Didumos69

Looks very sturdy! Could also be useful for a bigger model. One question, I would think the angled 6L thin liftarms on top of the shocks should be able to tilt slighty in turns, but they appear to be rigid. How does that work? Or am I missing something?

I also envy your 'design with panels'-skills. I think you could actually do with one type of panel . I'm affraid I'm more a chassis type of man.

I do intend to make instructions in terms of errata for the minimally playable version soon. For the ultimately playable version I will probably only provide a LXF-file showing all differences in terms of groups.

In this post some images illustrate the engaged gears in each gear. From this It is easy to deduct that: 1. In each gear all axles rotate and all gears rotate. 2. In each gear the same number of gears is involved in transferring torque from input to output. But the number of gears in the gearbox was not the problem. This was. So Lego is delivering bull*** along multiple channels .

News on the minimally playable version (see my ultimately playable thread): A few days ago I asked Blakbird to testdrive (= review) my compilation of the most essential 'community-driven' modifications - a.k.a. minimally playable version of the Porsche. Let me quote: "After everything, the model moves REALLY smoothly." Blakbird provided me with some useful feedback that helped me narrowing down the most essential modifications even further. There were a few things that did not really prove to add to the overall smoothness, for instance the 5x7 frame on top of the gearbox. As a result I decided: - To replace the 5x7 frame on top of the gearbox with a more simple support for the axle running from the D+N+R gearbox to the differential. - To drop the improved support for the toggle joint in the D+N+R gearbox. It didn't really add much and required a 13L liftarm to be replaced with an 11L liftarm. - To revert to Attika's suggestion to simply flip the changeover catches in the PDK-unit instead of replacing them with 2L (+0)-liftarms. The replacement didn't really make much difference. This means that the overall recipe for succes now boils down to the following modifications (I also updated this list in the OP of the ultimately playable thread). In case I will be able to narrow down this compilation of modifications even further, I will of course report on that in my ultimately playable thread. But that does not withstand the fact that the current set will guarantee a smoothly moving Porsche. Btw, especially for the gear shifting MODs it is important that you apply all of them. They rely on each other: Gear shifting MODs (link) - Apply Paul Boratko's gear sequence fix as described in Jim's review. - Flip the change-over-catches in paddle-shifter-unit by 180 degrees (as suggested by Attika). - Add the simple 90° limiter to the gear selecter axle; use two of the four white silicon bands. - Remove the 8 tooth gears used to add friction; minimize friction in the selecter axle instead. - Use only one silicon band for each paddle shifter; wrap it around the neck of the ball joint once. - Extend both change-over-catches in the gearbox with half a stud (more info here). Friction reducing MODs (link) - Replace the pinjoiner in the D+N+R-console by bushes as suggested by Blakbird, see his detailed build report. - Avoid red gears from transferring torque on axles rotating at different speed, see eliminate friction in gearbox. - Add an extra support for the 15L axle running from D+N+R gearbox to differential, see alternative axle scheme. - Avoid axle connectors from rubbing against liftarms as suggested by nerdsforprez, see alternative axle scheme. - Replace the white clutch gear with a gearless friction clutch, see alternative axle scheme and white gear replacement. - Now you can gear up the engine: Replace the 2 16t gears with a pair of 24t-8t gears, see eliminate friction in gearbox. I also made an updated LXF-file available that reflects these modifications in terms of groups. In each group there is a subgroup representing the old structure and the new structure. In the LXF-file all new structures are embedded in the chassis and all old structures are placed to the side of the chassis. By clicking on a subgroup you select all parts in that group. That way you can inspect the differences. Besides the 'Minimal version' modifications listed above it contains HoG steering and a 4th to 1st gear block. If you want, you can skip the HoG steering; it's not essential for a smoothly moving model. Next step will be to provide instructions by means of an errata-sheet with references to the building steps in the original building instructions and a parts list. Enjoy! (Sorry for double post, but I thought this would be useful info here too.) P.S. Here's an image showing the complete set of modifications. The original parts are in the background:

News on the minimally playable version: A few days ago I asked Blakbird to testdrive (= review) my compilation of the most essential 'community-driven' modifications - a.k.a. minimally playable version of the Porsche. Let me quote: "After everything, the model moves REALLY smoothly." Blakbird provided me with some useful feedback that helped me narrowing down the most essential modifications even further. There were a few things that did not really prove to add to the overall smoothness, for instance the 5x7 frame on top of the gearbox. As a result I decided: - To replace the 5x7 frame on top of the gearbox with a more simple support for the axle running from the D+N+R gearbox to the differential. - To drop the improved support for the toggle joint in the D+N+R gearbox. It didn't really add much and required a 13L liftarm to be replaced with an 11L liftarm. - To revert to Attika's suggestion to simply flip the changeover catches in the PDK-unit instead of replacing them with 2L (+0)-liftarms. The replacement didn't really make much difference. This means that the overall recipe for succes now boils down to the following modifications (I also updated this list in the OP of this thread). In case I will be able to narrow down this compilation of modifications even further, I will of course report on that in this thread. But that does not withstand the fact that the current set will guarantee a smoothly moving Porsche. Btw, especially for the gear shifting MODs it is important that you apply all of them. They rely on each other: Gear shifting MODs (link) - Apply Paul Boratko's gear sequence fix as described in Jim's review. - Flip the change-over-catches in paddle-shifter-unit by 180 degrees (as suggested by Attika). - Add the simple 90° limiter to the gear selecter axle; use two of the four white silicon bands. - Remove the 8 tooth gears used to add friction; minimize friction in the selecter axle instead. - Use only one silicon band for each paddle shifter; wrap it around the neck of the ball joint once. - Extend both change-over-catches in the gearbox with half a stud (more info here). Friction reducing MODs (link) - Remove the pinjoiner in the D+N+R-gearbox. Original idea suggested by Blakbird, see his detailed build report. - Avoid red gears from transferring torque on axles rotating at different speed, see eliminate friction in gearbox. - Add an extra support for the 15L axle running from D+N+R gearbox to differential, see alternative axle scheme. - Avoid axle connectors from rubbing against liftarms as suggested by nerdsforprez, see alternative axle scheme. - Replace the white clutch gear with a gearless friction clutch, see alternative axle scheme and white gear replacement. - Now you can gear up the engine: Replace the 2 16t gears with a pair of 24t-8t gears, see eliminate friction in gearbox. I also made an updated LXF-file available that reflects these modifications in terms of groups. In each group there is a subgroup representing the old structure and the new structure. In the LXF-file all new structures are embedded in the chassis and all old structures are placed to the side of the chassis. By clicking on a subgroup you select all parts in that group. That way you can inspect the differences. Besides the 'Minimal version' modifications listed above it contains HoG steering and a 4th to 1st gear block. If you want, you can skip the HoG steering; it's not essential for a smoothly moving model. Next step will be to provide instructions by means of an errata-sheet with references to the building steps in the original building instructions and a parts list. Enjoy!

Some images of Box 1 and 2:

Early this morning I managed to build Box 2 (in 2h30m) and the marriage with Box 1 was no problem. All my MODs fit very nicely. I love it when a plan comes together .

EDIT: Now that I re-read your post i think I'm still not taking away your confusion. I think you should see it like a tangent, it doesn't exist for a 90 degree angle. In other words the image with lines coming together in a shared center point doesn't apply to wheels that line up straight. No problem. The image Appie showed is indeed confusing. It shows the ideal lines and not the lines you get when you use a 1L pivot offset with a pivot that lays 2L behind the steering axis. This is the geometry that me and DayWalker are using, I hope this takes away the confusion. Measurements are from heart to heart: Like I said, substantial slack in standard Lego wheel hubs give the wheels some range of freedom to find their own line - with the least friction. Apparently - given my observations regarding tire scrub - the range of freedom with this Ackermann setup includes the ideal line and the range of feeedom with the out-of-the-box setup does not. So, from a theoretical perspective this is not ideal, but from a practical - or playable - perspective it is good enough.

Yes it concerns the Minimal version, errata and parts list. I have to be a bit more careful with promises about the ultimately playable version, I'm affraid the modifications are to big to write them down in a errata-sheet. But I will certainly be sharing a parts list and a LXF-file showing all MODs in terms of groups for box 1 and 2.

This might be a quick fix for the front clearance. It won't work without body, as the rims rub the suspension arms, but it might be okay with body: EDIT: With this stopper it will also work without the body. Also fits with the body:

Great that you have taken the time to try! I agree that it will be more easy to apply most mods while building from scratch. That's why I'm planning to provide a BI for the 'Minimal version' in terms of an errata-sheet with references to the original building steps and a parts list. However, the 90 degree limiter should be doable without taking the chassis apart. Simply pull out the axles with the orange paddles, then remove the 3L liftarms inside the H-frame and put the limiter into place part by part. and finally insert the (different) axles. In the 'Minimal version' MODs that I summarized in the OP of this thread I thought I mentioned that it would be best to apply 2 silicon bands around the 90 degree limiter. Or did you even need 3? And did you remove the friction-generating 8T gears in the shift train? When it comes to shifting gears, it's very important that you follow all of the 6 steps summarized here. I you would need 3 silicon bands, then there is probably some friction somewhere in the shift train. Make sure all individual axles rotate without friction. I did not look into the clearance yet.

You're welcome! I also like to see active camber, but for one stud suspension travel I don't think it's worth the effort. Another issue is that the appr. 6 stud wide tires like to be flat on the road. This would even more be an issue when you would implement caster angle. Not me, that's for sure. But the car would be a perfect target for it. I've seen a video, but I didn't like the battery box being on the passenger seat. There's lots of space throughout the vehicle. I would remove the gearbox to make space for the battery box(es). That would also be a nice position to get the center of gravity right and with a removable body you should be able to reach the batteries easily.

I know what theory you are referring to. A quick sketch shows me that these lines intersect way in front of the diff. However, the substantial slack in standard Lego wheel hubs give the wheels some range of freedom to find their own line - with the least friction. Apparently - given my observations regarding tire scrub - the range of freedom with this Ackermann setup includes the ideal line and the range of feeedom with the out-of-the-box setup does not. So, from a theoretical perspective this is not ideal, but from a practical - or playable - perspective it is. EDIT: The line through the pivot point and steering axis makes 2 studs backwards for each single stud inwards. So it would arrive at the midline of the car 22 studs behind the front axles. That is 17 studs in front of the center of the diff.

I would be a bit careful on drawing conclusions like 'no direct need'. I think it would be a good idea to at least try without the white clutch gear first. I would really encourage anyone building this set to replace the white clutch gear with an inline friction clutch, use the gears that come free to gear up the engine and use the 16T gears that come off the back of the engine to replace the friction-generating red clutch gears in the gearbox, while giving them there own axle. This reduces friction substantially and is way more fun. See also the 'Minimal version' sections in the OP of my ultimately playable thread.

Given your inventive suspension setup history, I'm looking forward to seeing your front and rear axles .

EDIT: I updated the front axles after finishing box 3 and 4. See this post. Today I will report about the implementation of Ackermann steering in my playable build. In my opinion Ackermann steering is an advanced steering characteristic that is very noticeable in a playable model. When you push the Porsche without Ackermann steering, you can feel the tire scrub resistance in turns. You can also see the outer wheel making jumps to the side every few inches to overcome the lack of Ackermann-steering. Inspired by the Ackermann concept from DayWalker in the MODs and Improvements thread I designed a similar concept. I had to take into account the rear HoG steering and another important difference is that DayWalker doesn't use a gear rack and I do. In fact, I use a gear rack with stabilizing slider. Basically, my approach boils down to turning the whole front suspension around such that the back side faces forwards and the front side faces backwards. But let me tell youI the rest of the story in terms of a photo sequence. I started with changing the gear at the top of the PDK-unit to the other side, so the output axle rotates in the opposite direction: Then I disconnected the front suspension module from the rest of the chassis: I inserted the 10L slider axle and two 1L liftarms with perpendicular axles as sliders: I assembled the composite gear rack and a connection bridge for the upper back side of the front module: Then I attached the gear rack to the sliders and put the connection bridge into place: I put together the modified wheel hub extensions. The yellow 4L levers are lowered by half a stud, but the square 4L flat plate remains in the same height. This fits inside the rims without a problem and the photo of the wheel shows this doesn't affect the looks either: After putting the new wheel hub extensions into place the front module looks like this: Then I extended the chassis improvement I did earlier. Now I use 13L liftarms: And I put the front module into place. You can now see that it has been turned around: This yellow stabilizer makes sure the orange parts on top of the gear rack do not rotate: I placed all the axles and gears, also for the rear HoG steering: I added gear rack stoppers: I added the vertical liftarms: And finally I added the front frame: And it works like a charm. The angle difference is maybe hard to see, but it's there and with this setup the tire scrub resistance in turns is completely gone!:

Okay, thanks for clarifying. Good to know that you removed the intended friction. This does not surprise me. The chassis by itself is not very sturdy and bends under its own weight. This bending causes axle connectors to rub against liftarms and gears to be squeezed. It is mainly Box 2 that adds stiffness. I don't see this as a flaw or something, even though I tried to improve on this in my build. A self-supporting body is actually quite realistic these days.

@JunkstyleGio, I see you incorporated the 90 degree limiter. Did you also drop the 8T friction gear?

@DayWalker, I just finished my Ackermann version and it works as a charm. When you push the model without Ackermann steering, you can feel the tyre scrub resistance in turns. You can also see the outer wheel making jumps to the side every few inches to overcome the lack of Ackermann-steering. But now that I have incorporated Ackermann steering - which roughly boils down to your geometry - the resistance in turns is completely gone! This really adds to playability. Thanks again for hinting in the right direction! I will write a full build report on my playable thread tonight.

Great to see that you're happy with your Porsche. In the end I am too, but that's mainly because I like fixing stuff. Could you let us know which modifications you applied? EDIT: Never mind, you posted about that already. Thanks!

It's probably a matter of personal opinion whether this set is flawed or not. It depends on what you expect from this set. I personally expect gears to rattle happily and mechanical features to work properly. This might require some finetuning to minimize friction etc., but it shouldn't be necessary to change the model. Fact is that there are numerous reports on a badly functioning gear shifting mechanism and on severe friction in the drive train - also from Jim, Paul Boratko and Sariel. I have taken the paddle shifter unit apart several times and every time I rebuild it, it turns out to operate differently. Sometimes it works almost perfectly, sometimes it almost aligns on 90 degree positions instead of the ideal 45 degree positions. It's a bit of a gamble actually. I analyzed the friction in the gearbox and I can't imagine anyone who has built this set to end up with - especially in 2nd gear - without making changes to the model. Even after applying Blakbird's step 5 fix. If anyone did encounter happy gears in the out-of-the-box build, then please report on it.So my conclusion is that this set has two major flaws: The badly operating gear shifting mechanism causing double engaged gears and the from friction suffering drive train causing the clutch gear to slip a lot in some gears. Both can be eliminated with a few very straight forward changes that I summarized in the 'Minimal version' sections in the OP of my ultimately playable thread.

Thanks! I tested whether this would fit the rims and it does. The 4x1 square flat plate would not, but that one is still in the same position.

@DayWalker, I understand your considerations, thanks. Given that the wishbones are almost horizontal under the weight of the body - and thus the wheels almost parallel - you should see a better angle difference (Ackermann-effect) when steering than without the body. Can you confirm that? The steering rods should indeed be the same length as the wishbones to avoid bump steer. Btw, I think it's better to speak of heart-to-heart distances in this context, that is 5L for the rods and 3L for the used part of the wishbones. The current suspension setup can do with a single shockabsorber, because both ends of the suspension arm serve as moment arm. So if the full length of the suspension arm was used, you would need two shocks or one shock and a longitudinal torsion bar attached to one of the wishbones. I don't think I will go that far. This will be my shot at Ackermann steering in my playable build. I completely turned aroud the widthwise setup of liftarms an frames. I will be using a 7L rack with an additional slider. The yellow levers hollding the calipers - so not the calipers themselves - can actually be lowered - I checked - by half a stud, so a 2L (+0)-liftarm can be attached to the wheel hub. This way I could also preserve the exact angle of the steering rod as compared to the original build. I had to take into account my rear HoG steering, but where the rear HoG axle (with the U-joints) enters, the dashboard HoG axle could also enter. All fits within the boundaries defined by the body. LXF-file here. This might of course change while building.

(Sorry for quoting this image, but it's subject to this post.) @DayWalker, as the angle difference wasn't really visible in this photo, I wanted to try this first before putting in the effort of implementing something comparable in my ultimately playable build. Just for testing purposes I replicated your setup - or at least your exact geometry - at the front site of the front suspension. This gives of course the opposite of the desired effect, but it's only to investigate what the effect is. And just like in your photo, the Ackermann-effect didn't really show. But I also found what the issue is with this - and probably with your - setup: The ball-joint with axle that is used to connect the track rod to the wheel hub, does not fully insert into an axle hole. Now in your setup - and in mine - the ball-joint with axle is placed upside-down compared to the original setup. This causes the ball-joint with axle to move 0.2 stud more upwards than the ball-joint with pin at the other end of the track rod. As a consequence, the track rods are flattened out a little compared to the original situation, which in turn results in a slight toe-in-effect in your setup - toe-out in my setup. This means that the Ackermann-effect first needs to compensate for this toe-in before it actually takes effect. This explains the more or less parallel wheels in your photo. Here you can see the toe-out in my test setup. Your setup will probably suffer from a comparable amount of toe-in. Once again the solution can be found in silicon bands, but you could of course also change your setup to get the track rods similarly angled as in the out-of-the-box situation. This is an old image, in our setups both ball-joints point into the same direction. This is what it looks like with the silicon bands. This also significantly reduces slack in the whole steering setup. I don;t have a picture of the Ackermann-effect in this situation, but I can gaurantee it is much better visible than in your photo: