# Reel mowers: How many blades? What are the tradeoffs?



## KarmicDebt (Jul 12, 2018)

Swardman says the following about blade count:

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The fewer blades the cylinder has, the more suitable it is for mowing taller grass. With fewer blades, the mowing frequency can be reduced. Therefore, we recommend the 5-blade cylinder for beginners who do not intend to mow as frequently. The 6-blade cylinder is suitable for those who have already owned a cylinder mower and mow twice a week. Finally, the 10-blade cylinder is recommended for high-quality cuts under 20mm with a mowing frequency of three times a week or more.
---

The engineer in me is not happy with this description. Can someone please explain WHY less blades are better for high grass? My understanding is that since taller grass is less springy than short grass, the wider gaps between blades provides more time for the grass to bounce back. Is this correct? I heard this explained once in a youtube video, but I haven't found anything documented.

I suppose more blades provides more sharpened surface area to distribute wear across; however shorter, thicker grass also provides more surface area for the blades to cut. I would think that mowing frequency should be dictated by the height of cut rather than the number of blades on the reel. I suppose you can say there is an indirect correlation in that shorter grass needs to be mowed more often to meet the 1/3rd rule and remain the same height, and since more blades is more optimal for shorter grass, more blades means you need to mow more frequently?


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## Ware (Jan 28, 2017)

The ideal cut is when Clip Rate = HOC. Toro explains it well in this document (p. 11-15).


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## Jdaniel611 (Aug 12, 2018)

If your not into reading


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## William (Oct 2, 2017)

What Ware said. It's all about HOC and clip rate.


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## NoslracNevok (Jun 12, 2018)

Thanks for the info guys, good stuff.


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## KarmicDebt (Jul 12, 2018)

Ware said:


> The ideal cut is when Clip Rate = HOC. Toro explains it well in this document (p. 11-15).


Thanks, this document was extremely helpful. I was surprised to learn this:

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If the reel speed is too fast, in relation to ground
speed, the leaves of the grass plants impacted
multiple times before being cut. This can cause leaf
tissue damage, and is detrimental to the long term
health of the turf. 
---

This is exactly what I was looking for. Now I understand the theory. It is not clear to me how to determine what the current FOC is though. However, if I understand things correctly, I should be able choose a pace that I can do consistently, start with a slow reel rotation speed and increase reel rotation speed until the cut appears to be near perfect.

If there is a better strategy, please share it.


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## g-man (Jun 15, 2017)

^ well, not so easy. The reel is turned by a gear that also turns the rear drum, so they are linked (ground speed and reel speed are tied together). Your variables are, 1) adjust your hoc to match the foc, 2) change the reel to have less or more blades (changes the foc) or 3)some rare machines you could change the gear of the drum to turn slower.

There are some electrical motor driven reel (220E) that allow to adjusting the reel speed via a pot switch.


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## Shindoman (Apr 22, 2018)

So a few mowers I'm looking at describe it as cuts per yd. or metre rather than foc. They are talking about the same thing, correct?
One says it can be adjusted with the throttle position. I'm guessing it is measured at full throttle and by backing off it changes the ratio so foc changes.


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## Ware (Jan 28, 2017)

Shindoman said:


> So a few mowers I'm looking at describe it as cuts per yd. or metre rather than foc. They are talking about the same thing, correct?
> One says it can be adjusted with the throttle position. I'm guessing it is measured at full throttle and by backing off it changes the ratio so foc changes.


Yes, in the U.S. I would convert the meters to inches. For example, the 6-blade Swardman says 72 cuts per meter. Since 1 meter = 39.37 inches, I would say it has a clip of 0.55" (39.37" / 72).

On a machine like a Toro or JD, where the drum drive is synchronized with the reel, the clip remains constant at any engine RPM. On a homeowner reel like a Tru-Cut or Swardman, the drum drive can be feathered independently of the reel. This would result in a variable FOC.


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## KarmicDebt (Jul 12, 2018)

g-man said:


> ^ well, not so easy. The reel is turned by a gear that also turns the rear drum, so they are linked (ground speed and reel speed are tied together). Your variables are, 1) adjust your hoc to match the foc, 2) change the reel to have less or more blades (changes the foc) or 3)some rare machines you could change the gear of the drum to turn slower.
> 
> There are some electrical motor driven reel (220E) that allow to adjusting the reel speed via a pot switch.


I usually do not apply power to the drum, I just push it. The swardman does have a throttle, and I have read that they actually recommend keeping the throttle pretty low, so I guess that's my control.

The question no one seems to be answering is, how do I determine the FOC?


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## KarmicDebt (Jul 12, 2018)

Ware said:


> Yes, in the U.S. I would convert the meters to inches. For example, the 6-blade Swardman says 72 cuts per meter. Since 1 meter = 39.37 inches, I would say it has a clip of 0.55" (39.37" / 72).
> 
> On a machine like a Toro or JD, where the drum drive is synchronized with the reel, the clip remains constant at any engine RPM. On a homeowner reel like a Tru-Cut or Swardman, the drum drive can be feathered independently of the reel. This would result in a variable FOC.


Oh, looks like you answered my question again Ward, thank you. Nice to know the information is out there. Now to figure out how to get data on the 10 blade reel.


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## Ware (Jan 28, 2017)

KarmicDebt said:


> ...Now to figure out how to get data on the 10 blade reel.


Their 10-blade reel is 120 cuts/meter, or 0.328".

Their 6-blade reel is 72 cuts/meter, or 0.547".

Their 5-blade reel is 60 cuts/meter, or 0.656".

(1 meter = 39.37")


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