[MOC][WIP] Smart Fortwo

[johncarpenter]

Hello everyone!

This is a work-in-progress, or maybe work-on-hold project.

I wanted to do a simple, all manual Smart Fortwo, kind of matching the scale of the 42098 auto transporter.

I started off with the bodywork, and initally, it went quite well.

After some iteration, I was really happy with where it was going.

The back end is done, the front needs a little work, but I think the bodywork so far really captures the look of the Smart with the general shape and the minimal overhangs.

Next, I switched to the powertrain. My original plan was to have the 3 cylinder engine and a gearbox that would fit (maybe a 2 speed). While looking for compact gearbox designs, I stumbled across this CVT design on youtube:

https://www.youtube.com/watch?v=XmefDOFzLuY&t=3s

This looked very compact, and a CVT would be cooler than a 2 speed, so I went on with that.

My first draft of the powertrain was messy and fragile:

I redesigned this to a cleaner, still compact solution...

... and started to transplant the existing body to this new chassis.

At this point, I noticed that the CVT in this configuration did not really work. Most of the time, the motion is not transmitted enough to drive the 3 cylinder engine, so this solution doesn't really work.

The build is now on hold as I try to figure out how to move forward from here. I don't see any obvious way to make the CVT work better, so the options I'm thinking about are:

1. remove the CVT, no gears at all (very doable, but lacks ambition)
2. remove the CVT, make a 2 speed gearbox (difficult and 2 speed is "too litte")
3. put a Buwizz and some motors in it (not sure if everything will fit)

Looking forward to hearing feedback and suggestions...

[Scoar Sonander]

Wooh! Looking good!

[2GodBDGlory]

Lookin' good!

My sister adores Smart Cars, but I've never built one for her yet. Perhaps I could build yours to show her!

I would recommend your option #2 as being the right balance of complexity and possibility, unless you could figure out a way to get the CVT to work. Perhaps just lowering the gear ratio from the transmission to the engine could work by reducing strain on the transmission?

[syclone]

Looking really god so far, though maybe instead of the large 2x2 headlights the old transmission extension ring would look better. 

In regards of CVT, having built it myself too, I found it very dissapointing, since it couldn't handle even the slightest load. You could try using two cones with a rubber belt placed on them (sample below), though not sure how well it'd work if it's only the small 2x2 ones.

Spoiler

 

EDIT:

Or, keeping the same CVT as now, use the camshaft pieces instead of the 2L half-liftarms, then there'd be almost no resistance 

Edited April 24, 2021 by syclone

[Jurss]

Good start.

As mentioned, something is not OK with the front, not like smart.

[johncarpenter]

Thanks for the feedback. I'll report back once I figure out which direction to go.

Yeah, the front needs some work as well, I'll see if I can find that part.

[Kostq]

This Smart resembles an old one from here:

https://bricksafe.com/pages/Fanylover/Smart Fortwo

The door setup is almost the same and the front hood seems the same.

[johncarpenter]

Yeah, it looks like a pretty similar scale, so those panels are pretty obvious solutions. What is interesting is that this one does have power functions, even using the big battery box. It looks like it is a bit taller than mine, so a bit more space available. Even so, this gives me some hope that I could fit some motors in there.

[Kostq]

There's enough space there. If you put a smaller battery - even more space.

[LEGO Train 12 Volts]

Gorgeous MOC!

I like the final shape of the car, it looks like the real model!