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Rectifier added after factory assembly? Was Re: Help please with PWM sewing machine pedal
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bruce bowser
Dec 27, 2020, 2:04:51 AM12/27/20
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On Wednesday, September 9, 2020 at 4:05:35 AM UTC-4, Cydrome Leader wrote:
> pf...@aol.com <peterw...@gmail.com> wrote:
> >
> >> Did you mess up the timing of the motor by chance? The angle of the
> >> brushes makes a huge difference.
> >
> >> maybe? How's the motor run with no speed controller?
> >
> >
> > The brushes are sleeved and fit in only one way. About the only other
> > 'unusual' possibility is that Eric has a Euro version - which has flat
> > paper caps in the motor. They should be REMOVED and NOT REPLACED!
> >
> > Peter WIeck
> > Melrose Park, PA
> It's only somewhat related to this, but I have a precision drill press
> with a real goofy looking manufacturer supplied speed controller. I called
> them up about something unrelated and and issue of weird bursts in speed
> came up. You'd have no load on the motor and it would randomly start to
> race.
>
> The suggested fix was to open the speed controller and cut out a bridge
> rectifier that turned the AC output of the triac speed controller and just
> let the motor get AC.
So, the rectifier no longer turned AC output of the controller to DC? So, the controller wasn't used after that?
> It worked fine after that. I'm not sure why they added a bridge recitfier
> in the first place, or why removing it made a difference but it did.
Didn't they need DC to the controller's resistor circuit?
The
> motor is pretty similar is size to a sewing machine motor, and the
> standard universal motor type deal. The whole controller is cobbled
> together looking so I can't even tell if they added the rectifier or the
> OEM did.
Oh, the rectifier was added after the original sale.
> I'm sort of tempted to try the drill press with a properly designed
> industrial speed controller (Dart Controls), with and without the bridge
> rectifier to see how it behaves.
> pf...@aol.com <peterw...@gmail.com> wrote:
> >
> >> Did you mess up the timing of the motor by chance? The angle of the
> >> brushes makes a huge difference.
> >
> >> maybe? How's the motor run with no speed controller?
> >
> >
> > The brushes are sleeved and fit in only one way. About the only other
> > 'unusual' possibility is that Eric has a Euro version - which has flat
> > paper caps in the motor. They should be REMOVED and NOT REPLACED!
> >
> > Peter WIeck
> > Melrose Park, PA
> It's only somewhat related to this, but I have a precision drill press
> with a real goofy looking manufacturer supplied speed controller. I called
> them up about something unrelated and and issue of weird bursts in speed
> came up. You'd have no load on the motor and it would randomly start to
> race.
>
> The suggested fix was to open the speed controller and cut out a bridge
> rectifier that turned the AC output of the triac speed controller and just
> let the motor get AC.
So, the rectifier no longer turned AC output of the controller to DC? So, the controller wasn't used after that?
> It worked fine after that. I'm not sure why they added a bridge recitfier
> in the first place, or why removing it made a difference but it did.
Didn't they need DC to the controller's resistor circuit?
The
> motor is pretty similar is size to a sewing machine motor, and the
> standard universal motor type deal. The whole controller is cobbled
> together looking so I can't even tell if they added the rectifier or the
> OEM did.
Oh, the rectifier was added after the original sale.
> I'm sort of tempted to try the drill press with a properly designed
> industrial speed controller (Dart Controls), with and without the bridge
> rectifier to see how it behaves.
Cydrome Leader
Jan 11, 2021, 3:39:33 AM1/11/21
to
bruce bowser <bruce2...@gmail.com> wrote:
> On Wednesday, September 9, 2020 at 4:05:35 AM UTC-4, Cydrome Leader wrote:
>> pf...@aol.com <peterw...@gmail.com> wrote:
>> >
>> >> Did you mess up the timing of the motor by chance? The angle of the
>> >> brushes makes a huge difference.
>> >
>> >> maybe? How's the motor run with no speed controller?
>> >
>> >
>> > The brushes are sleeved and fit in only one way. About the only other
>> > 'unusual' possibility is that Eric has a Euro version - which has flat
>> > paper caps in the motor. They should be REMOVED and NOT REPLACED!
>> >
>> > Peter WIeck
>> > Melrose Park, PA
>> It's only somewhat related to this, but I have a precision drill press
>> with a real goofy looking manufacturer supplied speed controller. I called
>> them up about something unrelated and and issue of weird bursts in speed
>> came up. You'd have no load on the motor and it would randomly start to
>> race.
>>
>> The suggested fix was to open the speed controller and cut out a bridge
>> rectifier that turned the AC output of the triac speed controller and just
>> let the motor get AC.
>
> So, the rectifier no longer turned AC output of the controller to DC?
> So, the controller wasn't used after that?
Correct. The chopped up AC was no longer full wave rectified into choppy
> On Wednesday, September 9, 2020 at 4:05:35 AM UTC-4, Cydrome Leader wrote:
>> pf...@aol.com <peterw...@gmail.com> wrote:
>> >
>> >> Did you mess up the timing of the motor by chance? The angle of the
>> >> brushes makes a huge difference.
>> >
>> >> maybe? How's the motor run with no speed controller?
>> >
>> >
>> > The brushes are sleeved and fit in only one way. About the only other
>> > 'unusual' possibility is that Eric has a Euro version - which has flat
>> > paper caps in the motor. They should be REMOVED and NOT REPLACED!
>> >
>> > Peter WIeck
>> > Melrose Park, PA
>> It's only somewhat related to this, but I have a precision drill press
>> with a real goofy looking manufacturer supplied speed controller. I called
>> them up about something unrelated and and issue of weird bursts in speed
>> came up. You'd have no load on the motor and it would randomly start to
>> race.
>>
>> The suggested fix was to open the speed controller and cut out a bridge
>> rectifier that turned the AC output of the triac speed controller and just
>> let the motor get AC.
>
> So, the rectifier no longer turned AC output of the controller to DC?
> So, the controller wasn't used after that?
DC. I never looked at the waveforms, but they were probably awful.
>> It worked fine after that. I'm not sure why they added a bridge recitfier
>> in the first place, or why removing it made a difference but it did.
>
> Didn't they need DC to the controller's resistor circuit?
wall mounted light dimmer or something cheap like that inside the box, but
with an electronics-looking knob.
> The
>> motor is pretty similar is size to a sewing machine motor, and the
>> standard universal motor type deal. The whole controller is cobbled
>> together looking so I can't even tell if they added the rectifier or the
>> OEM did.
>
> Oh, the rectifier was added after the original sale.
support people suggested.
>> I'm sort of tempted to try the drill press with a properly designed
>> industrial speed controller (Dart Controls), with and without the bridge
>> rectifier to see how it behaves.
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