On Sat, 19 Jan 2008 14:33:35 -0500, "SBH"
wrote:
Thank you all for the helpful advice. Please, keep them coming if there is
more to learn.
If anyone is willing to provide advice on saw blades, I'd like to learn a
bit about them to provide a multifunctional shop. Or, perhaps it would be
better for me to start another post.
Some newcomers to the RAS world will likely come on and tell you that
a "RAS blade" is necessary. There is no such animal. Shoot, back in
the day when I got mine ('72, as noted above), there was no such thing
as a "RAS blade." You got your RAS and your table saw blades out of
the same bin.
What happened was, in the '90s, blades with negative hook angles
became available (Forrest was one of the first with a negative hook
blade which was marketed as a "RAS blade"), just about the time that a
lot of people inexperienced with RASes started posting their ignorance
on the internet. Consequently, horror stories abound concerning
ripping on a RAS (a very benign procedure, if you follow directions),
and the "bite" of a RAS in a climb cut (which is its normal crosscut
procedure). Negative hook angle blades (and blades marketed as "RAS
blades") are often touted as "necessary" for successful and safe RAS
use.
However, the key to successful RAS use (especially so when dadoing) is
to learn the technique of reading the feedback your arm is getting as
you pull the carriage back for a cut and compensate for the "bite" by
reducing the pulling pressure. In some cases, you may actually
introduce some pushing pressure to compensate. In any event, it's
easily learned and is a normal part of RAS use.
That is not to say that the negative hook angle doesn't have its
place. It may very well be somewhat safer than a conventional grind
with the RAS. You will, however, give up some cutting ease
(aggression) with one, a benefit which is readily enjoyed with a
conventional blade and proper technique (as above).
When sliding compound miter saws (SCMS) came on the market, people
(likely those with no RAS experience, but plenty of miter saw
experience) started pushing the saw through the work instead of
pulling, as you would do with a RAS, which the slider emulates in many
respects. Some, new to woodworking, most likely, reverse apply the
"technique" when learning how to use a RAS after having used a slider.
DON'T!
There is one huge difference between a slider and a RAS, and that is
that the slider head (with blade) is/can be lifted above the work
table for repositioning--the RAS cannot. Therefore, to emulate a
slider, one would have to have the RAS carriage out, the work in place
behind it, then the saw fired up and the carriage pushed through the
work. I'm still not convinced that's the proper technique for a slider
(and I don't think there has been any evidence to indicate there is a
"proper technique"), but it absolutely is NOT EVER the proper
technique with a RAS.
Check with anyone who used a RAS before, say, 1980. See if anyone ever
bought a "RAS blade." See if anyone ever had trouble with or
trepidations about ripping. See if anyone ever pushed a carriage
through the work. I'm confident such a person does not exist for any
of those categories.
By the way, the acquisition of the RAS for the use you describe, is to
my way of thinking, a perfectly acceptable, even desirable, purpose.
It's one of the reasons I dislike multi use machines (ShopSmiths or
European combos). No matter what setup you have on your principal saw,
sooner or later you need to make a cutoff or rip for an extra piece of
stock or a jig. With a RAS around (and to a lesser extent, bandsaw,
miter saw, slider, etc.), there is no need to disturb a fussy set up.
Just go to the other machine and zip, zip--Bob's your uncle.
--
LRod
Master Woodbutcher and seasoned termite
Shamelessly whoring my website since 1999
http://www.woodbutcher.net
http://www.normstools.com
Proud participant of rec.woodworking since February, 1997
email addy de-spam-ified due to 1,000 spams per month.
If you can't figure out how to use it, I probably wouldn't
care to correspond with you anyway.