Lawnmowing: manual and electric powered

[amberwolf]

Yard care is different in the soutwest eh?

Yeah, you wouldn't know anything about that, would you? :lol:

Here in Phoenix, you either have to have gravel, rock, or grass (or artificial turf); plain bare dirt is theoretically not allowed (although there's plenty of it despite that). Since I'm renting I do have to take care of the lawn and stuff; it's part of the lease. I don't do as good a job as I should in keeping it growing, because I can't really afford that big a water bill. I concentrate on the trees and on the areas where it will help keep the yard and house cool the most.

The dogs prefer the grass, of course, but they actually don't like it after it's been cut; they want it at least 8 or 10" high, and 6" is the max allowed. Since I can't always keep up with it then it tends to get up to that 6" in the shaded areas most of the time. Sometimes it gets worse, when I am sick or working the wrong hours to be able to do it when it's survivable :lol:, or when all of the lawncare tools are down at the same time.

Most of the AC units here are on the roof, where there is zero shade to cool them. Mine's on the ground in the "nook" at the north wall but towards the west end of the house--one of the hotter parts of the backyard, until we started growing a big shade tree to cover both it and the swamp cooler, which it is now getting big enough to do.

 

[John in CR]

I've gotta get one of those hover mowers. After reading reviews of the FlyMo Turbo 400 - http://www.amazon.co.uk/product-reviews/B0001IWHRU/ref=dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1

They seem to be a UK thing, so I need to get creative to get one here, but it seems worth it. I can cut earlier in the am before the sun gets so strong, and no worries about wet, which currently delays my cutting resulting in way too long and real pain in the ass grass to cut. Rolling on wheels really sucks this time of year.

John

 

[Harold in CR]

Hover mowers were in use in the 80's-90's. Had a fiberglass square dishpan, it could cut on hillsides, also.

I have a Shindaiwa Weed Whacker. Engine is toast. Needs a new cylinder for $75.00. I want to convert it to battery. How long do you guys get to cut on a full charge, and, what capacity Battery pack ?? Lithium, NiCD, ??? Figure a back pack and styart on top of the hill, working my way down to the creek. Then, go to the house

 

[amberwolf]

Using the little Johnson Controls brushed motor it came with, my Ryobi cordless weedeater ran about 20-30 minutes on a 12V7Ah SLA before it would begin stalling on grass blades.

Ran lots longer on a car battery on a pull-cart, but I eventually overheated the motor and damaged it from running it too long under heavy load (it isn't meant to mow whole lawn, much less in one sweep!).

So I'd guess it partly depends on what motor and controller you use to replace the engine with, and what type of battery, as to what capacity you'll need. Just like an ebike. :lol:

If you wanna go high-voltage, you could use the universal or the PMDC motors out of other weedeaters that run on AC power, or out of a drill, or a vacuum cleaner. They'd all need whatever your line voltage is to run at the right speed (as fast as possible).

To stay low voltage you could go with RC motors, I suppose. Or cordless drill motors.

 

[John in CR]

If 3krpms is a good speed then the 24v DeWalt motor I have from a cordless circular saw should be just the ticket....Nice and light but pretty noisy since the motor turns at 20krpms or so, and is geared down. It's fan ventilated, which should help it hold up, and the robot war guys report 2hp at 24V, which should be more than sufficient for a weed wacker. Guessing at a 1/2hp avg draw while in use, that's 3 hours of cutting with a 1kwh battpack on your back.

Hmmm, I've got a 26V Konion pack perfect for a good hour of use unused and ready to go, so maybe I shouldn't be so quick to give away that motor. Nah, it's to noisy for me, so you're welcome to it.

John

 

[Harold in CR]

John. Sounds like a deal. You have enough of those "other" cells, that I might make a decent pack to run that motor ?? I wouldn't have thought that a saw motor could run long term ??

 

[amberwolf]

Keep it cool and any motor can keep running as long as you like. Well, if it has brushes you may have to stop sometime to replace them.

 

[John in CR]

Those motors have little fans in them to help keep them cool. That's the only reason such small brushed motors can run at such high power. In this implementation you should open up the air slots in the plastic cover for improved airflow, since it won't be down next to the blade of a circular saw sucking in sawdust.

Re my runt cells, I don't have as many as before. I'm sure they'll run it, but no telling for how long till Harold goes through them.

 

[Hyena]

I've got a mate who's looking at buying a few of these types of mowers and starting a small "green" grass cutting business

http://www.victa.com.au/index.cfm?p=9592516C-6FBA-42E8-845AB0A16B50058D

He's asked me for help to upgrade the batteries which I can do but I'm not sure about the motor. He was eyeing off a 20" hub motor I had but I dont think they'd spin fast enough to efficiently cut grass. He mentioned something about 3000rpm which you also also said John but this not in the realm of normal hub motors. I suggested if he wanted upgraded motors he try running the "24v 500w" motors on 36v and see how they go. I havent had a look inside one to see if they use a controller but I imagine they wouldn't really need one - a simple on off switch should do the job.

If he didnt want to mount the batteries in the mower an 8S lipo 'bat utility belt' would be 4TW :lol:

 

[amberwolf]

If you run into one, a 4-pole powerchair motor probably runs around 3000-3600RPM, minus the gearbox. Ones like mine can be run without the gearbox; the shaft is not part of the gearbox (unlike the 2pole versions I've seen so far). But since the shaft is not very long, only about a centimeter, you'd need to keep whatever original driveshaft there is for the blade and devise a way to connect the two shafts. At 24V, you'd have around 650W with the motor off my CB2, for instance, at that RPM.

It's kinda heavy, though, because it's designed for continuous use at full power. No controller needed, since it's brushed.

Then there are the pancake axial-flux 4pole brushed radiator fan motors I used on DGA's friction drive, which I think were the same speed (@24V, around 1500RPM at 12V), but probably significantly lower total power. Uses a D-shaft with a threaded end for a nut to hold the fan on.

 

[Harold in CR]

Doesn't those radiator fan motors use a lot of ahrs ?? Seems I read somewhere, someone was testing them under a load, and the amps were higher than other motors of the same voltage-wattage ?? Is this possible ?? Maybe efficiency wise ?? Is a hvy duty motor less efficient than a moderate duty motor ??

The weed whacker has a splined shaft that fits into the clutch mechanism on the gasoline engine. I haven't torn all that apart, yet. I have E&J wheelchair?? motor, 36V. I have a trolling motor. When I get that one from John, I will have some testing to do.

The Weed whacker has a bevel gear setup at the end of the shaft tune. That, I have put new gears and bearings into. One day, I will weigh the motors and engine, to see where I am. It's very steep where I need to use this thing. I can kill off the tough tall grass. Then, keep the weed type stuff whacked down, until I decide if I want to mess with a couple calves and a milk cow.

I'm NOT going to be doing the milking. Been there, done that at 60 head at a time. NADA MAS.

 

[John in CR]

I thought about using my trolling motor for a waterproof bike, but decided against it for thermal reasons. You'd think the design takes advantage for the motor being submerged, so running in air for an extended period may overheat and kill it.

 

[Jay64]

I just stumbled on this thread, read the first page, but gotta run to work, so I don't know if this was mentioned in the following pages. I sell lawn mowers. We have the black and decker version of electric mowers. I saw mentioned on here that some of you have the 24v version. I want to also point out that they now make a 36v version, just sold one the other day. And the price is only $50 more then the corded version. You would pay more then that in a good gauged outdoor electrical cord, so it is actually cheaper to get the cordless version if you don't already have a good cord.
I have some dads come in and buy the reel mowers to make their kids use while they are grounded. They get to use the regular mower when good, and have to push the reel mower for punishment. I always crack up on that one.

 

[veloman]

I looked at an older McClane reel mower and it worked horribly. The grass wasn't that long, but I guess it was kind of thick. It couldn't go more than 5ft without jamming up.

I watched some videos on the Scotts Classic mower - it looked to work really well. Please tell me there is a reel mower that actually works properly in normal grass!

 

[amberwolf]

Doesn't those radiator fan motors use a lot of ahrs ?? Seems I read somewhere, someone was testing them under a load, and the amps were higher than other motors of the same voltage-wattage ??

If they are brushed 4-pole motors, they will use more current than a (otherwise identical) 2-pole motor because they have twice as many windings active at once, but they also have twice as much torque (assuming the same winding otherwise, same diameter wire, etc). Remember also that they were designed to spin at very high speeds without much of a load on them, so when you bog them down with a heavy load and don't let them reach the RPMs where backEMF goes up, they will naturally have higher currents flowing than a motor designed to run at the lower speed with that load, which will have a higher backEMF at that speed, and lower currents.

If they're brushless motors then the latter part still applies.

The weed whacker has a splined shaft that fits into the clutch mechanism on the gasoline engine. I haven't torn all that apart, yet. I have E&J wheelchair?? motor, 36V. I have a trolling motor.

I don't know what speeds those motors were made to run at; you'd have to either check their specs if any, or use a tachometer to measure.

The Weed whacker has a bevel gear setup at the end of the shaft tune.

If yours is like my older Ryobi electric, that shaft is flexible rather than solid, and sits inside a ton of grease inside the pole. You can lighten up the whole thing if there is any way to put the motor down at the far end, but you then have the issue of balance (although you can put the batteries where the gas motor was to help that out, depending on their weight).

Please tell me there is a reel mower that actually works properly in normal grass!

AFAICT, they're like electric shavers--only meant to keep the stubble trimmed. :lol: Can't do the job of the shears, equivalent to the other types of mowers. Now, they do fine as long as the blades are super sharp, but that doesn't last very long in any of them I've used, because the blades are just steel, and usually not hardened, at that. So they don't hold an edge, opting for brute force over cutting edges, just like the other mowers.

 

[zap]

Please tell me there is a reel mower that actually works properly in normal grass!

Even more important than sharp blades is "tuning" it up correctly... mostly setting the correct distance between the reel and the cutting bar. Even fairly dull blades will cut long grass pretty well if everything's set right.
[youtube]4xjt7zuCg7g[/youtube]

 

[veloman]

So I got a corded electric mower for $40 yesterday. It works great, with the exception that it is a pain to manauver with the extension cord. I plan to make a sort of retractable reel for it so that it will always keep the cord tight, and off the ground.

I'm also looking at this $30 battery electric mower someone has on craigslist. I'm certain it will need new batteries, which will run about $75 shipped for two 12v 17ah SLAs. Or if it's 36v, I can use my ebike battery pack!


The thing is, I can cut the majority of the lawn that is near our house really quickly, so I don't think I will have a problem with range. I can complete everything in the "obstacle laden area" within 30 minutes. I still have a huge far-backyard to cut, so that will be an engineering challenge if I want to completely avoid using the ICE tractor mower. That grass grows really fast and thick too.

I'm still looking for a cheap Scotts Classic reel mower in my area, but no luck so far unless I want to drive 80 miles rountrip (defeats the purpose of a reel mower - kind of). They are going for $75 shipped, new, on ebay though. I might just do that. I REALLY want to try out the reel mower since it's so lightweight and should be even faster due to the better manauverablity.

It was GREAT to cut grass for the first time with the electric mower though! So quiet and light, no smelly exhaust.

 

[TylerDurden]

Scotts are junk IMO. I've given two away, just to be rid of them.

This is the only type I have found worth money:

http://www.reelmowersetc.com/silent_cut_18_reel_mower_for_upright_grasses.htm

Mine were branded Agri-Fab.

 

[TylerDurden]

more info here:
http://www.peoplepoweredmachines.com/

 

[veloman]

Scott's are that bad? I was watching reviews on youtube and came to the conclusion that they would work the best over the most lawns. I was just about to buy one on ebay for $70 shipped... not worth it?

Well, 400/500 or so reviews on amazon were good, and for $64 shipped, I'm giving the Scotts a try. There's nothing for sale on CL around here than isn't ancient or overpriced. The Silent Cut types are just too much of an investment (new) for me right now. I cut a sharpening kit for $8 on ebay too.

I did just snag a cordless B&D 24volt rotary mower from CL, for $30 tonight. I'm assuming it needs batteries, but the guy didn't seem to know much about it.

I feel like I won't have much need for the corded mower I got, with these other two, but they were all so cheap I'll test them all out for a while.

 

[dogman dan]

Go for the 24v mower and lipo it.

Reel mowers can work great, but they have to be adjusted right. Set right they almost sharpen themselves, Set wrong they get duller and duller and jam a lot. I used to mow a golf course with a tractor that had 12 reels on it. Maintaining those reels was nearly as much time as the cutting, but they were getting a years use for a house every week. Set right, you hear a nice snick snick sound as the reel swipes the bedknife, too tight and it rubs too much. Too loose and it jams instead of cutting. Typically it gets real hard to get all the blades on the reel to fit. One high one will cut while the others that are low jam up. If a reel mower gets wonky, it takes a lot of work to get it to cut even without special sharpening tools.

 

[veloman]

I got the Scotts today and used it tonight to cut a fair bit of my lawn, which is very thick (not overly tall). On the high settings it's easy as heck to push, but it does take some effort on the lowest setting, going through the thick 4" tall grass, no complaints though.

I suspect the blades will need sharpening more often then I'd like though. I'd love to be able to use a reel mower in such a small-scale lawn cutting business, but I'd probably need to sharpen every week. I don't know how it would turn out long term.

Next on my list is the get the 24v rotary mower running. Lipo would be nice.... it's even nearly comparable to SLA in price (excluding charger/balancers). Do you think I could run that 24v mower with my 36v Fatpacks?

 

[dogman dan]

That's something I'd like to know too. Right now I have good sla batteries in my 24v B&D. But they sag like hell long before I mow the whole lawn. Adding an 8 ah nicad pack in paralell helps, and adding 16 ah of nicad kicks butt. But by then I'm pushing a pretty heavy mower. I figure to use the slas for the rest of this year, and then at least convert it to the nicads for next season. The cheapskate in me just had to use the sla's for awhile, rather than just get rid of them now.

I'd love to just put 10s lipo (36v) on the thing, but I'm not exactly clear if the electronics inside could handle it. Looking inside I see a charger, but nothing that is obvioulsy a controller, and there is no throttle. I think it might be a brushed motor and an on off switch, but I'm not positive of this.

 

[dogman dan]

For the scotts mower, keep your bedknife adjusted on the tight side, and it nearly self sharpens. You want the reel to rub the knife just enough to feel it, but not so tight it's really hard to turn. If the reel spins too freely, then you start getting dull blades a lot quicker.

 

[gogo]

I suspect the blades will need sharpening more often then I'd like though. I'd love to be able to use a reel mower in such a small-scale lawn cutting business, but I'd probably need to sharpen every week. I don't know how it would turn out long term.

With reel mowers its more a matter of maintaining the the distance between the reel and the bed knife than "sharpening". I left a cheapo Lowe's Task Force out in the snow last winter and what ended up happening is the corrosion grew into the places that had larger tolerances between the reel and knife bed. It cut better than when it was not corroded. What you're actually doing when you "sharpen" a reel mower is grinding off the high spots to make a more uniform tolerance between the reel and knife bed. The way to dial in the adjustment is to take a piece of printer paper and tighten the tolerance to the transition point of where the paper gets bent over to where it gets sheared clean. Cheaper reel mowers don't hold the tolerance as well.

I like the results of mowing with a push reel mower but while using it I keep thinking about making it powered.