re:Router Cutting Aluminum

Joe wrote:

>What are the disadvantages of using a wood router for cutting
>aluminum?

Joe,

You've gotten some interesting feedback.

I routinely cut aluminum plate (wrought and cast 6061,6063,2024 and
sheet 5052) with several routers (porter cable, bosch, B&D ). My $.02

Disadvantages?
First, the NOISE! Cutting with a router for any length of time
REQUIRES the use of ear protection. Milling is more peaceful. An
industrial spindle (Perske, Elte, Colombo;from Germany,Spain,Italy
respectively) will run MUCH more quietly. MUCH higher cost. Perske is
the most "marketed" to the lower end users, like us. Big wood working
routers often have Colombo heads.

Industrial spindles are nothing more than high precision routers, and
they are used to cut aluminum every day!

Jon E mentioned the bearings (not a problem, IMO) but I "have" put
Grade 8 bearings in routers from time to time over the years "just
because"... (If I'm changing them anyway...)

The aluminum dust is not a major problem (for the router), but see
more as to why further below. The router is designed for wood dust
operation (and porter cable at least, has become the De Facto
standard in low to mid range CNC routers. They KNOW these things are
being used on aluminum and stone, and concrete, tiles, composites
(graphite, like alum., conductive) and they work just fine. The
airflow through a typical wood router is FROM the top TOWARD the work
surface. This tends to keep the motor free of damaging particles. IF
you keep your shop air clean...

As far as DISadvantages, that's about it. But...

To use them effectively with aluminum, you MUST:
1) Provide lubrication.
2) Use appropriate cutters/tooling.
3) Take appropriate cuts.
4) Protect your health

1)Aided by tooling material/geometry, Lubrication is THE secret to
success! Lubrication can be anything from a squirt of wd-40 ahead of
the cutter, to A-9 and other "designated" aluminum lubes; to one of
my favorites, Beeswax. (for the cutting; It's a B#$%& to clean up) It
is sold in tubes (like the old push-up ice cream) and works WELL.

side note:Cutting 1/2 or 5/8 plate on a table saw with a wood blade
is easy if you rub this wax along the cut line (material top surface)
and "charge" the teeth and sides of the sawblade. I've done this "one
pass", but two or three is easier on the technique and tool. That
aluminum gets hot. Protect your arms and eyes!!! "Triple chip" blade
is safer than an "ATB". Ask the sawblade mfr. :-)

Back to routing. You can submerge the work in a cake pan of coolant
and just cut (assumes the gcode toolpath is "proven") or provide
coolant to the point of the work with a "mister". Trico Mfg. and
Koolmist are two reliable mfr's. Wd-40 really does a good job, and
the smell is better than the kerosene we used to use.

2) Tooling geometry and material is the 2nd part of the "secret". Use
tooling DESIGNED for routing aluminum. ALL the major manufacturers
have it. (a VMC with a hi-speed 15K+ head and travels of 900IPM is a
ROUTER!) If not at least pay attention to clearance and rake angles
when "adapting" other tooling. Make sure there is room for the chips
to get out!

It's worth mentioning here, that "stiffer is better" as machines go.
You are not going to get the same results from a flimsy machine that
you are going to get from a bridgeport! (which as was recently
mentioned, used to be considered a "flimsy" machine! :-) )

These two items will cure most of the "problems" the earlier posts
(answers) alluded to.

3)Next is the tool "path". DON'T plunge a bit endwise into aluminum
(unless it's a drill :-)... ). Use ramped cuts and KEEP THE TOOL
MOVING through the stock! Calculate the chip loads (at YOUR available
feeds/speeds) so you know when you're trying to do the impossible.
Take cuts as FAST as your machine will reliably move and adjust the
toolpath depths/ overlaps to suit.

4) Aluminum dust is not good for you. And if you are using a low
feedrate CNC machine with a wood router you WILL be making some dust.
You simply CAN'T go fast enough to avoid it! (Tools WILL dull a
little sooner too, but it's not so bad to stop ya, IMO) Be sure to
provide YOURSELF with a dust mask and the hearing protection already
mentioned. The liquid coolants will obviously help the situation, but
stay safe. Keep your shop air clean. The fan/filter box(es) sold for
this is a good thing.

Remember that you ARE pushing the envelope here. A cutter may break
at any time! So be sure your eyes/ body are protected,too!

Use a woodworking router to cut aluminum? Sure! I wouldn't be here
(on the list) if it weren't.

Hope this helps. Good luck.

Ballendo

P.S. Fine Woodworking magazine (Taunton press) had an article a few
years back on using "wood" tools to make machines from metal and
plastics. Worth the back issue price, prob'ly.