Possible to stack 2 blades on a mower deck spindle?

[LD1]

I have never heard of this before. But I like the idea:laughing:

So much so that I think I am going to try it on my scag 61" today, since I ditched the regular blades and put on gators, I can run them BOTH now. Why didnt I think of that???

Anyways, my only question is the blades arent keyed or "stared" to the hub. So what keeps them in that + patter if one happens to hit something???

And Would running them like = be just as effective?

And should I run the gator on top or on bottom??

 

[JDgreen227]

I have never heard of this before. But I like the idea:laughing:

So much so that I think I am going to try it on my scag 61" today, since I ditched the regular blades and put on gators, I can run them BOTH now. Why didnt I think of that???

Anyways, my only question is the blades arent keyed or "stared" to the hub. So what keeps them in that + patter if one happens to hit something???

And Would running them like = be just as effective?

And should I run the gator on top or on bottom??

OP here, my Deere 7-Iron deck has a round flange on the botton of the spindles the blade fits over, and a bolt with a large, thick washer secures the blade. I could put a washer in the second blade center hole as a bushing, and the mounting bolt is certainly long enough to add another quarter-inch to the blade stack, but as you ask...what would keep mine in that + pattern? In an earlier post here I inquired about pinning the blades together.

Secondly, I would think blade balance would be super critical, especially if you used two different types of blades as you say you will try today. Let us know what the results are.

 

[LD1]

OP here, my Deere 7-Iron deck has a round flange on the botton of the spindles the blade fits over, and a bolt with a large, thick washer secures the blade. I could put a washer in the second blade center hole as a bushing, and the mounting bolt is certainly long enough to add another quarter-inch to the blade stack, but as you ask...what would keep mine in that + pattern? In an earlier post here I inquired about pinning the blades together.

Secondly, I would think blade balance would be super critical, especially if you used two different types of blades as you say you will try today. Let us know what the results are.

Mine dont have that flange. Both of my last two mowers did. A JD240 rider, and my JD261 RFM have that flange.

But the scag does not. It is a 5/8" hole thru the blade and a 5/8" bolt:thumbsup:

I dont see balance being much of an issue. If the blades are balanced individually, stacking them isnt going to change anything. And even if they deviate from the + configuration and more towards =, the balance wont change. But performance may???

I am still wondering weather I should try the gator on the top or the bottom???

 

[jinman]

As was mentioned earlier, the lower blade would hit an obstruction first. If that were to happen, it seems to me that the top blade might continue to turn such that the blades were no longer perpendicular. I think it would be best to have some kind of index notch to hold the blades perfectly perpendicular, but never having done this, I don't know if slippage is an issue or not.

 

[JDgreen227]

As was mentioned earlier, the lower blade would hit an obstruction first. If that were to happen, it seems to me that the top blade might continue to turn such that the blades were no longer perpendicular. I think it would be best to have some kind of index notch to hold the blades perfectly perpendicular, but never having done this, I don't know if slippage is an issue or not.

You got me to thinking and your index notch is a good idea, or perhaps you could make a square "U" shaped bracket that the mounting bolt would go thru and the bracket would keep the blades at the + position. Or perhaps those with welding skills could tack weld the blades together?

 

[LD1]

I just put mine together. I wont know how they work till later on today I might try them.

All I did was put little spot welds on the lower blade at the 4 corners to "index the top blade. They arent welded together, but the spot welds should keep the upper blade from turning too much.:thumbsup:

 

[JDgreen227]

I just put mine together. I wont know how they work till later on today I might try them.

All I did was put little spot welds on the lower blade at the 4 corners to "index the top blade. They arent welded together, but the spot welds should keep the upper blade from turning too much.:thumbsup:

With your signature line, you just HAVE to be the perfect one to try out our weird ideas...:laughing:

 

[LD1]

With your signature line, you just HAVE to be the perfect one to try out our weird ideas...:laughing:

Bingo:thumbsup:

well, I did try it out this afternoon.

I really cant comment too much because this was the first year with the mower. And thus, the first fall with all the leaves.

The grass wasnt too thick but the leaves were. And it did seem to have pleany of lift and chopped them up pretty good.

I also will note that it did seem to take a bit more to get the blades moving. Like almost stalling the motor Due to the added weight. Maybe a pair of standard blades wouldnt be so bad, but my gators are the magnums, which are thicker plus 1/2" wider.

And they sound pretty cool too:thumbsup:

Thats all I have. I will wait to make a final decision next year and see how they do.

 

[90cummins]

It does take a bit more to get them turning but nothing that will overload the engine.
As for why they don't do this from the factory my guess is that it could be liability as the discharge is faster with a lot more volume which can throw something quite a lot farther. But I also found that if the engine has the power (tractor pto) you can run it at a slower pto speed with the same or better results than a single blade and it may even save fuel??
My blades do not stay in a perfect X pattern they do move but it does not seem to affect the cut or discharge. I would not weld on a blade as that will cause a stress riser that may propagate into a crack & failure & possible injury.
I installed 2 standard high lift blades which works very good when the grass gets ahead of me and it mulches it very, very fine and the higher discharge speed/volume spreads the clippings out better.
I would install the best blades on top because the bottom blade takes the beating from rocks & such and the top blade stays sharp longer.
Balance is not an issue if they are balanced individually.
I'm quite happy with the performance of my 52 walk-behind and my RM-59.
Tim

 

[boggen]

interesting idea! double blade. my concern, is the type / grade of bolt that is replacing the original bolt if needed to mount both blades. using a cheap off the shelf hardware bolt = good chance bolt shearing off and sending both blades flying dangerous out of the deck.