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Discussion Starter #1 (Edited)
Have been using a JD Z225 for about 11 years. Bought new. Total of 140 hours. Small lot but zero turn is essential. So far I have had to replace all of the following. 3 sets of belts, motor, both transaxles, set of tires, 4 air filters, 2 fuel pumps, 4 batteries, seat, seat switch, 6 covers. Other than it is the perfect size (42 inch ) and zero turn ( perfect for my lot ) and it is a mess.

So being an electrical and mechanical engineer I did a lot of research and am taking the plunge. My object is to duplicate the Hustler Zeon on a John Deere Z225 chassis. In the process I plan to correct all of the Zeon problems.

So here is my plan. I found a JD Z225 used and dead mower ( I need to keep mine functional to cut grass ) as a donor. I will rip off all of the belts, pulleys, and Hydro-gear transaxles an motor and gas tank. I have purchased the Zeon hydro gear SMARTEC electric transaxles and the deck motors from a Hustler dealer. The transaxles will mount very easily since I am replacing a hydro gear hydraulic with a hydro gear electric. Very similar mounting holes and frame sizes. It will be easy to make mounting adaptors to put the Zeon dual deck electric motors on the John Deere 42 inch deck. I am not going to use the SMARTEC electric controllers, They are 11 year old technology now and very proprietary information. I am going to use either Curtis or Kelly Electric ( leaning Kelly Electric real hard right now ). Will require 4 controllers, 2 for the deck motors ( 48 Volt AC at 2 HP each ) and the 2 wheel motors at 1.7 KW or about 2.2 HP.

Will be all 3 phase AC motors at 48 Volts with regen on all controllers. Will use Wig Wag Pots on the existing control handles so it will control just like the regular zero turn.

Am going to use 4 of the 100 AH 12 volt LI Ion batteries with a 4 output charger built into the mower, marine grade.

This is not a cheap build and not planned that way. It is to be a totally overbuilt and extremely capable and reliable mower.

At this point the donor Z225 is acquired. The deck motors and transaxles are on the way. Am picking out the controllers and starting on the wiring diagrams.

Will keep you posted.
 

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Discussion Starter #3
Every controller I have seen that will work with these motors has that option built in. Definitely usable on the traction drives. Questionable on the blades, but even the smallest AC induction drive with a 3 phase Hall effect speed feedback sensor has Regen built in. Probably the only time I could get any energy back from the blades, and it would be VERY small is going from full load to no load like running over a sidewalk and seeing the motor try and overspeed. Might also be a little when I hit the blade stop switch and the spin down quickly for safety reasons.
 

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Discussion Starter #4
I am posting this not as a reply but to tell what this original post is all about. I need to do that becasue the forum has deleted the original post that started this thread.

I am converting a John Deere Z225 zero turn into electric. I have been using an identical mower and it fits my lot and trimming requirements perfectly. I bought the mower new in 2007 so it is entering its 11 th year of use and has 140 hours total on it. In that time it has had the following parts replaced: both the left and right hydro gear transmissions, the motor, the tires, 3 sets of belts, 2 batteries, the seat , the seat switch, the gas cap, six covers, and the fuel pump. Currently it will fill the motor crankcase up with gasoline on about every third use ( leaks by the carb float and the electric fuel shutoff solenoid ( both of those also have been replaced). So I have spent over the cost of the mower in parts and repairs after only 140 hours. Other than all those problems it is a noisy and vibratating beast. Who ever thought that and 18 HP motor should be a single piston instead of a V twin was an idiot. However it is just the right size ( 2 blade 42 inch ) and manuveribility to cut my lawn.

So I have purchased the hydro gear electric zero turn transmissions and the two deck motors from a Hustler dealer ( originally used on the now discontinued Zeon mower ). I have found a donor used John Deere Z225 at a cheap price that is intact but not running. I will remove all of the belts, pulleys, hydrostatic transmissions, etc and install the electric transaxles and deck motors on this unit. Those devices are all 48 volt 3 phase brushless AC motors. Going to use Curtis or Kelly controllers. Install Wig Wag pots on the existing control handles and a 100 AH 48 volt lithium battery pack.

This will not be a cheap build. But it should be bullet proof and las a long time. Will keep you all posted on the progress.
 

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Discussion Starter #5
My project continues. The original mower has been totally rebuilt. That was more major than expected especially in the mower deck as some damage was there. In the end we sent all of the parts out for new power coating due to changes and new parts and brackets and damage. I have all new handle covers and decals and tires and a seat. Will be a really slick looking mower.

I have all of the electrical parts and am starting on the wiring harnesses now. I spend about 3 months fighting with the Curtis controllers and CAN bus. I used the Curtis devices for the main drives and am using Kelly controllers for the blade motors. The blade motors are BLDC with Hall transducers for speed. The main drives are 3 phase induction motors that use a Honeywell Quaderature encoder for speed and direction.

The Kelly controllers came with CAN bus enabled and transmitting several variables in broadcast mode which I easily captured with my Red Lion touch screen. The Curtis devices were a total mess in the CAN department. The end user is not able to turn broadcast mode on for these devices without using VCL language which Curtis will not let non dealers have nor will most of there dealers even want to mess with it. It to me 3 months working with 2 different dealers to get enough research to figure it out. You must have a CAN master on the buss to tell the Curtis to do several things so it will send you the preprogrammed MISO messages.

Wiring and testing is next and I should be ready to mow lawns in the spring. Still have to have a machine shop make the custom deck motor to blade adaptors.

Jim
 

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Wow, didn't know john deere made such junk.

I have a 2004 toro z-turn (42") and a 2015 (46"). The '15 has an hour meter - 150 hours on it and not a single issue.

The 04 I got last year...a few engine issues (it's a splash oiled B&S 14hp).

I've conssidered going elec on it..that or a bicycle will be my first project.

SIMPLEST would be ONE motor - use all the existing mower parts.

SOME use 2 motors for propusion and one for deck, most that to this way use one motor per blade.

BUT you'll need 4 motors, controllers for at least the drive motors.

If you do ONE motor it can just run full blast, right? Since 99% of the time it's mowing at full throttle with one engine.

I see no point to regen at all on a mower.

I was thinking simple and cheap - one motor and lead acid batts. Cheap, weight ins't an issue but an advantage on a tractor/mower.

As a mechanic and now hobby farmer i've learned - simple wins every time. Overcomplicating is bad.
 

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Wow, didn't know john deere made such junk.
They certainly do. Most of their product line is intended for agricultural, commercial, and industrial applications where they need to be relatively well-built to be effective and in many cases to justify a premium price; however, they also sell products for homeowners which compete with junk and are thus junk.

I have an John Deere L111 lawn tractor which was as cheap as other brands - I bought it because it was the cheapest two-cylinder hydro lawn tractor which had enough room for an adult behind the wheel. When a gear exploded in the transaxle I discovered that the hydrostatic transaxle couldn't be repaired, because John Deere had TuffTorq build a special version of their cheapest transaxle, which is even cheaper and has no parts available... it's disposable!
 

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Discussion Starter #8
I did some caculations on using 1 motor running at constant speed. You could not put enough batteries in the thing to make it around the yard twice. The losses in the belts and pullys and tensioners and bearings and especially the hydro static drives use up 45% of the motor HP. Then you have the fact that a small lot residential mower is not moving but about 70% of the time. You are on and off the thing moving hoses, kids toys, pushing sprinkler heads back down, etc. etc. Next is the reliability factor. in 120 hours I have replaced both hydo drives. Why would I want to keep 2 expensive and failure prone parts around. Aslo in a small lot you are running foward and back a lot for trimming and turning. You may not gain much in regen during those short decell cycles but every little bit helps. Then no way I would use lead acid batteries. TCO is not there. You do pay a lot up front with the LiIon but life cycle cost is on your side. Then there is the wieght factor. Mowing on a level heavily sprinkled residential lot sometimes requires mowing when you could not get the lawn dry enough ( firm enough ) to drive a heavy mower around without making ruts and tearing up the turf. The hydo drives have no forgivness and will tear the turf up if the levers are moved to fast. Tuning the electric drives for torque limit and accell and decell rates will prevent that problem.
 

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You do bring up some valid points. SOME hyd drives suck, and some are good (like anything else).

my 04 toro has good drives (hard to kill them everyone says). Not sure on my 14 model. One step higher and I could have gotten rebuildable ones.

But yes, the transmissions on most low end mowers are the weak link.

I see the advantage to motors on the deck...didn't consider the savings on all the belt/pulley drag.

As for torque ripping up the yard..I bet the elec motors will do that as well, if not more, and if tuning them not to is possible it MAY help...but I don't think you'll like it that way, functionally speaking.

How much battery do you think you'll need and how long a run time do you think you'll get?

This is where my brain implodes for some reason...:mad:


I did some caculations on using 1 motor running at constant speed. You could not put enough batteries in the thing to make it around the yard twice. The losses in the belts and pullys and tensioners and bearings and especially the hydro static drives use up 45% of the motor HP. Then you have the fact that a small lot residential mower is not moving but about 70% of the time. You are on and off the thing moving hoses, kids toys, pushing sprinkler heads back down, etc. etc. Next is the reliability factor. in 120 hours I have replaced both hydo drives. Why would I want to keep 2 expensive and failure prone parts around. Aslo in a small lot you are running foward and back a lot for trimming and turning. You may not gain much in regen during those short decell cycles but every little bit helps. Then no way I would use lead acid batteries. TCO is not there. You do pay a lot up front with the LiIon but life cycle cost is on your side. Then there is the wieght factor. Mowing on a level heavily sprinkled residential lot sometimes requires mowing when you could not get the lawn dry enough ( firm enough ) to drive a heavy mower around without making ruts and tearing up the turf. The hydo drives have no forgivness and will tear the turf up if the levers are moved to fast. Tuning the electric drives for torque limit and accell and decell rates will prevent that problem.
 

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Discussion Starter #10
Well my project is complete and I have been mowing since the start of the season on my project. I have had zero problems. I am still tuning on the drives. I have the deck motors running like I want. Still making some very minor tweaks about every third mow on the main drives. I have mowed wet grass and dry, tall grass and short. It is a mulching mower and nothing seems to phase it. I start mowing and the battery voltage is about 55 volts on the 48 volt Li Ion battery pack, 100 AH deep cycle. When I finish in about 40 minutes ( 1/2 acres residential lot ) with lots of trimming and turning and stop and go, I am still about 52 volts. The Li Ion battery pack should run down to 40 volts before cutoff so I think this thing would easily run 2 to 3 hours on a charge. I have blown it clean with the electric blower after cutting dry grass and sprayed down the deck with a hose and nozzel after cutting wet grass.

If you run into something the drives just go into current limit so the wheels don't slip and tear up the lawn. It drives and feels very close the John Deere hydrostatic that it started out as.

Was a great project with the typical electrical engineer ( I am a registered professional engineer ) overkill. The touch screen reads data over the CAN buss from all four of the drive controllers. Gives me amps and speed of all the drives and motor and controller temperatures.. Gauges and bar graphs. Total amps.

The electrical mechanical brakes set when parked and shut off. Upon turning the key on and to start the electromechanical brakes release and the mower uses the electronic brake feature of the motors when throttles are at zero. If you set the throttles to zero speed and flip the tiller bars out to the sides it will just set there and hold position, even on an incline. You can just barely feel the motor going from motor fwd to reverse to maintain absolute position.

As you go from running uphill to downhill you never feel the speed change but you can tell the motors are going from motor to regen.

It cuts really nice and it is so quiet. Only noise is the blades when they are on. I started with blades at 2500 RPM but changed to 3000 RPM. Cuts much better. The mulching blades like the speed to get suction. Did not increase the noise enough to tell.

The neighbors are very impressed. So am I.
 

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Great to hear your success story- I'm considering a similar project. Kohler engine died on my woods 60" mower. It's a well-built mower, so will repair it, but I'd rather put the money toward a conversion instead of a new ICE.

Can you give me an idea of the power required for your blade motors & the length of the blades they drive? Thanks!
 

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Discussion Starter #12 (Edited)
The blade motors are 2.2KW and are 3 phase motors with feedback. They work with Kelly Controllers. Voltage is 48 volts DC.

The main drive motors are about 2 KW and are 3 phase induction motors and use Curtis Controllers with encoder speed feedback. The are also 48 volt DC.

The deck is 42 inches wide and the blades are slightly staggered to get an overlap so the blades are about 22 inches long. I am currently running them at 3000 RPM right now. Everything is direct drive, no belts or pulleys or clutches or hydraulics. You should resist the temptation to use one motor and drive all the present blades with a belt from a single motor. The losses in any belt drive system will eat up a lot of extra HP and greatly reduce battery life.

Is you mower a zero turn? If not you could use only one main drive motor instead of 2. With a 60 inch deck like yours is suspect that you have 3 blades now. If you use the same type of blades motors that I did you will need 3 and 3 controllers.

I got my blade motors and the rear drives from a Hustler mower dealer as replacement parts for the discontinued Hustler Zeon electric mower. They are actually made by HydroGear and are there Smartec line of electric components.

Jim
 

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Thanks, that's really useful info. I'm converting a zero turn, so I'll be looking at 2 drive motors and 3 blade motors for each of 3 roughly 20 inch blades.

Based on your experience, looks like I might consider 5 identical motors rated at about 2 KW, but perhaps the lower speed on the drive wheels will require a different motor. (I'm still learning about motors.)

I can't imagine typical motor bearings are sufficient for the abuse a mower blade will inflict, so one challenge will be figuring out how to couple my motors to the existing blade mounts in the space I have. Are the replacement Zeon motors tough enough that the blades just mount directly on the motor shaft, or is there a separate bearing assembly?
 

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Discussion Starter #14
The Hustler Zeon motors I used are speciffically made to have the blade mounted on them. The have a flange that just bolts to the deck and a heavy duty front bearing. You could get them at a Hustler dealer as a replacement part. You might also look and the new Ryobi electric zero turn that is on sale now. You could probably buy that blade motor as a replacement part also.

2 KW for the rea wheels is mor3 than adequate. Your motor will need a set of gears with about a 45:1 ratio to step down the motor speed. If you try and have the motor turn the rear axle with anything less than that you will need a huge motor to make up the torque lost by not useing a gear box. I though about that also and that is when I decided that the prepackaged motor , axle, gear box with speed sensor as a Hustler part was very attractive. There would have been a lot of searching for gear boxes and fabrication of bearings and axles otherwise.
 

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Thanks guys. All great info. It's hard to imagine that it won't be worth the cost to buy at least the deck motors designed for the purpose from hustler (or smartec if they sell direct.) There's just not enough space above the deck to get very creative with a gear or chain drive.

What does the Hustler dealer charge for those?
 

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Great job with this one . I'd love to see some pics and some idea of the cost of the hustler parts. I had no idea hustler had an electric model, will need to read up on that one.
It seems like overkill to run 4 controllers - couldn't you just parallel the deck motors use a big relay to switch on/off? Why did you need a controller for each one?
I've been very interested in the new Ryobi electric ztr. In a couple years they might be available dirt cheap with dead batteries. If the motors and control systems are solid it might even be worth buying parts now to convert my gravely...
 

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It seems like overkill to run 4 controllers - couldn't you just parallel the deck motors use a big relay to switch on/off? Why did you need a controller for each one?
They're AC motors, so they need an inverter/controller.

Induction motors could be run from a common power source (controller), depending on the ability of induction motors to slip (run under the supply frequency), but separate controllers running at the right frequency to produce the most appropriate degree of slip gives better torque to accelerate to running speed.

If they are synchronous AC motors, the power to them must be in phase with the rotor position; since the blades are not mechanically linked to each other, their motors are not in synch and so their supply power will not be in phase... so separate controllers are needed. The Smartec motors appear to be synchronous.
 

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Jim
I live in Australia and have 2 Smartec deck motors which I got off ebay. The Smartec deck controller is very expensive even if I could get it here. I was wondering which model Kelly controller you used and the programming you set?
Thankyou
pglee
 
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