Electric motor problem

I have a small drilling machine driven by a 1/4 HP induction motor
(British) sometimes it fails to start and just hums, if I switch off
and try again normally it runs. This happens not on a regular basis,
sometimes it goes for days OK then plays up. Is there some sort of
maintenance needed? David

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stereotype
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On 25 Jul, 20:47, stereotype <stereotype.2ua...@rcgroups.com> wrote:
> I have a small drilling machine driven by a 1/4 HP induction motor
> (British) sometimes it fails to start and just hums, if I switch off
> and try again normally it runs. This happens not on a regular basis,
> sometimes it goes for days OK then plays up. Is there some sort of
> maintenance needed? David
>

sounds like the start /run cap is on its way out. when its not working
if you spin it up by hand does it run?
new caps are quite cheap.

of course I could be wrong, no doubt someone more knowledgeable will
be along shortly.

Dave

On Wed, 25 Jul 2007 14:47:15 -0500, stereotype
<stereotype.2uansn@rcgroups.com> wrote:

>
>I have a small drilling machine driven by a 1/4 HP induction motor
>(British) sometimes it fails to start and just hums, if I switch off
>and try again normally it runs. This happens not on a regular basis,
>sometimes it goes for days OK then plays up. Is there some sort of
>maintenance needed? David

What tune does it hum ?

stereotype wrote:
> I have a small drilling machine driven by a 1/4 HP induction motor
> (British) sometimes it fails to start and just hums, if I switch off
> and try again normally it runs. This happens not on a regular basis,
> sometimes it goes for days OK then plays up. Is there some sort of
> maintenance needed? David
>
>

Check all the wiring for continuity and tight connections first,
especially the leads that go into the motor terminals. They can
sometimes work loose on older motors. As someone else said, after that,
it's most likely the start capacitor, or it's wiring...

Chris

"stereotype" <stereotype.2uansn@rcgroups.com> wrote in message
news:stereotype.2uansn@rcgroups.com...
>
> I have a small drilling machine driven by a 1/4 HP induction motor
> (British) sometimes it fails to start and just hums, if I switch off
> and try again normally it runs. This happens not on a regular basis,
> sometimes it goes for days OK then plays up. Is there some sort of
> maintenance needed? David
>
>
> --
> stereotype
> ------------------------------------------------------------------------
> stereotype's Profile: http://www.rcgroups.com/forums/member.php?u=119209
> View this thread: http://www.rcgroups.com/forums/showthread.php?t=718458
>
If it has a centrifugal starting switch (you can hear a click when it starts
and again when it is nearly stopped) the switch contacts and the mechanism
to operate it can be in need of cleaning. This usually requires disassembly
of the motor. No lubrication is normally used.

Don Young, USA

On 25 Jul, 20:47, stereotype <stereotype.2ua...@rcgroups.com> wrote:
> I have a small drilling machine driven by a 1/4 HP induction motor
> (British) sometimes it fails to start and just hums, if I switch off
> and try again normally it runs. This happens not on a regular basis,
> sometimes it goes for days OK then plays up. Is there some sort of
> maintenance needed? David
>
> --
> stereotype
> ------------------------------------------------------------------------
> stereotype's Profile:http://www.rcgroups.com/forums/member.php?u=119209
> View this thread:http://www.rcgroups.com/forums/showthread.php?t=718458

Pretty sure it the cap that's getting old & 'leaky'. Hasn't failed
altogether as it would never start or possibly blow mains fuse. They
just get a bit worn out sometimes. Your cheapest and quickest option
is to replace the cap, they don't cost much and are (normally)
external so dead easy to get access to & replace. Tip - just be
careful fiddling with any connections if you have recently attempted
to start it, as the cap may hold a nasty residual charge which might
make your hair stand on end, eyes light up and teeth rattle a bit!

Mike

In article <vhdfa350t18719r9nnm80r98vlv2b2ccg7@4ax.com>,
John Stevenson <john@stevenson-engineers.co.uk> in
uk.rec.models.engineering wrote:

>On Wed, 25 Jul 2007 14:47:15 -0500, stereotype
><stereotype.2uansn@rcgroups.com> wrote:
>
>>
>>I have a small drilling machine driven by a 1/4 HP induction motor
>>(British) sometimes it fails to start and just hums, if I switch off
>>and try again normally it runs. This happens not on a regular basis,
>>sometimes it goes for days OK then plays up. Is there some sort of
>>maintenance needed? David
>
>What tune does it hum ?

Anything, it doesn't know the words, so it has to hum.

Regards,

David P.

Don Young Wrote:
> "stereotype" <stereotype.2uansn@rcgroups.com> wrote in message
> news:stereotype.2uansn@rcgroups.com...
> >
> > I have a small drilling machine driven by a 1/4 HP induction motor
> > (British) sometimes it fails to start and just hums, if I switch
> off
> > and try again normally it runs. This happens not on a regular basis,
> > sometimes it goes for days OK then plays up. Is there some sort of
> > maintenance needed? David
> >
> >
> > --
> > stereotype
> >
> ------------------------------------------------------------------------
> > stereotype's Profile:
> http://www.rcgroups.com/forums/member.php?u=119209
> > View this thread:
> http://www.rcgroups.com/forums/showthread.php?t=718458
> >
> If it has a centrifugal starting switch (you can hear a click when it
> starts
> and again when it is nearly stopped) the switch contacts and the
> mechanism
> to operate it can be in need of cleaning. This usually requires
> disassembly
> of the motor. No lubrication is normally used.
>
> Don Young, USA
Thanks for all your input, yes Don it is a cetrifugal start motor, i'll
take it apart and check the contacts. David

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	#1
stereotype	Electric motor problem I have a small drilling machine driven by a 1/4 HP induction motor (British) sometimes it fails to start and just hums, if I switch off and try again normally it runs. This happens not on a regular basis, sometimes it goes for days OK then plays up. Is there some sort of maintenance needed? David -- stereotype ------------------------------------------------------------------------ stereotype's Profile: http://www.rcgroups.com/forums/member.php?u=119209 View this thread: http://www.rcgroups.com/forums/showthread.php?t=718458

	#2
dave sanderson	Re: Electric motor problem On 25 Jul, 20:47, stereotype <stereotype.2ua...@rcgroups.com> wrote: > I have a small drilling machine driven by a 1/4 HP induction motor > (British) sometimes it fails to start and just hums, if I switch off > and try again normally it runs. This happens not on a regular basis, > sometimes it goes for days OK then plays up. Is there some sort of > maintenance needed? David > sounds like the start /run cap is on its way out. when its not working if you spin it up by hand does it run? new caps are quite cheap. of course I could be wrong, no doubt someone more knowledgeable will be along shortly. Dave

	#3
John Stevenson	Re: Electric motor problem On Wed, 25 Jul 2007 14:47:15 -0500, stereotype <stereotype.2uansn@rcgroups.com> wrote: > >I have a small drilling machine driven by a 1/4 HP induction motor >(British) sometimes it fails to start and just hums, if I switch off >and try again normally it runs. This happens not on a regular basis, >sometimes it goes for days OK then plays up. Is there some sort of >maintenance needed? David What tune does it hum ?

	#4
ChrisQuayle	Re: Electric motor problem stereotype wrote: > I have a small drilling machine driven by a 1/4 HP induction motor > (British) sometimes it fails to start and just hums, if I switch off > and try again normally it runs. This happens not on a regular basis, > sometimes it goes for days OK then plays up. Is there some sort of > maintenance needed? David > > Check all the wiring for continuity and tight connections first, especially the leads that go into the motor terminals. They can sometimes work loose on older motors. As someone else said, after that, it's most likely the start capacitor, or it's wiring... Chris

	#5
Don Young	Re: Electric motor problem "stereotype" <stereotype.2uansn@rcgroups.com> wrote in message news:stereotype.2uansn@rcgroups.com... > > I have a small drilling machine driven by a 1/4 HP induction motor > (British) sometimes it fails to start and just hums, if I switch off > and try again normally it runs. This happens not on a regular basis, > sometimes it goes for days OK then plays up. Is there some sort of > maintenance needed? David > > > -- > stereotype > ------------------------------------------------------------------------ > stereotype's Profile: http://www.rcgroups.com/forums/member.php?u=119209 > View this thread: http://www.rcgroups.com/forums/showthread.php?t=718458 > If it has a centrifugal starting switch (you can hear a click when it starts and again when it is nearly stopped) the switch contacts and the mechanism to operate it can be in need of cleaning. This usually requires disassembly of the motor. No lubrication is normally used. Don Young, USA

	#6
MikeH_QB	Re: Electric motor problem On 25 Jul, 20:47, stereotype <stereotype.2ua...@rcgroups.com> wrote: > I have a small drilling machine driven by a 1/4 HP induction motor > (British) sometimes it fails to start and just hums, if I switch off > and try again normally it runs. This happens not on a regular basis, > sometimes it goes for days OK then plays up. Is there some sort of > maintenance needed? David > > -- > stereotype > ------------------------------------------------------------------------ > stereotype's Profile:http://www.rcgroups.com/forums/member.php?u=119209 > View this thread:http://www.rcgroups.com/forums/showthread.php?t=718458 Pretty sure it the cap that's getting old & 'leaky'. Hasn't failed altogether as it would never start or possibly blow mains fuse. They just get a bit worn out sometimes. Your cheapest and quickest option is to replace the cap, they don't cost much and are (normally) external so dead easy to get access to & replace. Tip - just be careful fiddling with any connections if you have recently attempted to start it, as the cap may hold a nasty residual charge which might make your hair stand on end, eyes light up and teeth rattle a bit! Mike

	#7
David Powell	Re: Electric motor problem In article <vhdfa350t18719r9nnm80r98vlv2b2ccg7@4ax.com>, John Stevenson <john@stevenson-engineers.co.uk> in uk.rec.models.engineering wrote: >On Wed, 25 Jul 2007 14:47:15 -0500, stereotype ><stereotype.2uansn@rcgroups.com> wrote: > >> >>I have a small drilling machine driven by a 1/4 HP induction motor >>(British) sometimes it fails to start and just hums, if I switch off >>and try again normally it runs. This happens not on a regular basis, >>sometimes it goes for days OK then plays up. Is there some sort of >>maintenance needed? David > >What tune does it hum ? Anything, it doesn't know the words, so it has to hum. Regards, David P.

	#8
stereotype	Re: Electric motor problem Don Young Wrote: > "stereotype" <stereotype.2uansn@rcgroups.com> wrote in message > news:stereotype.2uansn@rcgroups.com... > > > > I have a small drilling machine driven by a 1/4 HP induction motor > > (British) sometimes it fails to start and just hums, if I switch > off > > and try again normally it runs. This happens not on a regular basis, > > sometimes it goes for days OK then plays up. Is there some sort of > > maintenance needed? David > > > > > > -- > > stereotype > > > ------------------------------------------------------------------------ > > stereotype's Profile: > http://www.rcgroups.com/forums/member.php?u=119209 > > View this thread: > http://www.rcgroups.com/forums/showthread.php?t=718458 > > > If it has a centrifugal starting switch (you can hear a click when it > starts > and again when it is nearly stopped) the switch contacts and the > mechanism > to operate it can be in need of cleaning. This usually requires > disassembly > of the motor. No lubrication is normally used. > > Don Young, USA Thanks for all your input, yes Don it is a cetrifugal start motor, i'll take it apart and check the contacts. David -- stereotype ------------------------------------------------------------------------ stereotype's Profile: http://www.rcgroups.com/forums/member.php?u=119209 View this thread: http://www.rcgroups.com/forums/showthread.php?t=718458