I was at the bird shop to get my birds nails trimmed. The lady had a
Dremal tool plugged into a sewing machine restate (sp?). It let he
control the speed without having to adjust the speed control switch on
the tool. Would this in any way be damaging to the tool? I have a
single speed tool that I was thinking of doing this with. Seemed like
a good idea.

It doesn't hurt anything. Dremel sells a speed controller to do exactly
this. It rectifies the waveform and chops it to make pseudo-DC of varying
magnitude. So you can run your motor anywhere from 0 to half its speed on AC.

Grant

Cuezilla wrote:

I was at the bird shop to get my birds nails trimmed. The lady had a
Dremal tool plugged into a sewing machine restate (sp?). It let he
control the speed without having to adjust the speed control switch on
the tool. Would this in any way be damaging to the tool? I have a
single speed tool that I was thinking of doing this with. Seemed like
a good idea.

On 20 Nov 2003 11:37:11 -0800, the renowned
(Cuezilla) wrote:

I was at the bird shop to get my birds nails trimmed. The lady had a
Dremal tool plugged into a sewing machine restate (sp?).
^^^^^^
rheostat

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

"Grant Erwin" wrote: It doesn't hurt anything.
Dremel sells a speed controller to do exactly this(clip)
^^^^^^^^^^^^
Well, not exactly. The speed controls used on AC
/DC tools like drills, routers, and the Dremel, cut down the width of the
on-time of each half-wave. This lowers the speed but does not lower the
torque much. A rheostat lowers the voltage, so as the speed goes down, so
does the torque. This probably does not matter if you're only filing the
toenails of a bird, but if you were using your Dremel for grinding or
carving, you would find the speed variation under load to be very annoying.

What makes a rheostat especially bad is that as you increase the load you
increase the current draw, which increases the voltage drop, further
lowering the speed and torque.

On Thu, 20 Nov 2003 20:58:27 GMT, the renowned "Leo Lichtman"
wrote:


"Grant Erwin" wrote: It doesn't hurt anything.
Dremel sells a speed controller to do exactly this(clip)
^^^^^^^^^^^^
Well, not exactly. The speed controls used on AC
/DC tools like drills, routers, and the Dremel, cut down the width of the
on-time of each half-wave. This lowers the speed but does not lower the
torque much. A rheostat lowers the voltage, so as the speed goes down, so
does the torque. This probably does not matter if you're only filing the
toenails of a bird, but if you were using your Dremel for grinding or
carving, you would find the speed variation under load to be very annoying.

What makes a rheostat especially bad is that as you increase the load you
increase the current draw, which increases the voltage drop, further
lowering the speed and torque.

A variac works very nicely if you happen to have one. It lowers the
voltage without increasing the source impedance.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

If I'm not mistaken Dremel only recommends that their speed control
attachment be used with single speed Dremels not the variable speed models.
I don't know if that makes any difference in performance and torque rating
though.

Jimbo

"Leo Lichtman" wrote in message
...

"Grant Erwin" wrote: It doesn't hurt anything.
Dremel sells a speed controller to do exactly this(clip)
^^^^^^^^^^^^
Well, not exactly. The speed controls used on AC
/DC tools like drills, routers, and the Dremel, cut down the width of the
on-time of each half-wave. This lowers the speed but does not lower the
torque much. A rheostat lowers the voltage, so as the speed goes down, so
does the torque. This probably does not matter if you're only filing the
toenails of a bird, but if you were using your Dremel for grinding or
carving, you would find the speed variation under load to be very
annoying.

What makes a rheostat especially bad is that as you increase the load you
increase the current draw, which increases the voltage drop, further
lowering the speed and torque.

Harbor Fright (sic) has a nifty little router speed control for $10 Says it
will work with any ac/dc brushed motor to 15A Item # 43584-3VGA I've used
it for my roto-zip, grinder and hand drill with good results.

Wali

I never said "rheostat" I said "rectifier". There *is* a difference .. - GWE

Leo Lichtman wrote:
"Grant Erwin" wrote: It doesn't hurt anything.
Dremel sells a speed controller to do exactly this(clip)
^^^^^^^^^^^^
Well, not exactly. The speed controls used on AC
/DC tools like drills, routers, and the Dremel, cut down the width of the
on-time of each half-wave. This lowers the speed but does not lower the
torque much. A rheostat lowers the voltage, so as the speed goes down, so
does the torque. This probably does not matter if you're only filing the
toenails of a bird, but if you were using your Dremel for grinding or
carving, you would find the speed variation under load to be very annoying.

What makes a rheostat especially bad is that as you increase the load you
increase the current draw, which increases the voltage drop, further
lowering the speed and torque.

In article ,
Grant Erwin wrote:
I never said "rheostat" I said "rectifier". There *is* a difference .. - GWE

Leo Lichtman wrote:
"Grant Erwin" wrote: It doesn't hurt anything.
Dremel sells a speed controller to do exactly this(clip)
^^^^^^^^^^^^
Well, not exactly. The speed controls used on AC
/DC tools like drills, routers, and the Dremel, cut down the width of the

*You* didn't say "rheostat", but the original poster did (sort
of, the spelling was somewhat strange), and you said "do exactly this",
so it looked as though you were suggesting that Dremel offered a
rheostat, even though you weren't.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Thu, 20 Nov 2003 20:22:55 GMT, Spehro Pefhany
wrote:

On 20 Nov 2003 11:37:11 -0800, the renowned
(Cuezilla) wrote:

I was at the bird shop to get my birds nails trimmed. The lady had a
Dremal tool plugged into a sewing machine restate (sp?).
^^^^^^
rheostat

Best regards,
Spehro Pefhany


OK, now that rheostats are out of the way...
I had cause to look carefully at the speed controller of a Dremmel when mine
stopped working. The speed controller is a simple variable resistor-diac-triac
circuit AKA a light dimmer!

In other words, get a light dimmer that will handle the current, one sized at
150 watts will do, and that should do the job. The universal motor on a
Dremmel is quite an inductive load and triacs like that sort of load, so you
shouldn't have any problems with it.

HTH

Mark Rand
RTFM

Mark Rand wrote: (clip)In other words, get a light dimmer that will handle
the current, one sized at 150 watts will do, and that should do the job. The
universal motor on a Dremmel is quite an inductive load and triacs like that
sort of load, so you shouldn't have any problems with it.
^^^^^^^^^^^^^
That's odd. Every light dimmer I have ever looked at carries a warning that
it is not to be used with inductive loads. On the other hand, I have
ignored that warning, and have not had problems. I once used a light dimmer
to control the speed of a vacuum cleaner motor I was using as a forge
blower, and it worked perfectly.

I guess the answer is to size the dimmer large enough to stand the
punishment. What do you think?

In article , Mark Rand
writes:

In other words, get a light dimmer that will handle the current, one sized at
150 watts will do, and that should do the job. The universal motor on a
Dremmel is quite an inductive load and triacs like that sort of load, so you
shouldn't have any problems with it.

Does it have the feedback detection mechanism that tells the controller that it
isn't running at the speed that the dial position indicates?
Engineman1

The motor in a Dremel is a universal motor and, as such, has no problems at
all with the usage of a reostat or variable resistor in series with the
motor. I'll note that there are models of the Dremel that have a built in
electronic speed control and you can use that in series with the reostat to
limit the max. speed of the Dremel. The electronic speed control works by
the phase control of the power so it will do its thing while the reostat
will do voltage reduction. There may be a minor loss of control (motor
stops) if the input voltage gets too low for the electronics in the tool.

--
Bob May
Losing weight is easy! If you ever want to lose weight, eat and drink less.
Works evevery time it is tried!

I bought the router speed control from
http://www.mlcswoodworking.com/shops.../speedcon.html

$24 including shipping. In a previous thread, someone said this
device worked better than the one from HF.

I tried it on a Singer 401 sewing machine. Huge improvement over
rheostat control! No "hand starting" even at very low speed.
Making a footpedal control for it is now on my project list.


On Thu, 20 Nov 2003 22:29:54 GMT, "wialgmes"
wrote:

Harbor Fright (sic) has a nifty little router speed control for $10 Says it
will work with any ac/dc brushed motor to 15A Item # 43584-3VGA I've used
it for my roto-zip, grinder and hand drill with good results.

Wali

"Bob May" wrote in message
...
The motor in a Dremel is a universal motor and, as such, has no problems
at
all with the usage of a reostat or variable resistor in series with the
motor. I'll note that there are models of the Dremel that have a built in
electronic speed control and you can use that in series with the reostat
to
limit the max. speed of the Dremel.

Just what I do. Works just fine. By the way, the cheapest rheostat for
the purpose I have found is a sewing machine rheostat. Even new, their
about $10. I've bought them for a buck at junk shops.

Boris

Nope, lights don't really need it either because their load doesn't vary.
And it adds to the cost of the circuit, which really scares the
manufacturers.

Doug

"Engineman1" wrote in message
...
In article , Mark Rand
writes:

In other words, get a light dimmer that will handle the current, one
sized at
150 watts will do, and that should do the job. The universal motor on a
Dremmel is quite an inductive load and triacs like that sort of load, so
you
shouldn't have any problems with it.

Does it have the feedback detection mechanism that tells the controller
that it
isn't running at the speed that the dial position indicates?
Engineman1

Only by sensing current, not via a chopper wheel or mag input.

Most SCR or Triac or Quadrac type controllers are like this to most
extents.
Remember the line to the motor is inductive as well. Be sure the unit
is
rated for inductive loading - so the inverse kick of the motor doesn't
zap it.

Might not be on the label - so be prepared. Always best not to force
stop
as the electric field in the windings has to go somewhere. Normally
into the
Semiconductors - but if it coasts down or stops by itself it is best -
lest there
is protective circuits - e.g. buy a power plug strip that has lightening
strike
protection - and use it between the speed controller and the motor.
That will
protect both motor and speed controller to a great extent.

Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder

Thing I don't like about those superstrip overvoltage protectors is that
yes, they work - once. After that, you don't have any more protection.
And you have no way of knowing!

So a prudent guy would be soldering in new whatever-they-ares, look like
Chiclets with leads on them, every few months. And who's going to do that?

Grant Erwin

Eastburn wrote:

- e.g. buy a power plug strip that has lightening
strike
protection - and use it between the speed controller and the motor.
That will
protect both motor and speed controller to a great extent.

Don Foreman wrote:

snipped

I tried it on a Singer 401 sewing machine. Huge improvement over
rheostat control! No "hand starting" even at very low speed.
Making a footpedal control for it is now on my project list.

If it hasn't occured to you Don, consider changing the speed control's pot to a linear
or "plunger" pot, which will make the foot pedal design a no brainer.

You could put a little DPDT switch and a three pin socket on the present controller and
plug in the foot pedal pot when you need to trade off tasks with SWMBO...(Or is it you
who does the sewing too?)

Jeff





On Thu, 20 Nov 2003 22:29:54 GMT, "wialgmes"
wrote:

Harbor Fright (sic) has a nifty little router speed control for $10 Says it
will work with any ac/dc brushed motor to 15A Item # 43584-3VGA I've used
it for my roto-zip, grinder and hand drill with good results.

Wali

In article , Grant Erwin wrote:

Thing I don't like about those superstrip overvoltage protectors is that
yes, they work - once. After that, you don't have any more protection.
And you have no way of knowing!

actually, they work multiple times, it is just the catastrophic surge
that snuffs them. momentary 6-1200 volts spikes are not destructive.

So a prudent guy would be soldering in new whatever-they-ares, look like
Chiclets with leads on them, every few months. And who's going to do that?
Grant Erwin

right, nobody. there must be a way to test, some newer units have an
led condition indicator. older models sometimes had a window over the
MOV. i guess it looks "zapped" when it is. --Loren


Eastburn wrote:

- e.g. buy a power plug strip that has lightening
strike
protection - and use it between the speed controller and the motor.
That will
protect both motor and speed controller to a great extent.

In article , Don Foreman wrote:
I bought the router speed control from
http://www.mlcswoodworking.com/shops.../speedcon.html
$24 including shipping. In a previous thread, someone said this
device worked better than the one from HF.

this sounds like a good match for the dc treadmill motors many have
bot for their home shops. it says up to 3.5hp.

I tried it on a Singer 401 sewing machine. Huge improvement over
rheostat control! No "hand starting" even at very low speed.
Making a footpedal control for it is now on my project list.

yes, sewing machines have used solid state speed control for many
years. what is _not_ commonly known, is that the foot control is
simply an air chamber. the actual circuit resides in the head and
is pneumatically controlled. --Loren

On Thu, 20 Nov 2003 22:29:54 GMT, "wialgmes"
wrote:

Harbor Fright (sic) has a nifty little router speed control for $10 Says it
will work with any ac/dc brushed motor to 15A Item # 43584-3VGA I've used
it for my roto-zip, grinder and hand drill with good results.

Wali

I have a variable speed dremel that fried the speed cotnrol and I by
passed the control after not being able to get replacement board, Then
I took a push button , on off light dimmer wall switch
and mounted it in shallow wall box . With a large round rubber heel
from old shoe made a foot operated swich that allows for speed control
also. Works good.

Cuezilla wrote:

I was at the bird shop to get my birds nails trimmed. The lady had a
Dremal tool plugged into a sewing machine restate (sp?). It let he
control the speed without having to adjust the speed control switch on
the tool. Would this in any way be damaging to the tool? I have a
single speed tool that I was thinking of doing this with. Seemed like
a good idea.

Dale Randall wrote:
I have a variable speed dremel that fried the speed cotnrol and I by
passed the control after not being able to get replacement board, Then
I took a push button , on off light dimmer wall switch
and mounted it in shallow wall box . With a large round rubber heel
from old shoe made a foot operated swich that allows for speed control
also. Works good.

Pretty much the only part that can fail on
the control board is the surface mount
triac BT134W, which costs about 2usd..
I've replaced one to my dremel.. Pretty easy.

Kristian Ukkonen.

On Fri, 21 Nov 2003 04:47:29 +0000, Mark Rand
wrote:

OK, now that rheostats are out of the way...
I had cause to look carefully at the speed controller of a Dremmel when mine
stopped working. The speed controller is a simple variable resistor-diac-triac
circuit AKA a light dimmer!

In other words, get a light dimmer that will handle the current, one sized at
150 watts will do, and that should do the job. The universal motor on a
Dremmel is quite an inductive load and triacs like that sort of load, so you
shouldn't have any problems with it.

HTH

Mark Rand

Quite true. A lamp dimmer will work with any universal motor tool like a
dremel, a drill, router etc, though may not give good speed regulation due
to lack of feedback. A variac will do the same. However you should not use
an electronic speed control on a tool that incorporates one internally.

On Fri, 21 Nov 2003 05:41:58 GMT, "Leo Lichtman"
wrote:

That's odd. Every light dimmer I have ever looked at carries a warning that
it is not to be used with inductive loads. On the other hand, I have
ignored that warning, and have not had problems. I once used a light dimmer
to control the speed of a vacuum cleaner motor I was using as a forge
blower, and it worked perfectly.

I guess the answer is to size the dimmer large enough to stand the
punishment. What do you think

You can hook a MOV across the load to kill off spikes.

Kristian Ukkonen wrote:

Dale Randall wrote:
I have a variable speed dremel that fried the speed cotnrol and I by
passed the control after not being able to get replacement board, Then
I took a push button , on off light dimmer wall switch
and mounted it in shallow wall box . With a large round rubber heel
from old shoe made a foot operated swich that allows for speed control
also. Works good.

Pretty much the only part that can fail on
the control board is the surface mount
triac BT134W, which costs about 2usd..
I've replaced one to my dremel.. Pretty easy.

And the variable resistor.
It died on mine in such a way that the arcing has destroyed at least
the wiper, and possibly the resistive track too.
What should the end-end resistance of the track be?