General Information On Flail Mower Vibration - Alamo Industrial Traxx RF Operator's Manual

General Information on Flail Mower Vibration

EXCESSIVE VIBRATION
Vibration is a MONSTER and if allowed to continue unchecked, can cause the complete break-up of a machine
in a very short time.
A properly operated Flail Mower will produce very little vibration. If vibration does occur, the mower should be
stopped and the trouble corrected, as warranty does not cover failures resulting from continued operation after
something happens to cause the mower to vibrate excessively.
Vibration is caused by a rotating part which is out of balance. This could be the cuttershaft bearings, blades, or
a problem with the belt drive system.
The cutter shaft will run out of balance if:
1. Wire, rope, string, rags, etc., around the cutter shaft, are holding the knives in a folded back position.
Remove such foreign objects and be sure all knives are free to swing to the extended position.
2. Knives are missing or broken. Replace missing or broken knives.
3. Knife hanger lugs are broken off shaft. This condition usually results from continued operation in contact
with large hard objects where the knife hanger lugs themselves are hitting the hard objects. Lugs should be
replaced using arc welding equipment so as not to direct too much heat in one area of the shaft.
4. Cutter shaft bearings are worn enough to have radial "play" in them. Replace bearing and other worn parts
to eliminate "play".
5. Shaft is bent. The shafts are straight within a thousandths of an inch when they are made. It is possible that
they will become bent in use, such as if the shaft is hooked on a stump while the tractor is moving forward
at a good speed.
6. Shafts are operated at improper speed. Rotating shafts have what is known as a natural period of vibration.
The same is true of the cutter shafts on the Flail Mowers.
The actual speed at which the harmonic vibration will occur will vary with each mower and each installation. To
avoid this harmonic vibration when operating the mower, it may be necessary to adjust the engine speed of the
tractor up or down.
Some units have a harmonic vibration which occurs below the nominal operating speed. On these units, it will
be noticed that there is always a little vibration at a particular RPM as the mower is being sped up to operating
speed. This occurs as the shaft passes through its normal harmonic vibration point. As long as the mower is
operated at the proper speed, then harmonic vibration will not be an issue.
TRAXX RF 04/14
© 2014 Alamo Group Inc.
MAINTENANCE
FLAIL MOWERS
INFORMATION BULLETIN
Maintenance Section 5-31