6' rotary cutter blade broke off

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curtis cutter
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Joined: Fri May 18, 2012 11:46 pm
Location: Curtis, WA

6' rotary cutter blade broke off

Post by curtis cutter »

I was using my 6' rotary cutter in some very light stuff in the pasture and one of the blades broke off.

Made a mess out of the side of the brush hog as it departed. It broke where the bolt goes through (the thinnest part). Man did it make a noise and throw the unit out of balance. I do not have to remove the grass from the underside at least as it did a pretty good job of shaking it loose all by itself.
Gregg
Just let go of it, it will eventually unplug itself.
spro
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Re: 6' rotary cutter blade broke off

Post by spro »

Memorable experience, for sure. Wish I knew more about that deck without guessing. I hope the repair goes well because you're going to need it.
curtis cutter
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Joined: Fri May 18, 2012 11:46 pm
Location: Curtis, WA

Re: 6' rotary cutter blade broke off

Post by curtis cutter »

I backed it into the shop and will put it on the car lift to get to top and bottom. At first look at the attaching bolts and nuts a saw that they were welded so as to not come loose I suspect. Oxyacetylene and/or plasma cutter may be in order.
Gregg
Just let go of it, it will eventually unplug itself.
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Harold_V
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Re: 6' rotary cutter blade broke off

Post by Harold_V »

I had a small brush hog (42") that I sold because it was no longer needed. Even with both ends of the blade intact, it didn't run very smoothly. I can't imagine what it must have been like when the end broke off of yours. Dangerous tools, those brush hogs.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
Russ Hanscom
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Re: 6' rotary cutter blade broke off

Post by Russ Hanscom »

Did the blade actually break or come off? The blades are pretty tough, I cut off a fence post with mine once - quite by accident, it was bent over and hiding in tall weeds.
curtis cutter
Posts: 559
Joined: Fri May 18, 2012 11:46 pm
Location: Curtis, WA

Re: 6' rotary cutter blade broke off

Post by curtis cutter »

It separated at the point where it swivels. The weakest point as there is maybe 1/2" of material on either side when new. The blade weighed about 12 pounds so yes Harold, it shook a bunch.. :)

I found both parts and it looks to have been weakened over time and there is evidence of fresh break at about 75% of the separation point.

Having started yesterday with pulling my septic pump and replacing a float switch, it was a long day.
Gregg
Just let go of it, it will eventually unplug itself.
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SteveHGraham
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Re: 6' rotary cutter blade broke off

Post by SteveHGraham »

My bush hog has a big hole in the steel plate on the side. Those blades must move pretty fast when they cut loose.
Every hard-fried egg began life sunny-side up.
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liveaboard
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Re: 6' rotary cutter blade broke off

Post by liveaboard »

I have a dual axis one; 9' wide. when I bought it one blade was missing, broken off near the hub.
One time, I hit a heavy root and the hub broke right off; the whole blade assembly spun out from under and stopped near the ankles of the guy I was working for.

Now I've added an extra bar to each axis, so it has double blades; it works MUCH better than before, I can use twice the wheel speed now, this saves me a huge amount of time, almost an hour each time I mow.
blades + hardware.jpg
mower arm spacers.jpg
mower on edge 8 blades.jpg
mower on wall.jpg
spro
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Re: 6' rotary cutter blade broke off

Post by spro »

I suppose many are in stunned silence after seeing your deck. Totally cool in many ways. Your rebuild is first rate. I knew it was going to be awesome but didn't expect this. Thanks for sharing the larger version with us.
There are many other things which could be said or appreciated and silence isn't an answer.
curtis cutter
Posts: 559
Joined: Fri May 18, 2012 11:46 pm
Location: Curtis, WA

Re: 6' rotary cutter blade broke off

Post by curtis cutter »

Do they rotate in the same direction? How fast do you turn it?
Gregg
Just let go of it, it will eventually unplug itself.
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liveaboard
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Re: 6' rotary cutter blade broke off

Post by liveaboard »

The blades counter-rotate, it's all shaft drive so they stay in sync.
The drive shaft speed is 550 max, I run it a little under that. There are 3 gear boxes and I did calculate the final ratio when I first got the thing but I don't remember what the result was.
It's a UK made agriculture thing they call a 'topper', meant for 'topping' or rough cutting a field after grazing and/or before plowing.
Between a brush cutter and a mower, I use it for both.
It came with skids, I added castor wheels. The first ones were pneumatic tires and couldn't take the load, so I switched to little gas cylinders. Not good on hard surface but they spread the weight out nicely on my [for lack of a better word] lawn.
new LPG tank castor wheels.jpg
I cut about 1.5 acres as lawn, and brushcut around 3 acres outer field once or twice a year with the skids.
It's heavy; 500 / 600kg.
curtis cutter
Posts: 559
Joined: Fri May 18, 2012 11:46 pm
Location: Curtis, WA

Re: 6' rotary cutter blade broke off

Post by curtis cutter »

liveaboard wrote: Tue Jul 23, 2019 4:29 am The blades counter-rotate, it's all shaft drive so they stay in sync.
The drive shaft speed is 550 max, I run it a little under that. There are 3 gear boxes and I did calculate the final ratio when I first got the thing but I don't remember what the result was.
It's a UK made agriculture thing they call a 'topper', meant for 'topping' or rough cutting a field after grazing and/or before plowing.
Between a brush cutter and a mower, I use it for both.
It came with skids, I added castor wheels. The first ones were pneumatic tires and couldn't take the load, so I switched to little gas cylinders. Not good on hard surface but they spread the weight out nicely on my [for lack of a better word] lawn.
new LPG tank castor wheels.jpg

I cut about 1.5 acres as lawn, and brushcut around 3 acres outer field once or twice a year with the skids.
It's heavy; 500 / 600kg.
Does it do a good job of spreading what is cut? I like the discharge to one side as I can overlap the cuts slightly and kind of "mulch" the material. I was using it as a "topper" as you described. Hayed the 20 acre area then grazed it and was cutting down the stuff the cows were not interested in.
Gregg
Just let go of it, it will eventually unplug itself.
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