Unironically want to do a DIY Vehicle Of Some Sort

[saiyaken_PHOENIX]

I've been a tinkerer for as long as I knew how to break things. From computer hardware, to open source software, to now offgrid solar, I've been looking to keep my mind sharp and move on to bigger projects. How about an Open Source Car?
Ganoo car memes aside, I have for awhile had a plan to retrofit something of a similar chassis build to a small car with a Lifepo4 battery array and some direct drive electric motors to all wheels, and maybe use a gas engine to keep the batteries topped up and maybe add to the output of the wheels, maybe run on gas until the batteries get warmed enough in colder climates (I've ALWAYS been baffled at so many electric only cars don't even have heaters built-in for the batteries in cold weather times). Whatever I do, I want it to be lightweight, simple and modular; Lightweight to keep battery life and travel distance per charge long. Simple enough to be easily replicable, none of that proprietary systems nonsense that no one but the manufacturers know how to set up. Modular for whoever wants to do any modifications to it... Hell, if someone wanted to throw a Harbor Freight/lawnmower engine or stuff an LS in it, go for it!

What I'm saying could very well much be a pipedream, but I'll be damned if I don't attempt something like this, I'm already having fun describing it. Any other thoughts on this?

 

[OffGridForGood]

DOT
FMVSS
NHTSA

 

[teal95]

However the laws are pretty loose for limited production.

 

[OffGridForGood]

Insurance

 

[saiyaken_PHOENIX]

DOT
FMVSS
NHTSA

Making it fully street legal would be later, right now is just coming up with something that would be viable enough to warrant pushing forward

Also insurance has always been a racket lol

 

[saiyaken_PHOENIX]

To put more clarification on what I had in mind as far as plans for this thing:

The overall car size would be somewhat similar to a Miata, possibly larger up front and in cab for engine compatibility; basically want to make a two-seater that at least has enough comfortable room for both.

Would probably be difficult to have some sort of unified drivetrain, especially given the different configurations between ICE and Electric. My original plans were to have the electric motors direct drive at all four wheels, with the gas engine powering backup battery power when needed, or directly adding power to the motors. How I imagine the Fisker Karma does its drivetrain configuration.

Part of the modularity is the batteries; planning to size for the largest rackmount batteries and for six of them total in the main space along the bottom of the car, that way smaller rackmount batteries can fit in the same slots without issue. And, if needed, maybe four more in lieu of trunk space, if possible.

I'll probably be listing more ideas later on

 

[TommySr]

How about an Open Source Car?

Can't think of a better time then now, the city I live in just pasted laws that let these
types of cars operate on city roads.

and the parts are just a click away.





very exciting time to be a tinkerer.

 

[saiyaken_PHOENIX]

Can't think of a better time then now, the city I live in just pasted laws that let these
types of cars operate on city roads.

and the parts are just a click away.

very exciting time to be a tinkerer.

Holy hell, that's JUST what I needed to experiment with!

 

[TommySr]

Holy hell, that's JUST what I needed to experiment with!

unless I had deep pockets, I would start out making a small scale prototype.

 

[OffGridForGood]

I am thinking the lawn tractor as the first attempt, low speed, no permits required. If it goes too slow, the grandkids can use it as a toy - with the mower head removed naturally.

 

[saiyaken_PHOENIX]

I am thinking the lawn tractor as the first attempt, low speed, no permits required. If it goes too slow, the grandkids can use it as a toy - with the mower head removed naturally.

Sounds like a good plan, was thinking of either ATV or golf cart as a starting point

 

[TommySr]

I am thinking the lawn tractor as the first attempt

a lawn tractor with 5000W 48Vdc motors could keep me entertained for hours.

 

[OffGridForGood]

I have thought about swapping out the gas engine for one motor - size to be determined.
Or use three motors, two for the mower head, and one for the drive axel, to eliminate the drive belts altogether.

 

[TommySr]

I tried it with 24V 500W motors, but corn cobs and Barbie dolls stalled the motors.
but it was still hours of entertainment.

 

[D71]

.

I tried it with 24V 500W motors, but corn cobs and Barbie dolls stalled the motors.
but it was still hours of entertainment.

View attachment 195133

that is interesting …. what are you using to control the 24volt 500w motors? How big are those blades?

How about the drive wheels? I see what looks like a sprocket on each rear wheel Is that correct?

Those new electric zero turn are expensive. I keep looking for used electric zero turn with bad batteries on my local fb marketplace.

 

[OffGridForGood]

I figure the mower blades need to be 2-3kW motors (each) for a 46" cutting mower (23" blades each) these can be a set single speed really.
and the drive wheels need a variable speed motor to control forward speed to suit conditions.

 

[TommySr]

what are you using to control the 24volt 500w motors?

to control the speed controllers I used an Arduino Mega

How big are those blades?

the 18" yardworks real mowers I got from Home Depot ten years ago

How about the drive wheels? I see what looks like a sprocket on each rear wheel Is that correct?

yes, they used the same motors as the mowers, I used the chain and sprockets to reduce the
speed and increase the power. they used the Sabertooth 2x60 speed controller

I tested timing belts to reduce noise, but chains worked the best.

 

[TommySr]

I figure the mower blades need to be 2-3kW motors (each) for a 46" cutting mower (23" blades each) these can be a set single speed really.

I believe you are correct, I also tried three over counter 21" rotary type mowers but found them lacking enough power.
too bad it didn't work out for me, 60" electric mower would have be sweet.

 

[TommySr]

I keep looking for used electric zero turn with bad batteries on my local fb marketplace.

A few years ago I had my heart set on a standup electric 54" mower.













because of the size of my test area I had to keep the 14hp gas engine to run the blades and install an alternator to keep the batteries charged for the drive wheels. I also had to install 2- 500cfm blowers to keep the alternator from over heating.

after I got my fix for a standup, I changed it to an automictic mower

 

[D71]

There was a time when local colleges would build robotic lawn mowers and the expanded competition go around USA - foreign country for robotic challenges - first ones were more rc oriented vs running on their own. It was suppose to be student engineers vs student engineers but like most everything the professor vs professor took it over as more and more competition grew. The colleges began to compete and advertise college robotic training with the lawn mower competitions. Then they went international. Mexico actually won several of the competitions. I stopped watching it when it became almost professor vs professor. Don’t even know if there are still robot lawnmower challenges at colleges. The originals drew crowds.

Japan was or had been doing it for a while - they made lawn mower like robots that would battle - broadcast it on tv. Parts would fly everywhere. I have not watched anything like that in years because it was to point of being silly. The robot lawn mowers had a purpose. I found them more of a practical application vs battle mowers. It was interesting and competition is a good thing to a point.