Electric conversion of a lawn tractor.

[Jags]

Thought I would introduce my new project that I have been working on. With two grand boys at home and "tractor" being a favorite word, I thought I would tackle a project with the boys in mind.

My plan is to take a small ride on lawn mower and convert it to an electric drive using a 24V motor from a reclaimed craftsman 20" push mower.

The ride on is a "Falls" brand that was made in Sycamore, Illinois. It is quite small but built of the old design where the engine belted to the transmission (3 forward, 1 reverse) and the transmission was chained to the axle (a true differential). This differs from the newer design of the transaxle found in most mowers today. This works to my advantage by allowing more wiggle room for gearing.

The 24V motor is the approximate equivalency of a 1.5 HP electric or 3 hp gasser. Plenty for ground travel with a 40 pound kid and a small trailer (I'll bet some of you are reading in to this already :coolsmile: ). The other advantage of using electric (other than the obvious) is that I can wire safety switches into any design I want.

There will be a switch on the seat (for occupancy) as well as in series to a switch on the pedal. The pedal will be configured as a "tension" pedal, meaning you push to go, not release to go(as in a clutch). As long as somebody is in the seat, when the pedal is pushed, it will start the electric motor and then as the pedal continues to travel it will engage the tension pulley to begin the forward/reverse motion. Release the pedal and everything stops. I have also considered wiring another switch to a "bumper" so if it bumps something, it will stop the electric motor.

I was originally thinking about retrofitting one of the available electric kids ride on toys, but they simply do not have the power or build to allow for a trailer, or maybe even a tiny snow plow (it could happen).

I currently plan on building a plate that will only allow the selection of 1st gear or reverse.

My bet is that the electric motor will not even grunt with my 240 pounds on it, but we will have to wait and see about that. So there is my GREEN conversion project for the cold months. Waddaya'll think? Crazy old coot - or cool papa Jags??

Edit: for a size reference, the front tires are 6" solid rubber and the engine is a 7HP Briggs, so as you can see, this is a very small mower. Also - no mowing will be involved, the deck is already in the dumpster. :lol:

 

[Delta-T]

I say cool beans, it'd be even cooler with a flame thrower on the front instead of a plow.

 

[Jags]

I say cool beans, it'd be even cooler with a flame thrower on the front instead of a plow.

Good idea but I gotta keep the front open for the feller/buncher attachment.

 

[Shari]

Well, my vote is "Cool Grampa"!

When our kids were small we inherited a Toro rider with a rear engine. Mower deck was bad, steering wasn't the greatest, only 1st gear worked - but hey, our sons had a blast riding that around the yard like a 4 wheeler!

By the way, a friend of ours has a 1970's vintage GE electric rider, original equipment electric that is... It's an interesting machine!

Shari

 

[Jags]

...our sons had a blast riding that around the yard like a 4 wheeler!

Yeah, thats kind of the same idea with this conversion. The electric motor part is just a bit easier to deal with for me because they are still pretty young. No hot engine. No flammable fuel, etc. They will be watched carefully and taught proper operation. I have even thought of how to wire up a remote shut off in case they aren't paying attention, but that might be going a bit far.

Those old electric GE tractors are quite collectible today (pretty cool in their own way).

 

[midwestcoast]

Cool project! Check out this link: http://ecorenovator.org/introducing-ecorider-riding-mower-electric-conversion-project/
searching EcoRider on the ecorenovator blog & forums will bring several more posts. I never followed the build, but the project looks to be well detailed on the posts.

 

[Dune]

Thats what I'm talking about! Good practice for your next cat-track wheel chair conversion too.

 

[Gary_602z]

What are you thinking for batteries? 6V or 12V? How many?

Gary

 

[Jags]

What are you thinking for batteries? 6V or 12V? How many?

Gary

I actually have a free source for 24V cells used in hydraulic lifts and such. I also have a couple of good 12V 78AH deep cycles from a fairly large UPS that should give a run time of approx. and hour or better. Keep in mind that this would be consistent run time. At an idle it uses NO juice. I'm thinking that after an hour of run time - I will be tired of chasing this thing around the yard. Who knows what the run time of the 24V cells would give.

Note to Jags: put a key shutoff in line.

 

[Jags]

Thanks for the link Midwestcoast. It appears that he is going a few steps deeper than I am. He actually wants a riding mower as the finished product. Looks like he is going about it in all the right ways.

 

[billb3]

If that little motor doesn't have the HP, you can always start finding golf cart parts.

 

[Jags]

If that little motor doesn't have the HP, you can always start finding golf cart parts.

And there are lots of them out there. Thought about going that route, but then you need a controller and other stuff. I am willing to bet that this motor will have more power than necessary. As a matter of fact, I may keep a loose drive belt, just for another safety feature.

One neat feature of this motor is that the way it was designed, it had a safety feature (as most new mowers do), that you had to hold a lever against the push bar of the mower for the motor to run. This is a low amp line that goes to the motor that engages or disengages the solenoid for the "real" power (high amp). In other words - light duty switches (safety switches) can run the motor.

 

[kinshipknight]

Very cool man. Let us know how it tuns out!

 

[kinshipknight]

Very cool man. Let us know how it tuns out!

 

[Jags]

Very cool man. Let us know how it tuns out!

I sure will. I should have a couple of more pics coming. I was fitting the motor to the frame last night ( I need to readjust the position a bit). I hope to get an accurate reading on the RPM of this motor to try and match the drive pulley size to be close to the original ground speed. The gasser would have run at about 3600 RPM - but I doubt if the electric runs that fast. We shall see.

 

[homebrewz]

Very cool project. You should make a video.

You could even at some point build a solar charging station for it.

 

[Jags]

You could even at some point build a solar charging station for it.

When the ROI makes sense - I will have the whole house on solar. ;-P

 

[Adios Pantalones]

It's too bad that you live so far away- you seem to have time to burn (I could put you to work building/destroying stuff for me)

 

[Jags]

It's too bad that you live so far away- you seem to have time to burn (I could put you to work building/destroying stuff for me)

Ha ha - it may appear that way, but I'm just not a very good sit-er-down-er. After I got home from work (5:30 p.m.) cooked supper, played with the boys for a bit, go out to the shop and play some more, I walked into the house at 10:00 p.m. Get up and do it again.

I got more stuff that I would like to do than the time I have left to live. I would love to get deeper into wood work, Biking, ornamental metal work, carving, and a whole host of other things. Just dealing with a 115 year old farm house and a 5 acre yard and large drive (to plow) is a job in itself. Then throw on a cabin on the Mississippi river, a hand full of old tractors (my main mower is a 1939), current hobbies, and hell...just typing it makes me tired. :lol: Its not very often ya see a half hyper dude that weighs in at 240 pounds. I should be skinny.

But I do like building and destroying stuff. :coolsmile:

 

[Adios Pantalones]

You sound an awful lot like me... only 60# more

 

[Jags]

You sound an awful lot like me... only 60# more

I feel pretty lucky that I have the facilities and equipment to pretty much get any job done that I want to. With a full shop and a whole bunch of tools at hand, I dream up all sorts of stuff to do. Then of course there is the storage of all this junk - My shed is 54x74 and just full of treasures. :cheese:. Thats not even counting the building that my shop is in (40x60) Jeesh - thats a bunch of stuff.

 

[Jags]

Moving along on the build - I ran a hand held tach on the motor. It appears to run at 2700rpm no load speed. That should work well with the ONE pulley that I have, that fits it. The original drive pulley was 2.5". The one I will be using is 3". So going from a 3600 rpm gasser to a 2700 rpm electric with this pulley arrangement should get me close to the original ground speed.

 

[Jags]

Good news - after actually LOOKING at the inline fuse - it is a 30 amp which will yield about 720 watts.

A test run has been completed. This motor has no problem with pulling a 240 pound human through 6" of snow. WHOOHOO!.
1st gear plenty of power
2nd gear - still no problem
3rd gear it worked it pretty hard in the snow, but on flat, clean ground it ran quite well.

I would guess that this is running a little faster ground speed than the original gasser, but 1st gear should be quite manageable for the young 'uns. My concern at this point is that in first gear, this thing is pretty powerful. It will pop the front wheels off of the ground slightly - if you do stupid stuff (hey, this is R&D, I gotta test it. :coolsmile: )

 

[Dune]

An ideas on range yet?

 

[Jags]

An ideas on range yet?

That will be a direct result of battery capability. I am thinking on the small side, because after chasing this thing around the yard for an hour, I will be done. I need to outlast the batteries. :lol: