On 12/10/2016 10:03 AM, Jack wrote:
On 12/9/2016 12:11 PM, Leon wrote:
On 12/9/2016 8:26 AM, Jack wrote:

Stick with what works. ;~) My old 1983 Craftsman contractors saw had
an industrial v-belt on it when I sold it about 16 years later and it
ran relatively smoothly.

Perhaps old belts run smoother than new belts? If my belts are anything,
they are old. On the other hand, I don't get how a belt weighing a few
ounces would make a 300-1000lb machine vibrate severely?

Think about how a 1 oz. wheel weight in the wrong place on a wheel makes
the whole car shake. Industrial belts are not as precision made and or
come in a variety of qualities, as automotive, they often have high
spots and wide spots. Automotive belts are pretty uniform in shape

Good point. On the other hand, I'm thinking about how a grossly out of
balance fly cutter on my drill press does not make my DP vibrate
severely. Also thinking about off centered turnings on my lathe. It
takes a whole lot to get it vibrating severely or at all, far more than
a lowly v-belt could possibly deliver. I'm thinking a wheel on a car is
attached to springs that allow movement, unlike a stationary tool that
is designed not to move so much. At any rate a fly cutter is grossly out
of balance vs a v-belt, or a 1 oz tire weight. Does your drill press
severely vibrate with a fly cutter?



The farther the heavier spot is from the center of rotation the more the
vibration will be amplified.

Springs on a vehicle are to absorb bumps, struts/shock absorbers prevent
over oscillation of the springs.

BUT if you have ever seen a vehicle going down the highway/freeway and
the tire is bouncing on a smooth surface that is typically an out of
balance wheel/tire along with a worn out strut/shock absorber.

AND a little known fact, most tires are checked for balanced at the
factory before they are mounted on wheels. If you look at a quality
brand new tire that has never been mounted there is almost always a
small wax spot, typically red or white, stuck on the tire near the bead
on the out side surface. That dot is the lite location on the tire. It
is to be placed adjacent to the valve stem, the heavier spot on the
wheel. ;~)



I have not used a fly cutter at all. But concerning that if you upped
the rpm on the fly cutter the vibration would be more noticeable.

But virtually all vibration disappeared when I replaced the two factory
belts with the link belts. And I might add that the vibration was not
much noticeable on the lower half of the speed range with the factory belts.

AND the link belts are intended to be used in a single direction so
I'm mot sure how that works on lathes with a reverse feature.