4WD Electric Scooter

Steeltrap

1 µW
Joined
Aug 8, 2022
Messages
2
First, thanks for any responses that I get about this subject.

I currently own a highly modified 48V electric EZ-GO Golf cart that I use for hunting in the woods...getting to places to fish, etc. I've owned this cart for over ten years and about 4 years ago I made the conversion to lithium via building a 14 module pack of used Nissan Lithium batteries and a third party BMS. My questions here are not related to my cart, but I just wanted to post my "skill level" (which is not high on the charts!!).

I have a basic understanding of "stuff" (very basic) and I'm looking to possibly build (more likely to modify an existing disabled mobility scooter) a 4WD mobility scooter that has a size big enough to carry my 200-lbs, and small enough to fit in a commercial airline cargo hold (like my current DI scooter), but powerful enough to take across uncut fields, through woods, across cobble stone roads\sidewalks and up outdoor stairs.

You know.....simple easy stuff.

I know that I will want\need a suspension but my thinking is that if it's doable to mount 4 hub motors\tires of say a ten inch diameter, have each motor run off their own controller, but one throttle device, and one battery pack.

So....that's my "want's" but I don't know if that's possible. There are a few OPMD's on the market that can handle the "woods\streams", but these are too big for airline travel and\or far more powerful than what I think I need to "fit" what I want. In addition, these units run in excess of $20,000.

So, as of yet I haven't found any type of a mobility device (scooter) that has been built. Any thoughts or input on this would be greatly appreciated.

Thanks!
 
It's easy to use just one throttle to power multiple motors; there are various 2WD, 3WD, AWD threads here that discuss the ins and outs of that part, and other shared wiring between controller/motor systems.

This doesn't account for steering, however, so you may wish to create a "balance control" (like on a stereo) that reads the steering input and changes the amount of throttle input to each side based on this. It's not required, but it will make steering in some situations easier (less problems with scrub / traction loss in poor conditions during a turn), since it will actually help power you thru a turn. I never got very far with the idea but there may be some info on the necessary ideas in my Nano Tidbits thread (and more buried in my SB Cruiser trike thread in various posts). Can be done entirely analog electronics, which is how I had started out with the idea, but it's probably easier to do (and modify) using something with an MCU, like an Arduino Nano, etc., via software.

Mechanically it will be simpler to use hubmotors (QSMotors and others make single-ended axle hubs for this purpose), but it means designing (or redesigning) the suspension to work with the extra weight in the wheels for it to work like it would normally.

Regarding airline travel, you'll need to make the system with removable batteries that you can ship separately via ground to your destination, since a battery big enough to be useful for this application will not be allowed to fly with you or the vehicle.

If there isn't any existing vehicle that does what you want, I would recommend locating some that each do part of what you want, and compiling them here in this thread, noting the specific parts of each that you're interested in, to then be able to work up a complete design that *will* do what you want, and doesn't cost an arm, leg, and next of kin. ;)


BTW, I also have a mind like a steel trap. Everything comes out crushed and mangled. ;)



Steeltrap said:
First, thanks for any responses that I get about this subject.

I currently own a highly modified 48V electric EZ-GO Golf cart that I use for hunting in the woods...getting to places to fish, etc. I've owned this cart for over ten years and about 4 years ago I made the conversion to lithium via building a 14 module pack of used Nissan Lithium batteries and a third party BMS. My questions here are not related to my cart, but I just wanted to post my "skill level" (which is not high on the charts!!).

I have a basic understanding of "stuff" (very basic) and I'm looking to possibly build (more likely to modify an existing disabled mobility scooter) a 4WD mobility scooter that has a size big enough to carry my 200-lbs, and small enough to fit in a commercial airline cargo hold (like my current DI scooter), but powerful enough to take across uncut fields, through woods, across cobble stone roads\sidewalks and up outdoor stairs.

You know.....simple easy stuff.

I know that I will want\need a suspension but my thinking is that if it's doable to mount 4 hub motors\tires of say a ten inch diameter, have each motor run off their own controller, but one throttle device, and one battery pack.

So....that's my "want's" but I don't know if that's possible. There are a few OPMD's on the market that can handle the "woods\streams", but these are too big for airline travel and\or far more powerful than what I think I need to "fit" what I want. In addition, these units run in excess of $20,000.

So, as of yet I haven't found any type of a mobility device (scooter) that has been built. Any thoughts or input on this would be greatly appreciated.

Thanks!
 
First, thank you for the information. I've read your post and I will take some time to understand your info and read the links\suggestions in order to get a better handle on this.

It will take a little time as my grandkids are coming to stay for a few days and that allows me time for nothing!! But it's a great nothing!!

I'll post my questions when I can.....you know....when the rust get's brushed away and I know what I wanna ask!! :shock:

I know the steering links\tie rod ends, etc will need beefed up over standard scooter "stuff" and I've read somewhere that using IIRC golf cart tie rod ends and tie rods will usually be adequate. (Based upon my own experience with my cart and where I take it, I've never had an issue with cart linkage ...even when I hit that hidden ditch and cracked the cart frame!!)

As for the battery "issue" there actually (from what I've read) ways to have a lithium battery on a scooter....but frankly I'm thinking of a lithium pack shipped ahead, and using a lead acid for getting around the airport.

Plus, if I can put a 4WD on\off switch and have the scooter just power the rear wheels....I don't know if that will put less power demand on a lead acid pack....but there aren't that many hills in an airport.

Again,

Thanks!! Dave
 
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