[Lupinthief]

Hi. I'm fairly new here and have been fascinated by the wisdom and information available here. I am, however, intrigued because there seem to be very few people building from scratch and those vehicles which are aren't usually for road use.

I reckon that if a car were build from scratch and some concessions were made to the necessities of weight, rolling resistance and aerodynamics, and one modified one's expectations of what the car could do (i.e. accept that there is limited boot space etc.) then the performance and range for a given elecrical setup could be significantly improved.

I've built a few vehicles and reckon (if using LiPos) that a 2-seater vehicle could come in well under 300kg without passengers, if not close to 200kg and have a CDA of under 0.2 if well designed.

Has anyone tried to build from scratch or have any advice on such a policy? There must be something I'm missing.

Thoughts and inspiration welcome

 

[Woodsmith]

Ahem! (Stands up and waves hand!)

It's all very well suggesting that though.
Most, almost all, people either don't want to, are unable to, or can't afford the time or money required to build from scratch. Also not every country makes it easy to build from scratch and be road legal either.

There is a lot of work involved and it doesn't always yield the desired results from a DIY approach unless a great deal of skill, or luck, is used on getting the design right to even get close to matching a good mass production car in terms of handling or aerodynamics.

If you have the skills and experience it would be good for you to share what you have done or your plans for your EV.

 

[Lupinthief]

Ok, well it started with Ford Greenpower, which was pretty basic. Then I got involved with solar cars at uni and built one which we got road legal (with certain restrictions) in the UK. Then we built this one to race in Australia (see below, white one). Seeing what we achieved and, moreover, what some of the more experienced teams were able to do with a 2kw continuous, 5kw max setup has convinced me that there is mileage in electric cars (although I remain unconvinced by solar). One team clocked 157kph and the winners in Australia averaged 100kph over 3000km on an average of about 1.6-1.8kw.

I take your points, these were expensive vehicles to build but I wouldn't be looking to do quite such a Hi-tech job and the whole solar aspect would be cut out. I'm quite happy to compromise on space, handling (to a degree) and safety (I already accept that if I crash I'm basically done for). Fortunately the UK makes it relatively easy to get home builds legal (my runabout is an ICE trike).

What I would be planning is a lightweight spaceframe chassis (probably alloy) with two hub motors driving rear wheels and a single front wheel. Looking for a total power of about 10-15kw if I can find motors with adequate starting torque. Encapsulate the whole thing in a balsa and GRP shell (because I can't afford Nomex or carbon and don't have the facilities for anything but a wet layup). The shape of the car is inspired by one built a few years ago by Bochum and was actually designed as a potential two seater (yellow, below)


Happy to answer any questions or offer any ehlp I can.

 

[nimblemotors]

building a car that proves a concept or wins a race means very little in the real world of 1-ton trucks, stop-n-go traffic, parking, freeways, 50mpg winds, rain, ice, snow, 16yr old drivers, 96 year old drivers, etc, etc. It isn't about whats POSSIBLE, it is about whats PRACTICAL and SAFE.

Ok, well it started with Ford Greenpower, which was pretty basic. Then I got involved with solar cars at uni and built one which we got road legal (with certain restrictions) in the UK. Then we built this one to race in Australia (see below, white one). Seeing what we achieved and, moreover, what some of the more experienced teams were able to do with a 2kw continuous, 5kw max setup has convinced me that there is mileage in electric cars (although I remain unconvinced by solar). One team clocked 157kph and the winners in Australia averaged 100kph over 3000km on an average of about 1.6-1.8kw.

I take your points, these were expensive vehicles to build but I wouldn't be looking to do quite such a Hi-tech job and the whole solar aspect would be cut out. I'm quite happy to compromise on space, handling (to a degree) and safety (I already accept that if I crash I'm basically done for). Fortunately the UK makes it relatively easy to get home builds legal (my runabout is an ICE trike).

What I would be planning is a lightweight spaceframe chassis (probably alloy) with two hub motors driving rear wheels and a single front wheel. Looking for a total power of about 10-15kw if I can find motors with adequate starting torque. Encapsulate the whole thing in a balsa and GRP shell (because I can't afford Nomex or carbon and don't have the facilities for anything but a wet layup). The shape of the car is inspired by one built a few years ago by Bochum and was actually designed as a potential two seater (yellow, below)


Happy to answer any questions or offer any ehlp I can.

 

[Lupinthief]

Very true, but I'm not talking about a viable production vehicle or even one with resale value above that of the components. I'm talking about an efficient design which has practical performance, is minimal and which is safe enough that I am happy to drive it. I admit it is ambitious and not to everone's taste but I think it could be practical for getting from A to B, and I don't see why rain should be a problem. Strong winds, however, might be a concern.

These cars were driven through cities and raced on the highway overtaking and being overtaken by two or three trailer road trains so they're not as vulnerable as they may appear.

building a car that proves a concept or wins a race means very little in the real world of 1-ton trucks, stop-n-go traffic, parking, freeways, 50mpg winds, rain, ice, snow, 16yr old drivers, 96 year old drivers, etc, etc. It isn't about whats POSSIBLE, it is about whats PRACTICAL and SAFE.

 

[LithiumaniacsEVRacing]

Building a car from scratch is not an easy task, unless you have a complete fabrication shop in your hands. The frame must be built with specific 'load' supports and welded, it needs to be measured on a frame machine that can pinpoint all your heights and angles. Your best bet is to buy a chrome-moly chassis from a chassis shop and build from there.

http://www.cachassisworks.com/c-106-avengerpro-mod-chassis-kits.aspx

Hi. I'm fairly new here and have been fascinated by the wisdom and information available here. I am, however, intrigued because there seem to be very few people building from scratch and those vehicles which are aren't usually for road use.

I reckon that if a car were build from scratch and some concessions were made to the necessities of weight, rolling resistance and aerodynamics, and one modified one's expectations of what the car could do (i.e. accept that there is limited boot space etc.) then the performance and range for a given elecrical setup could be significantly improved.

I've built a few vehicles and reckon (if using LiPos) that a 2-seater vehicle could come in well under 300kg without passengers, if not close to 200kg and have a CDA of under 0.2 if well designed.

Has anyone tried to build from scratch or have any advice on such a policy? There must be something I'm missing.

Thoughts and inspiration welcome

 

[Lupinthief]

Thanks, looks like a pretty interesting company, I'll have a browse. You're right, getting the chassis safe and legal is the toughest part.

 

[Woodsmith]

Very true, but I'm not talking about a viable production vehicle or even one with resale value above that of the components. I'm talking about an efficient design which has practical performance, is minimal and which is safe enough that I am happy to drive it. I admit it is ambitious and not to everone's taste but I think it could be practical for getting from A to B, and I don't see why rain should be a problem. Strong winds, however, might be a concern.

These cars were driven through cities and raced on the highway overtaking and being overtaken by two or three trailer road trains so they're not as vulnerable as they may appear.

It sounds like a good concept but the other thing in reality is that it would need to not just survive being overtaken by trucks but also the occasional contact.

In the real world you would want something that is also easy to get in and out of in a suit or a dress, carry the shopping/baby/dog, has good visibilty both driving and parking, etc.

The is a big difference between one off concepts that prove what is possible and a realistic day to day vehicle.

What market or use are you aiming to design and build for?

 

[MalcolmB]

Has anyone tried to build from scratch or have any advice on such a policy? There must be something I'm missing.

It's something I will probably do eventually, but I'm working my way up to it gently. The plan you've sketched out is something I think a lot more people would do if it weren't for the practicalities/perils of coping with existing traffic. Personally I think most cars are at least three times as heavy as they need to be, given average speeds (in the UK), but no matter how much I curse SUVs and pickup trucks, people keep on buying more of them. Having built a recumbent (pedal) trike, and converted a motorcycle to electric, I'm now converting the smallest car I could find (an old Mini), as it's the best compromise I can find.

Your plan sounds good and I love the yellow streamliner, but if you're serious about reducing weight I think the hub motors would be a heavy choice. Better to use a lighter, faster-spinning motor, or motors, mounted inboard with a single ratio reduction.

 

[Ingot]

What I would be planning is a lightweight spaceframe chassis (probably alloy) with two hub motors driving rear wheels and a single front wheel.

Three-wheel systems are horrible; no offense, but they are. Not sure what everyone's fascination with them is, really.

 

[toddshotrods]

Ahem! (Stands up and waves hand!)...

Joins in with Woody (standing and waving), count me in that mess!

The thing about any serious custom project, especially a scratch-built vehicle, is there are just a tremendous amount of decisions to make. As I'm sure Woody, and the other scratch-builders here, can attest to - just getting to the point where you know what you really need/want to build for a chassis can be like climbing a mountain. Every decision leads to ten more... That's before you ever throw the first spark. Unless you're building an exact replicar, clone, spec-class racer, or something otherwise pre-determined, that process grows exponentially as you build. Most people simply don't have the time and/or finances and/or patience to become that involved.

building a car that proves a concept or wins a race means very little in the real world of 1-ton trucks, stop-n-go traffic, parking, freeways, 50mpg winds, rain, ice, snow, 16yr old drivers, 96 year old drivers, etc, etc. It isn't about whats POSSIBLE, it is about whats PRACTICAL and SAFE.

I think it's also easy for people to underestimate the time, money, design, and engineering that goes into a standard production vehicle. Honestly, most modern production vehicles are hard to beat. So, when you do a conversion, you take advantage of millions of dollars of development work. The challenge is just to do the best you can to make the EV conversion a seamless part of the original vehicle. That can be a serious challenge in itself for even a decent custom or conversion shop.

I've seen many custom vehicle projects, based on production vehicles, over the years I've been in the industry that resulted in almost immediately dissatisfaction when the owner finally got to enjoy them. It's easy to make a production vehicle feel, handle, and ride like a pile of crap - much easier to build a pile of crap from scratch. That makes a conversion an easier risk to swallow.

 

[nimblemotors]

that is hilarious, they do such a great job.

oh yeah, scratch built car, I suggest starting at the bottom, rather than the top of the automotive hobby,
build a go-cart before a F1 racecar, convert to an EV. start simple. My friend and I built three go carts before I was 16.
My first custom car I was 18 years old, swapped a complete Toyota drivetrain into a Anglia. This was after rebuilding my V8 engine twice
and a third time I put a stock motor in.. That Anglia was horrendous. Handled like crap,
I remember seeing the tires were low, filled them up to 30lbs, the car was scary as hellll, pulled over and let the air back out.

Three-wheel systems are horrible; no offense, but they are. Not sure what everyone's fascination with them is, really.

 

[Ingot]

that is hilarious, they do such a great job.

oh yeah, scratch built car, I suggest starting at the bottom, rather than the top of the automotive hobby,
build a go-cart before a F1 racecar, convert to an EV. start simple. My friend and I built three go carts before I was 16.
My first custom car I was 18 years old, swapped a complete Toyota drivetrain into a Anglia. This was after rebuilding my V8 engine twice
and a third time I put a stock motor in.. That Anglia was horrendous. Handled like crap,
I remember seeing the tires were low, filled them up to 30lbs, the car was scary as hellll, pulled over and let the air back out.

I'll agree with that! I have no experience in building a car or anything other than computers and networks but I'll say that I'm sure it takes a lot of knowledge to be able to build a car from scratch.

I mean, there have been a lot of EVs built from scratch, specifically for longevity, power, practicality, etc. Look at http://www.progressiveautoxprize.org/ for some examples.

Other than that, unless you're very, very rich, or backed by a very, very rich source of lots and lots of money, there's not much sense in starting from scratch because you're not going to make the best car you could make.

Not wanting to shoot down your dreams, you've obviously had more experience than me, I say just build what you can, as well as you can, with a pre-existing car. Convert and modify the hell out of it, make a blog about it, make videos of it, show off the build, and be proud of it, I guess? Won't be the best car in the world, but hey! Better than what most people will build in their lifetimes, most people won't even attempt a build, and even more won't keep at it or finish it.

 

[toddshotrods]

Just for clarification, there are two reasons (that I can think of right now) for building a vehicle from scratch.

1. A Sense of Satisfaction that only comes from transforming raw materials into something real and functional. Making custom parts is an awesome feeling in itself, but seeing an entire vehicle rise from the dust, and knowing you're the reason, is beyond descritption.
2. A Concept for Which No Good Base Exists. Sometimes there is just nothing even close enough to avoid compromising the design and goals of the project. Many custom one-off hot rods happen this way, because there just isn't anything original close enough, or worth starting with. The job is easier from scratch.

The key is that real-world functionality, in the two cases I listed, is a subordinate goal - if one at all. I decided to build mine solely for the first reason. I have been doing custom work for over two decades, but never did a complete scratch build. I did a couple that were so intense they would have been better if they had been started from scratch (lesson learned), but I wanted to put the notch on my walking stick of having done a full scratch-build.

In it up to my neck now, with an incredibly long way to go, I wouldn't trade the experience for anything I have ever done before! It's beyond description. I see myself doing it again...

 

[Duncan]

Hi Lupinthief

I'm building a scratch built - its fun - I expect to end up with a fun toy! - it won't be able to compete with a conversion for practicality but it should be fast

See - Duncan's Dubious Device

Saying that if you want a trike - two wheels at the front please!!!

You have two possible routes
Electric HPV type - aim for maximum weight 150Kg
Small car - difficult to get below 450Kg

If you try and split the difference you will end up with a heavy thing that fails

Look up Locost for chassis ideas -
note the chassis is the easy bit its all of the things that hang off it and have to work together that take the time

 

[Lupinthief]

Good thoughts everyone, thanks.
I've already been looking at locost chassis and they look promising with some modification.

As for real world practicalities, the idea is to be able to transport one or two people and an overnight bag, not do the weekly shop or collect a ton of hardcore. It isn't aimed at any market at all, just my own enjoyment and a steep learning curve. That said it won't be the first time I've built from scratch, just the first EV, and the first where weight and aero are a consideration.

Good points re. hub motor weight and two wheels at the front, although I've never had any complaints about the handling of my ICE trike with a single front wheel.

 

[Woodsmith]

I'd also second Todd's reasons.

I want to have the feeling of personally creating something from the ground up and only using those parts that I cannot (or cannot justify to) make for myself.

I am aiming for a 70mile round trip at 70 mph to get myself to work and back with the option of carrying a little light luggage/shopping and/or a passenger.
Though I could do that with a standard converted vehicle I can build a little lighter to save battery pack capacity and have a vehicle that only meets my requirements and not requirements that I don't need.

Also for the effort involved in finding the time and money to invest in it I want something that I will 'love' and 'cherish' more then a random cheap mass market hatchback that I have no personal connection with.

I look forward to how your designs develop here, Lupin.

 

[Lupinthief]

I'd also second Todd's reasons.

I want to have the feeling of personally creating something from the ground up and only using those parts that I cannot (or cannot justify to) make for myself.

I am aiming for a 70mile round trip at 70 mph to get myself to work and back with the option of carrying a little light luggage/shopping and/or a passenger.
Though I could do that with a standard converted vehicle I can build a little lighter to save battery pack capacity and have a vehicle that only meets my requirements and not requirements that I don't need.

Also for the effort involved in finding the time and money to invest in it I want something that I will 'love' and 'cherish' more then a random cheap mass market hatchback that I have no personal connection with.

I look forward to how your designs develop here, Lupin.

Thanks, that's very much my perspective. I'll keep working on it.

 

[Woodsmith]

That's good.

As much as this forum is mostly DIY conversions the builds and scratch builds are great to learn from and read about and would hopefully inspire others in detail as well as in the overall concept.

The best thing about scratch builds is when they are completed, working and on the road.

 

[Thumper]

I'm working on a scratch build.
It's a two seater sports car. I've finished the chassis and am starting to mount the fiberglass body. Winter is holding me up as it's too messy and dusty to do fiberglass work in the shop.

The car has an AC50 drive using suzuki swift transaxle and a 96 volt 100Ah LiFePo4 battery pack. It's final weight should be around 1100 lb. I expect 0 to 60 mph to be around 6 seconds.

It's a lot of work and engineering build a car from scratch. I started over a year ago and since I'm retired, I can work on it pretty well every day.

Complete build log here -> http://www.szott.com/zot2/zot2.html

Happy to answer any questions.