Timing / Blade Positioning for Mid Mount Mower Deck

[sodak]

I changed the blades for the first time since buying a 72" Mid-Mount Mower Deck for my B3030. I wasn't paying much attention when I took the blades off, though.

Should the blades all be in the same position when you put the blades on or do they need to be timed for optimal performance? If so, what positions are best? I think I have the outside blades the same and the middle one turned 90 degrees.

I notice a streak sometimes now, but I did let the grass get too long before mowing so maybe that is just a sign that I need to slow down some.

 

[North Idaho Wolfman]

There is no "timing" of the blades.
While they are all connected together, they have the ability to spin at different rates to reduce damage from being tied together.

 

[85Hokie]

I changed the blades for the first time since buying a 72" Mid-Mount Mower Deck for my B3030. I wasn't paying much attention when I took the blades off, though.

Should the blades all be in the same position when you put the blades on or do they need to be timed for optimal performance? If so, what positions are best? I think I have the outside blades the same and the middle one turned 90 degrees.

I notice a streak sometimes now, but I did let the grass get too long before mowing so maybe that is just a sign that I need to slow down some.

Blade placement is not a concern, placing them right side up is! - Many folks have placed them upside down!

On a typical 60" deck - there are 3 blades, each blade is approx 20.5" long and in theory should hit one another, but if you notice, the spindles are offset, the middle is slightly more forward than the out 2. This way the 2 outside blades sweep will overlap the middle by just a little bit. If you turn the deck over, you will see the blades come very close to one another too!

Streaking or leaving a little row uncut sometimes occurs when you turn hard to one side or the other, this eliminates that "offset" and the blades are not overlapping due to the radius of the wheels being turned. Somewhat hard to explain, but easily seen when cutting.

Make sure the washers are put on correctly too, on most there are double cupped washers that got on cup UP against the blade!

 

[rjcorazza]

In the past I have mounted blades each 90 degrees from the adjacent blade after reading somewhere that this improves clipping flow through the deck. In the real world, the blades end up randomly positioned almost immediately upon use.

 

[bxray]

Interesting
My deck manual states that there is a positioning for the blades.

It is to prolong the blade service life.

Ray

 

[85Hokie]

Interesting
My deck manual states that there is a positioning for the blades.

It is to prolong the blade service life.

Ray

As much as that makes "aerodynamic" sense of pushing the grass out, I am with rjcorazza - after a few cuttings, them blades might not be in that perfect position .....then again, they might!

 

[JackJ]

Interesting
My deck manual states that there is a positioning for the blades.

It is to prolong the blade service life.

Ray

I interpret that graphic to show how the blades are to be moved from spindle to spindle after removing them for sharpening. I agree that I think it's to even the wear from blade to blade, serving the same purpose as rotating tires on a car.

 

[bxray]

Well I know no one hits sticks or rocks

It does say to periodically reposition them, thus they expect movement.

Ray

 

[D2Cat]

I interpret that graphic to show how the blades are to be moved from spindle to spindle after removing them for sharpening. I agree that I think it's to even the wear from blade to blade, serving the same purpose as rotating tires on a car.

I'm quite sure JackJ is correct. You place the blades on a different spindle moving them in a pattern to get more even wear. The wear is caused by the amount of grass the blade goes through before it is ejected from the mower.

Very few folks do it, but that is the way it's recommended.

 

[jpf]

I usually mow using the left side of the deck to get closest to any trees or other objects and therefore the left blade has a better chance to make contact with dirt or "stuff" so the left blade wears faster than the others that is why I rotate the blade position from left to right after sharpening the blades to even out the wear factor.

 

[Tooljunkie]

My left blade ends up over the driveway to blow clippings away from driveway. So moving blades would make sense. There were some riders that used a timing type belt with cogs. Rear discharge and counter rotating blades.

 

[sodak]

Thanks, everyone. It has rained here a lot in the last few weeks and I think the problem has to do with the fact that I let the grass grow too long and it held a lot of moisture - streaks not easy to avoid with that combination.

 

[Tooljunkie]

Thanks, everyone. It has rained here a lot in the last few weeks and I think the problem has to do with the fact that I let the grass grow too long and it held a lot of moisture - streaks not easy to avoid with that combination.

I feel for you, 9 acres and i still havent got it all cut first time yet this season. Have a pair of geese in the back, dont want to disturb them.
Always rains,when i have free time to cut grass. Never fails.