gyenesvi

I don't quite get what the two different problems are. In the first case, you say that 3 wheels were moving out of 4, so you rebuilt the rear axle. In the second case, you said that one back wheel was not moving. It sounds like the same problem to me. And how do you have perfect 4 wheel drive if one back wheel is not moving? It's sounds kind of a contradiction. What I would do is I'd trace the path of moving parts when the motor spins. How far the spinning is transferred? Does it go to the front / rear axle properly? Inside an axle, is the housing of the differential is spinning properly? Finally, are the wheels spinning? If the differential housing is spinning and the wheels are not spinning, then something is either wrong in the differential itself, or one wheel is jammed and the diff is routing the power to the other wheel. Can you spin all wheels by hand? Isn't one harder to spin than the others? To check the differential itself, if you take it out from the axle, and spin one end (one thin axle coming out of it), the other end should be spinning in the opposite direction (that's normal), and the movement should be smooth / easy. How is that?

Would that be a short but wide wing shape?

This looks really clean indeed. The design is either 3D printer friendly with that flat surface, or you polished it a lot to look nice :) I think a reason might be that at this size you'd want to use them with a wheel hub with a 3-pin connector, but a 2 stud long steering arm that those have would not fin inside such rims, so it is kind of not usable with existing 3-pin wheel hubs for a steered axle, only that small one. It could maybe work with a wheel hub that has Ackerman geometry on the steering arm. Thanks, that's good to know! Is it something new? A few weeks ago when I looked through all the parts I have not seen them.

I assume that would be a solid axle, so a much simpler solution to your problem would be one of the proposed shorter suspension arms.

Looks good to me! Thanks! I like this idea, it would make the mounting more stable and it's good that it leaves space for the springs, though I don't see any other options to place the springs, which could limit its use. It would be nice ti have a part file for it so that we can experiment with it virtually.

Amazing piece of engineering! The looks are smooth and fluid, and the mechanics are great. For me the dynamic steering and lifting feature is what makes it most interesting. I like how the two features are made possible at the same time, not bothering each other. Great job! No wonder it takes so much time to build something like that, but it is really worth it :)

Ha! That's a great idea! A bit more curvature might be necessary towards the neck of the towball, just like on the outer edge, and then it should be fine. And I guess the 4th ball is unnecessary, so we should take that off in order not to weaken the structure on both sides. I was wondering how we could test this idea. If you'd put this out to shapeways, we could print this and when the Ford GT comes out, it should be possible to test with 5L liftarms and the new CV joint part. Also, I see you have 5L steering links on shapeways so we could use that as well. By the way, how is the quality of printed steering links and towballs, towball sockets and CV joints? I assume you have tested them already.

That would look great, but unfortunately I found another problem. Although the suspension arms have enough clearance to tilt on the ball because their tip has a slope cut out, the steering link does not have enough clearance and cannot tilt. I tried it on the short towball on this hub. I see you made the wall of the female CV joint housing even thinner, but I think even that's not going to be enough. It would have to be almost just the radius of a 1x1 liftarm to make enough room for the steering link, but that's not possible..

I don't think it would be fundamentally impossible regarding the space. I derived the ball hub from this hub which has the female CV joint in it. True that that CV joint head in this one is a little bit slimmer than the standalone female joint's head, but with a very little widening of the hole, a regular female joint would fit and could spin. The bigger ring that holds the towballs would still be thicker than a liftarm's wall, so if that's solid enough, this would also be, especially for smaller builds. I think we could 3D print this hub for a test using a regular female CV joint :) @efferman, do you think such a hub would be printable (while having a female CV joint insertable)? I know Efferman also has printable steering arms.. Or maybe @Zerobricks would want to experiment with these as well :) Moving on with parts, here are a few generic connectors that I could have used in some builds. They are mostly variations on existing ones. My personal favorite is the one at the bottom corner, which is a shortened version of on one side and having an axle hole in the other side. The one above it is a longer version of the same existing connector. Then there's a variation on with the orientation of the two ends swapped. The axle-to-axle connector has been mentioned by others as well, and then there's the variation of with the extensions cut off. This piece is really versatile, but sometimes that extension is in the way. The L-shaped corner piece I found in the page of Barman referenced above by @allanp. It could be useful as an alternative to because it has its pins fixed, some of which are sometimes in the way and different pin types cannot be used (3L or axle-pin for example).

Oh, that's a pity :( Any chance of going back to it? I'd be interested in testing a printed version at some point, and it would be great to share the part file so that we can experiment also in part designer and virtual builds. @allanp, though in this thread I was thinking more about simpler parts, that could actually be produced by TLG, I really like some of your ideas. This is an example that's specialized but would be quite reusable in many car models I guess. It would be great if you could make part files from these, I'd really like to experiment with them in studio. I guess you have a 3D model anyway used for printing already. Not sure how to turn them into part files, but @efferman probably knows, he seems to be doing that. Thanks for this link, quite a few interesting ideas in there, some of them even matching my ideas! I'll try to turn some into .part files. As cool as this could be, I don't see these being produced by Lego, because this could be a very deep rabbit hole I guess. I like this idea of a composable link, but I'm not sure if this would be strong enough, whether the clips/axle connection would be able to take some abuse of a 4-link suspension on an off-roader. But if such a towball socket part with a regular axle hole would be available, I'd surely try to glue it with some axles of various length :) That would be good for all kinds of rims. Would love that. More sensors for the PU system could indeed be interesting. And to keep listing my ideas, here are some more special beams from the alphabet, some of them have been noted by others as well. The S shapes would be useful for frame structures, maybe the 5x10 is less important because it's similar to existing ones, but the 3x9 in the middle could be really useful, sometimes the existing similar part turns in the 'wrong' direction. The Z shapes (3x7 or 3x9) are also interesting mentioned by someone I can't find now. The T and H shapes are things that I occasionally would find useful (for example the H shape in my render of the small independent suspension above, and the T shape can be useful for connecting geartrains in a solid way).

Okay, I thought you have less ambitious plans regarding the spacing and the steering pivot. But you are right, why not. So indeed, in that case we need to go smaller. I've got these rims and experimented. So here's the updated part. It goes all the way into rims 56145 or 56904 and 42716 from the deep side, and there's basically a 1x1 beam between the female CV joint's head and the rim. In case you are wondering if that half stud sticking out could be removed: with rims 56145 or 56904 it would be pointless, it could not go deeper anyway, only with rim 42716. But even in that case, only a 1x1 half beam would hold the female CV joint, and it would be pretty wobbly I think. Yeah, I figured that's the only way, and that is also only possible without proper differential I think. So here's what I built with these, it uses quite a few parts from this catalog (the small hub, 4L towball arms, 4L links, the 4L double headed male CV Joint, and also a female CV joint with a longer 3L axle on one side to be able to connect the two sides). What do you think? Don't worry about that, we are just throwing arounds some ideas :) That's TLG's problem, haha. But jokes aside, how many parts do we have so far? 100 maybe? Just look at how many crazy not so generic parts other themes have. Many of these would actually be pretty usable in various contexts. Okay, got you, then it would work in principle, but as we noted, those U-joints would probably be too fragile (thin material) to bear large load. Yes, that's a good idea! Hmm, interesting, is that meant for locking two free spinning gears together (permanently)? And extending that diff housing for more gearing options?

@efferman do you maybe have a part file for a 32T gear? Also for the modification of the official lego portal hub that we came up with together a while ago? Thanks!

One thing I may have misunderstood. Do you want this to go inside the deeper end of the rim? I thought you want to put this on the shallow side, then it would not rub. If on the deep side, then only your idea could work on the hub side. However, answer me one thing. How on earth will you route your steering links around the differential (or smaller gears instead)? That placement is just too close to the axle center longitudinally I think. It's already quite challenging with the longer steering arms.. The difference will be in the ground clearance. And the authenticity of the mechanism; portal vs planetary.

Indeed, a poll would be interesting, I think we need @Jim for that. However, it is a bit meaning as long as we are only doing this for ourselves and we don't have any means to communicate it to TLG. Though I only wrote it somewhat jokingly that they would look at this and make any of these parts. I think they have already considered or even prototyped most of these. But it would be quite cool if a part that we vote for would actually be produced. Also, for actually understanding the utility of some parts, example builds would be needed. I was actually thinking of a virtual building contest with all these parts.. I've got a couple more categories to cover, almost done just need to make renders and organize them into the catalog. Here's another interesting category: steered driven wheel hubs. The first is @keymaker's idea, something like that, right? I had a similar version, but with 3-pin holder, the second one. The third is similar to the currently existing steered one, but the steering arms centered. I often find that better, like on the planetary hub. The last one is an updated variant of the portal hub that fits completely inside the Defender rims (we designed this together with @efferman, btw do you have part file for it?). With Unimog tires, this setup has it's steering pivot 2.5 studs closer to the wheel than the current portal hub! Unfortunately, with large tractor tires some more (half stud) spacing would be required, but even in that case, steering center would be 2 studs better than with the current one. Finally, the planetary hubs could have an ungeared variant too (maybe also with these kind of slimmer steering arms, as that L shape on the planetary I find practically needless for steering, it's just in the way all the time). @1gor, just look at this beauty :) btw I don't think that U-joint idea would help with the current portal hub, because you cannot move the steering point 1 stud out towards the wheel without moving the whole hub (there's nowhere to build mounting points 1 stud out on the hub frame). Or do you mean you'd use the 3L side in the portal hub, and the 2L side in the diff frame (first I guessed the other way around)? That's quite a small family, and that part does not have an actual head. I think that part would be a shorter version of this part, that's why the head should be like that. Okay, then manufacturing could work :) Now I better understand your motivation about it. But what does POOP mean? I guess it's an abbreviation for something :) Okay, so then you don't need the gear there, but rather an axle, onto which you can put the liftarms (which already exist). The problem is with the servo not with the lego parts I think.

Another area where I miss systematic variation of sizes is flat panels. They are pretty useful for making nice looking surfaces, when they happen to be the right size. But when not, we have to resort to stacking beams on them, which can introduce ugly discontinuities, when applied to the longer sides. Continuing the shorter side with beams works well, though that would be more applicable to shorter panels, which are lacking, especially for width of 5. They would be pretty useful for sides / doors / bonnets / roofs of smaller vehicles for example. Interestingly, the size variability of curved panels is much better, there seems to be a lot more focus on those due to lots of sportscars, especially nowadays with the new small ones, which is really good. I think the flat ones should not be neglected either. It would also be interesting to have a shorter trapezoidal one as well. Yet another interesting part could be links with pinhole ends. Unfortunately it only exists in 16L size. They would be useful for linkages that need clearance near other parts as they move and hence beams cannot be used; for example a steering tie rod.

Like this? That's a bummer :( So it won't be useful in places where a bit of deviation from the length of 5 (+ or -) or some sliding would be required (like drivetrain going to floating axles). Sure, we can still cut them, but it's not the same, not accepted in MOCs. Why can't they make things as if it was.. Lego. Are you sure or just joking? :) Thanks, I believe you :) So @2GodBDGlory your reasoning could have been right in the end! Don't make it too similar to Cada..

So did you mean something like these? I assume if they existed they would come with this kind of head like other connectors to allow a gear to pass next to them (for example 8T). Another interesting class of connectors is these ones (that Cada has). I think they make arbitrary sized frame structures quite a bit simpler. Not entirely sure about the 2L, but the rest would be useful for sure.

I don't mind having them here because one purpose of the thread was indeed to possibly test manufacturing and usability of these part ideas. I'd like to stimulate discussions on why they would be useful or useless, what problems they would solve. And the best way to answer that is by testing physically :) So thanks for these interesting experiments! I tried to measure it with the existing pieces, and calculated it would touch the female part at around 25 degrees. But if there is some structure built around it, it could touch/rub that earlier, depending how edgy or round that part is. In your example you are lucky because the axle-pin connector under it that holds the suspension arms is round. If that had edges, they would touch earlier, no? That's interesting, so you increased the slope, right? In that case it should get blocked by the female part earlier than the original, which is around 25 degrees. Maybe you can force it a bit more, but it would have a lot of friction and wear when running. How smoothly does it run with your part at max angle? Yeah :) Wow. You could leak it on FB maybe :))) Indeed, that could be interesting to have. Though probably quite big and so impractical for transmission in actual cars if it was implemented with existing lego gears. I understand that, true that it can be confusing for novices. It's kind of a trade-off though. It should not be too similar for novices, but if you want to support advanced compact building, such length variations would be useful. And I don't think some of these are any more similar than a 2L pin and a 3L pin (or axles). Color coding can always come to the rescue :)

What do you mean too similar? That's exactly the point. Similar to the existing ones but longer versions to allow them being used for connecting multiple parts at once. As for your idea, that's interesting, what I don't understand is why would you start with a 2L pin variant, when even a 1L pin variant does not exist. Also, can you tell what it's necessary for? Couldn't most use cases be covered by #1 and #2 connectors with 2L / 3L pins inserted? Maybe one use case I can think of is when an axle needs to be angled as in a triangle and it would not result in a full stud length and such a part would allow it to 'overflow' a bit? Wow, cool mechanism and parts! Though I find it a bit too specialized and might get mechanically and structurally complicated to frame all that, no? I am not sure what you want to achieve then. You talked about thin liftarms previously as servo arms (isn't that the same as a servo-horn). How do you want to connect that to the gear? I thought you'd want to take off the gear and replace it. If not, how does it connect to lego?

Exactly :) On that note, here are my ideas for pins and axles. These are mainly longer versions of existing ones (sometimes shorter), plus I added the angled axle connectors that came up before (@langko and @Thirdwigg). I'd especially like the longer towball pin/axle, and the short 2L pin with no stop in the middle. It would be nice to have that with friction (to be able to sandwich a full beam between two half beams), but I guess if that ever comes, it would only be without friction for easy disassembly. Also, the 6L / 7L stops axles would be useful quite often for me, but luckily that's easy to make at home by cutting an 8L shorter. Furthermore, there could be angled variants of the perpendicular pin connector as well, though I think that would be less usable than the one with the axles. The 2L axle + 2L pin can be replaced with a 4L axle with end stop, but sometimes using an axle in pinholes results in weaker connections. One note about the short axle-to-axle perpendicular connector: in theory it could look like below, nicely round like the axle-pin connectors, but that would be out of the system of existing axle connectors. Indeed, that is true, though I'd imagine that stress would be very small, especially since the pins have longitudinal cuts at that position to allow for being squeezed more easily.

Well it does work, people use it all the time. Sure, it's not 100% legal, but that's the best we have for now.

I managed to do it, hopefully this is what you have been thinking of. However, I am not sure this would fit the system nicely, it feels odd, neither am I sure that this could actually be manufactured (because of the pinholes being closed from the center). Maybe an open center variant, essentially resulting in a 3x3 frame is more of a possibility? Though still can't figure really good use cases that could not be built maybe with short alternating beams instead?

What about this part? Sure, I agree with you in that there are uses of half beams that result in weak structures or are restrictive in their use. All I am saying is that there are interesting uses that result in solid assemblies, so I see a lot of potential in them. Indeed, this is use case comes up quite a frequently and it would be great if it was supported. Now the best we can do is stick the 2L end of a 3L connector in that 2L space and let the 1L part stick out. It would be great for example to have a 2L version of this new pin ideally with friction. That would make such assemblies possible in a solid way! Indeed, to some extent you are right that if we have more thin liftarms then connectors that support them also become important, but I think it's not too much that would be needed (it's not like we'd need a half stud version of everything). But there are 2L, 3L, 4L and 5L thin beams with axle holes in the end, those are useful for servo horns, no? Also, the longer it gets, the weaker the power will be. Even at 4L it's getting too weak for steering a car. For other more light weight applications, it could work. It depends on how you use them I think. The existing 3x3 thin L beams are pretty useful. Think about these frames as an extension of those. I would use these vertically, for connecting layers. And you can always double them up to make them stronger. Or put one on one side of a beam, or another one on the other side. They would be pretty useful for straight axles for example, like this one below (could hold the planetary hub), that uses a few of these custom parts, nicely complementing each other. But still, they are quite generic structural parts I think, that could be used for similar structures for many purposes. Thanks a lot, indeed, that model focused on laying out the drivetrain and suspension compactly. It's true that as the 24T gets closer it gets harder a bit because it needs more space, but here's the general idea of how I'd do it. As for the framing goes, short flip-flop beams would be great help for such structures, so I used them here for the sake of illustration (otherwise it would be more cumbersome to make a solid and compact frame for it). I totally feel this too, there is a lot of potential in half stud offsets, and some parts to support this more would be useful, though I don't have clear generic ideas for that yet (except one or two maybe).

I don't agree with this, as I have seen a lot of examples for builds with existing half beams. The key is that you don't add just one half beam somewhere, but two, so you use them rather for half stud offsetting of sub-structures that themselves often remain multiples of 1 stud. Imagine as a simple case for example a beam with some half beams on both sides, connected by 2L (or longer) axles. Everything adds up nicely without the need for half length connectors. I think such techniques are used quite often.

Many people (@dhc6twinotter, @1gor) would like to see more parts with towball sockets, so here are my ideas. The obvious ones are shorter liftamrs, the shortest one with an axle hole. Also, two variants for L-shapes; those would be very useful for building solid axles with planetary hubs. The wide one has a pinhole on the back. I imagine it would also be possible and useful to have something more like but I could not make it in Studio. Let me know if you have any more ideas for this! Indeed, I use that a lot, but as you say, the curve is often in the way. Hmm, I think I get what you mean.. Let's see if I can make something up. You'll have to show me how you'd use it in a build then! How about the new curved 2x5 panel extender? Would that work in some situations? Or would the curve be often in the way?