Didumos69

[MOC] Rugged supercar - Hammerhead (1:9 scale)

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Rugged supercar - Hammerhead (1:9 scale)

 
This project was not something I started very consciously. Also for me it evolved into something special. I was especially happy with the interference (in a positive way) of other builders. A big thank you to this community, for pushing me in the right direction on several occasions!
 
The most special part - to me - of this build, is the chassis. It combines a simple 4-speed AWD transmission, a flawless sequential shifting mechanism and advanced suspension setups with Ackermann steering, anti-roll bars, torsion bars, 2 studs ground clearance and 2 studs suspension travel. All wrapped together in a very flat yet rigid and coherent structure with a mid-console width of only 5 studs.
 
I did not want the bodywork to make any compromises to these features. I wanted the body to continue the line of durability set in by the chassis. Flex-axles do not fit that image, hence no wheel arcs. They would also sit 2 studs above the hood - not very elegant. The result is a car that does not only look fool-proof; it is fool-proof. After a rough treatment, you don't need to tighten connections or fine-tune gears to avoid friction. You can carry the car by the sides, by the trunk door (rear wing), by the nose and by the bumpers without displacing any parts. You can even grab the 2Kg build by the roof and turn it upside down to see the bottom side without a problem. So I did not intend to level with great bodywork builders. To me the biggest compliment is that some have referred to this model as the successor of 8865 and 8880.
 
     Drive train
  • AWD with 3 differentials
  • Sequential 4-speed gearbox
  • One-finger shifter
  • V8 fake engine
     Suspension
  • Double wishbone suspension
  • Anti-roll bars (front & rear)
  • 2 studs suspension travel
  • 2 studs ground clearance
      Steering
  • Ackermann steering
  • Gear-rack sliders
  • Working steering wheel
  • HoG steering
     Chassis
  • Sturdy and durable
  • Integrated bumpers
  • Adjustable seats
  • Narrow mid-console (5L)
     Bodywork
  • Sturdy and durable
  • Integrated roll-cage
  • Lockable doors
  • Openable trunk
     Liftable
  • By the roof
  • By the sides
  • By the nose
  • By the trunk door

Instructions are available on Rebrickable. There is a full-featured version called 'Rugged supercar' and a chassis-only version called 'Flat AWD chassis'. The chassis-only version confines itself to part 1 of the instructions of the full-featured version. Special thanks to @Blakbird and @BusterHaus - with Blakbird being the driving force - for taking on the task of making these beautiful instructions! Making instructions for a build like this is a tremendous amount of work. Even more so, given the fact that I have been very demanding in sticking to my original design.

- 32005a (Link 1 x 6 without Stoppers) - used for the anti-roll bars and steering tie rods - is preferred over 32005b (Link 1 x 6 with Stoppers), because each link has tow-balls inserted from both sides. 32005b can be used too, but in that case each link will have one tow-ball that needs quite some force to insert.
- 32056 (Liftarm 3 x 3 L-Shape Thin) - used for the door locks - is preferred over 32249 (Liftarm 3 x 3 L-Shape with Quarter Ellipse Thin). 32249 can be used too, but makes it more likely to accidentally lock the door while it's open, which is not a big deal of course.
- 76138 (Shock Absorber 6.5L with Soft Spring) - used for the door locks - should be soft springs. They are quite rare in red, but you could also use two LBG soft springs.
- 85543 (Rubber Belt Small (Round Cross Section) - used for the 90 degree limiter and the return-to-center of the gear shifter - should be relatively new, say max 2 years. Not that they wear out quickly, but the older ones are slightly less tight.

Images of the full-featured version can be found here. Images of the chassis-only version can be found here. LXF-file of the full-featured version (with placeholders for the Porsche wheel hubs!) can be found here. LXF-file of the chassis-only version (with placeholders for the Porsche wheel hubs!) can be found here.

See the entry on The LEGO Car Blog!

P.S. Where real cars start with a sketch, evolve into a professional design and finally have their technical details filled-in, this project started with some technical details, evolved into a complete design and ended up in a sketch ;-).
 
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Spoiler
Background
Suspension
The first thing I built was the suspension. I didn't want shocks on top of the upper wishbone - not even push rods like Paul has in his latest chassis - because it would increase the height of the whole suspension setup too much. So I tried a few things and eventually found a way to pack everything together in a 6 stud high setup. It uses the Porsche wheel hubs, rims and (13L) gear rack. It includes Ackermann steering and gear rack sliders. I used the full length of the suspension arms and two normal springs for each wheel. That's actually too weak to carry the car, but it creates the opportunity to use the axle holding the upper wishbone as torsion bar. The resistance of these torsion bars can easily be adjusted by using different parts to secure them. By giving the rear suspension a little more resistance I will be able to incorporate a subtle rake angle. Both suspension setups have 2+ stud suspension travel. The front has 2+ stud ground clearance and the back 2.5+ stud ground clearance. The last thing I did was adding anti-roll bars to both the front and the rear modules.
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Gearbox
Even though I only planned for a 4-speed sequential gearbox, I did want to cover a wide range of ratios. So not something like 1:2.5 upto 1:1, but rather something like 1:3:5 upto 1:0.8. Another requirement I had, was that I didn't want red clutch gears to transfer drive on axles rotating at different RPM. This is a common practice, but from modding the Porsche I know it induces a lot of friction on the axles involved. When not engaged, red clutch gear should only make dummy rotations and not transfer drive. And finally it all had to fit underneath the engine and I didn't want the gearbox to be routed through the entire chassis.
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Edited by Didumos69

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Looking good Didumos!  I'm looking forward to the rest of this coming together,  especially to see how you work in your new sequential ideas.  

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Looks really cool so far, sorry if I missed this but is it going to be RC?

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Everything seems very solid and foolproof! You have reinforced the suspension arms to prevent wobbling or backlash. Nice brake calipers! I like your logical approach and sure you have all the main ideas in your head already so you can succeed very soon with the chassis. The chase for the “ultimate” can turnout endless though, especially with your skills and perfectionism :look:... But who cares – the route is the goal. (And I´m still wondering if you´re working for TLC as a matter of fact :laugh:...)

I have to admit that I still need to get used to the rough and bulky “post - Porsche” big scale looks… I have failed miserably with several 1:8 MOC attempts in my history already, but nothing will stop me to trying to build mine next Gorilla soon :wink:. Thanks for sharing, I will follow this :thumbup:!

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Looking forward to your car definitely. Looks really robust. I am really sure that it will be an ultimate car like the Steppenwolf :wink:

 

 

 

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On 11/11/2016 at 2:03 PM, DugaldIC said:

Looking good Didumos!  I'm looking forward to the rest of this coming together,  especially to see how you work in your new sequential ideas.  

Thanks! I'm actually looking forward to working in those ideas myself. I hope to come up with a clean build alltogether.

On 11/11/2016 at 2:29 PM, JJ2 said:

Looks really cool so far, sorry if I missed this but is it going to be RC?

I didn't plan to make it RC, but you'll never know. I'm quite sure though that this front module would be firm enough for a motorized build.

On 11/11/2016 at 3:05 PM, brunojj1 said:

Everything seems very solid and foolproof! You have reinforced the suspension arms to prevent wobbling or backlash. Nice brake calipers! I like your logical approach and sure you have all the main ideas in your head already so you can succeed very soon with the chassis. The chase for the “ultimate” can turnout endless though, especially with your skills and perfectionism :look:... But who cares – the route is the goal. (And I´m still wondering if you´re working for TLC as a matter of fact :laugh:...)

I have to admit that I still need to get used to the rough and bulky “post - Porsche” big scale looks… I have failed miserably with several 1:8 MOC attempts in my history already, but nothing will stop me to trying to build mine next Gorilla soon :wink:. Thanks for sharing, I will follow this :thumbup:!

The route is the goal, I second that. It sure is solid. I always try to work some lengthwise and widthwise long beams through this kind of setups, preferably at 2 levels. And of course connect them with some vertical 3x5 frames - my favourite part - to make a structure that is solid in all dimensions.

About me working for TLG, I regard that as a big compliment. However if I would, I'm afraid I would have vetoed the Porsche :classic:.

It doesn't need to be ultimate this time. It should first of all be clean and solid. If an 1:8 scale body will turn out infeasible I will stick to the chassis only, but I will certainly give It a go.

Edited by Didumos69

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4 hours ago, Jonfensu said:

Looking forward to your car definitely. Looks really robust. I am really sure that it will be an ultimate car like the Steppenwolf :wink:

Thanks! I hope I can live up to the expectations :sceptic:. At least I'm excited to work on this for the next few weeks or months.

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Looks great so far!

A couple of guesses to what car this is inspired by:

  • Jaguar F-type SVR?
  • Lamborghini Huracan?

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hey didumos,

very nice looking. Could you provide a lxf-file of the front axle? I'm keen to disect how you stabilized your wishbones and axle core.

and MindGarage i would go for a F-Pace instead ;)

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On 13-11-2016 at 10:50 AM, TheMindGarage said:

Looks great so far!

A couple of guesses to what car this is inspired by:

  • Jaguar F-type SVR?
  • Lamborghini Huracan?

Thanks! I'm actually more into building my own 'fantasy' designs, and in this case the inspiration - at least for the looks - also comes from a fantasy car. To get expectations right I will no longer make a secret out of it: It were in fact 2 cars from the Zootopia movie that caught my attention and they are both on my wishlist :wink:. Designed by John Mays as far as I know, known from the 1997 New Beetle, the Audi TT, the 2015 Ford Mustang, the Aston Martin DB9, and more. But I guess you need to have kids to know about these two models :laugh::

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It's the red one that is on my mind for this project. But like I said, it just might turn out completely different :wink:.

On 13-11-2016 at 1:19 PM, AkiyamaWataru said:

hey didumos,

very nice looking. Could you provide a lxf-file of the front axle? I'm keen to disect how you stabilized your wishbones and axle core.

and MindGarage i would go for a F-Pace instead ;)

I added a link to the bottom of the OP, but to make it easy for you here it is again. The lower wishbones come close to real A-arms and span 5 studs where they are mounted to the chassis. The upper wishbone is 3 studs wide. The tricky part is how the 'third' middle suspension arm is mounted. There was not much space to make that sturdy.

Edited by Didumos69

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5 hours ago, Didumos69 said:

I added a link to the bottom of the OP, but to make it easy for you here it is again. The lower wishbones come close to real A-arms and span 5 studs where they are mounted to the chassis. The upper wishbone is 3 studs wide. The tricky part is how the 'third' middle suspension arm is mounted. There was not much space to make that sturdy.

I must have missed that thank you :) I'll just have to make my order @p&b and finish my own monomonster, before I can tackle your front axle

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I've been working on this a little more. I added an anti-roll bar to the front suspension (LXF-file here). There was just enough space to mount a track rod to the lower suspension arms. I also lowered the lengthwise liftarms by 2 studs. They are part of the main structure of the chassis that runs all the way from the front to the back. Otherwise that structure would rise far too high compared to the rest of the car. I guess I still have to get used to building this close to the ground :wink:. However, there is still 2.5 stud ground clearance and 2 stud suspension travel, all well for an AWD supercar.

I didn't have time for a video, but here are some images of the front suspension at this stage:

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I also designed the rear suspension (LXF-file here). I wanted it to have the same signature as the front suspension, so also 4 stud between the lower and upper wishbone (heart to heart). And also the shocks between the wishbones instead of on top of the upper wishbone. It also has 5 stud wide A-arms, an aniti-roll bar and fake brake calipers. There is place for another anti-roll bar at the backside, but I don't know whether that would be very realistic. Does anybody know? This is what it looks like at this stage (I still have to build it):

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Edited by Didumos69

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Oh my that's getting quite intricate but it looks great!  I like the sway bars as well,  I'm currently trying to fit some into my next build after I saw them on Jorens Ferrari. 

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3 hours ago, Didumos69 said:

 There is place for another anti-roll bar at the backside, but I don't know whether that would be very realistic. Does anybody know? This is what it looks like at this stage (I still have to build it):

 

How realistic do you want the fantasy movie vehicle to be? :laugh:

But I guess that anti-roll bars on both front and rear suspension make sense. The centre of gravity will be somewhere in between the two axles, so both axles need the extra stiffness of the anti-roll bar during cornering. At least on the Ferrari 308 they were present on both axles.

The axles are looking good!

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Nice anti-roll-bar! But somehow the yellow catches with crossholes seem suspicious to get damaged if the function is supposed to work under heavy stress.. But otherwise I´ve never seen such a solid axle :thumbup:.

41 minutes ago, Jeroen Ottens said:

How realistic do you want the fantasy movie vehicle to be? :laugh:

...

2,5 studs ground clearance seems already not to match the above shown car :grin: ... But I like it if the direction is going to some kind of muscle car (?...)

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Nice axles, but they look a bit over-complicated. You are aiming for rigidity and stiffness, but the bottleneck is not the A arms but the hub itself. I fear that you are adding weight for no significant gain.

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4 hours ago, Jeroen Ottens said:

How realistic do you want the fantasy movie vehicle to be? :laugh:

But I guess that anti-roll bars on both front and rear suspension make sense. The centre of gravity will be somewhere in between the two axles, so both axles need the extra stiffness of the anti-roll bar during cornering. At least on the Ferrari 308 they were present on both axles.

The axles are looking good!

Thanks! Part of picking a fantasy car is that it leaves some room for interpretation :wink:. I actually ment to ask whether it would be an option to have two sway bars for the rear axles only, one at the back and one at the front of the rear axles. But I have another idea for the backside of the rear axle, something I've spoken about with...

5 hours ago, DugaldIC said:

Oh my that's getting quite intricate but it looks great!  I like the sway bars as well,  I'm currently trying to fit some into my next build after I saw them on Jorens Ferrari. 

...@DugaldIC before. The axle holding the upper wishbone rotates along with the suspension arm and can be used as a torsion bar. What I plan to do is replacing all springs with softer springs. That should serve two goals: 1) It should give some default compression which gives a more natural feel and reduces the ground clearance slightly and 2) it gives the opportunity to finetune the suspension by playing with different ways to secure the torsion bars. That way I can also realize a realistic rake angle. Good to know that you're also working on sway bars, I'm getting more and more curious what you're working on :wink:.

3 hours ago, brunojj1 said:

Nice anti-roll-bar! But somehow the yellow catches with crossholes seem suspicious to get damaged if the function is supposed to work under heavy stress.. But otherwise I´ve never seen such a solid axle :thumbup:.

2,5 studs ground clearance seems already not to match the above shown car :grin: ... But I like it if the direction is going to some kind of muscle car (?...)

I'm aware of the volnurability of the catches with cross holes. I was also afraid that the ball joint would pop out of the catch, but apparently that doesn't happen. The sway bar is 15 studs long and the amount of resistance when twisted is not that big. But I will keep an eye on them as I will probably stress the sway bar about 10000 times before I finish this build :wink:.

2 hours ago, Lipko said:

Nice axles, but they look a bit over-complicated. You are aiming for rigidity and stiffness, but the bottleneck is not the A arms but the hub itself. I fear that you are adding weight for no significant gain.

You are right of course, the wheel hubs are the bottle neck. It's true that I aim for rigidity, but in this case I also seek for a rugged appearance. I don't think the front axles can be simplified a lot though, given that I want the springs to sit between the suspension arms. But I agree the rear axles seem a bit over-complicated and 5 stud wide A-arms are maybe a bit overkill. Still, reinforcing the standard LEGO suspension arms to say 3 studs and mounting them rigidly at both ends certainly reduces sloppynes of the whole setup. The way the front suspension arms are mounted in the Porsche for instance - with a single liftarm inside the suspension arm - is really sloppy and could be easily improved this way.

Edited by Didumos69

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@didumos69 (no idea if that's how you tag someone in a comment lol,  still trying to figure out all of eurobricks details) I like your thinking,  torsion bars at great and utilizing a sway bar as torsion is quite clever.  Actually the first car I ever did torsion bar on was an open wheel Ferrari that had no suspension and I didn't have any shocks so I managed to do a cantalievered torsion bar set up with no springs.  Now I'm trying to encorperate all three torsion,  springs, anti roll bar and 4wd to boot just because.  As for your curiosity,  no leaks yet but possibly a few teasers once the suspension and framework is done ;) 

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On 16-11-2016 at 10:44 PM, Victor Imaginator said:

Wow, that anti-roll bar looks so awesome. Great building technique)

Thanks!

On 17-11-2016 at 3:52 AM, DugaldIC said:

... Now I'm trying to encorperate all three torsion,  springs, anti roll bar and 4wd to boot just because...

This is exactly what I had in mind too. I used the axles holding the upper wishbones as torsion bars. For the front suspension I secured these axles slightly more relaxed than for the rear suspension. At this stage the suspension doesn't compress under the vehicles own weight, but the idea is that when all is finished it does. That gives the opportunity to tweak the suspension height by playing with the way the torsion bars are secured. I ordered 8 red normal springs, for it might be that eventually 8 hard springs turn out too hard, but we'll see.

I tried to simplify the rear suspension by leaving out the black side arms, but they turn out to reduce sloppyness significantly. That was also the idea; they actually serve as stabilizing links.

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I made a temporary frame connecting the front and rear modules to get an impression. I'm quite content at this stage. Next step will be the gearbox and shifting mechanism. Here are a few images and a quick video of the current state:

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LXF-file (with placeholders for the Porsche wheel hubs!) can be found here for the front axles and here for the rear axles. Comments and (suggestions for) improvements are welcome.

Edited by Didumos69

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I'm still in the process of trying to figure out what's going on the rear but whatever it is it's working perfectly!  I also like how similar the front and rear suspension are, the only issue I forsee is tweaking the ride height by pre compressing the springs with torsion may be a little much for the axles to take but I guess we'll find out soon enough.  Looking good though 

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I have a question, are you having any issues with the cv joints rubbing the inside of the hub in the front when steered? I played around with several front drive designs I had seen online and noticed that the steering is very limited due to this issue. I know you are using ackermann steering and it looks like your steering is quite sharp where this problem would occur.

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4 hours ago, DugaldIC said:

I'm still in the process of trying to figure out what's going on the rear but whatever it is it's working perfectly!  I also like how similar the front and rear suspension are, the only issue I forsee is tweaking the ride height by pre compressing the springs with torsion may be a little much for the axles to take but I guess we'll find out soon enough.  Looking good though 

The anti-roll bars indeed have some effect, but part of what you see also happens when I unmount the yellow anti-roll bar catches. But I guess real anti-roll bars also have a limited effect judging by the fact that they are generally quite modest in appearance (they are thin). I guess that eventually the independence of the suspension should prevail over the anti-roll effect. As for the tweaking of the ride height, the idea is that the torsion bars help lift the car, they should mitigate the compression of the suspension. But that will only work when there is some default compression, which should eventually come from the cars weight.

3 hours ago, Meatman said:

I have a question, are you having any issues with the cv joints rubbing the inside of the hub in the front when steered? I played around with several front drive designs I had seen online and noticed that the steering is very limited due to this issue. I know you are using ackermann steering and it looks like your steering is quite sharp where this problem would occur.

I know what you mean, the CV-joint can only handle a limited angle. The effect you are referring to does not occur in this build, not even on the inner wheel. The chances of the effect also depend on the angle made by the suspension arms. I tried to find a setup that keeps this angle within similar positive and negative margins. Actually the steering is not that sharp, it is comparable with the steering of the Porsche after removing the gearrack blockers. It's about 20 degree max angle I guess. The Ackermann steering gives a nice feel though. No tire scrub. And another advantage of the outer wheel not steering very sharp, is that it gives room for the ant-rooll bar track rods at the front side of the suspension arms.

Edited by Didumos69

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2 hours ago, Rodzilla4 said:

This is fantastic! Glad to see you making your own moc. Looking forward to seeing this progress

Thanks!

@Meatman, I just checked again and when I make the sharpest possible turns the wheel making the inner curve makes a slight wobble and gives a little resistance. So it does occur a little. When I push the suspension to make horizontal suspension arms, the effect disappears, which is a little encouraging. So it's caused by the combination of the steering angle and the suspension angle. The idea is that eventually - when the model is finished - the suspension is somewhat compressed and the front suspension arms will be close to horizontal, so under normal circumstances the CV-joints won't get damaged. It's a little disappointing though, but for this model I decided to accept the limitations of LEGO CV-joints and LEGO wheel hubs.

Edited by Didumos69

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