# Toro Super Recycler blade sharpening



## kaptain_zero (Jun 2, 2018)

I purchased a new Toro Super Recycler this year and I have been very happy with it. There were 4 different models to choose between, the base model, the blade clutch model, the Honda powered unit and the electric start version.

I went with the base model as I discovered that the extra "fan blades" used to improve mulching are not included with the blade clutch model as there is no room. The Honda powered version didn't seem to have anything over the Toro engine, so that one was out. The electric start was perhaps nice, but..... If I can't pull the cord, would I still be capable of mowing the lawn?!?!?

Anyway, when I purchased the mower at my local Toro dealer, I elected to buy an extra blade so I can just swap them when one gets dull and not have to sharpen it right then and there. Looking carefully at the new blade as well as the one on the Super Recycler, I discovered that these are ever so carefully twisted when manufactured so the edge is not perfectly straight, but rather twists slightly. It is a subtle twist and you need to look at a new blade carefully as once the edge is ground straight, you would likely not notice. I also noticed that the tips of the blade drop slightly towards the outside, very much like gull wings on the down stroke (and I'm guessing it's done to reduce drag on the tops of the cut grass, allowing the engine to keep it's revs up, even in heavy grass).

I suspect many have just ground these blades straight and never noticed, but if you are as obsessive about your tools as I am, the delicate twist can be maintained using a fixture on a narrow belt sander and probably a bench grinder. I will try and take a photo tomorrow. It's nothing more than a piece of plywood with a "nub" on it that guides the back side of the blade, but the nub has to be offset to one side in order to make things work smoothly. It's easier to show in a picture than to try to explain with words.


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## thelawnengineer (Jul 15, 2018)

I am interested in seeing those pictures! Let me know how the sharpening went!


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## kaptain_zero (Jun 2, 2018)

I forgot all about taking photos until today..... Here's a few for anyone interested:

This shows the "twist" in the blade.



To duplicate the edge from the factory, I found it necessary to make a guide like this for my 1" belt sander.



The offset of the *nub* allows the blade to twist as you move it across the platform and being offset, it isn't affected by the cut off corner on the back of the blade. The next two images shows the grind starting at the inner end of the sharpened edge and the second shows the blade when you reach the tip. If you keep the blade touching the *nub* as you go across the edge, the guide keeps the blade at the right angle... more or less.





This is NOT perfect, but it's as close as I'm going to go, or as AVE on Youtube says.... "It's good enough for the girls I go out with". As you can see in this last image, the grind angle gets a little off towards the inside of the blade, so it's slightly steeper, maybe by 5 degrees. It's not perfect, but it should be better than just grinding the blade straight across.

I find it works just as well as when the blade was brand new. I do not make it razor sharp, butter knife sharp is plenty good. The outer tips of the blade do all the cutting, the inner part of the edges only do the mulching bit, so being a little more obtuse probably helps those edges stay fairly sharp a little while longer.



I use a 40 grit belt, but a 60 or 80 grit belt would be fine too. I would think this could be done on a bench grinder as they use the same sort of platform.

Is this really necessary? I doubt it, and I suspect that the Toro dealer would just grind it straight across as with other flat blades. But..... I fuss with my lawn..... err..... weeds, so I might as well fuss with my mower blades.


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## ctrav (Aug 18, 2018)

@kaptain_zero I have a Toro Recycler model 20340 and have never sharpened blades before. I just purchased an Angel Grinder to do the job. Do you think this will be ok? Im also considering upgrading to the Super Recycler or even the Toro Commercial. Any thoughts are appreciated!


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## dfw_pilot (Jan 28, 2017)

kaptain_zero said:


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Nice!


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## jessehurlburt (Oct 18, 2017)

ctrav said:


> @kaptain_zero I have a Toro Recycler model 20340 and have never sharpened blades before. I just purchased an Angel Grinder to do the job. Do you think this will be ok? Im also considering upgrading to the Super Recycler or even the Toro Commercial. Any thoughts are appreciated!


I use and angle grinder and have good results.


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## kaptain_zero (Jun 2, 2018)

ctrav said:


> @kaptain_zero I have a Toro Recycler model 20340 and have never sharpened blades before. I just purchased an Angel Grinder to do the job. Do you think this will be ok? Im also considering upgrading to the Super Recycler or even the Toro Commercial. Any thoughts are appreciated!


It does not matter what you use as much as HOW you use it. If you use the angle grinder correctly, it will work just as well as anything else. The regular Toro Recycler uses a flat blade, so no worries about any twists.

From what I have seen, the Super Recycler does a better mulching job than the standard steel deck recycler, but honestly, if you are following the 1/3rd rule when mowing.... I don't think there will be much of a difference between the two, if any.

I have no experience with the commercial Toro, and I see the local lawn care services on my street use regular Toro recycler mowers.

Again, regarding one abrasive over the other. be it belt sander/grinder, bench grinder, angle grinder or a hand file etc... they are all capable of doing a great job if the person wielding the tool does it right. No tool will prevent the operator from doing a bad job. A flat 45 degree bevel is all that is required (twisted in the case of the super recycler), rounding the bevel or getting it too shallow (less than 45) will result in an edge that is sharp but dulls quickly. Too obtuse (more than 45 degrees) will result in a blade that doesn't cut as cleanly, even when freshly sharpened. When I say that, I don't mean 44 or 46 degrees... that's plenty good.... you just don't want it being closer to 35 degrees or 55+ degrees.


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## kaptain_zero (Jun 2, 2018)

kaptain_zero said:


> ctrav said:
> 
> 
> > @kaptain_zero I have a Toro Recycler model 20340 and have never sharpened blades before. I just purchased an Angel Grinder to do the job. Do you think this will be ok? Im also considering upgrading to the Super Recycler or even the Toro Commercial. Any thoughts are appreciated!
> ...


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## JDgreen18 (Jun 14, 2018)

I just did this today used my angle grinder with a 60 grit disk. It worked fantastic. It is so sharp I can cut paper.


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## ctrav (Aug 18, 2018)

kaptain_zero said:


> ctrav said:
> 
> 
> > @kaptain_zero I have a Toro Recycler model 20340 and have never sharpened blades before. I just purchased an Angel Grinder to do the job. Do you think this will be ok? Im also considering upgrading to the Super Recycler or even the Toro Commercial. Any thoughts are appreciated!
> ...


Thanks for the detailed explanation on this. Much better than the guy at the Lawn store. He said my old blades were fine and that if I had them sharpened they would be too sharp. I think they are super dull! I try my best to adhere to the 1/3rd full and only get sidetracked by unavoidable reasons.

I have a neighbor who just moved in that is looking to get a lawn mower so Im fairly certain I could get $300 for mine (paid $400). Then again most of my cutting is done with my ZTR. Although the last 2 times I did the front (8k) with just the push mower because I enjoy it.


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## MichiganGreen (Aug 7, 2018)

ctrav said:


> kaptain_zero said:
> 
> 
> > ctrav said:
> ...


I wonder what he thinks would be the problem if something was too sharp?


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## ctrav (Aug 18, 2018)

He said the blade would dull faster and require more sharpening, blade would be more prone to knicks which would lead to bad cuts....

I think he was trying to get me to shy away from doing it myself since thats what I told him I was going to do. I just put new blades my ZTR and they were not sharp at all!! Someone said thats just the coating but they still feel dull to me. Oh well I will practice with the original blades and see what happens...


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## kaptain_zero (Jun 2, 2018)

The edges on a rotary mower blade CAN be too sharp! It does not cause a problem in mowing immediately as it will cut the grass very nicely, it's just that the edge becomes so weak, it dulls very quickly.

Butter knife sharp is what you are looking for, a sharper edge will just fold over and become excessively blunt in a very short period of time. There are always small pebbles, bits of dirt/grit or twigs and such, that get swirled up in the way of that blade. A razor sharp edge cannot take such abuse and will simply fold or crumble. A broadsword/butter knife edge on the other hand, has some meat behind it, and it will tolerate the abuse for some time. When freshly sharpened, the edge should not be so sharp as to cut paper unless it is rotating at normal mowing speed.

A lead rifle bullet can punch a hole through a hard steel plate, as if it were drilled, because of the speed the bullet is traveling at, not because of the shape of it's point. The same applies to the tip of a rotary blade which comes around 3200 times per minute. The tip is traveling at almost 300 feet per second! Reel mowers are very different. They work like scissors and "clip" the grass blades, so they will be honed to a finer edge. Note that they do not whirl around at high speed, so they don't kick up sand or dirt. And for those of us who had to use a push reel mower as a kid... we know all to well what happens if a twig got caught in the reel.... it just stops dead and you have to remove the twig. We quickly learned to rake up any small twigs first, before mowing! :mrgreen:


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## ctrav (Aug 18, 2018)

kaptain_zero said:


> The edges on a rotary mower blade CAN be too sharp! It does not cause a problem in mowing immediately as it will cut the grass very nicely, it's just that the edge becomes so weak, it dulls very quickly.
> 
> Butter knife sharp is what you are looking for, a sharper edge will just fold over and become excessively blunt in a very short period of time. There are always small pebbles, bits of dirt/grit or twigs and such, that get swirled up in the way of that blade. A razor sharp edge cannot take such abuse and will simply fold or crumble. A broadsword/butter knife edge on the other hand, has some meat behind it, and it will tolerate the abuse for some time. When freshly sharpened, the edge should not be so sharp as to cut paper unless it is rotating at normal mowing speed.
> 
> A lead rifle bullet can punch a hole through a hard steel plate, as if it were drilled, because of the speed the bullet is traveling at, not because of the shape of it's point. The same applies to the tip of a rotary blade which comes around 3200 times per minute. The tip is traveling at almost 300 feet per second! Reel mowers are very different. They work like scissors and "clip" the grass blades, so they will be honed to a finer edge. Note that they do not whirl around at high speed, so they don't kick up sand or dirt. And for those of us who had to use a push reel mower as a kid... we know all to well what happens if a twig got caught in the reel.... it just stops dead and you have to remove the twig. We quickly learned to rake up any small twigs first, before mowing! :mrgreen:


Thanks for the feedback - I will practice on my old ZTR blades with the new grinder when it gets in. I did pick up a Gator blade for my push mower just so I can see how it works.


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