[WIP] AMG GT R- A huge problem arose......

[Lipko]

Using a dog-clutch gearbox for the steering modes will introduce huge slack between the front and rear axles (unless you gear it down with a large ratio, but then steering will become unresponsive and tedious). I think the main reason behind the design in the Claas is not the possibility to switch modes while steered but to reduce slack. The possibility to switch between modes when steered is possibly just a (awesome and realistic) side effect of the mechanism.

Edited August 17, 2017 by Lipko

[move5]

@Lipko I am also concerning about the slack, but as I said earlier, I want to try it first and I will tell you if it failed or not.

Btw, I also currently have no idea how to put the 42054 steering mechanism into a independent-suspension car 

[Jeroen Ottens]

Just now, move5 said:

@Lipko I am also concerning about the slack, but as I said earlier, I want to try it first and I will tell you if it failed or not.

Btw, I also currently have no idea how to put the 42054 steering mechanism into a independent-suspension car 

Trust me, the slack will kill the steeringangles. Using a linkage system is the only way to make a variable steering (and even with a linkage system the slack is a concern, especially when you want to have a somewhat realistic steering angle in the back). And I know it is possible to implement a 42054 system in a independent-suspension car
I won't be able to post WIP pictures from my version since it is an exclusive commission. I can show a belly shot once it is finished though.

Edited August 18, 2017 by Jeroen Ottens

[move5]

@Jeroen Ottens Well, then I will work on implementing the 42054 mechanism..

Btw a commission from Mercedes? That is awesome !!!

I hope that day comes in my technic life, too 

[Jeroen Ottens]

Just now, move5 said:

@Jeroen Ottens Well, then I will work on implementing the 42054 mechanism..

Btw a commission from Mercedes? That is awesome !!!

I hope that day comes in my technic life, too 

Not a commission from Mercedes unfortunately, it is from someone who wants to buy this car and wanted to have a LEGO technic version next to it.

The four wheel steering gave me the most headaches in the designphase, but when it finally worked it was well worth it. So go for it and keep improving your design until you're completely satisfied.

[move5]

@Jeroen Ottens Thanks a lot for your advice 

[1gor]

On 8/17/2017 at 3:36 PM, ThatOneBuilder said:

Pretty sure its called that as it connects the piston to the rest of the engine or the crankshaft...

[Aventador2004]

7 hours ago, Jeroen Ottens said:

Not a commission from Mercedes unfortunately, it is from someone who wants to buy this car and wanted to have a LEGO technic version next to it.

The four wheel steering gave me the most headaches in the designphase, but when it finally worked it was well worth it. So go for it and keep improving your design until you're completely satisfied.

What color is the actual car, and what color is the lego one?

[Jeroen Ottens]

Just now, Aventador2004 said:

What color is the actual car, and what color is the lego one?

The actual car is Magnogreen, which is close to bright green. My version is white (with a black roof).

[Aventador2004]

Just now, Jeroen Ottens said:

The actual car is Magnogreen, which is close to bright green. My version is white (with a black roof).

I wasn't sure, a youtuber I watch was ordering one, and he also has a lego mini, so I asked.

[ThatOneBuilder]

8 hours ago, Jeroen Ottens said:

The four wheel steering gave me the most headaches in the designphase, but when it finally worked it was well worth it. So go for it and keep improving your design until you're completely satisfied.

The real one has a four wheel steering system? What?

[Jeroen Ottens]

3 minutes ago, ThatOneBuilder said:

The real one has a four wheel steering system? What?

Yep it does:

http://www.autoexpress.co.uk/mercedes/amg-gt/100174/2017-mercedes-amg-gt-r-review

[ThatOneBuilder]

1 minute ago, Jeroen Ottens said:

Yep it does:

http://www.autoexpress.co.uk/mercedes/amg-gt/100174/2017-mercedes-amg-gt-r-review

Oh. My. God.

What an absolute marvel of engineering... im speechless...

[Leewan]

I recently had an idea for a system that links the rear wheels steering to a sequential 4 speeds gearbox :

 

The red axle is the input, which comes from the gearbox selector. When the red axle makes a quarter of turn (shifting from 1st to 2nd gear) the purple axle doesn't move. When the red axle makes another quarter of turn (shifting from 2nd to 3rd), the purple axle makes a quarter of turn too. With the 24:12 ratio, the green axle makes half a turn, and pushes the tan fork towards the rear of the car (the green liftarm isn't connected to the axle of the 12t gear). When the red axle makes another quarter of turn (3rd --> 4th), the purple axle doesn't move.

The dark tan fork connects the orange frame (which is linked to the steering axle) to one of the two sides of the dark blue parallelogram. Changing the connected side will change the turning direction of the wheels, and the wheels don't have to be in center position to switch speeds. So when you're in low gears (1st and 2nd), the rear wheels will turn in the opposite direction as the front wheels, and when you're in high gears (3rd and 4th), the rear wheels will turn in the same direction.

It's not perfect, it wouldn't work with a separate reverse gear (unless you find a way to lock the system when you switch to reverse), there's no "non-steering wheels" position and, above all, it's way too big (I don't know how to make it more compact). But still, maybe that could help you. Here's the link for the .lxf file. 

[move5]

@Leewan Thanks for your tip