Blade Wear Seems Odd ???

[OldDiyer]

I have a Craftsman Model 917.272452 42in deck lawn tractor and at the beginning of the season I put on a new set of blades. I did notice after cutting the lawn sometimes didn't just look right to me but went thru all the normal things, check tire pressures, reset the deck, also reset the guide wheels. As I also use the machine for snow blowing I do all the cutting setups at the beginning of the year. So back to the problem ( maybe ). When I removed the blades I saw the odd to me the way they have been cutting. Because of them being new the paint showed how they have been cutting. Seems that some parts are not even cutting because the paint is still on the parts of blades not cutting. These blades seem to have a slight pitch to them so it is hard to tell if they are bent or twisted wrong from the factory. I installed another set of blades but can't tell how they cut because I will have to wait for grass to grow some before I can tell. The set I installed are the original set and have been sharpened. Am downloading pictures : I understand the high spots but if you look to the right of the photos you will see the areas I'm thinking about. Thanks in advance for the help. Picture 1-4 and 2-3 are the pairs

 

[Rivets]

Looks normal to me. You have 3 in 1 blades and I’ll bet you are side discharging, which is why I’m saying normal.

 

[OldDiyer]

At this time I have cover on and am mulching. I only use discharge in the fall because of the leaves and than I use bagging till I get all the leaves cleaned up. But even if I was discharging why would the blades not seem to cut in some areas??

 

[Rivets]

Craftsman mower decks are not designed to do a good job mulching, they don’t have any baffles to keep the clippings in the air to chop them up fine. This will mean that areas of the blades do not show signs of cutting in certain areas. For your unit I don’t see anything out of the ordinary.

 

[bertsmobile1]

Hard to tell from that photo but to me it seems like the blades might be upside down
Double check you have them fitted the right way
Most will have "grass side" stamped into them.

And yes only the outer few inches will make contact with the growing grass.
If you think about it by the time the grass gets to the middle of the blade it has already been cut so it is only the clippings touching the middle of the blade.
We use a lot of swing back blades down here that are only a couple of inches long and bolted to a solid disc because it is only the tips that do any work .

 

[OldDiyer]

I did check and for sure the blades were mounted correctly. Guess I just never noticed this before with my other sets of blades. Seems odd that they make the blades with the longer sharpened edges that don't do anything, seems that if the blades are turning all the edges should be cutting. If you look at the pictures why would it be that one blade is kind of using that whole edge but the other is not ? Guess I just can't get my head around this but trying to understand it.

 

[4getgto]

I did check and for sure the blades were mounted correctly. Guess I just never noticed this before with my other sets of blades. Seems odd that they make the blades with the longer sharpened edges that don't do anything, seems that if the blades are turning all the edges should be cutting. If you look at the pictures why would it be that one blade is kind of using that whole edge but the other is not ? Guess I just can't get my head around this but trying to understand it.

Were these blades the same exact blade you had been using.?
I know some don't do as well as they are advertised to do..and they may on a given deck..
They (some) give them some funky name and design and claim to be the end of all blades.

 

[OldDiyer]

No these were an exact part number replacement blade set and with them next to to other set they look the same.

 

[hlw49]

Mulching blades only cut with first few inches of the blade the rest of the blade is to chop up the clippings. To do the best job of mulching you need to mow really slow.

 

[StarTech]

I see no one mention that primarily the blade tip are main cutting section of the blades. It does the bulk of the cutting so it wears the most. When mulching the rest of the blade is mostly circulating the grass clippings keeping them aloft then as they fall back down at the rear of the deck the blade tip again cuts them. And the internal sharpen edge cuts the grass but not as much, even on straight blades you will find that they wear very similarly that why when we re-sharpen blades they get tapered to the tips as we must take more off the tips to remove the blunt edge.

Now as your cutting not looking right we can't see that but if the blade tips are not meeting level at the center of the deck to can cause cut problems. As well when in full mulch mode you must cut a lot slower giving the blades time to do their job. Personally this really a heavy load on the mower.

I recently did a full mulch Toro rider and I had to nearly creep across my lawn or I would stall out the deck and sometimes even the engine. It is probably why I just don't see many full mulch mower setups here in the country. We do tend let our grass grow taller between mowings. Personally I do use standard mulching blades with discharge. It don't grind up the clippings but does produce smaller clippings. And if I mow CW most are cut a second time leaving clippings that disappear fairly quickly once they are dried. I do need to spread the center of the cut area out a little but that is to be expected.

I was to full mulch my lawn I would have do it at least every other day here too which mean I would not get anything else down as 6 acres is a lot of cutting.