Rotary Cutter Rotary Cutter Blades

   / Rotary Cutter Blades #1  

DaveM

Silver Member
Joined
Mar 9, 2001
Messages
223
Location
Tioga county, NY
Tractor
Kubota B2710/LA402 FEL, R4's
OK, (in my best Steve Martin imitation) "I blame myself". I probably rambled on too much and then obscured my real questions even more by throwing in the multi-flora rose killer question /w3tcompact/icons/smile.gif. Although I really did appreciate those replies! So please let me try this again.

I wrote... <font color=blue> I did discover a few large stones though and these did not do
the blades any favors. Both blades now have some major "ripples" in the cutting edge. I
suspect that this season will be toughest on these blades as I cut brush for the first time.
Future cuttings will be mostly grasses and thin shoots from the roses and saplings I cut
now. If I removed the blades, could I hammer them back, more or less, to their original
shape? Should I not worry about it and continue to use them this way for the rest of the
season? Maybe get new blades next year and save these blades for future rough stuff? <font color=blue>

<font color=black>Thanks- Dave
 
   / Rotary Cutter Blades #2  
Dave, sorry about that; the board's been so slow yesterday and today that several times I've just given up and come back an hour or two later, and by then I've forgotten which messages I intended to respond to.

You might be able to hammer the blades back to near their original shape, but I doubt it. I bought a spare set of blades, take the dinged ones off, put the new ones on, then sharpen the damaged or dull ones on a bench grinder to have ready to put back on next time. When I sharpen blades, I weigh them to try to keep the weight the same to keep them in balance, and of course, I don't put nearly as sharp an edge on them as I do on a finish mower blade.

Bird
 
   / Rotary Cutter Blades
  • Thread Starter
#3  
Thanks Bird! I never lost hope /w3tcompact/icons/smile.gif and I too have noticed the board has been very slow, especially today. I think Muhammad is moving the site to a bigger/better (?) server during the next week or so and this may explain the sluggish response.

I guess I need to add a 5/8" (or larger?) socket set to my list along with a big torque wrench. Those blade nuts are way bigger than any of my current sockets!

Thanks- Dave

<P ID="edit"><FONT SIZE=-1>Edited by DaveM on 04/17/01 04:51 PM (server time).</FONT></P>
 
   / Rotary Cutter Blades #4  
Dave, I agree with Bird and add what I learned from my similar question last fall. If the blades are fairly sharp it is possible to get a nice looking cut with the right cutter angle adjustment. On the other hand, if you've got brush and small trees to cut the duller blades will work better as they tend to shatter the stumps making them less likely to puncture your tires. I've hit some good sized stones with dents in my cutter to match /w3tcompact/icons/frown.gif I've not sharpened and my cutter still does what I need it to. One other thing, from what I've heard the attaching bolts are on there "pretty ugly" so plan on a good sized breaker bar to get them off. Hope this helps /w3tcompact/icons/smile.gif

18-32437-790signaturegif.gif
 
   / Rotary Cutter Blades
  • Thread Starter
#5  
Thanks Hoosier /w3tcompact/icons/wink.gif! Those sound like some good points to know. I cut some more gnarly stuff last night and you're right, the sapling stumps were kind of pulverized! The torque specs sound pretty big to me so I think they'll be a hand-full to get loose. I'll have a breaker bar handy when the time comes.

Thanks Again- Dave

PS- The deck shows no signs of damage... so far!
 
   / Rotary Cutter Blades #6  
<font color=blue>5/8" (or larger?) socket set</font color=blue>

Dave, I'm not sure whether Bush Hog has changed any of the bolts or not, but when I had the SQ48, I had to buy a 1-5/16" impact socket - half inch drive which I had to special order since most folks who use sockets that large use 3/4" drive. I had no problem at all removing them with my impact wrench, but doing it with a breaker bar may break the bar instead./w3tcompact/icons/frown.gif Do the Bush Hogs still have the hole in the deck to insert a socket onto the nut (nut on top instead of bottom of the blade)? I know some folks who say they simply cannot remove their blades so they try to sharpen them a bit with a hand held grinder - I hate to even think of how much work that would be. Of course, the good news is that you don't sharpen them very often.

Bird
 
   / Rotary Cutter Blades #7  
Bird,

[[[ ...of course, I don't put nearly as sharp an edge on them as I do on a finish mower blade.]]]

How come this is "of course"??
I'm new to rotary mower stuff, ... always believed if you're gonna cut something - sharper is better! Not so? /w3tcompact/icons/shocked.gif

Thanks,
Larry
 
   / Rotary Cutter Blades #8  
Larry, look at a brand new rotary cutter blade and compare it to a new lawnmower blade and you'll see the difference. Generally, I'd agree with you - sharper is better for cutting, and that's what you want your lawnmower blade to do - cut. However, rotary cutters (also known as brush hogs or shredders) actually break and tear more than actually cutting. For one thing, as Rob mentioned, the duller edge will shatter a lot of little stumps, not leave as sharp a "stob" sticking up to puncture a tire, more likely to kill the plant, and to make it rot faster. For another thing, "sharper" means "thinner" edge. Every little pebble, and even some wood (limbs, saplings, etc.) will make another nick in the blade. Now if you know that all you'll be cutting is grass and weeds, then I'd say sharpen those blades down to fine edge and get a pretty job. But for general purposes, I just grind them down to an edge similar to a new blade. You couldn't cut your finger on it if you tried.

Bird
 
   / Rotary Cutter Blades #9  
The instructions with my Woods 600 BrushBull say to leave at least 1/16" of dull surface on the leading edge when "sharpening" the blades. I'd say "sharp" is a relative term when you're talking about brush cuttin'. They stressed even weight between blades much more. If you work one down much more than the other so that the difference causes a serious vibration, it could damage the gearbox. (IAW with the book) I haven't even hung it on a tractor yet - the blades still have paint on em.
mike
 
   / Rotary Cutter Blades #10  
Bird,
<font color=blue>I know some folks who say they simply cannot remove their blades so they try to sharpen them a bit with a hand held grinder - I hate to even think of how much work that would be. </font color=blue>
I just did what you describe, sharpen the cutter blade still attached to the mower. Once again, the top hydraulic saved the day. I raised the 3 pt, shortened the top link, and I could easily reach the blade to sharpen it with my hand grinder. Took about 10 minutes total. Couldn't weigh it of course so I wouldn't do that often. I have to tools to take it off so next time I'll remove the blades so I can keep the balance. My point, in case it was missed, was to sing praises to the Hydraulic T&T again!!!!

Larry...
 
 
 
Top