Shaping with a Router - MetosExpo - Free

Q & A (continued)
Ed Cowern replies: Speed controls offered for universal motors
will not work with induction motors. The speed of an induction
motor is set by the way the motor is wound (number of
magnetic poles) and the frequency of the power being used. In
most of North America, the frequency is 60 cycles while overseas
most power is supplied at a frequency of 50 cycles. Speed controls
for universal motors change only the voltage to the motor.
In induction motors, used on most fixed power tools, adjusting
the voltage will decrease the torque available from the motor for
starting but will not control speed.
The only effective way to dlange the speed of power tools with
induction motors is by changing the frequency to a different value,
and this is an expensive process. The most practical way to change
tile speed of an induction motor in a small shop is to employ mechanical
means, such as step pulleys. By using a matd1ing pair of
step pulleys on both the motor drive shaft and the arbor shaft of
tile machine, you can dloose from three or four (depending on
tile pulleys) different speeds as quickly as you can slip me v belt
from one position on tile pulleys to anomer.
[Ed Cowern is an electrical engineer and president of EMS, a
company that distributes Baldor electric motors.]
Drying spalted logs
I have a supply 0/ logs that are damp and many 0/ which
contain lovely spalted wood. Should I resaw the logs into
lumber now and stack the resulting boards under pressure to
minimize warping, or should I let the logs dry naturally first?
-Robert K Moxon, M.D., Columbia, S. C
Bruce Hoadley replies: I would end coat and then resaw the
spalted logs into slabs, flitches or boards now. Make sure to saw
me stock slightiy thicker than what's desired for use, to provide
shrinking and dressing allowances. Sawing tile logs now and initiating
drying will arrest the development of me fungi and prevent
extensively spalted areas from progressing to tile advanced decay
stage. Further, tile best pieces can be selected and given special
attention in dlying; tile badly decayed or unspalted portions can be
discarded. As with any material, stacking in well-stickered, weighted
piles will enable the most efficient drying with minimum warp.
[Bruce Hoadley is professor of wood technology at the University
of Massachusetts at Amherst and a contributing editor to FWW]
Sheet goods and formaldehyde safety
I own a small cabinet shop in western Washington and have
been building cabinets for nearly 20 years. The growing popularity
0/ particleboard sheet goods, such as Kortron and melamine,
now widely used in casework, has made me more
concerned about exposure to the formaldehyde that's said to
be offgased by these products (my customers are concerned
too). How much 0/ a health threat is there from working with
these sheet goods? -Joe Ciskowski, Eastsound, Wash.
Chris Minick replies: The subject of me release of formaldehyde
from manufactured wood products has been researdled for
years by bom particleboard manufacturers and government agencies.
A brief explanation of where tile formaldehyde comes from
and what can be done about it is in order. Formaldehyde is liberated
from me adhesive used in the manufacture of particleboard,
medium density fiberboard (MDF), and hardwood plywood during
the adhesive bonding step of the production process. Some of this
formaldehyde becomes trapped in the wood product and is slowly
released to me atmosphere over a period of several montils.
The most common human reaction to high formaldehyde levels
in the air is excessive eye blinking, eye irritation and respiratOlY
(/)
0 III
rn
• ROUTER TABLES · INCRA »
FREE OJ
CATALOG
II
»
(/)