Older BR400 blower problem

[bertsmobile1]

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]

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]

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]

Here are the specs.

 

[trooper1954]

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]

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

 

[Fish]

Here is a bulletin

 

[StarTech]

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]

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]

I just Smurf 'em down tight!!