amorti

One of my two buwizz 2 couldn't hold a connection, and was rattling. The aerial had fallen off. Looks like it's just plonked on the board and blob-soldered, there's not even a hole for the wire to pass through. Anyone else had this happen? Not sure whether to try and fix it myself or not. It's under two years old so I guess this is still in warranty. Emailed support on Friday, let's see what they say. Btw, do we need a new thread for buwizz 3?

Seems reasonable there would be a connection. A wheel with a fixed weight will give a certain amount of gyroscopic effect, which needs to be enough to overcome the tendency of the bike to just fall over. In real bikes, it's often said that you don't feel the weight of a large bike (Pan European for example) once you get it moving. The inverse being true - at slow speeds, it's a pig to keep them upright. The higher up the CoG is, the more you're going to need to force the bike to change direction. This holds true in real bikes, too.

Way back in the early days of overpowered Japanese bikes like the Z900, it was common practice to brace the neck to stop speed weaves. You could go a lot faster if the two wheels are kept in line. I think that is all this bike needed, too. Notice in the video, the headshakes are basically gone?

Edit: Apologies for the upright filming and wind noise. Turns out mrs amorti isn't Spielberg. Still, you get the idea! This was normal (7.2v) but as we know, you can turn it up to 11 with ludicrous mode.

Amazing how few pieces you have on that dirt bike. I'd have to take something apart for an XL motor but if you're willing to share the model, ofc I'll build it. The XL will be a MouldKing motor, they're not as strong as CaDA Pro but still a lot stronger than Lego.

I see why you'd suggest it, but this is exactly what this topic isn't about. We don't want this... We want proper, self-balancing motorcycles. Made of Lego. It sounds mental, but it's really possible as shown by @piterx's Fastest Bike and Baja Bike. I've built both of those and driven the Fast Bike (still waiting for tyres for Baja Bike) and can confirm it works. Download the stud.io files I've uploaded, and try for yourself! As far as I can tell, the main tricks are sufficient trail for it to track true, even balance down the centre line, and a stiff chassis for stability. Not sure about this one, at least not if you want to drive it outside. Having previously said I doubted the suspension would even move, I've now driven the fast bike and the suspension definitely does eat up bumps. I think the frame stiffening I did helps, because the front of the frame now forces the fork to eat impacts, rather than making the frame flex.

Even with the buggy motor centred in the Fast Bike from piterx, it tends to wander just a little to the side the gears sit on. Even that much imbalance makes a difference, so if your whole motor is off centre, that'll be a main reason it's not working. You could try putting the battery a stud over to the other side, see if it helps? I didn't test this idea yet but it seems sensible. I found it useful to try this stuff with it freewheeling. Then you can try it at a slower speed just by pushing it. Slack in the headset doesn't help stability but shouldn't completely stop it balancing. I also see your buggy motor is mounted across an axle, and the shock bottom eye is across an axle. At high speeds, this much slack really matters. My modded version of the Fast Bike has minimal slack anywhere, everything is pin and axle into matching holes. It's way stiffer, and it doesn't get head shakes anything like as much as the original version. Part of that is using CaDA pins 'with friction' in the headset. They have almost no friction, but also almost no play, whereas Lego non friction pins have a lot of slack. I'll post more on that thread when I've got a video of it driving.

Maybe mods can move these last few posts?

I've just been playing with this. It's awesome! Lessons from a first run outside: I think the scrambler tyres might have been better, as the street tyres don't much want to hook up, to get it to self right. I'm really glad I reinforced the forks, as you crash a lot and the front end would grenade without that. Use 8L axles with stop on the front spindle and through the bottom triple clamp, use a 10L axle through the buwizz instead of a 9, and make any "outside" half bushes on it yellow ones as you'll never find grey ones. Edit: Since you need an axle with stop the extra width is unavoidable, so crank handles are ideal, and help make the front end even more rigid as they tie that axle hole in the fork into the top triple clamp.

Cool! Show us what you've made mate. My best guess is instability will be due to looseness in the chassis or a lack of trail. Lego Moto suspension takes about half a kilo to get much of any compression. It won't move noticeably on a small imperfection.

Nicely done

Thanks! Don't know what I did, but I've not managed to make that work properly.

Getting the hang of Stud.io now. Stud.io file here: https://bricksafe.com/files/A_morti/baja-bike/baja.io There are some modifications: strengthened the bevel box so it's pretty much impossible for the gears to skip now. It could fit inside the futuristic wheels but has to hang outside with the buggy wheels. rejigged the steering mechanism which now supports the frame backbone making the whole thing much more rigid. The steering can still skip if you force it, but I think that's unavoidable if using 8z gears. the main frame is now form-locked to the rear frame so it can't pull out. By ruler, the tyre should still clear (<fingers crossed) The gold wheels were just a moment of madness while ordering up the tyres (not here yet) on Bricklink 177 parts only! And not a single red or brown one in sight. edit:189 - stud.io counts sub assemblies as one part :/ But it needs to be 179... Anyone out there kind enough to help me add the 69909 tyres which are not available in Stud.io? Either by doing it for me and re-uploading, or giving me some hints how to do that? Thanks :)

My tyres and buggy motor are here now! I've done a quick trial in the house - just enough to terrify the dog. A few revisions came out of the trial, mostly turning the bent beam in the swingarm the other way around as that bottom corner was getting in the way of it self-righting, which has added strength and improved ground clearance; and remounting the rigid hoses and flex axles, mostly to allow more solid mounting of the "radiator cowls" which happen to hide the ugly frame bracing, and maybe add a little more strength now they're not mounted on a flex hose. Looks like this now: stud.io file updated - I can't quite believe there are only 226 parts in this thing. Even then, two are PF plugs and if you rationalised a few pins, removed the headlight and 2L pin connectors on the forks, removed the seat pad, put the 21/22 panels on the tail one stud forward, etc... I reckon you could get right around 200. It really is awesome to see it self-right and just shoot off! Now I just have to look forward to the weekend, and the chance to drive it outside. Cheers, @piterx

I just got my 1995 8422 motorbike in the mail. Decades ago, we didn't even have studless. No... I bet TLG was caught with their pants down, and are now playing catch-up. They'll probably put a design protection on these pieces they never used yet but someone else already has in their catalogue, same like they did with a 1x5 plate.

It's certainly amazing what you can build with those freshly-invented cross beams... As you can see in this video released six months ago by CaDA.

@piterx I reckon the CaDA motor can make the bevel box skip even if a Lego motor cant. Anyway, I can't help myself I picked up this cross-bracing habit from Didumos (a pinhole not used is one wasted) and until the tyres arrive, all I can do is tinker at it. What do you think about the futuristic wheels? I like the idea of putting the bevel on the inside but I'm not sold on the rubber-band tyres.

I've not driven one yet, but I suspect it'll be pretty important. Otherwise the bike will be very unstable if all you have is bang-bang steering. Your question got me thinking, to the point I've just played servo Tetris and got a proper Lego one for both these bikes. Balloon tyres won't work on this bike as it's designed, they're too wide. Probably too big on the radius too. That's not to say you couldn't make it work. Just put an extra angled beam in the middle of the frame and change the pins around, should be possible. Should also be possible to put the frame one more stud further back as needed.

In the CAD renderings, it's geared black 12z to grey thin 12z. It's easy to get various combinations of 12/12, 12/20, or 20/12, but that's all you can easily do. I guess you could get the new 28z gears involved with a bit more effort, but it still wouldn't be 2:1.

I don't have suitable tyres yet, but anyway I built it. It's built with CaDA Pro motors. CaDA servos aren't proportional, but I'm all out of accessible Lego servos and they cost 80€ each now. CaDA L-motors have been measured here at 715rpm versus 388rpm for Lego, pulling 2049mW, which is nearly double what a Lego motor pulls. Noting that I could make the bevels click by hand, I've beefed up the bevel box. I used a CaDA 20z gear, as the teeth on them are squarer and less prone to skipping. Experience tells me this motor will happily pull 20:12 gearing giving 715* 20:12 = 1191rpm, which is about the same speed as a buggy motor. Even flipping the gears to 12:20, it'll have 50rpm's more than a Lego motor, so probably just do burnouts eveywhere. The space also allows for two black gears giving 1:1, but I want to keep the CaDA 20z gear in there. @piterx, any ideas if this will cause an issue for ground clearance and self-righting, either with futuristic tyres or baja tyres? I'm looking at that bush-pin at the bottom (replicated on the other side just for table-testing of the motors). If it's close, it could also be a slightly smaller pin-pin-axle, I would even snip the end of it, but I can't get rid of it completely. The only other mod I did was to support the ends of the steering slider axle and add an 8z gear on the other end of the gear rack, as without that, the 8z gear tends to skip across the gear rack. Guess I need to get on Bricklink and order up some tyres I'm tempted to get the Futuristic wheels as a quick mock-up on Stud.io says they *should* allow the bevel box to go inside the frame. I could use either the skinny or the fat one up front. There again, new spiky tyres look great and maybe the extra sidewall height provides some rear suspension. I'm open to opinions - please, let's hear them :)

@SaperPL I think you could make it work with the two port powered up hub and two new L motors. The motors are a stud longer and the battery box a brick taller, which should be not such a big deal? The main problem is AAA batteries are a *lot* heavier than lithium cells. Even so, powered up motors can make very accurate servos, so (once you'd got started) just swing the weight less. This one would be way more likely to be released than the fast bike (because of the buggy motor and 1990's tyres, and the fact you're definitely going to crash it and break pieces, a lot). Edit: actually the main problem could be the PU cables hanging out the side of the battery box. They'd be very vulnerable.

Don't have those either, nearest I have is probably 81.6 balloon tyres (too wide), or Arocs tyres (too square). I'll build it! It'll just have to wait until a next bricklink order to get the tyres. Would you mind sharing the studio / LDD file? Btw, sure this and the other one would do well on rebrickable if you decided to make instructions for it. I've never made instructions but it seems like you have done the hard part already by digitising it. I know I'd happily put a few sheckels for it.

Looks good! Slower, easier than the fast bike. Will have a go later on. I don't have the tyres but I probably have the rest. Have a look at these motors, they're almost twice as fast as Lego motors and have more torque too. Should be great for this? https://www.custombricks.de/motors-cables-sbrick/cada-power-functions-l-motor.html

Thanks! No, I've still not received my vintage set with the tyres yet. I'll definitely have a look at the other bike too :) Interesting you mention cheaper. When you have a 10€ buggy motor, this isn't expensive at all. https://www.bluebrixx.com/en/assortments/401268/MOU-M-00007-Monster-Motor-Mould-King