Re: [CAD_CAM_EDM_DRO] mini mill spindle vs trim router

On Fri, 18 Jul 2003 20:54:27 -0000, you wrote:

>I'm would like to build my first minimill. I have three acme thread
>driven cast-iron positioning tables for the x, y, and z axis and two
>6 inch rotary tables for the 4th and 5th axis.

If they are the standard variety, then they might be rather crude in
design, so that is a factor to think of.

If the whole table does X and Y, you will only need to do something
for the Z axis. That could be one of the tables set on the side,
perhaps a bit crude, but it might work.

>The question I have
>is which would be better to use for a spindle. Would a 3/4 hp router
>that can turn at 30k rpm or a .5 mini mill spindle with variable
>speed control that runs 2500 rpm be better? Here's the spindle
>http://www.littlemachineshop.com/products/product_view.php?
>ProductID=1912
>It says it can drill up to 1/2" and face up to 1.25" and end mill up
>to 5/8".

The mini-mill would be the more general purpose item for metal. If
you want to do just wood, and route that, then the router is the way
to go. You might want to consider using both with the appropriate
motor plate.

>Has anyone compared these? I'd like to mainly do small
>cuts engraving and the like in aluminum.

If you are doing engraving, you might want to consider something like
a dremel tool, since that would get you the high RPM, and you do not
have to worry about cutting thick metal.

Much depends on the drive power of your xy table, and what you intend
to do with it. An engraver does not quite have the same requirements
as a pc board driller, or a metal mill, or a wood engraver.

Harvey

>How do the spindles compare for run out? Is the effect negligible?

The router is probably worse.

Harvey

>Thanks in advance
>Virgil
>