VS Dimmer Switch Use
 

Folks -

Okay, question about lekturcity here... Could I use a standard incin..
incandces... encand.... oh hell... light bulb dimmer switch as a variable
speed switch for a router. If the router draws less than the switch is
rated for, will I run into a problem? I don't care about the switch, I just
don't want to damage the router.

I built the router table in FWW from several months ago and I have it set up
so I can mount three routers on the beast... unfortunately, none of these
are VS, and I will need to cut the speed down so I can use a panel raiser in
one of them.... I have a cheap HF plunge router that I set up for the
horizontal routing, a Melwilke.... Malwalkie.... Milwaulck... dammit.... Red
"body grip" router for table use, and my DeWalt Plunge router for the
overhead routing.

My only VS router, the Bosch 1617, is my favorite, so I am saving that for
hand-work and I don't want to put that one in the table.

Please let me know if y'all think this'd work, or if I'm asking for trouble.
As for not buying a VS router control, or yet another router, I don't need
help with that... I already know that I'm cheap!

John Moorhead

John Moorhead wrote:
Folks -

Okay, question about lekturcity here... Could I use a standard incin..
incandces... encand.... oh hell... light bulb dimmer switch as a variable
speed switch for a router. If the router draws less than the switch is
rated for, will I run into a problem? I don't care about the switch, I just
don't want to damage the router.

I built the router table in FWW from several months ago and I have it set up
so I can mount three routers on the beast... unfortunately, none of these
are VS, and I will need to cut the speed down so I can use a panel raiser in
one of them.... I have a cheap HF plunge router that I set up for the
horizontal routing, a Melwilke.... Malwalkie.... Milwaulck... dammit.... Red
"body grip" router for table use, and my DeWalt Plunge router for the
overhead routing.

My only VS router, the Bosch 1617, is my favorite, so I am saving that for
hand-work and I don't want to put that one in the table.

Please let me know if y'all think this'd work, or if I'm asking for trouble.
As for not buying a VS router control, or yet another router, I don't need
help with that... I already know that I'm cheap!

John Moorhead


It would probably not work very well. Incandescant lamps are resistive
loads - motors are inductive. So, even if the 'watts' label matched it
is not a safe setup.

I have an old 3HP ryobi (Not soft or electronic start) in my router bench
and use a 4 speed ceiling fan switch which to date hasn't started any fires.
I do find I only use 2 speeds though medium and high. After 20 minutes of
routing dadoes nothing is hot to the touch.

On Wed, 19 Jan 2005 05:13:15 GMT, "John Moorhead"
wrote:

Okay, question about lekturcity here... Could I use a standard incin..
incandces... encand.... oh hell... light bulb dimmer switch as a variable
speed switch for a router.

This is a common enough approach, but it's more useful for drills than
for routers. Many routers now use up to 2000W, which is considerably
more than a light dimmer can handle. The biggest low-cost light
dimmers I know of are about 500W max.

Routers with built-in speed controls usually have soft-start and may
have feedback control of speed, both of which are an advantage worth
having.

So for a small router, and a big light dimmer, then I _might_ go for
it, if it as my only option. But it's not something I'd particularly
recommend.

As to the inductive load business, then I wouldn't worry additionally.
It won't stop it working, just de-rate the maximum capacity -- and
you're already having to worry about that.
--
Smert' spamionam

On Wed, 19 Jan 2005 14:48:22 +0000, Andy Dingley
wrote:

On Wed, 19 Jan 2005 05:13:15 GMT, "John Moorhead"
wrote:

Okay, question about lekturcity here... Could I use a standard incin..
incandces... encand.... oh hell... light bulb dimmer switch as a variable
speed switch for a router.

This is a common enough approach, but it's more useful for drills than
for routers. Many routers now use up to 2000W, which is considerably
more than a light dimmer can handle. The biggest low-cost light
dimmers I know of are about 500W max.

Routers with built-in speed controls usually have soft-start and may
have feedback control of speed, both of which are an advantage worth
having.

So for a small router, and a big light dimmer, then I _might_ go for
it, if it as my only option. But it's not something I'd particularly
recommend.

As to the inductive load business, then I wouldn't worry additionally.
It won't stop it working, just de-rate the maximum capacity -- and
you're already having to worry about that.

Ok, Andy.. but that leads me to another question:
I've heard that some motors, mostly ones in appliances, will be
damaged by low power... but I don't know if they're talking voltage,
amperage or watts....
Can the router be damaged by the reduction from the dimmer switch?




mac

Please remove splinters before emailing

I think you would do better with one of these..

http://www.pricecutter.com/ and search on "speed control"

or go to http://woodworker.com/cgi-bin/FULLPR...ARTNUM=821-539


John Moorhead wrote:
Folks -

Okay, question about lekturcity here... Could I use a standard incin..
incandces... encand.... oh hell... light bulb dimmer switch as a variable
speed switch for a router. If the router draws less than the switch is
rated for, will I run into a problem? I don't care about the switch, I just
don't want to damage the router.

I built the router table in FWW from several months ago and I have it set up
so I can mount three routers on the beast... unfortunately, none of these
are VS, and I will need to cut the speed down so I can use a panel raiser in
one of them.... I have a cheap HF plunge router that I set up for the
horizontal routing, a Melwilke.... Malwalkie.... Milwaulck... dammit.... Red
"body grip" router for table use, and my DeWalt Plunge router for the
overhead routing.

My only VS router, the Bosch 1617, is my favorite, so I am saving that for
hand-work and I don't want to put that one in the table.

Please let me know if y'all think this'd work, or if I'm asking for trouble.
As for not buying a VS router control, or yet another router, I don't need
help with that... I already know that I'm cheap!

John Moorhead

On Wed, 19 Jan 2005 07:55:10 -0800, mac davis
wrote:

Can the router be damaged by the reduction from the dimmer switch?

How many possible variations of dimmer and router are you concerned
about ? 8-(

There's a problem in running any motor at low speeds, in that the heat
dumped into the motor for a given torque will rise. If you throttle
the motor back, and a high load slows it even further, then you have a
risk of overheating.

There's also the waveform issue. Simple dimmers work by phase control.
Their output wavefom becomes "spiky", which means there's an added
high-frequency component. Electric motor windings don't care for this,
and again there's more heating going on.

So you can run a motor with a dimmer, but you need to de-rate it for
useful power and to watch the temperature of the windings.


With a drill, the use of a speed control might be for low-power
low-speed uses like a polishing mop. It works well enough.

For a router though, such an additional speed control is typically
used with an underpowered high-speed router swinging a large
speed-limited cutter. This still needs a fair amount of torque and
thus power, and the power may already be marginal for a small router.
This is less successful.

--
Smert' spamionam

Unless your router is a DC motor, a dimmer can burn out your motor.
Purchase a router with built-in speeds if that's what you need. My PC
router is variable speed but I use 22,000 rpm most of the time.

On Wed, 19 Jan 2005 05:13:15 GMT, "John Moorhead"
wrote:

Folks -

Okay, question about lekturcity here... Could I use a standard incin..
incandces... encand.... oh hell... light bulb dimmer switch as a variable
speed switch for a router. If the router draws less than the switch is
rated for, will I run into a problem? I don't care about the switch, I just
don't want to damage the router.

I built the router table in FWW from several months ago and I have it set up
so I can mount three routers on the beast... unfortunately, none of these
are VS, and I will need to cut the speed down so I can use a panel raiser in
one of them.... I have a cheap HF plunge router that I set up for the
horizontal routing, a Melwilke.... Malwalkie.... Milwaulck... dammit.... Red
"body grip" router for table use, and my DeWalt Plunge router for the
overhead routing.

My only VS router, the Bosch 1617, is my favorite, so I am saving that for
hand-work and I don't want to put that one in the table.

Please let me know if y'all think this'd work, or if I'm asking for trouble.
As for not buying a VS router control, or yet another router, I don't need
help with that... I already know that I'm cheap!

John Moorhead

On Wed, 19 Jan 2005 20:45:29 GMT, Phisherman wrote:

Unless your router is a DC motor, a dimmer can burn out your motor.

And how many routers are there that don't use this type of motor ?

On Thu, 20 Jan 2005 02:09:32 +0000, Andy Dingley
wrote:

On Wed, 19 Jan 2005 20:45:29 GMT, Phisherman wrote:

Unless your router is a DC motor, a dimmer can burn out your motor.

And how many routers are there that don't use this type of motor ?


Cisco?

On Wed, 19 Jan 2005 16:56:19 +0000, Andy Dingley
wrote:

On Wed, 19 Jan 2005 07:55:10 -0800, mac davis
wrote:

Can the router be damaged by the reduction from the dimmer switch?

How many possible variations of dimmer and router are you concerned
about ? 8-(

There's a problem in running any motor at low speeds, in that the heat
dumped into the motor for a given torque will rise. If you throttle
the motor back, and a high load slows it even further, then you have a
risk of overheating.

There's also the waveform issue. Simple dimmers work by phase control.
Their output wavefom becomes "spiky", which means there's an added
high-frequency component. Electric motor windings don't care for this,
and again there's more heating going on.

So you can run a motor with a dimmer, but you need to de-rate it for
useful power and to watch the temperature of the windings.


With a drill, the use of a speed control might be for low-power
low-speed uses like a polishing mop. It works well enough.

For a router though, such an additional speed control is typically
used with an underpowered high-speed router swinging a large
speed-limited cutter. This still needs a fair amount of torque and
thus power, and the power may already be marginal for a small router.
This is less successful.

Thanks, Andy...
I don't have a need to change speeds, but now I know that I wouldn't
try a dimmer switch if I did want to..

What made me ask the question was something that came up recently in
an RV forum, about checking the voltage and amperage at RV
parks/hookups...
Someone said that appliances, especially refrigerators, could be
damaged by "power drops" more than power spikes..


mac

Please remove splinters before emailing

On Wed, 19 Jan 2005 22:27:21 -0800, mac davis
wrote:

Someone said that appliances, especially refrigerators, could be
damaged by "power drops" more than power spikes..

I don't know much about US practice for fridges in RVs, but the UK
practice is to use a different type of fridge mechanism anyway.
Although there's a well-known problem with some domestic fridges and
under-voltage, this shouldn't affect the RV type.

--
Smert' spamionam