EcoRider - riding lawn mower electric conversion - Page 7

Tango Charlie · 06-01-09, 01:51 PM

Good stuff, Daox!
Sounds like a good excuse to take a break while mowing the yard.

Hugh Jim Bissel · 06-03-09, 03:20 AM

Quote:

Originally Posted by Daox

I'll also have brakes then!

Brakes? Ya don't need no steenking brakes! Thats why its got a bumper!

In other news, the mow in 2 cycles sounds like a good plan until you figure out what you want to change. It looks like 1/2 at a time was your original plan/hope anyway. But if you decide to go for broke, Sydney or the bush; then you could pull a small trailer with batteries in it perhaps, or (hard to tell from the camara angles) looks like there's room to hang a battery (or two?) from either side of the frame, over top the mower deck, just in front of the rear wheels; this assumes your legs rest in a position thats high enough to clear them.

Daox · 06-03-09, 07:39 AM

After thinking a while, I have a few ideas.

1) Rebuild the mowing deck. It just seems to be sucking up way too much power. Clean up the bearings, repack them, adjust anything that needs it and tighten it all up. Heck, the thing is almost 40 years old! Sure can't hurt.

2) Play with voltage. Possibly go to 48V. I'm not really sure I want to do this though.

3) Like Jim said, tow a trailer with batteries. The previous owners of my house were kind enough to leave me one actually, so this isn't a bad idea! But, this wouldn't allow me to use it for other things like yard work... trade offs, whatcha gonna do?

4) ? Still thinking.

jwxr7 · 06-04-09, 12:21 PM

Nice work so far!

It seems V-belts aren't the best for efficiency. You could try cogged v-belts. I think they are less lossy because they bend nicer around smaller pulleys. I was able to use one on the deck (the belt under the cover running the spindles) of my simplicity like yours.

Hugh Jim Bissel · 06-04-09, 09:40 PM

Quote:

Originally Posted by Daox

...But, this wouldn't allow me to use it for other things like yard work...

How is the trailer set up, is there "wasted space" that batteries could go? For example there's a small landscaping trailer (prob 3x6) at work that has the bed completely over top of the tires. This leaves close to a foot to hang batteries underneath.

Could you put the batteries in the bed of the trailer and put a platform over top to use the trailer for other stuff too? or down both sides and leave the middle and on top of the batteries?

Or have the smaller batteries onboard to pull the landscaping trailer, and make/buy/scavenge a second trailer thats just a frame for all the batteries you need for mowing. Then, if one set of batteries isn't enough to do the lawn, you could eventually set up 2 battery trailers and swap halfway through...

Daox · 06-08-09, 04:30 PM

I don't think there is much room to spare in the trailer. Its a pretty narrow, all metal trailer. I'll take a look at it again though. I've never used it.

Daox · 06-08-09, 04:42 PM

I finally got to bring the mower to the Milwaukee electric car club's EV build day. I got another member to come to my house and pick it up with a trailer to bring it down to the build day.

I talked with the guys about my problems and we all agreed the deck should be looked at. So, we removed it and found that at least two of the three spindles bearings that should be replaced.

We got the deck off the mower, and tipped it up to get a better look at the bottom to see what kind of adjustments I had. One of the guys thought I could adjust the drive belt so I might not need a new one. He adjusted it and thinks it might work just fine now.

With the deck off, I set about taking it apart. I took the top covers off and found tons of grass clippings stuff around the pulleys and belt. It was a real mess. This picture is after I cleaned a good deal of it all up already.

Another good idea that one of the guys there had was to get a cogged belt for the deck. The cogged belts can more easily bend around tight radii and thus less power will be spent. This should lower my amperage at least a bit.

After it was all said and done, the entire deck was take apart. I have the bearings and will be stopping by a local bearing shop to find something to replace them with.

There was also much talk about battery configuration of the mower. I mentioned that I had run it at 36V and it pulled 100A. The pulleys are a bit large at that voltage. If I went lower, the pulleys would be sized pretty much perfectly, so 24V is kind of looking like what I am going to go to. One of our members works at a golf course, so I am going to contact him and see what the possibility is of me getting four 8V batteries.

I also cut a few more slots for the motor into the frame. Unfortunately, my bolt circle is off, and the right side bolt is going to be a small notch in the frame rather than a slotted hole. Oh well, I think 5 bolts will hold!

MetroMPG · 06-08-09, 04:56 PM

Quote:

I mentioned that I had run it at 36V and it pulled 100A. The pulleys are a bit large at that voltage. If I went lower, the pulleys would be sized pretty much perfectly, so 24V is kind of looking like what I am going to go to.

Can you explain what you mean here? Are things turning too fast at 36v because of the pulley size? How did that conclusion get made?

Daox · 06-08-09, 05:01 PM

The motor is rated for 3200rpm @ 24V. At 36V, the motor will spin proportionally faster, so 4800 rpm. I sized my pulleys the same as the original gas engine. According to reading and talking with people, most small engines run 2500-3400 rpm (feel free to correct me here, I haven't got anything incredibly solid). So, if I drop back down to 24V, I should be right in that range. Otherwise, I am going to need smaller pulleys to get the drive and mower deck speeds back down.

cgates30 · 06-09-09, 08:00 PM

Great thread. This is exactly what I'd like to with my Yard Bug mower. It's a sit over the motor rig with room for a grass catcher under the seat too. I'd like to put the batteries where the bag would normally sit.

It looks like my system is a 2 belt system, one belt driving the blade and the other driving the transmission. So, if I can swap the gas engine with an electric motor (and the motor rpm is similar to the gas engine) then it seems like it could be a nice conversion. I'm also assuming I don't need a motor controller since speed is normally zero to slow. I'm not really familiar with contactors, but my understanding is they're a physical connection in the line completing the circuit between the battery and motor.

I need to find a good source for a 24-48 V motor that spins in the 3500-5000 rpm range. I figure I'll also look for 2-4 deep cycle 12 V batteries, contactors and cables. Installing the batteries shouldn't be a problem since I need to build a tray that sits over the deck/under the seat.

Would a golf cart motor be a good candidate?

Am I missing something, or would this work? A motor controller would be nice so I can vary speed, but then my blade speed would vary too. 2 motors would be nice, but then things start getting hard to write off under the 'hobby' budget.

06-01-09, 01:51 PM	#61
Tango Charlie Minister of Silly Walks Join Date: Nov 2008 Posts: 32 Thanks: 0 Thanked 0 Times in 0 Posts	Good stuff, Daox! Sounds like a good excuse to take a break while mowing the yard. __________________ -Terry

06-03-09, 07:39 AM	#63
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	After thinking a while, I have a few ideas. 1) Rebuild the mowing deck. It just seems to be sucking up way too much power. Clean up the bearings, repack them, adjust anything that needs it and tighten it all up. Heck, the thing is almost 40 years old! Sure can't hurt. 2) Play with voltage. Possibly go to 48V. I'm not really sure I want to do this though. 3) Like Jim said, tow a trailer with batteries. The previous owners of my house were kind enough to leave me one actually, so this isn't a bad idea! But, this wouldn't allow me to use it for other things like yard work... trade offs, whatcha gonna do? 4) ? Still thinking.

06-04-09, 12:21 PM	#64
jwxr7 Apprentice EcoRenovator Join Date: Dec 2008 Location: mid michigan Posts: 191 Thanks: 0 Thanked 0 Times in 0 Posts	Nice work so far! It seems V-belts aren't the best for efficiency. You could try cogged v-belts. I think they are less lossy because they bend nicer around smaller pulleys. I was able to use one on the deck (the belt under the cover running the spindles) of my simplicity like yours.

06-08-09, 04:30 PM	#66
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I don't think there is much room to spare in the trailer. Its a pretty narrow, all metal trailer. I'll take a look at it again though. I've never used it.

06-08-09, 04:42 PM	#67
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I finally got to bring the mower to the Milwaukee electric car club's EV build day. I got another member to come to my house and pick it up with a trailer to bring it down to the build day. I talked with the guys about my problems and we all agreed the deck should be looked at. So, we removed it and found that at least two of the three spindles bearings that should be replaced. We got the deck off the mower, and tipped it up to get a better look at the bottom to see what kind of adjustments I had. One of the guys thought I could adjust the drive belt so I might not need a new one. He adjusted it and thinks it might work just fine now. With the deck off, I set about taking it apart. I took the top covers off and found tons of grass clippings stuff around the pulleys and belt. It was a real mess. This picture is after I cleaned a good deal of it all up already. Another good idea that one of the guys there had was to get a cogged belt for the deck. The cogged belts can more easily bend around tight radii and thus less power will be spent. This should lower my amperage at least a bit. After it was all said and done, the entire deck was take apart. I have the bearings and will be stopping by a local bearing shop to find something to replace them with. There was also much talk about battery configuration of the mower. I mentioned that I had run it at 36V and it pulled 100A. The pulleys are a bit large at that voltage. If I went lower, the pulleys would be sized pretty much perfectly, so 24V is kind of looking like what I am going to go to. One of our members works at a golf course, so I am going to contact him and see what the possibility is of me getting four 8V batteries. I also cut a few more slots for the motor into the frame. Unfortunately, my bolt circle is off, and the right side bolt is going to be a small notch in the frame rather than a slotted hole. Oh well, I think 5 bolts will hold!

06-08-09, 05:01 PM	#69
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	The motor is rated for 3200rpm @ 24V. At 36V, the motor will spin proportionally faster, so 4800 rpm. I sized my pulleys the same as the original gas engine. According to reading and talking with people, most small engines run 2500-3400 rpm (feel free to correct me here, I haven't got anything incredibly solid). So, if I drop back down to 24V, I should be right in that range. Otherwise, I am going to need smaller pulleys to get the drive and mower deck speeds back down.

06-09-09, 08:00 PM	#70
cgates30 Lurking Renovator Join Date: Jun 2009 Posts: 3 Thanks: 0 Thanked 0 Times in 0 Posts	Great thread. This is exactly what I'd like to with my Yard Bug mower. It's a sit over the motor rig with room for a grass catcher under the seat too. I'd like to put the batteries where the bag would normally sit. It looks like my system is a 2 belt system, one belt driving the blade and the other driving the transmission. So, if I can swap the gas engine with an electric motor (and the motor rpm is similar to the gas engine) then it seems like it could be a nice conversion. I'm also assuming I don't need a motor controller since speed is normally zero to slow. I'm not really familiar with contactors, but my understanding is they're a physical connection in the line completing the circuit between the battery and motor. I need to find a good source for a 24-48 V motor that spins in the 3500-5000 rpm range. I figure I'll also look for 2-4 deep cycle 12 V batteries, contactors and cables. Installing the batteries shouldn't be a problem since I need to build a tray that sits over the deck/under the seat. Would a golf cart motor be a good candidate? Am I missing something, or would this work? A motor controller would be nice so I can vary speed, but then my blade speed would vary too. 2 motors would be nice, but then things start getting hard to write off under the 'hobby' budget.