Re: [CAD_CAM_EDM_DRO] Re: Laminate Trimmer

> > What sort of material are you cutting with that trimmer?
>
>Plastic (acrylic, lexan, delrin) and wood.
>
> > I'd be interested in hearing how it goes for longer runs than 30 minutes,
>should you do one...
>
>I've done a couple now and it seems to be just fine. Doesn't overheat or
>make loud grinding noises (yet! :-)

<snip>

I use the orange $39 Harbor Freight trim router (currently on sale for
$19). I didn't want to spend more until I knew more about machining and
could make a better informed purchase. But it has worked so well for what
I do, it's almost not worth the effort to make a new mount for a better
trim router. I've had mine running for hours at a time (5 hours cont.
machining foam, 8 hours with pauses for tool changes machining 0.100" thick
aluminum). The runout isn't so great, and I had to make my own 1/8"
collet, but for machining front and rear panels for electronics enclosures,
it works just fine. I think the runout can be cleaned up by grinding the
inside of the shaft, the part that holds the collet, but I have not had the
need to do this. I use a variac for speed control, which allows me to push
the voltage a little, so I can run a little faster than straight out of the
outlet.

Aluminum chips really fly w/ a 1/4" carbide end mill at 30,000 rpm! I use
used carbide PCB drill bits for smaller end mills. Mostly 3/32" dia, but
1/16" for realy tight corners.

If you are new to machining, use coolent at high rpms! Aluminum will gum
up, and plastic will melt. I use Cool Mist in a hand held spray bottle,
reduced according to the directions (4 oz to a gallon of water). If you
are making a machine that might cut aluminum, design it so your machine can
get wet!

It's funny, Harbor Freight gives spare brushes for most of their products,
but I've worn out the bottom bearing before significant wear on the
origional brushes. I'd guess I have at least 100 hours on the trim router.

It's amazing how much a ridged machine will allow you to cut faster. Had
to cut the feed rate in half as the bottom bearing started to wear. Taking
an old one apart, I bet better bearings could be placed, but $20.00 for a
new trim router...

Good luck, have fun!

- Steven Ciciora