Flail Mower Flail mower vibration

[Robin158]

This is my final option hope someone had a great idea.

I have an OLD Flail mower, 6 foot heavy monster. Myself and my equipment shop all think it is a Mott. No serial, model or name.
Been working great up until few weeks ago. the mower started vibrating so bad i broke the belt, thows the tension wheel for the belt so hard it sticks against the stop and broke an end off one of my pto shafts. it is really bad when put in contact with the ground. it is only missing a half dozen cutter heads. everything turns freely by hand. no noticiable wobble or anything else.
equipment shop says the cutter drum must be bent so might as well junk it, to costly to replace. Hate to junk it cuz when it worked it worked great.

Any ideas ???


robin

 

[MJPetersen]

it is only missing a half dozen cutter heads. everything turns freely by hand.

The cutter drum on a flail spins fast (2500-3000 rpm) and if there are cutters missing, depending on where they are, you can have a bad balance problem. If the drum is not bent, then I would bet that is the problem.

Mike

 

[MtnViewRanch]

If the drum is bent, it can be straightened and rebalanced, my guess is that you are just out of balance because of your cutters. You may have to replace all of them to get it back to how it should be.

 

[smitty9266]

Check to make sure the mower is not tilted forward because the top link has shortened from vibration. Mine will throw you off the tractor when this happens it creates a very unhappy drive line angle and will snap u-joints. Yes I know this from experience. The mower skids should be parallel to the ground or tipped backward, never forward.

Jeff

 

[Hooked_on_HP]

Smitty's idea makes sense. You could also move some of the knives around and see if it changes the vibration.I would think if you hit somthing hard enough to bend the drum you would remember it.
Bill

 

[tommu56]

Check the drum bearings first.

Take all the blades off try running it again.

As some one else said u joint bad?

To check out of round/bent
mount a straight piece of pipe parallel (measure at each end) to drum.

Wrap tape measure around pipe and drum with a tape measure (just like measuring for a v belt).
Take a reading spin drum and read tape at the same time if reading changes then it is bent
Do it in 4 or 5 places down the drum.
The number isn't important the difference is if value go's up and down as you spin the drum then it is out of round or bent.


You could "tram" from pipe or mower frame to drum with a dial indicator but for a mower I don't think you need to,

If it is running true and is out of balance

Check with a electric motor repair shop if its out of balance.
The guy that balance's our fans at work it takes us longer to remove the doors and covers for him to put the weights on than him to balance it.

tom

 

[Eagleview]

Replace the cutters .

 

[J_J]

First, I would move all the cutters to the center, filling in all spaces, with equal distance on the ends. There should be equal cutters on each row. 20-20-20-20-20, etc. Check the bearing housing to see if loose.