On 2010-08-18, Bob La Londe wrote:
"Ignoramus11933" wrote in message
...
As I was messing around with text engraving, I realized that it would
be very cool to have a high speed spindle.

There is, apparently, a wide variety of purpose made and adapted
devices that are used for this:

http://www.cnccookbook.com/CCHighSpeedSpindleAddOn.htm

The best so far, looks to be this:


http://www.cnccookbook.com/img/Other...Manifold_1.jpg

This is a Bosch Colt palm router attached to the quill. It seems to be
nicely made, and low profile.

In my case, I can use a changeable toolholder to do the attaching, so
that it is easy to take off:

http://www.shars.com/products/view/1...nd_Mill_Holder

This way, I could run a 1/8" end mill at 30,000 RPM, without using the
main mill's spindle bearings. I would use a brake to hold this
assembly in the quill.

It would be, as I said, a quick change setup, easy to be swapped
out. I would just need to figure out a safety interlock mechanism, so
that the main spindle would not be turned on accidentally with this
thing mounted.

It would seem that a holder is easy to make from 6061 or some such,
and the whole project can be done under $200.

I engraved some text yesterday, which took something like 19
minutes. I did it at 2,400 RPM. At 30,000 RPM, it could take only 1.5-2
minutes.

I guess it depends on what you mean by engraving. Engraving is usually done
with a spring loaded bit holder that is dragged (not spinning) along the
surface of the material. This allows for engraving some surfaces that are
not perfectly uniform and even to some degree engraving curved surfaces. I
engraved the side of some larger sockets to see how far I could push it with
mine. You can make your own spring loaded engraver with whatever size shaft
is desirable. I would use a lathe, but if you have very low backlash or
have backlash compensation programmed well in your control software you
could do it on your CNC mill. If you don't want to make one there are
atleast two different people selling them on Ebay. Dremel actually sells a
decent tungsten conical point and a conical diamond dust point pretty cheap
that work nicely in my drag engraver.

If you meant to "mill out" letters and only do it rarely then find yourself
a high speed cutter of some kind and make your own mounting bracket for it.
I'm using a couple motors and handpieces right now, but the first link
Gunner listed is a nice example of one using a die grinder. Run out of your
bit or mill holder will determine how small a cutter and/or how fast you can
feed without breaking them. If you don't plan to use it often there are
some pretty cheap drive solutions out there. A decent quality trim router
turns at about 28,000 rpm and has a lot of power.

I would love to have one of those super high speed spindles that just go
right into the mill like a collet, but they are expensive. Of course I
would have to have a machine that would take them. LOL.

I look forward to seeing your ultimate solution.




What I means was using a small end mill to mill various shapes, such
as text (as in making panels), or 3D patterns, like toys.

I think that this Bosch Colt palm router is the nicest cheap high
speed motor, because:

1) It is relatively compact (unlike those die grinders), so I can
mount it next to the quill and I do not need a lot of headroom for it.
2) It is a Bosch
3) It has a high horsepower (compared to alternatives)
4) It has variable speed
5) It has a very nice straight round neck for mounting
6) It is only $100-116.
7) It has a 1/4" collet.

i