DayWalker

Thanks Didumos69 ^ ^

Here are few photos : First, this is an overview : Then, details on the front building (rear side) : and perspective of the front side ... and with the gears : Wishbones and arms are parallel, thanks to the dark gray 8L flat tile under the 11L dark gray beam, under the 2 4L toothed bars. And last, this is an overview of all elements :

Great ! Consequently, I am sorry for the tests I made, apparently I was wrong !

I have changed a little bit my Ackerman version using the double shock of the previous post, and inforce the arms to limit slacks on the bottom wishbones.I also removed gears to reduce weight, used a toothed bar, and adjusted the default position of the geometry so that it is perfectily Ackerman with the body : as a result, the steering diameter is 154 cm ! Photos will wait a little bit, if any interested ^^ Therefore, the didumos69 solution is better than mine, since I necessary have bump steering

Not sure at 100% since I had to take one of the back red shocks and my bulding was not symmetric. But apparently, it was not enough. In fact, when doubling the length of the wishbones, we need to double the strength of the shocks for the same geometry. If we change the geometry, this may change... and I think that using the diagonal of the parallegram is one of the most efficient solution (or an almost vertical shock as close as possible to the wheel).

BAD NEW ? You should really try with the body (and so finish it...). On my car, with your geometry, the 2 red shocks are not strong enough...

The black part where the direction and the fake brain are fixed can limit the steering if the fake brain and the direction are using the two sides. You are right : that is why I left the redh shock in the center and the gray outside ^ ^. After using it, it dos not move at all... but I would prefer using all the length of the whisbones.

Nice idea, with two shocks. I tried also to use the full length of the wishbones, but failed : my car was touching the ground, since the effect of the shock absorbers is reduced. Consequently, your mod is very interesting ^^. Have you tried with the body ?

For people who made an ackerman mod, there is a very simple solution to double the front shocks : quite usefull since the front wheels are almost touching the body

Last week, I worked almost on the same geometry, since it is compatible with the Ackerman mod, but I did not finished it. Is the height of the front of the car a little bit higher with the body ? How much is the difference ? The other advantage of this building is that if the rotation of the wishbones is the center of the 3x3 L gray parts, there is no parallelism issue in the ackerman geometry, but the effective strain of the spring is divided by 2... and so the variation of the height of the front due to the weight of the body ! Therefore, it is also possible to use 2 springs with such a geometry, instead of one !

I confirm that I removed all the bushes, and it was visible on one of my photos, you are right ! The idea was simple : reduce friction and let a little more spacing between the perpendicular axles.

Maybe we should simply change the front shocks with yellow ones with a higher stiffness ?

@Didumos : Aren't your fake brakes touching inside the rims ? Nice mod to get an Ackermann geometry too ! I agree with you. It is maybe the first time that a Technic set is really impressive for its look and close to the real car... but a non functionnal sequential gear system is a pity. The minimum thing that we expect from a supercar is an operationnal (ie, rotating) fake engine (and a HOG if the steering wheel is not easily accessed). To me, the 8880 (my previous super car) had a perfect mechanical system, and my only mod was "adjustable seats". Here, the porsche is a nice set, but "details" are quite a pity (wrong sequence of speeds, fake engine issue, no HOG, no inclined drinving wheel, no removable body, while it can be very easily done : even for the Ackermann geometry, I am almost sure that the difference is less than 150 parts, excepts for the Didumos Ultimate version ^ ^). The good point is that we can make a lot of improvements. The body is very nice, and except few details, certainly one of the nicest official reduction of a real car ^^

Yes, I assume, but I am not an expert in mechanics !

Yes another issue of the original version... Just to mention : with the body, wishbones are almost horizontal, so bumping is quite limited (situation close to the first photo of my previous post). I really hesitate in modifying the suspension, but it would also change the behavior of the front height VS vertical forces... Not sure it is necessary, and I begin to be limited with my stock parts (I bought a 42038 set, only for parts, since lego technics are very different from what I used to play when I was a teenager... with studfull). .

Nice study ^ ^ And you are right. In fact, I had to make a choice of the vertical position of the 11L bar on which balls are attached, because : the arms of the suspensions have a pivot almost at the middle ; the distance between the wheel and the pivot is 3 L the length of the tracks rods are 6L Consequently, depending on the hight of the chassis, the parallelism of the front wheels is not maintained (it is also an issue in the original setup). For a perfect design, I assume that we would need 4 L track rods. If it is not clear, have a look to the position of the tracks rods when the suspension is used ^ ^ EDIT : Here is a phot for which the arms and the track rods are parallel. For this position, the two front wheels must be also parallel. On this photo, (the other extrem position), we see that arms and track rod are not parellel, so front wheels are not parallel. I believe there is no perfect solution except using 4L long track rods (but it does not exist ?). So the only thing we can do is to tune the vertical position of the two balls per suspension system so that wheels are parallel for the default position of the suspension (and apparently, your solution is better than mine without the body ^^)

You are welcome ! I agree, the difference of the angles is not very obvious...

Thank you ! Here is a top view of the chassis at maximum position. Apparently, the inner part of the right rim (they are very wide !) is touching the arm. EDIT @Didumos : I believe you have a problem with the body (its fixation and the two 5x7 rectangles behind the front wheels) and the axis parallel to the toothed bar.

Well, on the initial building, the translation of the toothed bar seems to be a little bit less than +/- 1 stud. Here, 1 stud is possible. But, ok, the radius should be measured to be sure since the geometry is a little bit different ^ ^. ... and yes, everything fits in the body ! (my first tries were too wide... but here, it is ok, no issue at all). EDIT : apparently, without the body, I get a radius of 67 cm (half turn with 134 cm from center to center of the chassis). Could you measure the radius without the body to get the enhancement if any ? EDIT2 : I believe we can reduce the number of gears : it will be next step.

Hi guys ! Today, I will present you a solution to change the steering geometry into a Ackermann one. With the body on the car, the change is invisible ^^. Here are few photos to explain how to do 1-Fixation of the suspension It is very close to the original solution : I have added a vertical 7L gray bar to make the solution more rigid, since 2 bars of the original lego's build must be removed, and few elements in the gray 5x7 L rectangles 2-changes on the fake brakes We need to add a flat 2L black element like this : 3-The heart of the solution ... and we need a narrower system between the two arms, and the body of the car does not help. After different tries, I made this : As you see, there is no toothed bar, since apparently, it does not exist in the right length (from LDD). Consequently, I used another mechanical solution with a kind of gutter. The rotation of the gear is transmitted to the orange 2L studless part, and then moves the dark 11L gray with 2 balls at the ends. 4-On the front of the car If the HOG is already present, just use a 5L axis with Z=12. This axis should penetrate into the central hole of the gray 5L bar of the previous photo. 5-Assembling This is how the elements should be assembled. For those who look carefully, I have exchanged the right and left suspensions on this photo... ... but is ok on this following step : ... and when finished : Of course, it is fully compatible with the removable body ^^

Here are some aditional photos : To adjust the angular position of the indicator, I suggest you finish by the vertical 7L axis, and ajust the position of the top big gear (20 teeths). When OK, push the axis, til the bottom of the chassis. @Didumos69 : your chassis is impressive !

I saw that somebody was trying to get a numeric build of the porsche with the original build and the different "options". Maybe we should draw a kind of table for compatibility on the ultimately playable thread (I have just discovered your "very impressive" thread with your ultimate version ^^) ? ... so that people can choose the combination they want.

Finally, I have integrated by gearbox indicator : it is very compact, as you can see on the definitive integration : ... and there is no issue with the transmission axes ^^

Hi ! As you may know, I have removed evrything between the gearbox and the "H" where Didumos 69 propose is 90-lock speed system and avoids the passage from 4 to 1 speed. As a consequence, I have a lot of free space in this part of the Porsche, and decided to check whether it is possible to indicate the engaged speed, and the answer is "yes" ! Here are 2 photos to show how it works (the 2 axis for the gearbox should not be a problem, even if they are not present on the photos, and the top gray 4x3 L is covered by the lateral black flat pannels (orange for this example) ). All the mechanism is located on the right side of the car. It is not a definitive set-up (axis lengths must be adjusted), but the rotation of the top light indicator is 32.5 deg per speed thanks to two 0.6 reduction systems. A quick calculus shows that the 2L long light arm indicator should move by 1L approximatively when rotating ^ ^. This last photo shows how it would look like (actually, I have built a the Ian's solution) : the vertical axis should benefit from hole of the 3x11 black flat pannel :

Well, apparently, I am wrong, my top spoiler is shifted by 1 stud... I'am trying to correct it ^^ EDIT : Done, and the 2x4 L can be used to fix arms (and keep the engine compartment open for demonstration). When the compartement is close, this arm is hidden ^^. This photo should help those who want to fabricate the same bottom spoiler. The following photo is not with the last solution (on this try, friction was poor for the bottom spoiler...), but it illustrates the use of the arm :