amorti

Buwizz is much smaller than a pf battery box. Now I'm wondering if it'll take a control+ hub. You could really use that as a solid centre of your chassis if so.

LepinWorld? Not a site of the company, just a dealer using the name to get Google hits. King, Queen, and Jack rose from the ashes. But you can tell their kits because they use Lego colours and really crappy quality Technic pieces.

Yet you were willing to buy some MouldKing motors? The first thing I'd like to say is that what you're doing here is the same as dismissing a post because it has bad grammar. Maybe try getting some perspective? If you're such an expert on Chinabricks, you'll know that Lepin was killed before the 7*11 frame existed, so I am pretty sure the pieces are not from Lepin. Brands King, Queen and King all sprung up not so long after Lepin died, but those companies copy Lego exactly 1:1 including colour, so I doubt the parts are from them either. I'd say the parts here from GoBricks . GoBricks make parts which are as near to Lego quality as you can get without being Lego, but way cheaper. They supply MouldKing pieces, among other Chinabrick companies (but not King,Queen,Jack who still use crappy Lepin pieces) . They also don't care about colours, so you can make white models with white pins, etc.

@nicjasno It was a lot of fun thinking along with the live stream, and I've now built one side which is also fun to see how it works and what happens when you move one reference point a stud in or out or up, or down... Unfortunately I won't order the parts to make the other side, as there are too many compromises. The ball joints have too much chance to pop off. This in contrast to the very sturdy "ordinary" suspension the model was designed with, which is pretty decently form locked. I can't find a way in the available space to form lock the pushrods , which keep coming apart under the weight of the car. I could glue them but as mentioned on the stream, it's cheating and doesn't feel good. The edge of the wheel rim rubs the steering rod in one direction, and the front wishbone in the other. It would be fine with land rover wheels but I don't have any. The two lower wishbones clash at full right steering causing the knuckle to rise. The one problem that doesn't seem like it would be easy to design a way out of, is that the wheel has moved forward in the arch almost 2 studs. The front bodywork can be moved forward to accommodate but the car starts looking too long, and even then it won't really be possible to fit a front hood. It would be possible to move the whole front wheel assembly backwards 2 studs, but then the top wishbones are fighting with panels. Still, I thank you for the master class, Alex. It was very enjoyable. If one day the feeling takes me to build a non motorised car, this will be the way to go.

Huge thanks to Alex at LPE Power! @nicjasno https://www.dropbox.com/sh/lapgx5lqw1urm0f/AAB0nR6K2cOXD1XOnt4QwHzUa?dl=0 @astyanax - how cool is that?? I don't have enough 9L steering links to build both sides, but I'll have a go at building one side myself tonight.

Absolutely! I'll get in the chat.

Basic brief: the car is really fast, so the suspension should be sturdy and bring stability. Ideally it would fit without changing the bodywork too much. I think that might also be interesting to you to prove a point that any technic car can have proper suspension and space constraints isn't a good argument. Everything else is open. Think of me like the dog: I will eat what I'm given, and be very happy.

Some of it is flex in the lower wishbone (it's not really any kind of final version) but really I mean because of the length of the top ball joint mount, the wheel doesn't pivot within its own volume, it flops back and forward while moving. Somewhat like the old wheels do. Sorry, not a great description I know. Multi link would be cool too. I do have plenty of 6L steering links and 6L wishbones spare (I think 8x of each), but only 2x 9L links, 2x 5L wishbones. Of course, bricklink has more.

https://bricksafe.com/pages/A_morti/konceptmantis/geometry-front-suspension/for-nic Few more pics anyway including an angle of the bottom, you can see where the wheel geometry "wagging" causes it to hit the bodywork but the other one doesn't. Some of the bodywork can be moved or taken away, however it's already not got a lot of mounting points holding it together. Is it worthy of a live stream? I can be online tomorrow. I'm interested to see what you get, and how close I got.

Alright I'll take it off if you can solve the other problems

Maybe! The two bigger problems are mounting the steering ball joint properly, and the wheel "wagging" causing a clash with the bodywork. The knuckles could be stronger too, although in use they don't at all look ready to fall apart. Other than that, it's basically complete at this point.

Well I think I answered all your points here. The wishbones are thicker and now supported on pins instead of axles. Even so it's not nearly as sturdy as the original version. The steering rod is straight and there's no bump steer, albeit the ball joint is not properly mounted in the picture (hanging down by half a stud). The ball joints align with the wheel hub's centre. There's 1 stud of caster, taken care of by the wishbones being offset only. Probably still pretending to be about a 5.1L thin liftarm, but much closer to legitimate. Now the ball joints are in line with the hub's centre, the thing has gained more steering lock. That's good, but also a problem. Since the top ball joint is 2 studs inboard from where it would be on a normal steered hub, the wheel "wags" quite a bit, and I'd have to redesign the whole wheel arch constructions for it to work. I'm coming to the conclusion that while this type of 3D puzzle is definitely possible and really interesting to do, it's not easy, and it's not necessarily suitable for RC models.

I was just looking at that. That wheel has a reduced steering lock compared to the other which isn't such a bad thing, but IDK what other effects that would have. I could put the ball joints in the centre line of the knuckle without a problem, but I'll have to look again at whether the wishbones can slide along to make that work inside the wheel arches. Like I said - I know it's not nice, but you need something to hold the ball joints together and it's the only spot to do it. I can probably make it a little nicer by using an axle with stop, but it's never going to be a beauty feature. I know it's not perfect - help me make it better :)

Yes, now I do! However, it feels like this is a new thread, rather than clutter @astyanax's thread.

First things first: This post isn't about them (and I'd prefer if it doesn't go that way) but it will show constructions which are obviously built using them. So, if seeing Chinabricks upsets you, best look away now. Following from @astyanax's Koncept Mantis MOC thread, I have been playing with some of @nicjasno's ideas for incorporating real suspension geometry into a model. Nic (and others!) - I'd really appreciate any feedback to the design, construction, etc. I've taken a bunch of pictures, here for full resolution gallery. Let's start by looking at the original suspension. It's actually not bad at all. It uses two 9L wishbone parts as the lower control arm, which gives it great stability and looks perfect for the car. The 9L steering links are used and it doesn't have any bump steer. Clearance is around 1.75 studs at the front, and it uses about half the spring travel before the car grounds out. Non-friction pins have been used instead of ball joints, they have a little play but are actually really pretty good. The top wishbones are shorter than the bottom ones like a real car. Although the lack of ball joints makes me wonder if it's "proper", it all works within the limits of the actual suspension travel without any binding. The springs have been attached at the bottom wishbones in really the only available place, although I did put those two red 3L thin beams in place of a 32184 connector, and mounted the springs there, which I preferred that as it softened the spring rate and gave a bit more clearance. Here's a comparison side by side with what I've come up with: It has (possibly too much?) caster angle. It's 1.5 studs further back at the top than at the front. I think ideally I'd like to move the bottom ball joint half a stud back, need to look again at whether I can get the wishbone mounted solidly in that spot. Which should also let the steering rod run completely parallel to the wishbone. That misalignment doesn't seem to be enough to cause a noticeable bump steer, though. The top wishbone is 6 studs long, the bottom wishbone is 9 studs long. The steering knuckle has some King Pin Inclination (KPI) which is shown by the grey 5L thin liftarm. That lets the tyre's scrub radius be just about where it wants to be just inside the middle of the tyre. Which is kind of a shame because this guy was a better part for mounting the top ball joint than the similar 3L part which only has pin holes rather than an axle hole in the end. The 5L thin beam being used as a brace isn't quite in system, I think. It gets hard to tell when you're dealing with angles all over the place. Either way, it's staying, because there's not much other chance to brace the two wishbones to each other and trap the ball joints. The spring is now a single. The car has around 3.5 studs of ground clearance, which is nearly 2 studs more than the original design by a trick of the knuckle (see below). Once it uses all the travel it still has about 1 stud clearance. It sags about one stud into the travel on the car's own weight, which seems good to me, however I can't get an accurate read on that until I do both ends and both sides... which will mean ordering up another pair of "rear" wheel hubs! I only got out of my Dark Age this Christmas and don't have that big of a collection, hence buying some Chinabricks to get it moving. The lower wishbones need to run pretty much flat to the floor of the car, but I wanted more clearance. You can see here that the wheel is not in the middle of the ball joints, rather it's been offset lower to give more clearance. The steering knuckle is sturdy enough, but still it could be stronger, I think. I have paid attention to Nic's pointer that it should have pins going through the hub not axles, but the top and bottom aren't the most solidly connected. Unfortunately I ran out of patience trying to make it hold together better whilst fitting inside the rim. There are more pictures from more angle in the BrickSafe Album. So gents, what do we think? As above, I'm really looking forward to feedback on this, and maybe suggestions for improvements.

RC servos use a potentiometer to sense position, whereas Lego servos use this 15-step sensing system. They're pretty much not compatible at all, so I think the 4 pin on top of the buwizz is the one you'd have to use. If it can give that output

I wouldn't want to rely on XL motors driving 8t gears. It's bound to kill them. For the same reason you may want to build it with locked differentials as the 12t gears can pop out the diffs under high stress.

There are some great examples out there, starting with this: https://rebrickable.com/mocs/MOC-27092/Madoca1977/tatra-t813-8x8-profa/#comments I'd consider using one motor per axle. This way you should have fewer frictional losses and you don't need centre differentials. It'll be slow with XL motors or need a lot of gearing up. Gearing up 3:1 likely means using an 8 tooth gear in there, which is certainly risky, or you need a few of the expensive 36t gears. Maybe you can put two motors either side of a 5*7 frame with a 36t on each, and 12t gears at each end going to the rear axles. And a third on its own for the front?

@2GodBDGloryI had two fail which I'd bought new just this year. They both had some white grease in them, it hadn't saved them though. In the end you're dragging what seems to be spring steel against copper/brass. It's a fight which only has one winner. I really don't understand why they had to reinvent the wheel here. RC servos are cheap and reliable and use a totally different technology, they should have copied that. I still have a dream that the port on top of a buwizz could power an RC type servo.

Just watched the whole 3 hour stream on this. The whole way through I was rooting for you and hoping for a modern day unimog fix. Also the whole time thinking how the ball joints for the 4 links were 7x11 apart and how much gearbox you'd fit right there between the suspension in a 7x11 frame and with all that extra engine bay. Rough luck with the CV joints, this has to be one to revisit if Lego ever gives us non reduction hubs on the new joints. I like how you build. "Let's see", "let's try", "we don't know yet". Refreshingly old school in a world of LDD. You give me a lot of inspiration to make better suspensions. Nothing useful done yet but I'll be working at it

Sometimes Lego Servos just quit returning to centre. There are lots of videos of this phenomenon on YouTube, and I know that plenty of us have had it happen. When it does happen, your first action should be to ask Lego for a new one. I've asked twice, and they've twice sent me a new one with no questions asked, and didn't require the old ones back. Now, when Lego sent you a new one (or if you didn't like to ask, or can't wait for the new one, or when the new ones run out) you'll be sitting looking at a servo which does something like this, or which doesn't return from one side or the other. First thing you need to do is use something sharp to remove two of the clips which hold it together. Even then, it's going to take some force to get this open. Keep in mind the servo will never hold itself together against pulling forces quite the same again, but generally it shouldn't be a problem. Inside you'll find it looks like this: The positioning circuit works by dragging the two stainless/spring steel contacts along the brass (copper?) tracks connecting various points in a circuit, then a chip figures out where the motor's head is pointing. However that's not a brilliant design, because the tracks are soft, and the contacts are hard. Here (click for high resolution), you can see the smaller tracks near the middle show clear signs of wear. I don't know whether it's happening by "smearing" the metal or whether it's by arcing between two blocks, but what happens is that two neighbouring blocks end up with continuity between them, where none should exist (click here to open it bigger so you can see where I'm testing). At this point, the logic circuit can't figure out where the motor is, and strangeness ensues. The fix is to use a small sharp blade to clear a gap between the tracks. If it's due to friction, grease should help (even then you're still dragging steel along a much softer metal) and if it's due to arcing, a dielectric (non-conductive) grease will help. I have this stuff and confirm it's safe for plastic. I would prefer something thicker, though. When you're done, you'll have a fully functioning servo again

It's finished in white! Yes, there are lots of Chinese bricks in there. No, it doesn't fall apart when you touch it. See all those white pins? They're there waiting for you on the darkside The "03" see stickers may not make the cut. The colour works but they were originally on doors and aren't oriented right for this. I deleted the airbrake. Decided I'd rather make the spoiler a little more sturdy. The exhaust pieces changed too. You can also make out how I modified the rear bodywork to suit the reinforcement of the transmission area. It's very tight for space around there. I've done a fair few mods tying panels together to make the wheel arches a bit sturdier. It's nothing anyone couldn't figure out with a few basic connectors so no pics unless anyone asks. Front suspension modded, gives a softer suspension that should be effective outside, and about 1 stud more ground clearance; as standard it has just under 1 stud which seems tight. The steering angle is marginally reduced, but it's still plenty and shouldn't stress the servo. Rear hubs modded using 5L axles with stops. Holds together better than originally designed. It's running with 4* Chinese +30% L motors, a Lego servo, and a MouldKing lipo battery box and digital remote. Only 8.4v but it's about as quick as a pair of buwizz and normal L motors on fast setting. Battery doesn't last long for outdoor play, so I may put an RC lipo in there, there's loads of room.

Not sure I'd build the 2* L motor variant, it's just not silly enough I already flicked through the instructions of the L motor version, but not yet the buggy motor version. Turned out you braced the rear subframe pretty similar to how I remodeled Mantis. I really like the pushrod suspension. Can't believe it has even fewer parts and looks so complete. There's definitely a benefit of using big panels.

Very cool! I still have Mantis on the bench waiting for the bricklink order with all the wishbones. I'm planning to finish that and enjoy it a while, maybe mess with the undercarriage some more... then rob the parts to build this one.

Got it, because otherwise the torsion bar can flex in the middle causing toe out. Your stuff is inspirational @nicjasno, and it'd be great if Lego would take some lessons from you. Sadly as the comments here show, many Technic builders are as/more interested in the use of panels, as the use of Technic. btw, I'm happy you make this one without any scissors, but other than that I couldn't care less about legal or illegal use of a brick - especially not when the results are so good.