Rotary grinding tool, that ISN'T as loud as a fire-station klaxon horn

[DocStein99]

My 91 year old father has to live with me, and his favorite hobby is to SLEEP.  So needless to say, I can do my soldering and otherwise tasks, but when it comes time for me to use the rotary tool Dremel, it is like I have to schedule that in the short time-frame for when Rip-Van-Winkle decides to be awake.

This stupid Dremel is actually so loud, I am annoyed.  It is actually louder and more annoying than the wet-dry shop vac, which cause my ears to RING when I use that in a bathroom.  I looked around at the hardware store, and it looks like most of the other options are all built the same way - I can clearly see the SIREN FAN inside of a housing connected to the motor.  If anyone has actually seen an air-raid siren klaxon horn from a firehouse, you would know it does resemble the same construction as the cooling fan on a Dremel.

I look for other options, and it seems either I get stuck with a quiet and lame thing that barely has power to sand a stick of butter -OR- I have a bomb-siren that is powerful enough to do body-work on a 1950 Cadillac with 14-gauge sheet metal.  I am sure they make a happy-medium tool somewhere that cost as much as a mortgage payment.

Recently a great idea came to me.  The women at the nail salon use rotary tools all the time, and it does not sound like an auto-body shop in there.  They have these nice fine tools, with foot-switches and dials and knobs (and some of the KNOBS in there are better than others, if you know what I mean...)...  Anyway.....  I am trying to figure out, why if a nail salon rotary can be so quiet - why the hell a Dremel has to be THAT LOUD ?  What is the malfunction here?  I do not see the stupid klaxon siren fan in the nail salon rotaries.

Unfortunately, they are mostly too expensive for me to buy & try.  Then, I go to youTube reviews and to receive my punished by the worst collection of people reviewing "manicure file" ever.  Long winded explanations about how the tool is so cute and how they feel - with ZERO technical explanation.

Does anyone here know anything about these tools, and can give me some real actual technical information, or have experience with the actual power grade of the tool?  Will I actually be able to polish some metal tools, clean corroded circuit boards, carve fibre/plenum PCB material - or is the motor that same tiny weak "engraver" 3v one that bogs down if I have a wire brush chucked-up and place that against wood?

[Paul_KD7HB]

Might be simpler to keep the sleeve bearings oiled a bit.

Paul

[steve1001]

To overcome the noise problem of my rotary tool, I put on my Peltor Optime III ear defenders. The problem goes away when i wear these. Get some for your dad, bless him!

I don't know anything about those girly nail rotary tools.

Steve

[DocStein99]

Oiled bearings?  They are sealed zz bearings.  By the time those bearings would need service, you can probably consider the rest of the $30 tool ready to replace.  The ball bearings ride against the 2-piece thermo-formed plastic tool housing.  Not exactly a precision instrument.

With the manicure rotary tools, I do not see ANY fan and the whole tool looks sealed and probably water tight.  They could be high rpm and low torque.  Probably have no fancy gearbox either.

[Paul_KD7HB]

You must have more expensive Dremel tool than I have. Mine are all simple sleeve bearings.

Paul

[DocStein99]

I do not throw anything away before taking it apart.  Lately now everything dismantled is broken down sorted into boxes, and shelved.  After bolting rotary tool to home made CNC gantry, it is practically useless.  They can not run over 15 minutes and continually cut anything - after about a week or two.

[dougp]

Mount a flexible shaft on the Dremel and insert the bit into that.  Enclose the power unit in a soundproofed box.  Use a footswitch to actuate.

[DocStein99]

Using a rotary tool with a flexible shaft is like accepting a deal with the devil.  That rigid shaft tube goes only where I do not want it, it breaks - gets hot, more friction.  Never had a fun time using that.

[Paul__B]

I do not throw anything away before taking it apart.  Lately now everything dismantled is broken down sorted into boxes, and shelved.

I see a lot of boxes.  

Using a rotary tool with a flexible shaft is like accepting a deal with the devil.

I have a proper one hanging in the garage.  Mind you, have not actually used it (15 years ... Should try it out).  It is however a proper one like (or is) the ones dentists used to use.  I doubt it is particularly noisy or stiff to use.

[DocStein99]

I used to have house filled of different boxes, all over the place.  Now I broke the habit, went and bought shelves.  And buy plastic storage boxes, all the same in bulk.  I label the boxes, and they go on shelf. So now all stepper motors in one box, dc motors with encoders, another box.  Belts, pullies, etcc...  I have one for floppy drives, cd / dvd drives.  I am finally happy to walk into the room, read a label and know they are all in one spot.

Dentists use sonic vibration tool now.  Not even a bit to swap, just a hand-piece with a shaped blunt pick, that shakes fast to rumble the pain in my mouth.

I spent last 4 hours researching more.  Pinned down a "nail drill".  12v dc handpiece, with a nice dc barrel jack, 6 inches.  No fan, aluminum body and absolutely quiet.  The drawback is the heat.  It will heat up, but usually only need it for like 5 minutes most of the time.  Variable speed controller, reverse and forward. At $20 if the heat becomes a problem I can afford 2 of these and just alternate using them.

[MorganS]

I've got a cheap battery-operated off-brand rotary tool. It's not too loud. Not too powerful either but good enough for small jobs.

For cutting plastic, I use an ultrasonic knife. Makes a great clean cut with no effort, no noise and no dust.

[DocStein99]

Here is the one I ordered to test.  This probably does not have the power to cut metal, but I may be happy for small sanding, deburing, polishing of small parts:

20k RPM eFile 12v variable speed forward & reverse

Here is a quick video compare test to cheap rotary tool and expensive one:

Cheap rotary -vs- Proxxon noise test

The Proxxon is a nice professional expensive tool.  It is also big, not something I want to use at my desk to clean and polish small jewelry sized items. 

[MarkT]

Brushless or 3-phase AC motor in a well engineered metal acoustic housing will be way better than any
plastic tool using a universal motor (they are the loudest motors due to the brushes and speed and open-frame
construction)  You pay a lot more of course.

[DocStein99]

Balancing the shafts at the RPM is also a big part.  I can lathe out everything, connect whatever motor I want.  When it comes to balance that shaft assembly, I am lost.