Air Grinder question

Hi all I have two questions; I have a flywheel diamond and I was
thinking in the possibility to use one of those air grinders that
harbour freight sells.The required speed for the flywheel is at least
25000rpm, My flex shaft is only 14000 rpm compared to the air grinder
that delivers 30000rpm which is in the range of the appropriate rpm’s
recommended for the flywheel safe use. Would it be a good idea to use
one of them instead of the flex shaft? Second question; which would
be the best fuel recommended for the bellow torch. I been using regular
gasoline but it smells like old truck. Any advice would be
appreciated.

Marco

Hi, The Air grinder will work very nicely for diamond cutting with a
fly wheel. Make sure to use a good airline filter and water seperator
…If water gets into the airmotor, it will ruin it quickly . Also,
Make sure that they have the correct collets for holding the flywheel
cutter… many automotive airgrinders don’t come with small (1/8")
collets or 3/16 collets… Do so before buying the unit as they may
not make collets or have them in stock

Daniel Grandi
Racecarjewelry.com

Marco, Most “standard” air grinders run at about 20,000 rpm NO LOAD.
Harbor Freight sells a pencil grinder that is supposed to do 50,000
or 80,000 rpm, for ??$80.00??. There are costly industrial air
grinders available for $$$$$$ that run 100,000+ rpm, that look like a
regular air grinder.

Another option is to get a flex shaft hand piece that is sold as a
"high speed" handle. That is what was recommended to me at a jewelry
demo/school/selling sort of show. Also at this show they were
recommending high speed, variable speed, electric motor in the hand
piece, expensive units. I ended getting the flex shaft high speed
handle, but have never used it.

John Dach

Here is a relatively cheap superfast air grinder:
http:www.turbocarver.com Uses 1/16" shank dental type tooling. Never
seen one.

Jesse

Hi John I just bought a variable speed Dremel which delivers
5000-30000 rpm. but there’s still a problem, The collet is too small
and the flywheel don’t fit in it, I looked up in the dremel catalog
and I couldn’t find the appropriate collet for what appears to be more
than 1/8 wide shank . And here I am trying to play the Engineer again.

Marco

I highly recommend the air turbine tools from Air Turbine Technology
http://www.airturbinetools.com . I have used them for over ten years
and the first one I bought is still running strong. They come in a
variety of speeds from 2500 to 65000 rpm and power ranges from .15
to .85 HP so they have lots of torque it is hard to stall one in fact
I have never been able to stall mine . I have the model 201SV and
model 202SV both are 65000 rpm. Another nice thing about them is that
they do not need oil in the air stream in fact it will ruin them so
you do not need to invest in an oil system for the tools and it keeps
your work area much cleaner. They have 1/8", 3mm, 3/32 and 1/16
collets available. You can get them from MSC

Jim
James Binnion Metal Arts
4701 San Leandro St #18
Oakland, CA 94601
Phone (510) 533-5108
Toll Free (877) 408 7287
Fax (510) 533-5439

@James_Binnion
Member of the Better Business Bureau

I agree with Jim, The Airturbine technology handpiece is the absolute
best there is for diamon d cutting and grinding…I managed a shop
back in the 80’s that had 10 people doing diamond flywheel cutting…
We used about 50 highspeed foredoms/year … They broke down
continuously when pushed to the levels we were producing. The
following year, we switched to the airturbine technology units and
they neve r broke down. Make sure you use absolutely clean air…No
water or oil … or the units will break down. I

Daniel Grandi

    Hi John I just bought a variable speed Dremel which delivers
5000-30000 rpm. but there's still a problem, The collet is too
small and the flywheel don't fit in it,   I looked up in the dremel
catalog and I couldn't find the appropriate collet for what appears
to be more than 1/8 wide shank . And here I am trying to play the
Engineer again. 

G’day Marco; I have a variable Dremel which came with about three
collets. But I needed one to handle drills of one millimetre or less,
and the place I bought it from weren’t terribly helpful. So I wrote
to the address on the tool itself asking if they did such a collet. I
got no verbal reply but instead received a complete selection of
collets including the one I wanted, and one to take a 1/8 shank plus
the cylindrical nut. (which I didn’t really need) Another happy
customer. I use that Dremel very frequently indeed, and use it via
an old sewing machine foot control. In fact one of the things I use
it for is to sharpen the cylindrical teeth of a chain saw using a
diamond cylindrical burr. There are many other uses. Don’t let the
Dremel grind you down. Incidentally I find I use lower speeds the
most. –

John Burgess; @John_Burgess2 of Mapua Nelson NZ

    Hi John I just bought a variable speed Dremel which delivers
5000-30000 rpm. but there's still a problem, The collet is too
small and the flywheel don't fit in it,   I looked up in the dremel
catalog and I couldn't find the appropriate collet for what appears
to be more than 1/8 wide shank . And here I am trying to play the
Engineer again. 

When I bought the High speed hand piece from Swest, I also bought a
set of collets along with the cutter. The cutter will not fit in ANY
of the collets (the set cost about $100) and Swest has NEVER been
willing, able or ?? to set me up. One of the reasons I have not used
the thing.

I sure hope you have better luck with Dremel than I had with Swest.

John Dach

Hi john Isn’t your Dremel the heavy duty one that’s look like a
foredom flex shaft,'Cause they have bigger collets for that version.
Old sewing machine foot control for my dremel? What an stupendous
idea! Tomorrow I’ll go in search of one. Thank you John. Marco