# Planning rider mower conversion



## stefrobrts (Oct 10, 2009)

Hi, I'm hoping to get some help planning a rider mower conversion.

I come from a family of mechanics, and I have restored a couple mustangs and finished up the restoration on a 68 Corvette. I rewired my vintage Airstream trailer when I restored it, and my husband and I did the wiring for our shop when it was built. I'm pretty handy as long as I understand what I'm trying to accomplish. I don't weld, or have a machine shop, but I either have friends who do, or I know where to go to get those things done.

I currently have a 10 year old 16hp, 42" deck MTD rider mower. It has a hydrostatic transmission. The motor shaft goes straight down and has two pullys, one for the drive belt and one for the deck belt.

I mow a 2 acre pasture with this mower, and I spend more time fixing the motor every year than using it. I am curious if I can make it electric for less than the $1000 it will cost for an equivalent new mower? Mostly because it sounds like a really cool project, it would be fun to build, more fun to drive, and I think it would be great to go electric. I'm also hoping to end up with a mower that's more reliable with less to go wrong.

Any advice would be appreciated.


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## PhantomPholly (Aug 20, 2008)

At an educated guess, you could not do this for $1000. Mowing requires as much continuous hp as freeway cruising (16hp) for extended periods of time. 900lbs of lead-acid batteries will only produce that much continuous power for about 20-30 minutes (20 miles at speeds requiring that much current draw) - and you aren't about to load 900 lbs of batteries on that little mower!


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## vpoppv (Jul 27, 2009)

You might want to check this out:

http://ecomodder.com/forum/showthread.php/ecorider-riding-mower-electric-conversion-5845.html


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## PhantomPholly (Aug 20, 2008)

Interesting thread. As I surmised, it takes quite a bit of power to develop the necessary hp continuously. Also, the author doesn't really tell the actual power he is generating, so it's a bit tricky to tell whether he's generating the equivalent of 8hp or not. 

Naturally, 16hp will take twice as much power.

Well, don't let me pooh-pooh the idea. I used to use a Sunbeam electric mower on my grandmother's lawn. It was a PITA with the cord - you had to start next to the house and go to-and-fro, flipping the handle over at each end (it was designed to do that). But even directly hooked to the house it was underpowered....


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## DIYguy (Sep 18, 2008)

There are lots of ppl who have successfully done mower conversions. I haven't done any math for it, however it's worth doing some. Perhaps you wont get the two acres done in one go... but there are some options. I often cut the front yard one day and the back another even with the gas job. You could also have two sets of batteries I suppose. Depending on what you can pick up for deals, I think you could do it for well under $1,000. Golf cart components are a great fit for this job. you may have to look a bit for a suitable motor though, as most don't have a DE plate..but share the transaxle mount for the end of the motor. There are still some out there that will work.


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## stefrobrts (Oct 10, 2009)

Thanks, I really appreciate all the input. 

Mowing the whole pasture in one shot is not necessarily a requirement for the finished product. It takes so long to mow anyway that breaking it into two or three afternoons of mowing would still be a satisfactory result.

I saw that link previously and it really got me thinking this was possible. One big difference is that my existing mower has the automatic transmission, and I'm wondering if that would make this mower a poor choice for a conversion?


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## Zemmo (Sep 13, 2007)

One of the guys in our EAA chapter built this lawn mower. It has worked out really well for him. I don't know what the run time is, but I believe he is just using starter batteries instead of deep cycle.

http://www.flickr.com/photos/mbarkley/sets/72157616705485636/


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## stefrobrts (Oct 10, 2009)

Thanks, that sounds like exactly what I'd like to do. I sent him a note through flicker to find out more about his conversion.


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## DIYguy (Sep 18, 2008)

stefrobrts said:


> One big difference is that my existing mower has the automatic transmission, and I'm wondering if that would make this mower a poor choice for a conversion?


Shouldnt be a problem. Both systems (ICE and Elec) will be belt drive with similar rpm. There is a chap on this forum who has built several special purpose "lawn-mowers" ... for tractor pulling. I think you should touch base with him as he could help you a lot. His name is Jim ... let me see if I can find him for you....Yep, here u go. Jimdear2 http://www.diyelectriccar.com/forums/member.php?u=3910 Jimdear2


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## TexomaEV (Jul 26, 2007)

The motor I'm using on the 2nd Generation E-Riding Mower was custom built by D&D Motor. They specially wound a 6.7" motor for up to 48vdc, without the need for a controller. It pulls an average of 40ish amps under load (typical height grass/level ground).

The mower has performed very nicely for me, as well has the 1st Generation E-Riding mower of which I still use at my other home. It's made from a motor salvaged from an old 3wheel golf cart. It's not specially wound, therefore I always keep the blades enabled to keep a load on the motor. It runs on a 36vdc battery pack.

A member of our NTEAA club, is looking into making a kit to convert riding mowers to electric using the readily available surplus open face golf cart motors. His kit will be a faceplate that matches the bolt pattern of the original gasoline engine, that you attach the open face motor to, so that it gives the motor an output shaft and support bearing. The output shaft matches the original ICE shaft so your double pulley slides on, and mounts the same way. 

So in closing you can have a custom motor built by D&D Motors or use a surplus golf cart motor successfully. Can't say cost, as that would be something you'd have to work out with D&D or our NTEAA member.

Here's a link to the 1st Generation E-Riding Mower:

www.flickr.com/photos/mbarkley/sets/72157605907919648/

Link to 2nd Generation E-Riding Mower:

www.flickr.com/photos/mbarkley/sets/72157616705485636/

Link to an Open Face Golf Cart mower a machinist friend of mine made a faceplate/bearing support/Output shaft for another NTEAA members gokart, this shows how easily one can use these open face golfcart motors for just about anything, and they can be had for relatively cheap. Pay attention to the last 4 photos in this set of photos, as they are the ones with the golf cart motor:

www.flickr.com/photos/[email protected]/sets/72157611265229139/


Hope all this helps get you into mowing "GREEN" by next year.


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