Re: Looking for a router alternative.

Message: 2
Date: Tue, 12 Feb 2002 00:16:45 -0000
From: "tig415" <classic66@...>
Subject: Looking for a router alternative.

Hi
I've got a fairly robust 48" x 60" router That I've built and I'm looking
for an alternative to the router head I have now. The router is great for
well ....routing but when it comes to drilling and milling on aluminum it
leaves a lot to be desired. Ultimately I would like to be able to use the
R8 tool holders from my mill . Grizzly has a 1/2" drill chuck that will
attach to a 1/2" or 5/8" shaft. I have a 1HP 90V DC permeant magnet motor
and I could mount that to it and mount the motor to my Z axis. That means
I'll have to buy a motor controller but then I'll have a variable speed
motor which is nice but I'm hoping someone has done something cooler.
I did some searches and could not come up with anything so I hope I'm not
rehashing something that's been covered.


Thanks
Derek

[Using a Jacobs-type chuck to hold high-speed router bits or endmills is not
a good idea, Derek. There is too much run-out, which is dangerous when
high-speed tools are involved (not to mention cut quality.) You don't
mention what sort of router-head you're using now, but it's almost certain
to perform better than what you're proposing. 1 horsepower is low for a
router-head- handheld models go up to about 2.5hp, and the sort used on
large CNC routers get much bigger. But the poor results you're experiencing
while attempting to mill aluminum probably have less to do with the
router-head and more with the generally low rigidity of your setup when
compared to a mill. Aluminum likes being climb-cut, but that requires a lot
of stiffness. Setting up a high-speed spindle (aluminum needs high speeds)
is more complicated than simply screwing a chuck onto the end of a motor's
extended shaft. You need high-speed bearings, a collet holder assembly (you
mnight be able to scrounge a R-8 holder from a scrapped machine tool), and a
way to get higher RPMs than the motor will deliver directly. Real
store-bought spindles tend to be pricy, but there's a reason for that-
inferior or unbalanced parts run past their tolerances could blow apart and
kill themselves- or you.]

Andrew Werby
www.computersculpture.com