[MOC] Speed of fun, Build the Porsche of your dreams entry

[Jeroen Ottens]

Hi,

Here is my entry for the build the Porsche of your dreams contest. It is a remote controlled, lightweight Porsche of an undefined type (unless someone recognizes this instantly as a particular Porsche type).

The model weighs 1.5 kg of which 300 g is 12 AA batteries. It is powered by 2 L-motors that have each their own batterypack.

Steering is done with a servomotor. The steeringwheel inside is functional as well (as in, it turns also when the servo turns):

I tried to minimize weight as much as possible, so I used both the motors and the battery packs as structural elements in the construction. Changing batteries is now not something you want to do .

I always wanted to make a model without paneling and since this model needed to be lightweight it was the perfect excuse to finally build a completely open model.

I particularly like the top view. Here you can really see how the lines flow on this model. Something that I find difficult to capture in the other shots.

As usual comments and questions are highly appreciated.

Leg godt,

Jeroen

[JGW3000]

Well done, clearly recognizable as having Porsche 'DNA', even with the well-executed minimalistic bodywork. Use of flex axles throughout works exceptionally well in this case. Any chance for video?

[BusterHaus]

The side picture looks great, too. You can't mistake it for any other car. Good luck in the contest!

[Leonardo da Bricki]

It is quite obviously a Porsche, if not a specific model. Can we get a video of it driving? I would like to see it's speed.

[ChrisYe]

Love this! Very aesthetically pleasing how the red lines stand out from the body showing off that well known Porshe shape.

Edited June 22, 2016 by ChrisYe

[Lox Lego]

Love this design. Wish I had that many red flex axles!! Please post video of performance

[offroadcreations]

Wow! All the flowing curves make this beautiful, and easily recognizable as a Porsche. Also, "Speed of Fun" is an awesome name!

[Victor Imaginator]

Side shot is just wonderful) Beautiful model.

[Didumos69]

It seems like you can dream in flex axles Very nice light weight bodywork. I love to see how you can bring forward the essence of a car with just a few lines.

[WvG_853]

Wow! I really like this minimalist and open design. It reminds a bit of a sketch for a new model and is instantly recognisable as a Porsche. Personally I prefer such a model on a shelf than a panneled model which may be more appealing to a younger public. Also nice how you have hidden the power functions.

Good luck!

Willem

[lcvisser]

Wow, this is so nice. Indeed instantly recognisable as a Porsche. Also the interior is nicely done with minimal parts. Excellent!

[ThomasGraafland]

Very recognisable and the shape is done beautiful. I'm not really a fan of the way you did the headlights, but I love all the rest of the car.

[Equilibrium]

I really like it. Especially from the side view. It would look even better if You curved back (rear window, engine cover) a little.

[agrof]

As a "panel guy", I never thought, but actually I really like this concept, how the wireframe body reveals all the chassis technic bits!

Would be even more exciting with fake engine + simle gearbox, so the classic supercar recipe.

Agree with above, the rear could be a bit more curved, but very well executed lines all in all.

Edited June 24, 2016 by agrof

[Jeroen Ottens]

Thanks for all the comments, much appreciated.

I used 8x 19L, 2x 16L, 5x 12L, 2x 11L and 1x 7L flexaxles. Of those only the 16L is getting rare/expensive.

I am planning on making a video, but that will take some time. I have a pretty busy schedule the coming weeks.

[JJ2]

I'm a little bit late to the party but this is a beautiful model and %100 a porsche, it almost looks like a corvette stingray mixed with a porsche 911.

[Jeroen Ottens]

Hi,

Here is the video:

Enjoy

Edited July 16, 2016 by Jeroen Ottens

[brunojj1]

Very nice Porsche IMO with the smoothest round shaped lines so far in the contest and the fastest supposedly ! Is this at "8x speed" at 0:05 ??

I must admit it seems you had a lack of passion (or were bored to death?) building this model and it wasn´t as much challenging / interesting to built, do you agree? Anyway, everything clean and pretty and I like the "alternative" approach though .

What does the gear reduction at the drivetrain look like? Why only 2 L motors and not 4 instead like in Madoca´s Icarus - plenty of space? Why 2 heavy batteries instead of 1 (come on "structural elements")...? Bottom picture available? Thanks in advance !

[Jeroen Ottens]

Very nice Porsche IMO with the smoothest round shaped lines so far in the contest and the fastest supposedly ! Is this at "8x speed" at 0:05 ??

I must admit it seems you had a lack of passion (or were bored to death?) building this model and it wasn´t as much challenging / interesting to built, do you agree? Anyway, everything clean and pretty and I like the "alternative" approach though .

What does the gear reduction at the drivetrain look like? Why only 2 L motors and not 4 instead like in Madoca´s Icarus - plenty of space? Why 2 heavy batteries instead of 1 (come on "structural elements")...? Bottom picture available? Thanks in advance !

Hi Brunojj

Thanks for the thoughtprovoking comments. Let me answer them one by one:

The speed is not edited , the L-motors have a 3x1 gear ratio to the diff (similar to Madoca's Icarus) and they seem to run at a pretty high rev

The reason to opt for only 2 motors instead of 4 was threefold:

1) I wanted to place the motors behind the rearaxle just like in a real Porsche. There the space is a bit more limited, plus the center of gravity would move further backwards if I added two more motors

2) I only have 3 L-motors

3) I don't have a V2 IR receiver, so I wanted to use only one motor per channel. With four motors I would need 3 IR receivers (2 for the motors + 1 for the servo). What I did try was to use three motors. But starting up the engine with an IR remote became very difficult. I think one of the motors would start just a bit later, thereby stalling the other two. Then the current protection would kick in and all motors would stop. And then it would start over again. The car sort of stuttert over the floor.

I do have some S-bricks and maybe they don't have this synchronization issue, but I haven't tried them since I wanted to be 100% Lego with this creation.

With two motors the car clearly accelerates for a second before it reaches top-speed. This could still be due to the motors not exactly spinning up at the same rate, or maybe it is just the normal acceleration of mass.

The reason for using two batteryboxes was to prevent currentlimiting at all cost. If I would use only one batterybox the maximum current per motor would be 0.5 A (and then the servo will take up some juice as well). Now it is 1 A per motor (minus a bit for the servomotor for one motor when it steers). Removing one batterybox will only save 15% of weight, so if the motors now use more then 0.58A this will be faster. At least in theory Whether or not this makes a difference in practice I don't know, because I haven't tested the single batterybox configuration.

This does beg the question whether 4 motors with 2 batteryboxes will be faster or not... You are then again limited to max 0.5 A per motor, but more likely to meet that limit then meeting the 1 A limit with one motor... Which is a good thing because you use more power from the batteryboxes... I think

I always try to design my cars mechanically sound. Since there is no stiffness to be gained from the bodywork I wanted to have a central column in the car that would give the rigidity. Otherwise independent suspension would also be completely pointless . The batteryboxes, the servomotor and the L-motors are all part of that central column. I also made sure that the car can be lifted by using the B-frames as a handle.

I am interested to know what brought you to the observation that you think I had a lack of passion building this model.

For me this was a build outside my comfortzone. Limiting the features to a minimum to save weight is not my favorite passtime . Also sculpting with nothing but flexaxles and beams is not my natural style . But, the moment this competition was announced, I knew this was what I wanted to build: A Porsche optimized for speed and speed alone. It would give me the opportunity to try to make a flexaxle body (which was on my wishlist ever since I saw Sariel's Zonda). I even considered not putting in any suspension, but than the car would become to non-functional I just couldn't bring myself to do that. The same holds for the interior. I could have done without it to save a few more grammes, but it just didn't look right (and I personally really like the two-tone, understated smooth look it has gotten).

But it doesn't have a lot of intricate mechanisms inside (like the Alpha Romeo or the LTM11200) which is what I usually really crave for in Technic models. The suspension setups are pretty standard and a RC drivetrain with 8 gears (differential counted as one) is not as exciting to me as a flappy pedal operated 8D+N+R gearbox with over 30 gears that fits below the rearaxle...

Still... The goal was different... The goal was speed in a lean Porsche design... And that goal was met (at least to my standards). It is fast. And it has some beautiful lines (which was easy in a sense that I just had to copy Porsche's design in flexaxles). Was it the most challenging design I ever did? No, definitely not. Did it turn out like I wanted it to? Yes it did. Did it spark my passions? Difficult to say. Designing and building was fun, but not too challenging. The end-result is very satisfactory, but since I more a builder than a collector I value that less I guess.

So I am not disagreeing per se with your observation about my passion and wonder what has given that away.

Here is a picture from the underside:

[Lipko]

The steering seems to jam a bit.

[WvG_853]

From all the candidates I have seen so far, this is my favourite...

[brunojj1]

Hi Brunojj

Thanks for the thoughtprovoking comments.

.......

I am interested to know what brought you to the observation that you think I had a lack of passion building this model.

Normally I would have expected more attention to details, light weight or not. E.g. the interiour could be made DBG unicolor or other interesting color (white?) to give some contrast to "mechanical" elements which are poor since only PF stuff / because of reasonable weight cutting. The lack of some additional components such as motors, SBrick or lighter batteries (with modified superstructure) is understandable. Also understandable that you don´t want to invest too much time being busy with more important stuff such as the Aston ...

The steering seems to jam a bit.

That´s some phenomenon you experience with servos when some beams`holes scrub against the gear rack. There is some pause between the regular rotation movement and final adjustment which pushes with the tiny extra amount of power overcoming the resistance.

Edit: don't know how to explain the weird fact that it often occurs on one side only...

Edited July 16, 2016 by brunojj1

[jorgeopesi]

The steering seems to jam a bit.

I think front wheels touch the wheel arch when turning, I have had a lot of headaches because I like small wheel archs...

[brunojj1]

I think front wheels touch the wheel arch when turning, I have had a lot of headaches because I like small wheel archs...

Now I see, thanks. Agree, like em too! Perhaps it's because of rigidity, you never know, minumum weight means few parts and clever statics... These wheels have a terrible offset compared to new Porsche wheels!

Edited July 17, 2016 by brunojj1

[Lipko]

I think front wheels touch the wheel arch when turning, I have had a lot of headaches because I like small wheel archs...

I thought you care much more about the mechanics than the looks