[MOC] 1:8 Lamborghini Huracan

[mihao]

Hi, below is my new MOC of Lamborghini Huracan, and different from my earlier design, it is 1:8 (no more 1:12). I hope you like it.

There are many challenges, among them the most interesting one is the gear box, and I’d like to share some details here.

I only did a simple two-speed gear box in order to motorize it as planned. To minimize the energy loss, I put the XL motor as close as possible to the wheels. I started with the driving ring (2L or 3L), but they both failed because when torque is applied, they slide. The XL motor is way too powerful. The only possible solution is a heavy duty linear gearbox similar to the one below:

http://sariel.pl/2011/02/2-speed-heavy-duty-linear-gearbox/

I created my own version of it by embedding a differential, which can reduce the overall length to fit into the car body, as below. (I have to hide many parts to reveal the gears.) The red parts can slide to change gears, and the green axle connects to the motor. Thanks for the zero-friction 8 tooth gear (the red one), so I have chance to connect the motor output to a mini V8 fake engine as well.

The next question is how to lock the gears when they are in position. Tried a ton of approaches, and my final solution is to use two 24 tooth clutch gears as below. (one on each side.). Enough grip is provided to prevent shifting.

I also tried the new differential (the one like a chestnut), which generates higher torque but lower speed. It is not good for my MOC because 1) it makes my Lambo slow. 2) higher torque causes the gears to grind when installed. So I am pretty happy with the old differential. 

I'd like to hear your thoughts. Thanks!

Here is the video how it works.

The building instructions are available here in case you'd like to build the MOC.

https://rebrickable.com/mocs/MOC-132159

 

Update #1: here is the video of the gear box. I chose to use one XL motor (instead of two L motors) because 1) It is good enough 2) Possible to take it out from the MOC without dismantling the whole car. 3) It is cheaper.

 

Edited December 29, 2022 by mihao

[gyenesvi]

Cool looking Lambo, the body looks smooth, although with the black color, the gaps are harder to see anyway :)

4 hours ago, mihao said:

I started with the driving ring (2L or 3L), but they both failed because when torque is applied, they slide. The XL motor is way too powerful. The only possible solution is a heavy duty linear gearbox

Not sure I understand this clearly. What did you try to switch the driving ring with? An old style red selector or the orange wave selector? With the orange selector, it should be impossible to make the driving ring slide, and I never had problems with such 2-speed gearboxes, even under high torque. Did you try that? Or is the gearbox manual? Even in that case, you could keep the stick functional, and use a HoG shifter to actually shift. And it would be easy to motorize that as well.

As I see, you are using a single PF XL motor. For this car, I'd try two L motors coupled, because they are 2x faster, and even stronger together. There should be enough space for that in such a big body.

[Aleh]

Looks very cool in black! Three critics points, imo:

1) Big V12 engine will suit here better than this small one

2) Rear endseems to me a bit squared/boxy/vertically flat

3) Exhaust pipes have nothing common with the original model (twice more than in original, too wide)

[brunojj1]

Thank you for sharing your work with us ! First of all – congratulations for having the courage to take on the literally BIG challenge! As you have realized, the fabrication of a 1/8 scale car is a challenge on its own, motorizing is another step up. Installing a working gearbox is again a challenge above that. Then making a heavy car move at reasonable speed is the pinnacle. You have achieved all of that, hats off!

Now to the critiques: Maybe you shouldn´t have called the car „Huracan“, rather say „inspired by“ or something – then nobody has the right to criticize anything like that. The car doesn´t resemble a Lamborghini Huracan, at least for me! The front lights are the most important characteristic detail, the „eyes“ which make a „face“ recognizeable at first glance. They need to be angled at 45 degrees at least. The overall shape of the car is too squarish, especially the rear end with the exhaust pipes in line. Of course it´s an edgy Lambo after all, but anyway – it has slightly rounded edges everywhere if you look carefully. Did you use any blueprints for your build? I suppose you know Lox Lego´s approach – he has captured it very well in these aspects.

Then a Huracan has a V10-cylinder engine, as far as I´m concerned. I make a lot of comromises everywhere else too when it comes to secondary details, you just can´t interpret everything 1:1. But for me it´s mandatory to be faithful to a primary detail like the engine at least. Having not enough space is no excuse here, you have reduced the size already by going „mini-scale" for the engine.

I would recommend to use at least 2x L or 2xXL motors on a big car anyway. You didn´t mention what kind of device you´ve used for powering the motors – this information would be important. An underbelly shot would be nice to see as well. Great job with the gearbox however! No matter it´s based on a design from somebody else (you gave credit) – you have worked in sweat and tears, used it and upgraded to next level – I love this kind of smart solutions! Unfortunately you didn´t present how it shifts gears in the video, that would be great to see. I can´t wait for your next supercar evolution in this scale! Thanks again!

[mihao]

4 hours ago, gyenesvi said:

Cool looking Lambo, the body looks smooth, although with the black color, the gaps are harder to see anyway :)

Not sure I understand this clearly. What did you try to switch the driving ring with? An old style red selector or the orange wave selector? With the orange selector, it should be impossible to make the driving ring slide, and I never had problems with such 2-speed gearboxes, even under high torque. Did you try that? Or is the gearbox manual? Even in that case, you could keep the stick functional, and use a HoG shifter to actually shift. And it would be easy to motorize that as well.

As I see, you are using a single PF XL motor. For this car, I'd try two L motors coupled, because they are 2x faster, and even stronger together. There should be enough space for that in such a big body.

It is a manual gearbox, there is no space to add another motor for that. What I tried is the old red one, and the orange selector sounds to be another way to probe. 2 x L motor should also work, but 1 XL is a more economical solution, isn't it? Both on money and space. 

4 hours ago, Aleh said:

Looks very cool in black! Three critics points, imo:

1) Big V12 engine will suit here better than this small one

2) Rear endseems to me a bit squared/boxy/vertically flat

3) Exhaust pipes have nothing common with the original model (twice more than in original, too wide)

points taken. Thanks.

What I followed is the 2017 model like the one below. The rear end looks square and the exhaust pipes are not narrow. Are you referring a different model? For the engine, it should be v10 from what I know. I thought about that, but given that I have already modified the doors, I can live with a modified engine too. (Why no one mentioned the door difference. )

[mihao]

3 hours ago, brunojj1 said:

hank you for sharing your work with us ! First of all – congratulations for having the courage to take on the literally BIG challenge! As you have realized, the fabrication of a 1/8 scale car is a challenge on its own, motorizing is another step up. Installing a working gearbox is again a challenge above that. Then making a heavy car move at reasonable speed is the pinnacle. You have achieved all of that, hats off!

Thanks!

3 hours ago, brunojj1 said:

Now to the critiques: Maybe you shouldn´t have called the car „Huracan“, rather say „inspired by“ or something – then nobody has the right to criticize anything like that. The car doesn´t resemble a Lamborghini Huracan, at least for me! The front lights are the most important characteristic detail, the „eyes“ which make a „face“ recognizeable at first glance. They need to be angled at 45 degrees at least

Totally, this part is hard to achieve with the existing part, especially above the front wheels which need a lot of turning clearance.

3 hours ago, brunojj1 said:

Then a Huracan has a V10-cylinder engine, as far as I´m concerned. I make a lot of comromises everywhere else too when it comes to secondary details, you just can´t interpret everything 1:1. But for me it´s mandatory to be faithful to a primary detail like the engine at least. Having not enough space is no excuse here, you have reduced the size already by going „mini-scale" for the engine.

Yes, I know that, will see if possible to add 2 pistons back in. the normal scale is way too big, which can't fit.

3 hours ago, brunojj1 said:

I would recommend to use at least 2x L or 2xXL motors on a big car anyway. You didn´t mention what kind of device you´ve used for powering the motors – this information would be important. An underbelly shot would be nice to see as well. Great job with the gearbox however! No matter it´s based on a design from somebody else (you gave credit) – you have worked in sweat and tears, used it and upgraded to next level – I love this kind of smart solutions! Unfortunately you didn´t present how it shifts gears in the video, that would be great to see. I can´t wait for your next supercar evolution in this scale! Thanks again!

I agree that 2-motor is better, but it needs more space. Let's me see if I can put some picture of the gear box in details. Thanks!

[Aleh]

5 hours ago, mihao said:

 

What I followed is the 2017 model like the one below. The rear end looks square and the exhaust pipes are not narrow. Are you referring a different model? For the engine, it should be v10 from what I know. I thought about that, but given that I have already modified the doors, I can live with a modified engine too. (Why no one mentioned the door difference. )

Hm, I simply googled and found this one

I think one is facelifted and one is old version.

About V12 my bad - I didn't know they have V10 :) 

Anyway My POV is that the model looks very cool and angry a bit

[mihao]

2 hours ago, Aleh said:

Hm, I simply googled and found this one

I think one is facelifted and one is old version.

About V12 my bad - I didn't know they have V10 :) 

Anyway My POV is that the model looks very cool and angry a bit

Thanks. That's good advise anyway, I am working on updating v8 to v10 to make it more authentic. (Though I will keep the scissor doors, lol)

[LEGO Train 12 Volts]

Very nice model!

[mihao]

21 hours ago, brunojj1 said:

Unfortunately you didn´t present how it shifts gears in the video, that would be great to see. I can´t wait for your next supercar evolution in this scale! Thanks again!

Here is a short video of the gear box

 

[vascolp]

Its funny, you even move the motor, that's unusual!

Thats what makes it difficult to add another motor. 

I also like the idea of using the two 24 tooth clutch gears to keep the whole thing in place, it might be a useful idea.

By the way, nice MOC!

[mihao]

6 hours ago, vascolp said:

Its funny, you even move the motor, that's unusual!

Thats what makes it difficult to add another motor. 

I also like the idea of using the two 24 tooth clutch gears to keep the whole thing in place, it might be a useful idea.

By the way, nice MOC!

by moving the motor, the gear change can be achieved by using only two axles, otherwise, 3 axles are needed, that means more space. Mostly of the time, I am fighting with space. Thanks.

[brunojj1]

2 hours ago, mihao said:

Mostly of the time, I am fighting with space. 

Are you kidding me ? Considering you are used to fighting with the lack of space, usually building much smaller, yet very functional models, come on, my friend! As I see, there is vast room above the XL motor, between seats and engine, which you could easily use, not least you have upgraded to the right amount of cylinders btw. Is that where you have put your battery? Which kind are power source & controls? Do youreself a favour and be open to any critique! Please don´t be shy, don´t hide anything - I see big talent in you, you shouldn´t waste it! There is always the next „perfect“ project for which you can learn. You will learn quickly where the right pockets are where you can fit in all the devices naturally, at least I see no big secrets here.

[Celeri]

Very nice and smooth model, and bonus for the choice of color: I have always liked black Lambos (black Diablo FTW)!

I really like your gapless panel usage, and the parts used for lights is also a very fine touch.

Congrats!

[mihao]

47 minutes ago, brunojj1 said:

Are you kidding me ? Considering you are used to fighting with the lack of space, usually building much smaller, yet very functional models, come on, my friend! As I see, there is vast room above the XL motor, between seats and engine, which you could easily use, not least you have upgraded to the right amount of cylinders btw. Is that where you have put your battery? Which kind are power source & controls? Do youreself a favour and be open to any critique! Please don´t be shy, don´t hide anything - I see big talent in you, you shouldn´t waste it! There is always the next „perfect“ project for which you can learn. You will learn quickly where the right pockets are where you can fit in all the devices naturally, at least I see no big secrets here.

The space you see between the seats and engine will be used to articulate the body work later, and in order to get the right angle of a panel (or panels), I have to anchor those panels to the right points by using beams.

The space above the XL motor can't be used, because it is used to take out the XL motor for other MOC. (Yes, all PF parts can be moved out the car without disassembling the car, that is one goal of my design at the beginning.)  And also leaving that space empty, you can see the windshield through the engine cover from the back, will that be a nice feature?

I am working on your feedbacks now, and once I gets the battery in, I will shoot a picture to reveal where/what it is. Hold on, my friend.

Thanks!

38 minutes ago, Celeri said:

Very nice and smooth model, and bonus for the choice of color: I have always liked black Lambos (black Diablo FTW)!

I really like your gapless panel usage, and the parts used for lights is also a very fine touch.

Congrats!

Thank you for your comments. First time try black, yes, it looks good. I am still trying to see how a Red one looks right now, but it takes time to collect pieces. There are still gap between panels as all LEGO models are, I tried to make them even across the board so none stands out from others. But it needs inner space to hook up those with irregular angles by various beams.

[mihao]

2 hours ago, brunojj1 said:

Are you kidding me ? Considering you are used to fighting with the lack of space, usually building much smaller, yet very functional models, come on, my friend! As I see, there is vast room above the XL motor, between seats and engine, which you could easily use, not least you have upgraded to the right amount of cylinders btw. Is that where you have put your battery? Which kind are power source & controls? Do youreself a favour and be open to any critique! Please don´t be shy, don´t hide anything - I see big talent in you, you shouldn´t waste it! There is always the next „perfect“ project for which you can learn. You will learn quickly where the right pockets are where you can fit in all the devices naturally, at least I see no big secrets here.

Here is it. (also updated the title post with this video.)

 

[vascolp]

Cool! What about putting the battery upside down so that you can charge it from below?

[mihao]

3 minutes ago, vascolp said:

Cool! What about putting the battery upside down so that you can charge it from below?

good suggestion. Actually it is not handy when charging with usb cable with all the body work. The inner space is really tight for bigger hand. The reason not doing is up-side-down is that there is no space for the cables to run through the bottom as for now. (The bottom is for the structure, so it is pretty beamed up.) But I'll think about it. Thanks!