Black Cat

[Zerobricks]

After a bit of teasing arround I managed to build an 8 speed transmission. So after making the tranny, I had to think of a car to use it. In my mind the car was a bit inspired by Lambo's look and a bit by Ford GT. Everything else was more or less improvized.

So here's the first picture. I just dont have the heart to peel off the race truck stickers

The rear opens up using two air springs to show off the massive V12 middle-to rear placed engine. Also the exhaust pipes are nicely visible.

I was limited with the number of black panels, so the doors may seem a bit skinny. Each door uses a spring to help it lift up and lower. It also keeps it in end position.

The crown of the car is the 7+R gearboy (A first that I know off) with next gear ratios:

1 1:3,472

2 1:2,778

3 1:2,083

4 1:1,667

5 1:1,25

6 1:1

7 1:0,75

R 1:2,25

These are possible thanks to 20 and 16 tooth gear combos.

The way the power is delivered from all the four wheels is also complex. More or less everything is placed assimetrically to gain as much room as possible. Notice where the central differential is placed. And the fact, that the rear wheels due to being larger than front have a slightly different gear ratio.

You may have noticed that the front diff is offset half a stud in front. This has two advantages. The steering rack is this way one the proper place. Also thanks to ackermann effect due to links, this allows the inner wheel to steer at a higher angle than usual, which translates to a higher steering angle.

Another view of the gearbox. Notice the angled chassis connectors. These are at such an angle to make room for gears and to better support the floor.

The rear of the car with its 4 exhausts and the spoiler:

Another new thing in this car is the suspension. The springs are not directly attached to the upper links, but via the 3L half beam. The lower arm is connected to that half beam with a yellow 5L half beam. What this does is, that when the suspension is pushed upwards, the yellow links pull down the 3L half beams, therebye additionally pushing the springs. There are two benefits. Being a sportscar this lowers the suspension travel and hardenes the springs. It also makes the spring move in a more linear fashion.

Another thing this car has is also an adjustable steering wheel, you can see that and more in the video:

[jorgeopesi]

Nice car, you give me an idea

[DLuders]

In my mind the car was a bit inspired by Lambo's look and a bit by Ford GT. Everything else was more or less improvized.

This is very nice! I can some design elements from the Ford GT40, and (on other topic) Phoxtane noticed its strong resemblance to the Lamborghini Gallardo:

[Zerobricks]

Thanks for thumbs up!

For those who cant see the original version, there will be a muted version available here:

http://www.youtube.com/watch?v=O42ZmfXBU4g

[mahjqa]

Some very fine work, especially with the suspension and steering.

[timslegos]

Another awesome MOC, nicely done.

tim

[TimH]

Very nice MOC!

[timslegos]

Are you going to remove the green screen?

tim

[Saberwing40k]

Sorry, but I built a 7+R gearbox, and published it before you did. It was part of my

8070 Super Sports project.

Sadly, it did not work all that well, so yours is better.

And it comes in a great wrapper, too!

[Paul Boratko]

Sorry, but I built a 7+R gearbox, and published it before you did. It was part of my

8070 Super Sports project.

Sadly, it did not work all that well, so yours is better.

And it comes in a great wrapper, too!

I think he means with those specific gear ratios that he stated... His reverse gear is also on the opposite side of his transmission which is different than the one that you built, making this gearbox a little more unique... The key to getting 7 speeds(and reverse) to work well is stability in the structure that houses the axles and gears... If your structure is strong and rigid and your gears and axles stay true using liftarms rather than perpendicular connectors on axles, then everything should work smooth without binding up...

7+R gearboxes were done years ago, in fact there were gearboxes done with 14 speeds that I have seen many many moons ago and I am pretty certain that Zblj already knew that, so I think that he was referring to his own design here...

The problem with these larger speed transmissions is that it begins to alter the overall proportions of the car because they begin to take up too much room between the seats and make the car wider than it should be....

I think it is time for Lego to bring out some new sized clutch gears so we can start to build transmissions properly instead of making them harder than they need to be...

By the way Zblj, if you want to peel off the stickers, I'll be more than happy to hook you up with a brand new sticker sheet...

Just P.M. me your address...

Edited August 12, 2012 by Paul Boratko

[rm8]

idea

Stickers

[Andyrccar]

idea

Stickers

I love it , more sticker would be better

[Zerobricks]

I love it , more sticker would be better

Well I guess thank to Paul you wont see any stickers for a long time About the 7+r gearbox. The first design had lots of friction because the low gears were powered from the top ones down, making a long chain of gears. So in order to make it more efficient the gears are powered from low ones with highest gear ratios and therefor friction to the top ones, which roll smoothest. Also thanks to 24 tooth gears I was able to pull off 12:20 gear ratio for odd gears and room for another 8 tooth gear for reverse gear.

[Zerobricks]

So here's a stickerless version:

[Jurgen Krooshoop]

Good lookin' MOC with good functions . And it looks a lot better without the stickers. This is why I don't put stickers on my bricks in the first place.

Edited August 12, 2012 by Jurgen Krooshoop

[captainmib]

I like the stickerless version better as well.

Nice car and that gearbox is huge!

How many gears did you use? Around 20?

[Zerobricks]

I just counted them:

2 x 8 tooth gears

10 x 12 tooth bewel gears

5 x 12 tooth gears

14 x 16 tooth gears

8 x 16 tooth clutch gears

8 x 20 tooth gears

3 x 24 tooth gears

2 x knob gears

1 x old sytle diff gear

2 x new style diff gears

So the total is 55 gears.

[DLuders]

@ Zblj: Are you planning on making a Lego Digital Designer (LDD) .lxf file, or does meshing the 55 gears in LDD take too much time?

[Zerobricks]

@ Zblj: Are you planning on making a Lego Digital Designer (LDD) .lxf file, or does meshing the 55 gears in LDD take too much time?

Supply and Demand, David. If enoughy people demand, than I may make them.

[captainmib]

I just counted them:

2 x 8 tooth gears

10 x 12 tooth bewel gears

5 x 12 tooth gears

14 x 16 tooth gears

8 x 16 tooth clutch gears

8 x 20 tooth gears

3 x 24 tooth gears

2 x knob gears

1 x old sytle diff gear

2 x new style diff gears

So the total is 55 gears.

Wow that's a lot!

Haha, Dluders, you know how to put some pressure on a builder. Meshing that amount in LDD must be very very frustrating

[DLuders]

Yes, but Zblj is the BEST in the world in making difficult Lego Technic models in LDD. If anybody can do it, he can!

[grohl]

Yes, the version without stickers does look a lot better. The headlights are awesome.

[AndroTech]

Without stickers is definitely better. Well done. Can you take some more pictures from the different angles, so we can see this beauty better.

[mo_]

This is just amazing! You are a talented builder.

I enjoy seeing these types of creations, keep up the good work

[Zerobricks]

Thanks! Praise means a lot to me