"DoN. Nichols" wrote in message
...
On 2019-06-12, Jim Wilkins wrote:

[ ... ]

This suggests that adding a second set screw to lock the first does
help.
https://www.hobby-machinist.com/thre...-screws.36903/

What's your experience?

The web site insists that I register or log in, so I've seen
nothing of that site.

I know that in the Bridgeport spindle for R8 collets there is
one place where a dog-point setscrew is topped by a setscrew which
is
ground short enough so the Allen key can pass though the top one to
adjust the protrusion of the dog point. Then you back out the key
so it
turns only the fully hollow setscrew to tighten it to lock the other
in
place.

I also have used a square-headed setscrew over a normal setscrew
to lock it in place in the squirrel-cage blower in my furnace. That
has
worked well compared to using only the original setscrew.

Good Luck,
DoN.

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After upsizing from an L095 to an L099 Lovejoy coupler I haven't seen
any trouble. The L095 which has been satisfactory driving a log
splitter hydraulic pump for 20+ years was apparently overstressed at
the higher load service factor of the bandsaw mill. The setscrews kept
loosening and the rubber spider that connects the driving and driven
couplers disintegrated. Changing from the 5.5HP engine borrowed from
the log splitter to a 6.5HP 212CC HF Predator made it worse. That's a
very nice engine for $99, though.

The drive clutch is a belt tightener between the engine and the speed
reducer. With the engine off and clutch disengaged the belt slips but
when it's running the heavy motorcycle wheels continued to spin the
engine after shutting it off, until the new belt and pulleys wore
smooth. This reversed the direction of torque on the couplers' shaft
keys and may have loosened the setscrews.

I fixed and hooked up the (crashed) bike's speedometer and let the
wheels coast down to 10MPH before shutting off, which seems to reduce
the torsional shocks. The speedo is also useful to show the speed and
load on the blade and how far it runs before dulling. The recommended
5000 feet per minute is a little over the 55MPH line.

I don't understand why the loose belt behaves like a centrifugal
clutch that engages above some belt speed. It does this whether the
engine or the wheels are driving, but slips when turned by hand or
during gradual engagement at startup, with the engine at idle. It
seems to lock up around 20MPH wheel speed.

I didn't use a centrifugal clutch because I want to be able to
disengage the drive instantly if anything goes wrong.