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leeave96

Deck Set-up Question

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leeave96
The manual for the Sovereign type tractors when leveling the deck says: "7. ...Continue adjusting the yokes until the front tip of the center blade is 1/8” - 1/4” (3 - 6 mm) higher than the rear tips of the side blades." Every other color tractor I have used says to pitch the front blade about 1/8 inch lower than the rear so the leading edge of the blade is cutting the grass. Why is this different on Simplicity decks? Thanks! Bill

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GLPointon
I always thought it was to maybe help the bearings by spreading the cutting load all around the blade rather than just the front of the spindles only..? IMO one of my fav lines: "Don't try to out engineer the engineers" I just do as they say...usually sm01

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DanD
I've only had Simplicity mowers, but it makes sense to me also because you'll have shorter pieces of cut grass lying on the lawn instead of longer pieces. Helps prevent thatch. Don't know if that's a reason they say that or not.

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1Litre
It is due to the mounting of most Simplicity decks compared to the rest of the brands. Simplicity mounts the deck to the front axle. When you place the tractor on turf it compresses grass and soil under the tires with most of the weight of the unit and operator . The deck is much less weight and compresses what is below much less. The result is a lower front of deck and higher rear that will level the deck or lower the front slightly . You want the back of the blades not hitting the grass a second time to keep from beating the tips into split ends. When the grass is split on the tips when cut it yellows(dries out) and looks bad which customers take as a poor cutting unit . Sharp blades,Air pressure in the tires play a big part to the quality of the finished cutting.

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MysTiK
Huh? How does setting blades higher at front translate into blades being lower at front? did I miss something? I thought you had it until that point. And I am really wanting to know this. Ragged edge tips are caused by dull blades (rip and tear) as opposed to sharp blades (clean cutting). Cleancut tips can easily seal themselves off with little or no discoloration. Ragged tips are a larger open surface area, more prone to dessication and disease entry points. Ragged edge tips dry out, leaving slightly brown, yellow, white tips - which tend to appear as excessively bright whitish "stripes", rather than light green stripes - the dark stripes show this effect less, due to light reflection, less noticeable, which is how stripes are visible anyway.(or could be actually darker, but less noticeable). Got white stripes = sharpen blades! re deck setup. still a mystery to me. 8) (frustrated) What I heard was the front cuts most of the blade, and the rear cuts final finish. This utilizes entire cutting width/depth (front to rear) of deck. Sounds like 2 cuts happening. Perhaps like "double cutting" which is done pre-tournament on golf greens = faster roll, less friction. but usually done as 2 separate passes at right angles. makes ground profile matter. also "rolling" greens is done for enhanced accuracy. The weight of the deck? it's supported at front axle, so front tires are weighted. It's supported at rear by the rollers, full width, actually very little compression. The weight of the tractor is spread over the contact patch of the "turf tires", designed to minimize compression and compaction of soil. Tire tracks are hidden behind rollers, and also offset by the air flow lift of the deck, which stands the grass up for clean cutting. This organizes the grass for the cutting, and leaves it organized after cut, enhancing striping effects, and making them last until next mow, and beyond that even. I have also considered torque reactions of the deck as the result of power inputs through belt and pulleys. I think the heavy steel shell minimizes torque effects - perhaps more of a factor on cheaper lighter decks - potential concern on future decks. The huge mass stabilizes the cutters or cutting platform, if you will. It's possible the offset tip setting offsets variations in height due to uneven ground. (again like double cutting) The setup is still not clear. and the role of the yokes is unclear. but the shape of the yokes, and forces they offer and control are somehow related to the effects of the roller as it supports the back end and rides the ground. It seems the only stationary point is the front mounts - the rest is always in motion, action/reaction.... hmmm actually the rollers themselves also stationary, unless worn. It's the yokes that are moving, perhaps in multiple directions limited by the thread-adjusts. The deck shell might be moving up, down, fore and aft. The yokes are curved, so getting a grasp on what they do is mind-boggling. I tried adjusting them after studying - it was confusing. I think understanding this conundrum is the KEY. after all this; I don't know. What manual has detailed instruction on yokes - there's the question. Or finding some article on theoretical deck design = priceless. Somebody knows this. And an entire industry is either doing it or compromising. I think Simplicity did it for real. Big secret? I have also never understood that large U-shaped bar on top, which is connected to yokes. It extends the influence of the yokes, for sure. How is it needed? Forces are translated to rear area. Then what happens. Is there a stock spec for yokes - kinda like there's a stock beginning setting for carbs, just to get started.? I don't want to out-engineer the engineers - but what did they build into this highly respected design? It's clearly visible; just can't see it. So the approach to understanding needs to change perhaps. EDIT = The entire deck is pivoting on the front mounts - everything else is fixed. So the setup is adjusting overall fixed angles. There is no other fulltime movement. It's solid and fixed at the front mount pivot. maybe that is the view. I dunno. It's complicated by roller height adjust, or is it? Roller height is also pivot on front mount. But when set, everything is solid, only front pivots in response to ground as tractor travels. So what?

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MysTiK
another view - it seems the ultimate smooth cut should be from ultimate flat horizontal blades, all at same height. Taken to extreme extremes, a tilted blade, higher/lower, front/back, left/right will tend to cause angular cuts, or rounded troughs or valleys. A 1/4" difference is near unnoticeable. So what's the significance of that setting; what's the effect of front/rear being slightly different? What is accomplished by doing that? Seems insignificant. It has to be about uneven ground. Everything else is precision controlled.

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RedbarnRick
How much difference is there overall if the center blade and arbor are say 6 inches more forward than the two side blades and arbors and you are measuring blade tips as the blades are all facing fore and aft the difference could be spread across about 18 inches I'm guessing and would probably result in a 1/16 or less difference on all the blades if set to the 1/8 minimum setting. The triangular layout of the blades adds to the length of the cutting height when measuring front blade tip to side blade rear tips. Am I thinking this right?

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