06:18 AM, Al Borland wrote:
Quote:
On 4/21/2018 8:11 AM, James Wilkinson Sword wrote:
On Sat, 21 Apr 2018 12:54:04 +0100, Al Borland <al_at_binford-tool.edu
wrote:

On 4/21/2018 7:35 AM, James Wilkinson Sword wrote:
How hard can it be to put some kind of electronic limiter on a power
tool so if you over-stress it, it doesn't consume enough current to
melt the coils?

The motor is efficiently protected by voltage, current and
temperature sensors to prevent overloading. Stop buying junk and
start buying Hiltis.

https://www.hilti.com/cordless-systems/cordless-drills/r6636450#technical-data


I'm not talking about little cordless drills, I mean mains powered
tools of around a kilowatt. Even if they're cheap, surely these
sensors are a fraction of the price of the whole tool, and you'd get
so many less warranty returns.

Do you think you could handle a corded Hilti?


A powder actuated Hilti would be more fun. They are probably illegal in
the UK though.

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