On 2/3/2015 10:05 AM, Bob La Londe wrote:
"DerbyDad03" wrote in message
...
As far as I can tell, the standard material for Cross Cut Sled runners
is hardwood and typically 2 are used. However, I saw a couple of plans
that use aluminum as the runners and even one that suggests a single
miter gauge bar as the only runner.

http://www.finewoodworking.com/item/...-crosscut-sled


I think I see advantages and disadvantages of all options, but I'd
like to hear your opinions.

"2 hardwood runners is the way that it's always been done" will not
automatically be considered an "advantage". ;-)


Aluminum might react with the steel of the table top over time if left
unused for a while in a humid environment. Anodizing the aluminum would
virtually eliminate that. Anodizing has the advantage of creating a
hard wear resistant surface on the aluminum parts. So, the correct
answer is adult diapers. (It Depends.)

You can get electrolysis between aluminum and iron with the presence of
water, a good reason to insure that the coolant in your car engine bis
kept fresh, but Kreg miter gauges are 95% aluminum and I had one sitting
on top of my cast iron TS for years on end with out any problems. The
bar was silver so I am not sure if it was anodized, the blue upper part
of the gauge was certainly anodized. I did how ever encounter problems
with the Kreg miter gauge. Primarily the aluminum guide bar should have
not been made from aluminum, it flexed very easily and on wide panel
cuts the fence was less that steady because of the guide flex. Secondly
the brass indexing pin finally seized in the aluminum one morning and I
was unable to remove it after it had set in the sunlight for a few
hours. I then switched to an Incra miter gauge with steel guide bar and
anodize aluminum fence. FWIW the longer the guide bar the better the
accuracy especially when the fence is 12" shy of touching the front of
the saw table when cutting wide panels.




To those who might argue about anodized aluminum, there are modestly
decent life desktop size CNC mills that have anodized aluminum wear
surfaces. Strictly hobby stuff, but still.