Reel Lawn mower

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Cactus   1 µW

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Reel Lawn mower

Post by Cactus » Feb 11 2019 10:08pm

I bought an old reel type lawn mower with a gas engine. I'd like to electrify it by replacing the briggs and stratton gas engine with an electric motor, controller and battery that could last about 1.5 hours. I work with biomolecules for a living and don't know anything about electric motors, controllers and batteries or how to pair them (I know; you pair two things, not three). I have one EGO 56V 5Ah and one 7.5Ah battery, but I'd be happy to buy another battery pack that would work with a motor and controller. Any suggestions on how to pair an electric motor, controller and battery for a reel lawn mower? The mower probably weighs 50 lbs without the gas engine.

Are there scooter or ebike setups available that would work?
Thanks.

mark5   100 kW

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Re: Reel Lawn mower

Post by mark5 » Feb 13 2019 6:49pm

There's a Youtube video showing a conversion like what you want to do.

Johan grejar's Eljagaren - Electric reel mower build
https://www.youtube.com/watch?v=BeEtkvurkP4


You'll have to figure out how to couple your motor to the reel (see 0:19-0:24 & 0:34 in his video) and how to mount your motor.

Scooter motors come with or without gear reduction. With gear reduction they run much lower rpms. You'll have to figure out which type you need. I think without is closer to the gas engine.
Example 48V motors here: https://electricscooterparts.com/motors48volt.html

Cactus   1 µW

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Re: Reel Lawn mower

Post by Cactus » Feb 13 2019 7:25pm

LOL. Thanks. I am having trouble with the language. Norwegian? Swedish?
Also, I didn't want to use a heavy lead-acid battery, but suppose I could. I have a deep cycle marine battery laying around that goes with a Minn Kota trolling motor. My Tru Cut reel mower is quite a bit newer than that one, but as long as the knife is sharp and they don't rust, they last forever. I'm in Scottsdale, AZ, so no real humidity here.

Seems like I will do quite a bit of trial and error for the gear reduction to see what works best.

mark5   100 kW

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Re: Reel Lawn mower

Post by mark5 » Feb 13 2019 7:45pm

You can use your Ego batteries.

Johan grejar gave the English translation in the Youtube heading:
The texts appearing in the video:
-It all started with an old gas powered reel mower
-It was taken apart into pieces and totally refurbished
-The blades of the reel were sharpened by running them backwards against an emery cloth
-The stationary blade was sharpened on a grinding machine with a specially made jig
-A newly fabricated shaft replaced the old one
-It fits into the electric motor, which originally served as the power steering of a car
-The reel is driven by the same chain as before
-The mower is put back together
-Time to make the motor mount
-This required some thinking...
-Then pieces of sheet metal were cut and bent
-They were joined together with rivets
-Now the motor is securely mounted!
-An old car battery became the source of power
-Main switch, circuit breaker and a relay that controls the motor
-A trigger on the handle, just push it and go!
-There! Now we can mow the lawn silently and without pollution. And it's fun to use, too!

Cactus   1 µW

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Re: Reel Lawn mower

Post by Cactus » Feb 13 2019 9:26pm

Thanks.
What I am really looking for is the size of brushless motor I should use, what controller and what battery. I can disassemble an EGo battery, but I'd be happy to buy a new battery with Panasonic 18650 cells or equivalent.

mark5   100 kW

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Re: Reel Lawn mower

Post by mark5 » Feb 13 2019 10:01pm

No need to take your Ego batteries apart. Use them as-is. See Alan B's Ego battery topic.

Example motors & controllers:
https://www.ebay.com/itm/1000-W-48V-102 ... 1878201287
https://www.ebay.com/itm/48V-1000W-Brus ... 2604109673
Brushless motor example, needs brushless controller:
https://www.ebay.com/itm/1800W-48V-Brus ... 3141874590


3000 rpm is around gas engine rpm. Search ebay for "48V scooter motor" for others.

cricketo   100 W

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Re: Reel Lawn mower

Post by cricketo » Feb 22 2019 2:52am

Cactus wrote:
Feb 13 2019 9:26pm
brushless motor
Going with a permanent magnet brush motor would simplify/cheapify your setup quite a bit - brush motors can run without controllers, just on/off where RPMs are directly related to the voltage. You may think brushes are a maintenance item, but given how little use a mower is going to see (compared say to an EV), it's a good trade off.

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motomech   1 GW

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Re: Reel Lawn mower

Post by motomech » Feb 22 2019 11:03am

My Tru Cut reel mower is quite a bit newer than that one, but as long as the knife is sharp and they don't rust, they last forever.
That's not quite true.
The cutting, or " sicssoring" action is a two-part deal. One half of the "sicssors" is the bed knife, which also holds the grass blades upright and the other half is the reel, which being a spiraled helix, "shoots" across the bed-knife, cutting the grass.
Pretty much any used reel mower could use a proper grinding, which takes out the conical wear in the reel, trues it and puts the proper angle back on the blades. Any golf course would have the grinding machines, perhaps you could "spiff" the mechanic to grind your reel and a bed-knife.
Not being able to do this, you will have to "back-lap", using grinding compound, to lap the two components together. Back-lapping, never as good as a proper grind, only achieves a cut w/ contact and the "quality of cut" goes down-hill fast.
The whole idea of using a reel mower is to achieve a "clean" cut, which keep the grass blades from tearing and bleeding out the nutrients. If you are not grinding, or at least back-lapping, both you and the turf would be better off if you used a rotary mower, which the user can at least sharpen the blade.
As far as you conversion idea, I would suggest look around and see what a used electric walking mower from Toro or Jacobson are going for, they have been out for a number of years now. The battery units on those are expensive and I would think one w/ a bad battery would go cheap. Then you could get creative w/ a batt. solution.
Motomech

'03 Rocky Mountain Edge 2WD 260 Q100H frt and Ezee V1 rear 2 Elifebike 20A & 25A 9-FET controllers 12S/10Ah Multistar Lipo rear 4Ah Turnigy frt Luna Cyclops Extra lite Alex 24DM rims, Crazy Bobs run ghetto tubeless. 25 mph. Mean Well HLG-320H-54A
https://endless-sphere.com/forums/viewt ... =3&t=83430
'07 GT Idive 4 4.0, Q100C 201 14S LiPoly elifebike 9-FET 20A controller. 23 MPH.
https://endless-sphere.com/forums/viewt ... 4#p1378484

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