If you have a heavier end and it is down when the blade is vertical, it won't move. If you put it upwards, it will rotate. Being horizontal, it will rotate either way. I have an 1\8 in rod protruding out of the edge of my bench that I horizontally balance the blades. It is level and plumb with the bench and works very well. A cheap cone type balancer did not work well for me, not accurate enough.
Blade-balance oddity
- Thread starter bullet bob
- Start date
- Joined
- Feb 19, 2020
- Threads
- 93
- Messages
- 11,584
Exactly you remove material on the heaviest side until the blade balances.
Here is the balance I use that is mounted on the wall horizontally.
It cost me around $100 for the Oregon version but a clone can be gotten for as low as $34 off Amazon. But I prefer to stick with the Italian made one.
And before someone asks what the rod is for it is for checking bent blades and can be use for checking for off center blades when they are short enough.
The Oregon version is a clone too. The Magna-Matic is the original.
bullet bob
Well-Known Member
- Joined
- Nov 14, 2019
- Threads
- 23
- Messages
- 179
When I balance a motorcycle tire, once it is balanced it doesn't matter where the heavy part was. I can rotate the tire to any position and it doesn't move. Figured a blade should do the same........
- Joined
- Feb 19, 2020
- Threads
- 93
- Messages
- 11,584
A completely different thing it is round object and mower bar blade are basically just a long flat length of metal.
A wheel is constant circle and gravity affects it differently for one thing plus once balance it be balanced in any position as any slight out balance is spread out along the entire circle where on a bar blade any slight out of balance is focus on one end or the other.
Personally I would just accept that this how things work and stop worrying about it. Too many other things to worry about like that we are headed to WWIII; at least we know WWIV will fought with sticks and stones if anybody is left.
The earth spins east to west and wobbles. Is also an oblate spheroid that is squashed north to south.
How often do you require your blade to be vertical.
Balance applies to the plane of rotation.Is the hole in the blade round,or star or other shape?If not round,and perfectly centered your results will not be good.Use a level to check your tester with blade attached.Mark center of the level as precisely as possible.Check left to right across blade,and end-to- end.
A single nail in a post will offset the vertical (edge-to-edge) weight of the blade and give an error.
Computer balancing machines show placement of weights on both sides of tire to balance in 2 planes .
Good luck.
The real reason why. . .
Notice your blade is NOT symmetric. It is bent in and towards the grass at the 3" long cutting edges and squared off on the "backside"-- at a different angle to the axis of the blade. This difference makes its weight different from one side(across the 2" face) to the other. So, when balanced vertically, even on a perfect knife edge, that difference pulls it easily off to one side with only 1" leverage from the center. Once started, it really moves and, I'll bet, nearly flips vertical again. If the blade had a perfect bend on both sides with symmetric cutting edges, it WOULD stay vertical.