Older BR400 blower problem

bertsmobile1

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The key brole because the first time it happened it scored the shaft so the taper can not lock
he shaft will need any burr dressed off with a fine file then the flywheel & shaft lapped with some brasso .
 

StarTech

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Hi all,
After replacing the Woodruff key detailed above, the machine would not start. After two days of trying everything, I heard that familiar sound while pulling the cord....the key had broken again!!! Does anyone know what torque the flywheel nut requires, and is that maybe why the key broke a second time? I just tightened it without a torque wrench, and I'm thinking that didn't seat the key properly? Thoughts anyone?
Thanks
18.5 ft-lbs
 

Fish

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Yes, the key only keeps the flywheel in place while you tighten the nut, the taper of the shaft is what holds it into place.
 

Fish

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Here are the specs.

br400chart.PNG
 

trooper1954

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Thx guys,
Bertsmobile1, I looked carefully with a magnifying glass at both the shaft keyway,and the flywheel.... can't see any burrs or marks.
Waiting for the Woodruff keys....I ordered two this time!???
 

trooper1954

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BTW, I've heard that 1/2" torque wrenches are notoriously "out" quite a bit when set under 50ft lbs....any thoughts?
 

Fish

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Here is a bulletin
 

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StarTech

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BTW, I've heard that 1/2" torque wrenches are notoriously "out" quite a bit when set under 50ft lbs....any thoughts?
The way to know for sure is to do a calibration test. I something that I do once a year as I have found a couple of mine off by several pounds.
 

bertsmobile1

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BTW, I've heard that 1/2" torque wrenches are notoriously "out" quite a bit when set under 50ft lbs....any thoughts?
Depends upon the wrench and the way the owners uses or rather abuses it.
As a general rule you do not use a wrench in the lower or upper 10%.
Thus a 0 to 100 ftlbs wrench would only be used to torque between 10 & 90 ftlbs.
The closer to the middle the more accurate they will be.
The best are the deflecting beam and the worst are the micrometer adjustable wratchet types unless you paid a good 3 figure number for them.
 

Fish

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I just Smurf 'em down tight!!

smurf.jpg
 
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