TheMindGarage

It isn't. With the wheels I'm using, the midpoint is 1 stud from the end of the axle which is actually very slightly beyond the intersection point (meaning the setup undercorrects slightly rather than overcorrects).

This is my latest MOC: an Ariel Atom 500 in 1:9 scale! Technically it isn't a true scale model since I didn't use exact dimensions (I just build what I think looks best), but size-wise it's about 1:9. The real car is the fastest ever variant of the Ariel Atom, a street-legal car built for track racing. Released in 2008, the Atom 500 features a 3-litre transverse-mounted V8 made from two motorbike engines. It produces 500 horsepower (hence the name) and redlines at a rather insane 10,500 RPM. Other modifications include massive wings and the gold-painted exoskeleton. The car weighs only 550kg, giving it a power:weight ratio of over 900hp/tonne (higher than anything short of a Koenigsegg) - It recorded a 0-60mph time of just 2.3 seconds and could reach 200mph. It was the fastest road-legal car around the Top Gear Test Track for over two years. That record lap was on damp tarmac - had the track been dry, it would probably still be at the top. Only 25 of these cars were made, selling for around £200,000 each. My model features: Remote control drive and steering with Power Functions - 1 XL motor for drive and 1 M motor for steering 4-speed sequential gearbox operated with paddle-shifters Working steering wheel Full independent suspension with longitundinally-mounted shock absorbers Steering has zero scrub radius V8 engine replica with moving pistons The zero-scrub radius was a new idea for me. When playing around with suspension linkages, I discovered that mounting the links in a certain way would cause all four to move when turning (rather than just the steering link). The center of steering was further outwards, almost exactly in the middle of the wheels (I think it's where the suspension links would intersect when extended, but I'm not sure of this). The geometry I chose works almost perfectly for 68.8x36 ZR tyres on 56mm rims. Here's a picture of the steering links in their two extreme positions superimposed - the point where the wheel shafts intersect is the center of steering: The suspension is standard double-wishbone in the rear, but with a sideways lever converting the upwards motion of the suspension into longitudinal movement of the shock absorber: The transverse V8 was very difficult to fit in because it has even dimensions and the rest of the chassis has odd dimensions. It is connected directly to the XL motor The interior (or as close as you can get to an interior in an Atom) features two racing-style seats, a steering wheel and paddle shifters: The aesthetics were rather difficult at times. The framwork was very difficult even with the 42055 yellow parts (in fact, getting that set is the reason why I built this model), and at times I had to use some tricks. For example, the rear framework looks like it has two beams crossing in an X-formation when in fact the left and right halves of the "X" are two separate structures: I also replicated the exhaust pipes and gigantic rear wing. One of my favourite parts of the model is the side intake and its red stripe: The PF IR receiver is disguised as the air intake and roll hoop: For more pictures of the car, see my video below. Music is composed by me as well: [media]https://www.youtube.com/watch?v=RhmgbCIpHT0[/media] This project is also on LEGO Ideas! I know the success rate is extremely low for such projects, but it would be amazing if this set because a reality! Please support my project here. Any support is much appreciated.

Wow! Instantly recogniseable, and that's a seriously big scale! Any idea how much it weighs?

Nope.

My collection is probably about 9,000 pieces (most of that is from 42043 and 42055, plus some MINDSTORMS stuff and other random parts). I don't keep anything assembled - as soon as I finish a MOC, I take pictures, then salvage it for the next build.

The pneumatic one looks really cool! Are the parts all stock (apart from the Fanta airtank of course)? If so, I'm impressed...

If I have time (currently building something), I might enter. I have some rather interesting ideas - the real test will be whether I manage to pull it off within the deadline...

Try gearing up before the gearbox and down again afterwards. Reduces efficiency a little, but will reduce the amount of torque the gearbox has to deal with considerably. Also, I see you've also migrated from the Message Boards :D

I've tried this before and it's not a bad solution, but I've got a special steering linkage in use in my current MOC that will put the steering pivot in the center of the wheel. It can be used with independent suspension, but not with drive.

Looks amazing! For some reason I see a little bit of Dodge Viper ACR in there - maybe it's the red colour scheme. Definitely looks sufficiently aggressive, and congratulations on getting noticed by Koenigsegg!

Nice! Reminds me of the Ultima GTR.

Why hello there! Glad we'll be able to keep in touch when the LMBs are gone!

Looks cool! I've heard of the car, but haven't seen a LEGO model of it. Reminds me somewhat of the McLaren F1.

Nice! Reminds me a little of the Hennessey Venom GT (the front grille, the shape of the engine bay and the mid-mounted V8).

The 6-speed design has gearing to connect driving rings 1, 2 and 3, then the front and rear "halves" are connected with a different ratio. I used 20:12 gearing (that's 1.67x difference) between each driving ring and 16:12 (that's 1.33x difference) between the halves. If I were to do it the other way, the difference in gearing connecting the halves must be greater than the difference between the rings squared (the difference between ring 1 and ring 3), so I'd have to use 24:8 (3x) or higher. There is no way to reduce the difference between the driving rings since they have to be 2 studs apart.

Wow - you might have a future LEGO designer in your family! I'd suggest getting your son to build something simple on his own, or to "dissect" the official sets and look in more detail at how they work (start with something simple like the go-kart set with its transmission).

I was thinking about that, but it would lead to having gear ratios way too far apart.

I know how to do the 8-speed with 3 driving rings, but I want it to be a 6-speed since the real car has 6 speeds. Also, the 8-speed has quite a lot of friction and might be too big for this - I'm building a car in what is usually 1:10 scale (using 68.8mm wheels - it's 1:10 for normal cars, but it's probably closer to 1:8 for this particular car).

I'm building a 6-speed sequential gearbox for use in a future MOC and I've come across an issue. Basically, I need to control three driving rings with a single input, but I can't figure out how to do it. I'm familiar with the standard method of controlling two rings by using eccentric mechanisms 90 degrees out of phase, but this doesn't work with 3. I need six positions that can be selected with a single axle. I don't need a paddle-shifter - I can do that bit myself. The positions must be in order like this: [The three changeover catches are in a line, F means flipped forwards, R means flipped backwards, O means in the middle/neutral] FOO ROO OFO ORO OOF OOR This is all to do with the way the gears are arranged (I needed the ratios to be close; difference between each gear is around 1.3x). I can't change this. The crucial thing is that the mechanism must be compact. I can't give exact dimensions, but I'm quite pushed for space in this MOC. Thanks in advance for any help!

Very nice build! In fact, I'd go as far as saying that it's better looking than the real car (OK, I find the real car rather ugly). Just one problem: Why is there a Porsche badge on the steering wheel ?

I'm almost certain it won't cause any problems. I've done far more dangerous things (like coupling a Large motor to a Medium motor with 5:3 gearing in between) without any effects on motor performance. If you're going to leave the thing running for hours, a diff might be good, but even in heavy-duty situations (in fact, I'd say ESPECIALLY in heavy-duty situations), the diff will cause more problems than it'll solve. I've stalled a motor for about 30 seconds with no problems whatsoever. I should point out that the difference in speeds between identical motors is likely a few percent, which is negligible considering that loading a motor to max power output (torque times RPM) means loading it until it slows to half its RPM (varies between motors but this is a general rule of thumb that works for brushed DC motors).

I read about that too. I think it was in a car magazine. *splutters "1, 3, 2, 4"*

So, a $25 set has 4-wheel steering yet a certain set that costs over 10 times as much doesn't, despite the vehicle being modelled having 4-wheel steering? LEGO: Call it progress.

When going straight, all four motors are at full power (or near full power to allow for the differences in gearing and RPM). When turning, the motors driving the differential slow a little bit, and the motor on the inside of the turn slows down a lot (twice as much). It's somewhat like a castorbot. Yep - the drive motors control it - it's sort of like a tank. Yep - it is a little square because I lack flexible axles. I did experiment with using more pneumatic hoses but the result looked even worse. Maybe I should make a Lamborghini as my next car since their angular features suit my building style a little better... Sorry that you don't like the looks - looks aren't my strong point. I'm more of an engineer than a sculptor. Although I am seriously considering the Gumpert Apollo as a future model because when people say it's ugly (which they will), I can just show them the original car :D.

Well, I didn't update the WIP, and I ended up nearly two months behind my prediction, but I've finally finished it! And as far as I know, this is the first large-scale TECHNIC model of this car published online! The real Koenigsegg Regera is a groundbreaking "megacar" featuring a 5-litre V8 and three electric motors for a combined 1,479hp (1500PS). But it has no gearbox. Instead, there is one electric motor for each wheel, plus another electric motor coupled to the V8. The electric motors have instant torque and so the car doesn't need a gearbox to reach 250mph in 20 seconds! So, the full list of features: Remote-controlled drive - top speed is around 8mph Model of the real car's drivetrain Full independent suspension Castor angle on front axle (this is really important - you'll see why later) Triplex anti-squat bar on rear axle Adjustable camber angle and suspension stiffness for all four wheels - each wheel can be adjusted independently Synchro-dihedral doors Raisable rear wing Opening rear hatch to reveal "engine" bay Cabin with two seats, floor and steering wheel The drivetrain starts with a Large motor and a Medium motors (using different gearing). They are hard-coupled, but the gear ratios match very well and the EV3 can control the power it sends to each motor to make sure they aren't forcing each other to speed up/slow down. These motors drive a differential, with one Large motor on each side of the diff, just like in the real car. Then each output is geared up 1:9 to give the required speed - it's kind of a reverse portal-axle. Since the car isn't too heavy (it's about 1.4kg), the bevel gears aren't stressed that much, even with all this gearing up. I made a simulated dyno graph showing wheel torque and power with wheel speed in mph. This uses the official LEGO specifications of the motors and assumes no drivetrain losses: The front suspension is rather complex. All the adjustment controls are shown here: Now, you may have noticed there is NO steering rack. This is deliberate because it allows me to have an extra motor for driving. Instead, the motors on either side of the differential run at different speeds to steer, rather like a tank or castorbot. This is why it's so important that the castor angle is high. The top wishbones are able to slide in and out by 1 stud to change the camber angle. Just in case you wanted to put stance on your £1.9m megacar. The suspension uses both a torsion bar and a conventional shock absorber. The torsion bar's attachment point can be adjusted with a worm gear, allowing the suspension's stiffness to be changed. The rear suspension uses the same shock/torsion bar setup, but with an extra shock absorber between the wheels. This is what Koenigsegg calls Triplex, and it allows softer anti-roll-bars to be used (on this model there are none). The rear opens up to reveal the rear suspension. You can see the 24-tooth clutch gears here - those are to keep the rear wing in position. The doors are one of the most fun parts of this build. The doors slide forwards, outwards and rotate, all at the same time. They reveal the cabin. Unlike my previous models where the cabin is made a little smaller, the cabin in this model is proper-size. The aesthetics were very difficult. Because the front was so low, I decided to incorporate the suspension wishbones into the bodywork. I decided to exaggerate the front bumper, since to me that part of the real car stands out. I don't have any flexible axles, so I used pneumatic hoses for the windscreen. Since the roof's dome shape is very awkward to build, I decided to build it without a roof (all Regeras have removable roofs)! The side air vents don't widen enough towards the rear wheel - they look more like those on the Agera and CCX. Unfortunately, I don't have the right shapes of panels to make the vents properly, so I had to use a little artistic license. The air intakes on top of the car (behind the seats) stood out to me, so I made those prominent. Some have said it looks a bit like a 918 or Carrera GT. I also decided to exaggerate the rear diffuser - it looks almost Lamborghini-like to me (maybe a Veneno). And for some reason, the whole thing conjures up images of a McLaren F1 Longtail - I'm not sure why. But I guess if you combine the F1's speed, the 918's hybrid innovation and the Lambo's flair and doors, you pretty much have a Regera. Wow, that wasn't intended :P. Finally, here's a video I made. You can see a time-lapse of the building process, the suspension in action and the door mechanism exposed! I compose all my own music for videos - I hope you like it!