Re: [Harp-L] Re: tuning reeds...motors

["Vern Smith" <jevern@xxxxxxx>]

Even if you can control the speed, a Dremel motor is 
inconveniently large and heavy for tuning.  DC nail filing 
spindles are, IMO, better.

Most Dremel motors have a little dial on the side for 
controlling speed (5000-30,000 rpm) so that a separate speed 
control may not be necessary.

If I were determined to use a Dremel motor, I would get a 
Dremel flexible shaft that has a small-diameter and 
light-weight handpiece.  However, the stiffness of a drive 
cable is a minor inconvenience.

An induction motor's speed depends on the line frequency 
and not the applied voltage. Without special starting 
features, they cannot deliver enough torque to start under 
load.  Thus any motor that can run faster than 1800 rpm 
almost certainly has a commutator (brushes) to switch the 
currents faster than 60 Hz.  Commutator motors can be slowed 
down by reducing the applied voltage.  I cannot imagine a 
Dremel tool with an induction motor.

Certain motors have solid-state commutators that function as 
brushes.  These are better because the solid state 
commutators don't wear as do brushes.  High speed appliances 
and tools that use commutators include vacuum cleaners, 
blenders,  Dremel tools, and almost all plug-in hand tools.

I have used a 2KW light dimmer to slow down a vacuum cleaner 
to use as an air  pump for vibrating harmonica reeds. A 200 
watt light dimmer should work for a Dremel (1.15A x 115V = 
132 watts)  Modern light dimmers reduce the voltage by 
altering the wave form.  At low speeds, a dimmer-slowed 
motor's speed will be highly variable with load.  That is, 
you will set a speed but the tool will slow down a lot as 
you start to grind.  A better, but much more expensive, 
alternative is a variable transformer ("Variac").

Vern








----- Original Message ----- 
From: "Dane Paul" <Monsterharp@xxxxxxxxxxx>
To: "Michael Easton" <diachrome@xxxxxxxxxxx>; 
<harp-l@xxxxxxxxxx>
Sent: Sunday, June 28, 2009 1:16 PM
Subject: Re: [Harp-L] Re: tuning reeds


I have concacted Dremel...............they said if you use a 
non inductive
Dremel (the one with the brushes) you can use a reostat to 
slow your speed
down. I had an old sewing machine pedal which I repurposed 
for the dremel.
You can also use a ceiling fan speed switch, or a high 
amperage light switch
switch to make a desktop version.......KNOW YOUR AMPERAGE

Although I have made both, there is switches avalible 
through woodcraft and
other companies to acheive the same result. AGAIN MAKE SURE 
AMPERAGE IS
COMPATIBLE

DISCLAMER....................................

DONT ELECTR-O-CUTE YOURSELF IF YOUR NOT FAMILLIAR WITH 
ELECTRIC
........DONT<<<<<<(no not yelling just being enphatic)



----- Original Message ----- 
From: "Michael Easton" <diachrome@xxxxxxxxxxx>
To: <harp-l@xxxxxxxxxx>
Sent: Saturday, June 27, 2009 6:52 AM
Subject: [Harp-L] Re: tuning reeds


> Vern is correct about Dremels but there is a way to tame 
> the beast.    I use a multi speed Dremel and even on the 
> lowest setting it is too  strong.
> I've been using 'hand pieces" at work for over 30 years 
> and the key to using them correctly is learning how to 
> control the speed for the task  at hand.
>
> Since I don't have a grand to blow on the type I use at my 
> day job I improvised.  Anyone that already owns a Dremel 
> can do this as well.  I purchased one of
> those outlets for use with Christmas trees that allow you 
> to turn the lights on and off without crawling under the 
> tree to get to the wall outlet.
> They have a big red button on them that you control with 
> your foot.  I attached my Dremel to that and can press it 
> down enough with my foot without clicking it on.
> This way I can create a pulse to get the dremel working 
> but not enough  to bring it up to full speed.  I pump the 
> foot switch while working  the reed never allowing it to
> go to full speed. What you are doing is working on the 
> reed when the spindle is decelerating rather then revving 
> up.
>
> Good tool stores carry on/off foot pedals.  Try to get one 
> that allows you to turn it on momentary rather then having 
> to click it on every  time. That way it will be easier to 
> pump the switch. The only time I  actually leave it on is 
> when I'm retuning the reed to another note.
>
> Coast to Coast use to sell Brownies.  If they don't carry 
> them contact  me offlist.  One Brownie should last you for 
> years if you only use it  on reeds.
>
> I use them in combination with files and sanding wands.
>
>
> On Jun 26, 2009, at 11:10 PM, harp-l-request@xxxxxxxxxx 
> wrote:
>
> > Hello,
> > Any recommendations for tools for tuning reeds and where 
> > to get  them. I like the idea of a dremel like rotary 
> > tool and the shofu  brownee attachment. But don´t know 
> > specific model numbers or places  to purchase them. Any 
> > advice on those or any better methods greatly 
> > appreciated.
> > Thanks! Rich
>
> Michael Easton
> www.harmonicarepair.com
>
>
>
>
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