Emanx conversion

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Sjanders
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Emanx conversion

Post by Sjanders »

Hi All,

New member from the Netherlands here :D. For some years I have a project sitting in my garage, it's a VW beetle based Meyers Manx fiberglass dune buggy. Recently I decided to pick up the project again and decided to throw out the old gearbox and ICE and replace it for an electric drive. In my daily job I develop extraction machines to extract molecules from plants, I do not have any experience with EV conversions at all. So this forum feels like a gigantic, and a little overwhelming, playground to me!

My project:
Image

The recent period I've been searching for conversion solutions, most of the solutions keep using the original gearbox of the vehicle, I prefer not to use this. In my search I found the Toyota/Lexus MGR drive via this forum, the form factor and potential power output matches my project quit well. Normally the car weighs approx. 650 kg. My goal is to build a conversion that is capable of doing 110-120 kph with a range of 100 km.

Regarding the MGR drive unit; I prefer to use "off the shelf" parts to do the conversion. So, my idea was to rewind the MGR motor (inspired by the project Ustas is doing) to run on 108-144 Volts @ 400-500 amp (peak) and use a Curtis (or equivalent) motor controller to run it. And that is basically where my plans are. For the next step I need to find some answers, I tried to answer them for myself but I sort of got lost :?. Hopefully you knowledgeable people are able to point me in the right directions. At this moment I have the following questions:
  • Curtis controllers can work with a sin/cos sensor input, see image below. From what I've seen in various photo's, the MGR resolver has 2 sensor revolutions (based on the shape of the resolver) per mechanical revolution while the Curtis controller seems to need only 1 sensor revolution per mechanical revolution. My question on this matter: is it possible to modify the MGR's resolver to be able to use a Curtis controller?
Screenshot from a Curtis controller manual:
Image
  • I tried to find information on rewinding the motor to my needs, and found out that I don't really know where to start. If someone could point me in the right direction (or even better: is able to make the calculation for me) I will try to figure it all out.

At this moment I have no parts to start build yet, when I'm confident that I'm able to do a proper conversion for an acceptable amount of money I will start the build.

Thanks for reading and hopefully you can give me some useful tips and tricks!

Cheers
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Sjanders
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Re: Emanx - conversion -MGR

Post by Sjanders »

Hi All,

I thought I'd sent you all a little update on my thoughts. Yes, still in the process of deciding what to do.

So, as I'm more the builder type of guy, and not a programmer, I prefer to do the conversion using a complete kit of parts. Recently I came across a Zero SR/F motorcycle https://www.zeromotorcycles.com/nl-nl/model/zero-srf that has some damage due to an accident and is now for sale with a decent discount compared to new. The bike is only 1 year old and has a 3500 km drive history.

The bike basically has all components I need for my conversion. The electric motor has a power rating of 82 kW peak and 40 kW continuous. Max torque is 190 NM. Max rpm is ~6700. When applying appropriate reduction that reaches 140 km/h, I should have ~1500 NM of torque at the wheels.

The battery pack has 14.4 kWh (12.8 ish usable), for me that's enough. The bike also has some safety features that will not be applicable anymore in the buggy, I'm not sure how to override these feature to create a derivable car.

My idea now is to swap out the original gearbox for a suitable differential and connect the motor from the bike with a belt to the differential. In that way I'm able to swap out belt pulley's that fit my needs at that moment, smaller ratio for higher top speed and visa versa.

Is there any experience with such a conversion? Do you see any pitfalls to be aware of? Please share your thoughts!
Thanks
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mjc506
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Re: Emanx conversion

Post by mjc506 »

The Zero is a nice package, if it's still running. If you can get all the parts in the vehicles while keeping the electronics convinced that they're still a motorcycle, that's probably the easiest route. Upgrading the battery (more range) might be difficult though.

The MGR has some reputation of being underpowered, but it's also quite difficult to drive. An alternative might be an Outlander rear motor/diff/inverter, which can be driven relatively easily (you 'just' send commands to the OEM converter, which handles all the difficult power electronics/switching/etc).

You will either need to learn some programming as you go, or be willing to throw money at a commercial solution I think. There's lots of little things in the background that can be tricky to integrate (batteries/BMS, charging, interlocks/contactors....)
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Sjanders
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Re: Emanx conversion

Post by Sjanders »

Hi All!

Been a while since my last post...

Recently I decided to choose an Outlander rear drive as the motor for my dune buggy conversion, having made that decision I also bought a drive unit.

Besides figuring out how to control everything, which batteries are best to use, how to transfer the power to the wheels etc etc, I will start with designing a mechanical solution how to mount the drive unit to the VW chassis. Ideally I would like to use the original VW buggy ( = beetle) gearbox mounting points to mount the drive unit.

So I need two drive unit mounting brackets:
  • Front bracket: I think I will keep the original drive unit bracket and design an additional bracket to connect the drive unit bracket to the front gearbox mounting point
  • Rear bracket: I will remove the original rear brackets from the drive unit and replace them with a bracket that can be mounted to the rear gearbox mounting points
Regarding the bracket (mainly the rear one) design, the easiest way is designing a bracket without vibration dampeners. Of course this will generate some vibration in the car. Has anyone experience driving with this drive unit without using the dampeners? Besides the vibrations, are there other factors why keep the dampeners? If it is a better Idea to use the dampeners, what type of dampeners could i use?

Below some pics:

Image

Figuring out how to position the drive unit.

Image
The buggy with the body removed.




Keep u posted!
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