Understanding Induction vs. Universal Motors in Your Electric by eddaybrown

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									Understanding Induction vs. Universal Motors in Your Electric Power Tools
As a woodworker you've likely not given much thought regarding the two primary types of motors used to power your electric woodworking tools. The
differences in performance - and the number of zeros on a price tag - should have your attention. As in all considerations regarding power tools your
ultimate decision should be based on your projected USAGE. If you're a newbie just getting started then it might not be time to invest in the cast iron
induction-powered table saw. If you're running a professional shop then all six of your table saws probably have induction motors. Your duty to
yourself as a consumer is to make educated decisions. In that interest here are some of the differences between induction and universal motors...
without getting too technical and without taking a "one motor is better in all situations" stance. 1) Size and Weight Induction motors are typically
heavier than universal motors, making them ideal candidates for stationary tools that need the extra weight anyways to reduce rattling and improve
stability. Obviously at their weight and size they make poor candidates for hand held or portable tools. That's where universal motors come in to play.
Their smaller size and weight make them ideal for circular saws, bench top planers and your shop vacuum. 2) Cost Induction motors are more
expensive and found often these days in the top of the line electric power tools. They're made with more copper, aluminum and steel than universal
motors. Universal motors are less expensive and found in just bout every electric power tool known to man. 3) Speed Induction motors typically have
a slower max speed. Universal motors are only limited by friction. 4) Torque at Start Up Induction motors have less torque at start up - think of them
as "high gear" on your car or bicycle. Once they're at cruising speed they're good to go, but typically don't much like to be stopped and started
frequently. Universal motors typically have great torque at start up that get blades chewing through tough spots. They can cruise too but that leads us
to... 5) Longevity Induction motors are long-lived. There are stories of woodworkers using induction motor powered tools passed on by their
grandfathers. Universal motors are more likely to burn out in a shorter period of time. There are stories of universal motors lasting for 20 years and
more, but as a very general rule universal motors don't last as long as induction motors. 6) Noise Induction motors are quieter - far far far quieter -
than universal motors. Universal motors are widely known for their shriek and many residential areas have bans on their usage after a certain time of
day. (Note: you should wear hearing protection while using either one...) 7) Standardization Induction motors have been standardized by NEMA. This
means that it's easy to replace induction motors in your machines with standard motors from different manufacturers due to standard frames, shaft
sizes, mounting dimensions and more. Universal motors are typically characterized by their LACK of standardization, which can sometimes makes
replacement difficult. 8) Energy Efficiency Induction motors are highly efficient motors that require less amperage per horse power. Universal motors
require more amperage per horse power than induction motors. All this extra energy requirement turns into heat in the motor which will sometimes
burn them out - literally - if used for extended periods of time. 9) Application: Your Final Decider Ultimately whether you purchase a tool where there's
actually a choice between induction and universal (table saws and planers for example) you will have to ask yourself how often you'll be using the tool
and your likelihood of continuing with your hobby. Your induction motor tools will have a higher resale value if you bail out of woodworking, but will
cost you more in the upfront. Your universal motor power tools will have less of a resale value but cost less upfront. If you walk into your hardware
store with a basic understanding of the two major types of electric motors along with a firm idea of what your woodworking projects will be for the next
few years you're going to walk away with the right tool for you. And that's the most any woodworker can ask for.


About the Author
Garrett French is the Editor for ToolCrib.com. At www.ToolCrib.com you can find and compare tools, catch up on the latest topics and debates at the
power tool blog and save tons of money on power tools by subscribing via rss or email to our power tool deal of the day.


Source: http://www.articopia.com

								
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