Sharpened My Peruzzo Ditch and Bank Mower Today

[TerryR]

For the second time in he four years I've had it, I sharpened the hammer blades on my Peruzzo ditch and bank flail mower today. I hoped it might improve the cut a bit, and/or reduce the power requirement. If it did, it was only a small amount on either.

I'm not at all sure ordinary wear required sharpening. Some of the hammers were pretty beat up from when I was learning to set it up. I set it petty low trying to improve the poor cut quality, and managed to mow quite a few rocks (I found that wasn't the solution, which was removing the front guard). The blades are good, but no match for football-sized rocks embedded in the ground. I didn't get them all that cleaned up last time I sharpened them, but did better today.

Some here have advised removing the blades and sharpening them on a wet grinder. Good in theory, so I tried that last time. After getting modest success on 2 or 3 blades in an hour, it was clear that was never going to work. So I figured out I can hold the blades in place with a couple of sticks and some bar clamps and do a better job much quicker with an angle grinder:

Did the whole thing in maybe an hour, and did get most of the dings from mowing rocks out.

 

[1 Old Man]

Old thread, but thanks for posting the pic. I was looking for more efficient ideas.
This will work for me.

 

[RjCorazza]

Great method. When I need to sharpen my hammer blades I'll try it. I have those EXACT extended clamps, right down to the color.

 

[TerryR]

Old thread, but thanks for posting the pic. I was looking for more efficient ideas.

You're welcome. The clamps not only hold the blades, but are long enough to keep the rotor from turning as you use the grinder.

 

[1 Old Man]

You're welcome. The clamps not only hold the blades, but are long enough to keep the rotor from turning as you use the grinder.

This exactly! I've got wood clamps galore. And my rotor is free spinning, this one pic solved more than one problem. Nice solution.

Btw, did your flail initially have a scraper bar behind the roller? (or maybe it's there and I can't see it)
I ask because when mowing tank banks or fish ponds, sometimes my scraper bar gets absolutely packed with mud grass combo. I try to keep the end out of the water to prevent washing out the grease etc but
sometimes an edge will be washed out or dig into a pile of pond mud. Anyway, it takes a big ass flat head
screw driver to pry it out...even when still damp. (tried a jet nozzle too).

 

[TerryR]

No, mine does not have a scraper for the roller. It sometimes collects a little mud, but not enough to be troubling. But then I don't get near water like you do.

 

[1 Old Man]

No, mine does not have a scraper for the roller. It sometimes collects a little mud, but not enough to be troubling. But then I don't get near water like you do.

Good to know. Thanks.

 

[oosik]

Do you guys ever worry about unbalancing the unit when grinding the blades/hammers?

 

[leonz]

TerryR - did the John Deere help you with your hydraulic system problem?

What happended with your hydraulic system?

Was the issue with your mules pressure relief or the relief valve on the
flail shredder?

----============================================

Hllo Oosik,

If a single hammer knife is broken that is the time when the flail shredder
rotor becomes unbalanced and the broken hammer must be replaced before
any damage can occur to the flail shredder/flail mower rotor bearings.


With a hammer knife only the top edge is sharpened. When I last sharpened
my flail mower knives I used my WEN wet well grinder to sharpen the cutting
edge as it is a cool low speed grinding method that does not destroy the temper
of the knife.

 

[oosik]

Hey Leonz - thanks for the explanation. That can be a really lot of sharpening on some of those flails.

 

[leonz]

Hello oosik, yes it can be tedious but it's a rainy day or off season job.
Wet grinding is not hard to do as long as you have the proper knife angle
on the tool bed which for me is 37 degrees.

 

[TerryR]

TerryR - did the John Deere help you with your hydraulic system problem?

What happended with your hydraulic system?

Was the issue with your mules pressure relief or the relief valve on the
flail shredder?

Leonz,

What happened was summer -- too hot to work outside and no need to mow -- a planned cruise to Iceland, and Covid that scuttled the trip, in that order. So I've not addressed the issue.

The relief valve on the mower seems an unlikely culprit since is was sitting on my shop floor when I had the most recent issue. But taking it off did seem to greatly reduce the amount of trouble I had, so while wasn't the sole cause, it seems to have contributed to it.

 

[TerryR]

Leonz,
Your post prompted me to call my nearest dealer (30 miles away). He says the 870 isn't known for having loss of hydraulic pressure with age. He says they could test it, but only in their shop.

He suggests replacing the fluid, filter, and cleaning the screen, which I can't remember every having been done. So that's a possible issue, but the problem isn't low flow, but no flow under load. So I don't think that's the real issue unless the break-down of the fluid with age causes the pressure valve to release at too low a pressure. They want $300 to pick up and return the tractor, and probably close to that again for the fluid and labor. I'm not sure I'm up to trying to do it myself.

Most likely I'll wait until I do our fall mowing and see how it does with the relief valve on the mower off again.

 

[TerryR]

Wet grinding is not hard to do as long as you have the proper knife angle on the tool bed which for me is 37 degrees.

Leonz,

I tried wet grinding some years back after you suggested it. That was a total waste of time. Getting the hammer knives off was a real pain, with all the gunk on the threads of the bolts. Then it took forever to sharpen them with the wet grinder. After getting three or four done in an hour, I gave that up as a lost cause. The method I describe in this post worked much, much, better for me.

 

[aesanders]

I’m sure wet grinding is way better in theory, but as tedious as that sounds, I’d likely never do it. Terry’s methods looks like something I wouldn’t mind doing when I do add one of the ditchbanks to the stable.

 

[TerryR]

I’m sure wet grinding is way better in theory...

No doubt that's right. Using an angle grinder does run the risk of overheating the blades, so you have to be careful.

But removing 100 or so blades and sharpening them on a wet grinder, which is by nature very slow, I found was just not workable.