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Largo EV7 build blog.

5135 Views 12 Replies 4 Participants Last post by  kingyoungvee, 
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Hi Guys.

As promised in the tech question thread, I will post my build as it comes along. There will be spurts and there will be pauses due to the nature of my other interests and businesses, but now, at least for the moment, this is about number 2 priority.

Many know the timeline of the Lotus 7, released in 1957 and built by Lotus until 1972 when taken over by Caterham Cars in England, and much developed since, along with it's price, far removed from Colin Chapman's original cheap, simple concept.

Since Caterham took control, a number of other manufactures have come along to offer similar kits, also a book in the 1990's of how to build a similar sports car to the Lotus 7 for small sums of money, this earn't those builds the name of Locost, a play on Lotus. https://en.wikipedia.org/wiki/Locost

I considered building a Locost by the book but after a lot of investigation, found numbers of issues. handling, torsional strength for the HP I was seeking, and I struggled to get in one, and once in, my upper limbs were hanging out of the car, and you needed to be real good friends with your passenger!

So I designed my own chassis to tremendously up the torsional stiffness, locate the rear axle properly, and for 2 large adults to comfortably sit inside including all limbs. Because it might be seen of the Locost ilk, and because it's larger, the name "Largo" came to mind.

This all happened a few years ago, and the car was well under way when I had the offer of a very important business project that took up all my time, 24/7, and had to simply stop at that point.

Now my time is freeing up a little and since then I have come into possession of 2 electric cars, a Tesla S and a JAC iEV6S and being smitten by electric power, I now want to redo my Largo, but as an electric sports car, and so it begins!

Drawing from all my earlier Largo computer designs, I started a basic chassis last week, and last night drew up some early bodywork, then this morning lasered those panels out in preparation for fitment. Previously I had fiberglass bodywork, and still have all my molds, but I want to go predominately with aluminium panels this time. The test ones you see here are just galvanised steel sheets because they are cheap while I get the patterns for laser cutting right.

I'm meeting a few people over the next few weeks to sort out an electric driveline for it as my knowledge in the area is rather limited at the moment.

A picture you see below shows the earlier bodywork patterns, ironically I used alumnium to make the pattern at the rear for a fiberglass mold! (the bonnet/nose is made from wood convered in body putty).

The older mostly complete chassis that the new one is based on.

The new one last week.

And today looking towards shaping the new bodywork panels. The bonnet and scuttle are still flat here, although I did put a triangle fold up the middle of the bonnet for strength. (a plane I'm building and my Tesla on charge in the background).

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Duncan
Looking Good!

About your dash panel
Modern cars have the instruments a long way underneath the dash - so that you don't get problems with the sun on your instruments

I didn't do that and my instruments are nearly unusable most of the time

I didn't notice that as a problem back in the UK a few decades ago! Maybe something to do with the sun in the UK -
But here (NZ) I think I need to have the instruments buried quite a long way - 150mm? - inside the dash

Looking at your chassis you have done one of the things that I decided I SHOULD have done!

I have the passengers sit between the wheels - which limits the width of the passenger "box"
If I had moved the passengers forwards about 60 mm then I could have made the passengers box a bit wider

As it is with my wide transmission tunnel - which has the engine and the front of the dif in it - and my wide butt I have enough room to sit in the car but I need to do some gymnastics to get the seat belts into position

The most difficult thing about an EV like this is room for the batteries

By having the motor where a gearbox would normally live I managed to have a front rectangular battery box - yours looks better for that than mine
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Duncan
As far as the "Largo" bit is concerned

A "proper" Caterham is tiny - and I have been castigated for building something that is too big

But
Last year I took the Device to an EV display in Dunedin - 135 EV's!
And they asked to borrow it for a car show the next weekend

There were 5 EV's there (including mine) - but the interesting thing was they were displayed next to the "Lotus 7's" - about five or six of them

NONE of them were proper small Caterham's or Loti - they were all built around modern running gear and were all about the same size as my car - I'm a bit overbuilt so I think I was heaviest - But I was also the most powerful!
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Duncan said:
Looking at your chassis you have done one of the things that I decided I SHOULD have done!

I have the passengers sit between the wheels - which limits the width of the passenger "box"
If I had moved the passengers forwards about 60 mm then I could have made the passengers box a bit wider
Click to expand...
Sure, but at what point do you say this has nothing to do with the original Lotus 7 configuration, and give up on the separate-fenders look, with wheels outside of a tapered frame and people inside of it? Any typical sports car from the post-running-board era - so with full-width bodywork (or "envelope" styling) - is certainly a more usable package. For instance, something in the style of a Cobra replica would work. The Lotus 7 design makes sense for simplicity of bodywork, if you stay within the original packaging.

With a longitudinal motor driving a common IRS differential, one way to handle the problem of tunnel space could be to flip the differential and place the motor behind it (length available to the rear bumper would be an issue), leaving no need for anything but electrical cables down the tunnel and the whole front compartment available for battery. Of course ahead of the rear axle and behind the driver is better, but Lotus 7 proportions don't work very well for this; a "pancake" motor and short-nose diff might work.

With a beam axle (not independent suspension) you're essentially stuck with placing the motor in the tunnel or further forward. The are live beam axle setups with the motor behind the axle (such as common large buses, and the Solectria E-10 version of the Chev S-10 pickup), but that requires a lot of length behind the axle and isn't suitable for a sports car.
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Thanks for posting.

Duncan, yup, pasengers are as snug as a bug in a rug, it's a big car, not pretending it's of the Lotus 7 ethos. Modern tyres today allow one to obliterate that ethos though.

They are not dash panels, they are front and rear bonnet supports/shapers.

Actually with the bonnet, I sent my .dxf files to my laser guy and he asked what material, I just said 1mm gal will do (these are just test pieces) only to find this morning I couldn't curve the sides of the bonnet as it was too thick/strong!

So I popped over to the sheet shop and felt them, and grabbed a sheet of 0.6mm and cut it out this afternoon. See what becomes of it all tomorrow if I get an hour or 2.

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So I had a spare hour today and fitted the scuttle panel, was going to do the bonnet as well but my bonnet shaper/support panels were the wrong size, I screwed up on the computer. That's ok, that's why I use cheap steel on the first trial fittings.

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Bit more with getting a bonnet together today, getting the fitment right with this test one, and eventually will make the final one which will include you not seeing the rivets. .. and of course cut some louvres into it, gotta have louvres!

Now Duncan you can see that those dash panels are not dash panels!

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Duncan
Excellent - if a bit "overkill"

Now are you going to mount your actual dash panel at the front or the back of your scuttle?

https://www.google.co.nz/search?q=c...s-LYAhVHmpQKHcVUC2AQ_AUICigB&biw=1680&bih=959

This shows the "normal" way - but maybe we get a bit more sun here - I can't see the instruments most of the time
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Duncan said:
Excellent - if a bit "overkill"
Click to expand...
There is a reason for the way I do things, not always obvious to others. .. and FWIW, that assembly is lighter than a 'book' Locost bonnet even though it's larger.

The dash panel will probably be about 100 mm under, minor issue at the moment.
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Should have a fresh nose cone tomorrow, and at the same time I'm having a glass bonnet made up as well just to compare.

And who doesn't love it when a box of bits arrives! These lower wishbones already have coil over shock mounts from the factory ....

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Just plodding along getting my front suspension all sorted while I'm waiting for my nose cone and bonnet to be ready. Playing around with components from a couple of different vehicles to see which works out best.

Sadly I reckon I won't get a line on EV drivetrain until later next month as Chinese New Year is about to happen and they are slack before and after, can't get any info or anything done around this time.

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So my nose cone arrived, and I got a fiberglass bonnet off them at the same time, not sure how much of the bonnet I will use at this stage though.

I have been in heavy talks with an EV component supplier last week, quite disappointing price'wise, so I'll keep looking around.

Also receiving another new EV car today, not sure of all the details, think it's one of these ..

http://global.geely.com/car/emgrand-ev/

.
.

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kingyoungvee
LargoEV7 said:
Hi Guys.

As promised in the tech question thread, I will post my build as it comes along. There will be spurts and there will be pauses due to the nature of my other interests and businesses, but now, at least for the moment, this is about number 2 priority.

Many know the timeline of the Lotus 7, released in 1957 and built by Lotus until 1972 when taken over by Caterham Cars in England, and much developed since, along with it's price, far removed from Colin Chapman's original cheap, simple concept.

Since Caterham took control, a number of other manufactures have come along to offer similar kits, also a book in the 1990's of how to build a similar sports car to the Lotus 7 for small sums of money, this earn't those builds the name of Locost, a play on Lotus. https://en.wikipedia.org/wiki/Locost

I considered building a Locost by the book but after a lot of investigation, found numbers of issues. handling, torsional strength for the HP I was seeking, and I struggled to get in one, and once in, my upper limbs were hanging out of the car, and you needed to be real good friends with your passenger!

So I designed my own chassis to tremendously up the torsional stiffness, locate the rear axle properly, and for 2 large adults to comfortably sit inside including all limbs. Because it might be seen of the Locost ilk, and because it's larger, the name "Largo" came to mind.

This all happened a few years ago, and the car was well under way when I had the offer of a very important business project that took up all my time, 24/7, and had to simply stop at that point.

Now my time is freeing up a little and since then I have come into possession of 2 electric cars, a Tesla S and a JAC iEV6S and being smitten by electric power, I now want to redo my Largo, but as an electric sports car, and so it begins!

Drawing from all my earlier Largo computer designs, I started a basic chassis last week, and last night drew up some early bodywork, then this morning lasered those panels out in preparation for fitment. Previously I had fiberglass bodywork, and still have all my molds, but I want to go predominately with aluminium panels this time. The test ones you see here are just galvanised steel sheets because they are cheap while I get the patterns for laser cutting right.

I'm meeting a few people over the next few weeks to sort out an electric driveline for it as my knowledge in the area is rather limited at the moment.

A picture you see below shows the earlier bodywork patterns, ironically I used alumnium to make the pattern at the rear for a fiberglass mold! (the bonnet/nose is made from wood convered in body putty).

The older mostly complete chassis that the new one is based on.

The new one last week.

And today looking towards shaping the new bodywork panels. The bonnet and scuttle are still flat here, although I did put a triangle fold up the middle of the bonnet for strength. (a plane I'm building and my Tesla on charge in the background).
Click to expand...
is it possible if i could get the schematics of your largo chassis it seems to make more sense than the ones in the books
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