# Modified Fiskars FOC



## Sonoran Desert Lawn (Aug 22, 2020)

https://youtu.be/rEYq0kba4ug

Anyone have insight on how to accomplish what this video shows? I am not a pro at sprockets nor does this video give any details of materials used. If anyone can modify their manual like this, it could be a huge game changer.

I see larger wheels are added to assist in the FOC timing also.


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## kbgman714 (Apr 19, 2021)

How low are you cutting your lawn? I've used it to cut fescue at 3" with none of the lines he is speaking of. I'm presuming you are cutting lower and the bermuda is a denser turf.


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## Sonoran Desert Lawn (Aug 22, 2020)

Yeah. I am cutting bermuda at 1/2" to 1.25" at the tallest but I dont own the mower. I am mowing with a 7 blade manual Earthwise. It gets the washboarding wavy lines from 1.5 to 1 inch. Or so I hear anyways.


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## MasterMech (Sep 24, 2017)

It wouldn't surprise me if that kit costs as much as the mower itself or more.. Looks like he's had to extend the chassis in addition to adding to overdrive components. No info given outside of the video itself either.


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## frostyshake (Jan 3, 2021)

I am curious why there aren't manual reel mowers with faster reel speeds. My 7 blade Earthwise is fairly easy to push when the reel to bed knife clearance is set properly. The gearing could be changed without making it too much of a workout. I'd change it myself, but the drive wheels have the gear teeth built-in so it doesn't seem easy to do. The dream would be a chain driven manual reel mower where the sprockets could be switched out depending on the cutting height and desired frequency of cut.


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## Sonoran Desert Lawn (Aug 22, 2020)

I saw that too. I have been calculating the math. Even if one extra 24 tooth and 8 tooth are added between the factory sprockets, it should make a compound gear drive that cuts 2 to 3 times more per inch at least. It would be fun to find a cheap used mower to experiment. The below video could be replicated with sprockets. 3 to 1 ratio changed to 9 to 1.

https://youtu.be/-q5FmanzCw4

Someone with a little know how could produce something pretty good for cheap and charge Hudson Star prices. Lol


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## Sonoran Desert Lawn (Aug 22, 2020)

My 7 blade Earthwise just cant handle the thick bermuda turf. It floats too much. The floating is due to the bad design and bad FOC. The rear roller needs to weigh 20 pounds and the FOC can only be corrected if they added 20 inch wheels. The 20 inch wheels are double in size and would double the teeth, therefore doubling the speed by gear ratio.


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## frostyshake (Jan 3, 2021)

I don't have any bermuda experience, but the Earthwise cuts fine at 0.75 in for ryegrass with its current FOC. There are other ways to increase the reel speed besides bigger wheels. But yeah, no easy mods that I can see.

For the floating, you should check out the custom rollers thread if you haven't already. You can get some pretty heavy rollers that make a big difference.
https://thelawnforum.com/viewtopic.php?t=23804


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## Sonoran Desert Lawn (Aug 22, 2020)

Yeah. I created that thread. I currently use the Earthwise for my Rye overseed and my rotary for bermuda. Its hard to explain but bermuda stops the mower dead in its tracks. Rye grass is perfect for the Earthwise though. It stands tall with no lateral entanglements. I guess you could say mowing bermuda is more like mowing a net of grass rather than individual grass plants.


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## frostyshake (Jan 3, 2021)

Thinking about this more, you actually want smaller drive wheels to spin your reel faster. The setup in the video uses a huge gear ratio due to the double chains and then large wheels to slow the reel down some. You could probably get a Fiskars to have a FOC around 0.5 in using a combination of smaller wheels and larger rear sprocket. A 44 tooth sprocket adapter like this could work.https://mbrebel.com/product/410-cha...ers-30t-32t-34t-36t-38t-40t-42t-and-44-tooth/. The mower might be really hard to push though or the wheels might slide.


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## Sonoran Desert Lawn (Aug 22, 2020)

I figured I would keep the original wheels in the rear and do a thin diameter roller in the front.

The original sprockets on the Fiskars is 8 tooth and 26 tooth giving a gear ratio of 1:3.25. Any gear ratio of 1:6 or 1:9 would give a massive improvement.


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## Chocolate Lab (Jun 8, 2019)

Love this thread concept. Someone please try it.

(Still wish the Fiskars had more than 5 blades, though.)

I have an old McLane 7 blade push that I never use anymore, and it has a worn out rear tire anyway. Maybe I should try to put a smaller wheel on it...


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## Sinclair (Jul 25, 2017)

He kept saying "patented" so I checked Google patents, and he actually holds a patent on a reel mower with a chain and sprocket speed multiplier.

I can't believe USPTO granted a patent for this. It's entirely prior art...odd.


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## LawnRat (Mar 22, 2019)

I think adding an electric motor to one would be easier and much more useful than that big wheel set up. Motors run the blade at any speed you want no matter how fast or which direction you are going...makes trim work easy.

I put one on an old Scotts reel mower to test and it worked well. It would have been much easier on one of those Fiskars that come with a chain drive. I used a small old boat trolling motor that was 12v and 3 speeds...it got hot without being submerged in water, but the idea worked well. I no longer have the putting green or I'd do it again with the Fiskars and a cheap brushless RC motor or similar.


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## Sonoran Desert Lawn (Aug 22, 2020)

Patent troll. I dont see any production and Fiskars probably wont work with him to use their product.

After some more calculations...
Fiskars - 1 to 3.25 gear ratio (8/26)with 5 blades

Earthwise/Scotts - 1 to 4.38 gear ratio (13/57) with 7 blades

Mclane - 1 to 3.75 gear ratio (8/30) with 5/7/10 blades


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## frostyshake (Jan 3, 2021)

Added FOC calculation. The 10 blade Mclane would be sweet, but I'm not sure they are made any more and haven't been able to find one used.

Fiskars - 1 to 3.25 gear ratio (8/26)with 5 blades, 7.75 inch drive wheels, 1.5 inch FOC

Earthwise/Scotts - 1 to 4.38 gear ratio (13/57) with 7 blades, 10 inch drive wheels, 1.0 inch FOC

Mclane - 1 to 3.75 gear ratio (8/30) with 5/7/10 blades, 8 inch drive wheels, 1.3/0.96/0.67 inch FOC


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## Sonoran Desert Lawn (Aug 22, 2020)

Thanks for that info. Good stuff. I saw the 10 blade on ebay for 150 and 250 last year but was too hesitant to buy used. Wish I would have bought one of them.

So what would the FOC be on the Fiskars with a 1 to 9 ratio? .5 inch FOC?


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## frostyshake (Jan 3, 2021)

Yep. 0.54 inch to be precise. (drive wheel diameter)*(Pi)/(# of blades)/(gear ratio)


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## Sonoran Desert Lawn (Aug 22, 2020)

Not sure what the ratio is but this idea was already created a long time ago. 

Hudson Star with 11 blades and sprocket speed multiplier


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## MasterMech (Sep 24, 2017)

Wheel speed reluctor and a microproc (Arduino?) controlling a brushless DC motor via an ESC.

Could prototype the system with a Fiskars mower and a HD cordless drill. Decouple the chain drive from the wheels. 
Replace the trigger signal with an analog output from the microprocessor and you have FoC matched to forward travel speed. Add a control panel for the operator to start/stop the reel, initiate backlap mode, and possibly adjust FoC offset.

The reel problem however will be if it will perform nearly as well as a gas-powered reel. It's going to be 4-5x the cost of the base Fiskars and not weigh enough to power through thick low-mowed turf like Bermuda or Zoysia as well as a used greensmower would. There are now low-cost battery op reels entering the market so I'm not sure what the advantage would be to building your own.


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## Erickson89 (May 3, 2020)

I've watched this video many times trying to figure out the mechanics of it. My yard is about 6K sqft so battery options are tough (my ryobi 18v barely gets the job done with multiple 4ah batteries) so the mechanical idea is very appealing to me.

Someone who is a mechanical engineer needs to put up some designs here so the rest of us can bask in their knowledge!


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## Sonoran Desert Lawn (Aug 22, 2020)

This is the first lawn mower ever produced. This looks more quality than most garbage put out by china today. I digress, but the design is what I wanted to talk about. I have something in the works that should be similar to this design. Take a current mower and sprocket one side to the wheel at least 3 to 1 and sprocket the other side 3 to 1 to the reel.


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## MasterMech (Sep 24, 2017)

Erickson89 said:


> I've watched this video many times trying to figure out the mechanics of it. My yard is about 6K sqft so battery options are tough (my ryobi 18v barely gets the job done with multiple 4ah batteries) so the mechanical idea is very appealing to me.
> 
> Someone who is a mechanical engineer needs to put up some designs here so the rest of us can bask in their knowledge!


The problem is going to be that you are limited by the available power from the operator. Increasing the Reel speed in relation to ground speed requires more power, and make the unit harder to push, plain and simple. No powertrain overdrive setup is going to get around that.

If the goal is simply to increase FoC for better aftercut appearance, I'd try increasing the reel blade count before increasing reel speed if electric/gas assist is off the table. These manual mowers have low-count, sometimes larger diameter reels to accommodate owners that mow at 2" once a week. At some points of the season, you're cutting off 1"+ doing that. Increasing FoC at any height is going to mandate more frequent cutting.


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## Sonoran Desert Lawn (Aug 22, 2020)

I think I get what you are saying. The higher the gear ratio, the more torque required, right?


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## Erickson89 (May 3, 2020)

MasterMech said:


> Erickson89 said:
> 
> 
> > I've watched this video many times trying to figure out the mechanics of it. My yard is about 6K sqft so battery options are tough (my ryobi 18v barely gets the job done with multiple 4ah batteries) so the mechanical idea is very appealing to me.
> ...


I'm a big dude so the power issue isn't going to be a problem. I already cut my lawn 2-3 times a week as is.

Do you have any recommendations for a manual reel mower that can handle Tifway419 and TifTuf at 1-1.25 inches? Especially mid summer when it's super thick?


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## MasterMech (Sep 24, 2017)

Erickson89 said:


> MasterMech said:
> 
> 
> > Erickson89 said:
> ...


I'm a power guy myself. So I'm probably a bad person to ask about a manual reel. I'm in this thread because the mechanics of getting it to work intrigue me.

The problem on many lawns is that most manual mowers don't have enough weight to stop them from floating on a reel-low lawn. Ryegrass, Bentgrass, and KBG all get thick enough to float the mower when mowed under 1" too. Bermuda just gets that way quicker. So a powered reel solves that by adding weight and power (electric or gas) to the equation.

All of these lightweight manual mowers are intended to be operated at rotary heights but deliver better results. They aren't going to compete with a golf greensmower cutting at .500". Earthwise probably had the right idea with their 7-blade manual. It's purpose-built for what you are looking to do. I just can't guarantee it won't start floating in late July. Travis Feltner (Budget Lawns) on YT is usually responsive to questions and he ran one for a season before going to a Cal Trimmer.


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## Sonoran Desert Lawn (Aug 22, 2020)

I have the 7 blade Earthwise. It floats at .5 and I cant get the reel to scalp no matter how many passes I make. If I try to weigh down the rear roller with bricks in the catcher, it locks up in the thick turf or the tires slide. At .75 and 1" it cuts perfect but as discussed earlier, it has washboarding at .75 and below.

I believe the Fiskars and Mclane sprocket design and heavier weight may assist in carrying momentum. I feel the momentum would continue even better on thick turf if that reel is spinning 3,4, or even 5 times faster.


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## Erickson89 (May 3, 2020)

Sounds like adding the additional sprocket to increase the FOC and then adding a bar of metal on top to help weight it down even more would be a winning combo? I tend to cut in straight lines so I don't have to make turns. Any turns I usually go back over with a string trimmer to make sure I get everything.


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## frostyshake (Jan 3, 2021)

I don't own a Fiskars yet, but I'm entertaining the idea. Anyone with one know what size chain is used? I haven't been able to find a parts list for the mower. I'm looking at possible sprockets, but can't do much without knowing what the chain size is. Thanks


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## MasterMech (Sep 24, 2017)

Sonoran Desert Lawn said:


> I have the 7 blade Earthwise. It floats at .5 and I cant get the reel to scalp no matter how many passes I make. If I try to weigh down the rear roller with bricks in the catcher, it locks up in the thick turf or the tires slide. At .75 and 1" it cuts perfect but as discussed earlier, it has washboarding at .75 and below.
> 
> I believe the Fiskars and Mclane sprocket design and heavier weight may assist in carrying momentum. I feel the momentum would continue even better on thick turf if that reel is spinning 3,4, or even 5 times faster.


Adding weight to the reel would help store energy to power through each snip and add weight to the unit overall. If only I had all the time and resources to play in the garage!


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## Sonoran Desert Lawn (Aug 22, 2020)

I bought a Mclane for $10. It looks like the 5 blade model but it will do. I plan to add two more sprockets and create a spin rate around 14-25:1 (depending on sprocket teeth) on the tire rotation. This mower's bed knife can hit the dirt so it is only a matter of bringing up the RPMs. At minimum, the new rate will cut once every 1/3 an inch or .33ish". Not too bad.

The chain is a 40/41 with 1/2"pitch and a 5/8" bore sprocket. The median sprockets are what I will fabricate. It will more than like have a ratio of 40:8 then 30:8. I will keep you posted. Concept below:


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## Sonoran Desert Lawn (Aug 22, 2020)

So far I have built a sprocket stabilizer. The sprocket stabilizer takes up all slack in the chains. In the process, the stabilizer boosts a 11.67 spin rate of the reel. Overall the frequency of clip is .43". Not bad for a $10 reel mower. I will keep everyone posted.


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## Erickson89 (May 3, 2020)

Sonoran Desert Lawn said:


> So far I have built a sprocket stabilizer. The sprocket stabilizer takes up all slack in the chains. In the process, the stabilizer boosts a 11.67 spin rate of the reel. Overall the frequency of clip is .43". Not bad for a $10 reel mower. I will keep everyone posted.


Any updates on that modified McLane manual reel?


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## grumpsterfire (Jun 26, 2021)

Has anyone sourced a replacement for one of the fiskars sprockets? I just picked up a used fiskars and was looking into increasing the tooth count on the rear sprocket. I'm striking out on an off-the-shelf option.

Does anyone know where might be a good place to source these?


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