Electric Victa Mower Conversion Build Thread-The Electric Motor

Electric Victa Mower Conversion Build Thread-The Electric Motor

The Electric Motor selected for Victa Da Stinka Electric Mower Conversion.

The Electric Motor selected for Victa Electric Mower Conversion.

Whether you are doing an Electric Car Conversion, Electric Bike Conversion or an Electric Mower Conversion like this one, the Electric Motor is one of the major components of the conversion. The Electric Motor is the heart. The previous post discussed the fate of the 2 stroke engine and this post discusses the requirements of the electric motor for this electric conversion, what motor was selected and how it was evaluated.

What features and requirements was I looking for in an Electric Motor for Vikta Da Stinka Electric Mower Conversion?

The requirements and features I was looking for in an electric motor for this Electric Mower Conversion were:

  • Power and Torque – 3hp was my preference so that I could easily cut long grass, but anything over 1 hp would have been sufficient. I had read in Issue 105 of ReNew magazine of a similar electric mower conversion where they successfully used a 500 watt (0.7hp) electric motor.
  • A physical size that was no bigger than the original 2 stroke stinker it will sit on.
  • As cheap as possible – I wanted the whole project to cost under USD $400. Any more than that, then it is not economically viable as one could buy a decent battery powered Stihl Electric Mower for that price.
  • That the motor could be mounted on the motor face which would permit it to be bolted into an adapter plate.
  • The motor could rotate in an anti-clockwise direction.
  • A shaft where a coupler could be attached.
  • Something that would easily run without complex electronics. This limited choices to simple brushed DC motors.

What Electric Motor did I end up using?

After putting the word out there that I was looking to convert a mower to electric, I was given a Hitachi GSB107-06 Starter Generator rated at 12V 0.9HP. This motor was previously used as a starter motor and alternator for a gas engine and are often found on Yamaha Golf Carts. What is interesting is that there appears to be a set of terminals, used for starting and there are a pair of thin wires which I assume is used for the generator/alternator component. For this Electric Mower Conversion, the generator component will not be used as there is no other mechanical or rotational energy source to move the motor.

Armature Terminals of Hitachi GSB107-06 with red wire connecting A2 to F1.

Armature Terminals of Hitachi GSB107-06 with red wire connecting A2 to F1.

F1 Terminal of Hitachi GSB107-06 with red wire connecting F1 to A2.

F1 Terminal of Hitachi GSB107-06 with red wire connecting F1 to A2.

F2 Terminal and DF wires of Hitachi GSB107-06

F2 Terminal and DF wires of Hitachi GSB107-06

 

Although I did not pull the Starter Generator apart, it appeared to me that the starter part of the motor was a series wound brushed DC motor, especially with labels such as F1,F2,A1 and A2 stamped next to terminals and the external cable that connected A2 to F1. Although, I did not open up this motor, I have often found with motors that F1 & F2 typically denote the ends of the field windings whilst A1 & A2 typically denote the ends of the armature. There was also a DF terminal with two wires coming out from it. Typically, that is the dynamo field for charging purposes, but this wire was not required for this Electric Mower Conversion.

 How did I check this Electric Motor?

Once, I got possession of the Hitachi GSB107-06, before doing any work on it, I checked to see that the shaft would rotate when power was applied. Using a 12 volt battery and jumper leads, power was applied to A1 and F2. Since, it behaved like a series wound brushed motor, it did not matter what polarity was applied to those two terminals. Looking at the motor from the output side (where the pulley normally went), the shaft rotated anti-clockwise which meant that looking at the motor from the rear casing, it rotated clockwise. This meant that when connected to the mower in the method I was envisioning, it would rotate in the correct direction. (Note: To change the direction the shaft rotates, remove cable connecting A2 to F1 and instead connect A1 to F2 and apply power to A2 and F1.)

I was not able to measure the speed of the Hitachi GSB107-06, but without using a motor speed controller, I had to watch that the motor did not speed up with no load, otherwise there could have been a risk of it self distructing – something to watch for when using series wound motors with no load.

I was satisfied that the Hitachi GSB107-06 could be used for this Electric Mower Conversion so the next step was to work out how to mount this Electric Motor to the mower.

This is Al Bunzel signing out.

 

Electric Victa Mower Conversion Build Thread-Dealing With The 2 Stroke Stinka

Electric Victa Mower Conversion Build Thread-Dealing With The 2 Stroke Stinka

What decisions were made regarding the fate of the 2 stroke engine?

Left: Electric Motor. Right: Victa The Stinka with fuel tank removed.

Left: Electric Motor. Right: Victa with fuel tank removed.

 

The previous introduction post discussed why do an Electric Mower Conversion, the requirements of the Electric Mower, basic parts list and tools list. This post will discuss how we deal with the 2 stroke stinka engine and the basic design decisions that are being made. The advantages and disadvantages of the design decisions are outlined.

Most people who do EV conversions or Electric Conversions tend to remove the smelly gas engine to make way for a clean electric motor. This is a sensible approach so why would I keep most of the Stinking gas engine in my Electric Mower Conversion? The reasons why I intend to keep the engine block and crankshaft are:

  1. I’m not sure what strain the mower blades will have on the electric motor so I have two choices. One is to add another support bearing to the electric motor, but that is tricky for me. The other option is to utilize the existing bearing of the gas motor and bolt the electric motor to the crank case via an adapter plate.
  2. No need to take the blades off during this conversion.

What stayed and what got removed on the Stinka 2 stroke engine?

Obviously, I won’t be keeping everything on the Stinka 2 stroke engine. I don’t intend on making this a hybrid lawn mower, but rather a full electric mower. However, I plan on utilizing some of the gas engine components, but the incomplete gas engine will not be used to power the mower. Items removed from the gas engine were:

  • Recoil starter and cover.
  • Fuel tank.
  • Cylinder head.
  • Air filter and air cleaner hose.
  • Piston and conrod – although, originally I had thoughts of not removing these parts because
  1. it would have helped with maintaining balance.
  2. there would have been no need to remove the bolt on the crankshaft which held the conrod in place, especially when you don’t have the special Victa tool to remove that bolt.

Items that stayed on the gas engine were:

  • Engine block.
  • Crank shaft.

The advantage of keeping the existing, but incomplete gas motor were:

  • Protection of electric motor should the mower blade strike a rock since the gas motor bearing will be the first bearing to take the shock.
  • Easy conversion process.
  • This method has been successfully done before as published in ReNew magazine.

What are the disadvantages of keeping the existing gas motor?

There are several disadvantages of keeping the existing (but incomplete) gas motor such as:

  • Extra weight.
  • Space wasted which means where does one locate the batteries?

So now that the basic design decisions have been discussed, the next few posts will discuss the implementation and build processes of this Electric Mower Conversion.

This is Al Bunzel signing out.

P.S. Please check out the next article regarding the requirements, selection and evaluation of the electric motor used.

Electric Victa Mower Conversion Build Thread-Introduction

Electric Victa Mower Conversion Build Thread-Introduction

 

Electric Mower Conversion In Progress

Electric Mower Conversion In Progress – working out adapter plate.

 

Why do an Electric Mower conversion?

You may be wonder why I would want an electric mower, let alone bother converting a Victa 2 stroke mower to electric considering you can buy a decent electric mower at a reasonable price. Several reasons why I wanted an Electric Mower were:

  1. No need to worry about fuel. With a gas mower, every time I want to use it, I have to ensure I have enough gasoline and if I don’t I have to go the gas station and get some which results in wasted time traveling to and from the gas station.
  2. No need to worry about mixing 2 stroke fuel, changing air filters or spark plugs.
  3. No starting issues. I found gas mowers often had starting issues due to various reasons.
  4. Less things to go wrong with Electric compared to gas powered mowers.
  5. Less noise to put up with since electric motors are inherently more quiet than their gas equivalents.

The reasons why I did not go out and buy an electric mower from the shops were:

  1. To reuse a mower base where the only thing wrong was the gas engine.
  2. I wanted the ability to be able to service and repair my own mower and not be locked into a propriety system.
  3. I read in Renew Magazine several years ago about how someone converted a Victa Mower to electric & thought it was a good idea to do something similar.
  4. Because I can.

Requirements

The requirements of this Electric Mower were:

  • Be able to cut a quarter of an acre of grass within 4 hours.
  • Use an existing mower base (in this case a base from a Victa mower).
  • Battery operated so I don’t have to be plugged into a power point.
  • US$200 budget (excluding batteries).

 Parts List

The following was a rough list of parts which I believed I would require:

  • Mower base with blades and wheels – in this case, a Victa 2 stroke mower base was used.
  • An electric motor – in this case a Hitachi GSB-107-06 12V 0.9HP motor was selected. It will be interesting to see if this motor is capable of doing the job as per the above requirements.
  • Batteries – most likely selection will be Lithium Iron Phosphate (LiFePO4) cells.
  • Contactors.
  • Various cables and wires.
  • Possibly a motor controller if variable speeds are desired.
  • U-Channel to make a coupler.
  • Steel plate for making an adapter plate to mount the electric motor.

Tools List

  • Spanner or wrench set.
  • Socket set.
  • Screw driver set.
  • Hacksaw.
  • Angle grinder with cutting blade and grinding blade.
  • Marker.
  • Jigsaw with cutting blade that cuts metal.
  • Drill machine.
  • Drill press.
  • Drill bits of various sizes.
  • Center punch.
  • Hammer.
  • Transparent plastic that holds its shape – used for making a template for the motor adapter plate.

The next post discusses how the 2 stroke stinka (the gas engine) is dealt with along with design decisions and the advantages and disadvantage of the decisions. The subsequent posts will discuss the build process and the various issues faced.

This is Al Bunzel signing out

ElectricCarConversionBlog.com is under reconstruction

ElectricCarConversionBlog.com is under reconstruction

Hi,

due to various reasons (including replanning and working out which projects to do next), this blog is under reconstruction. As a result, my activities will be posted on https://www.facebook.com/ElectricCarConversionBlog

So come and join me on facebook and please like my page.

Thanks

Al

General Motors, Ford and Toyota to cease manufacturing in Australia by 2017 – a good thing for Electric Cars and Auto Workers!

General Motors, Ford and Toyota to cease manufacturing in Australia by 2017 – a good thing for Electric Cars and Auto Workers!

Ford factory facing extinction have still failed to electrify their cars.

Ford factory facing extinction have still failed to electrify their cars.

Within the last 12 months, General Motors (owner of Holden), Ford and Toyota have announced that they will cease manufacturing cars in Australia by 2017. I’m not happy about the resulting job losses and the negative impact it will have on their suppliers.

So why could it be a good thing for Electric Cars?

Ford and GM’s Holden did not manufacture any Electric Cars in Australia, so no great loss there from an EV perspective. Even when EV Engineering engineered a bolt in electric drive train for Holden with swappable battery packs, in my opinion it appears GM’s management failed to seize the opportunity that was handed to them on a silver plate. Toyota did manufacture the plugless Camry Hybrid so that was a half hearted attempt at electrifying their cars!

Electrification of cars (whether full electric or hybrid) is seen by many car makers as a way to meet upcoming tough emission laws being enforced in various markets around the world. Car makers that don’t electrify kill of their export sales potential.

However, the last time I recall a Toyota factory closure was in early 2010 which was the NUMMI (New United Motor Manufacturing) plant in California. GM also shared that plant with Toyota, but for GM, factory closures are nothing new. They do it quite regularly. However, what is significant is that Tesla Motors is manufacturing the Model S in the old NUMMI site, hence, it is not all doom and gloom for the workers.

If Tesla have managed to make a profitable Electric Car manufacturing business in the United States, then what is there to stop the same thing happening in Australia? Just like the United States, Japan and Germany, Australia has proven that it has a capable workforce to produce a car from inception through to production.

What’s more, in Australia, there are numerous people who have done Electric Car Conversions and Electric Vehicle Conversions so their experiences can be leveraged to good use. In fact, there are businesses involved in Electric Vehicle production in Australia, whether it be doing conversions or building vehicles from scratch. Let’s list a couple:

Then, there are companies involved in supplying parts. Here’s a list of some of them:

Why is it a good thing for auto workers?

In my opinion, the management at Ford and General Motors is pathetic. From my perspective, I could see decisions made that were not in the interest of auto workers and I feel the auto workers deserved better.

If EV entrepreneurs and the auto workers team up, they could produce really nice Electric Cars, just like what Tesla Motors did at the old NUMMI factory. Perhaps, some of those EV entrepreneurs could be the Auto Workers affected by the closures.

As mentioned already, there are EV businesses in Australia, but they are running at a small scale. With Ford, GM and Toyota closing up by 2017, it will create a void giving those EV businesses an opportunity to fill and hopefully provide sustainable employment for the auto workers affected.

Conclusion

Now is the time for EV entrepreneurs and auto workers to get together and secure their futures. EV entrepreneurs will have access to talented workers who are easy to retrain to manufacture Electric Cars. Suppliers will be willing to negotiate with EV manufacturing businesses (if they want to stay in business) and opportunities to acquire facilities (like the old NUMMI plant) to produce Electric Cars should become available.

Some auto workers may embrace expanding on their current skills and set up Electric Car Conversion businesses. Others will want to work for the EV entrepreneurs. Auto workers and EV entrepreneurs will need each other to take advantage of the opportunities presented to them.

EV entrepreneurs and auto workers need to act quick to minimize job losses and to get involved in what I see as a growing industry because if they pull this off, then it will be a great thing for Electric Cars and also for the Auto Workers.

This is Al Bunzel signing out.

P.S. Check out EV Secrets so that you can learn how to do Electric Car Conversions

http://www.batrium.com/

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