Re: Laser Engraving - how can I find brushless dc motor w controller

Jim, you may find this interesting. The reason I am interested in
laser engraving is because I am trying to do some of the work shown
in ( www.epiloglaser.com/downloads/brochures/epilog_brochure.pdf ).
Basically I'm trying to remove very small amounts of material. In a
sense a laser engraver is functionally like a high speed spindle.
After searching for them I have found the NSK Astro E-250. A top of
the line true high speed spindle which sells for $1,900 to $2,000.
The Astro E-250 is the cheapest NSK high speed spindle. It is a
brushless dc motor with rare earth magnets, with true continuous duty
cycle (must have ceramic bearings in the motor and spindle), 0 to
25,000 rpm, 105 watts max output, withstands 5,000 hours of
continuous use, 5 cN-m torque over the speed range, 1/8" collet
chuck, motor controller.

Another on I found is the Wolfgang Engineering TB-6070-BL sold on his
e-Bay store for $545. 300 watts of cutting power, ceramic bearings,
40,000 rpms, 1/8" collet chuck, and speed controller.

Most guys, as you know, use wood routers, laminate trimmers, etc.

What I have been trying to is make a high speed spindle my self. But
no matter how I search, I can't find sources for retail, small
quantities, with speed controller, rare earth magnet, brushless dc
motors with ceramic bearings. Does anyone know where I can find
them? I have found comercial sources who sell in large quanties, and
radio controll hobby, dc brushless motors.
You may find this link interesting. This fellow shows how to make
your own dc brushless motors.
( http: //users.cybercity.dk/~ccc16084/LRK.htm )

Thanks for your help.

Whelen

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jymmm <jymmm@y...> wrote:
>
> Hi Whelen,
>
> Last year I was looking to purchase a laser engraver.
> Here is what I learned, take it for what it's worth.
>
> Of the three big boys (Epilog, Universal, GPC) they use sealed
(gas) CO2
> laser tubes. Sealed CO2 tubes have a shelflife of about 3 to 4
years, even if
> in use or still in the box. After that, their power output decreases
> (basically).
>
> Most of the mfg's can recharge and replace the mirrors in the tubes.
>
> The older type of CO2 laser tubes are flowing (as opposed to
sealed), where
> you have the welding supply mix you up a special receipe of gases
and you
> just refill the tank when it gets low.
>
> CO2 lasers can NOT mark/etch/cut metals. The wavelength is wrong.
> You'll need a YaG laser for true metal work.
>
> The metal marking stuff is just like pottery glaze.
> You brush it on the metal, the laser "cures" it, and you wash away
the rest
> with water. It does not mark the metal in any way.
>
> Now, if you have anodized metal, a CO2 laser can "bleach" the
anodize itself
> (usually comes out a off cream color). It doesn't matter what color
the
> original anodize is (red, blue, gold, etc) the bleaching will
always be the
> same off cream color.
>
> You can even bleach the color out of denim to produce patterns in
fabric.
> (I was told this process of bleaching fabric it patented, so...)
>
>
> All of the laser use flying optics (moving mirrors to position the
beam).
> The laser *MUST* be focused to the top surface of the material
before each
> run. If not you will get a gooey blob (in the cast of plastic), so
altering
> the Z height itn't going to do it.
>
> A 35 Watt CO2 laser can cut 0.25" thick wood. But if the wood is
dense it
> might be better to make two passes instead of one big one to get a
nicer
> finish. I took a scrap piece of teak wood and had they cut it for
me. Not a
> pretty sight on such a low power laser. Too slow feed and low
powered cause
> the sap to melt/burn and char the edges.
>
> The power levels (like depth) is controlled by pulsing the laser
(plus
> something else I can't recall at the moment).
>
> They all use HPGL (plotter) and not G-Code for controlling
movement/power.
>
> Also most all of them are installed like a printer and most
everyone in the
> engraving industry uses Corel Draw.
>
> I started to ask around about used lasers and found someone that
engraves urn
> boxes (beautiful work) professionally. He was selling a 75 Watt C02
laser
> engraver because it was too low power to engrave on the surface of
softwood
> 0.125" thick in a reasonable amount of time.
>
> I hope I didn't ramble too much and the information was helpful.
>
> Jim...

> __________________________________
> Yahoo! Mail - PC Magazine Editors' Choice 2005
> http://mail.yahoo.com
>