gyenesvi

I can only post it later, I have no access to it now.. However, first I'll try this, because the Running Brake Level is at 9 now (that was the default setting for some reason), and I only tried lowering it, not pushing it up to 10. Previously I only experienced that it does not work well for value 1 (screws up sine startup).

Looks nice and interesting! I like the simplicity of the 4 motor drive, but can't the added power brake the U-joints? Maybe due to the planetary hubs it is not an issue. Can you show more of the axles, how the steering and diff locking is implemented? Is the back occupied by the batteries, or is it mostly empty?

Well, I was just curious, would not expect better results than on its own SurpassHobby ESC.. besides, that's what I am doing with the Injora ESC as it is AM32 based.. but I also recently ordered a bare AM32 board from Ali, so will test that as well. Do you think that the same programming board and software can be used for all AM32 ESCs? I have it for the Injora and did not order separately, from the videos it looks like the same software being used.

Yes, just measured, it's at 12.3V now. They are AM32 based, so they are configurable, and I have tried many different settings (motor poles, KV value, turning variable PWM on/off and setting PWM frequency to different values, turning sinusoidal startup on/off, turning brake on/off, etc). Checked that, but it should not be an issue as it seems to work fine with Injora motors Yes, but the startup is not the problem, that is quite smooth actually. Yes, Injora motors are sensorless too. Well that's interesting to hear, so maybe this is how they work normally? Which would be kind of weird. I'll try to borrow a SurpassHobby ESC for testing to see how it works with that.. Was it the same on AM32 ESC? Have you tested that?

According to the specs, the 3300 kv 2435 draws 22-24 A max, and the Injora ESC can deliver 25 A continuously, and 60 A peak, so I don't think it's that (the battery is 75C). And the ESC also works fine with the bigger Injora Fat Viper motor, which peaks at 50 A (even the 1721 peaks at 30 A). Also, a SurpassHobby ESC is rated at 25 A.

I finally wired up my SurpassHobby 2435 motor to my Injora ESC (I needed to solder some connectors to make them compatible). It is working, however, it feels like it's spinning the motor relatively slowly, given that it's a 3300 kv motor on 12V LiPo (feels/looks kind of like a Lego L motor). My Injora motors are running fast on the same ESC, and I tried setting the ESC parameters, but nothing seem to have changed. Does anyone have an idea what I could try (besides testing how it should actually run on a SurpassHobby ESC)? By the way, do you think these things should be cross-compatible?

We were talking about the phone control of PU system, so not sure how it is related to City and building techniques..

Do you mean put a switch between the ESC's BEC output and the receiver? Because on the AM32 ESCs I was looking at, the BEC is built onto the ESC board, so that's the only chance. But he BEC output is still usually about 1-2 A max, so still sounds high for the micro switches. I wonder what is done in ESCs that have the switch built in. Which connection does it break? And also, those ESCs are designed to be left on the battery, and just turned off, no?

Oh wow, they are phasing out a bunch of parts that were only introduced lately. But I hope that's in favor of releasing new parts! I guess they are thinking that Bricklink will take care of storing all the older parts.. I hope so too! I mean the planetary hub is surely the part that makes much of the bigger RC models possible, so why would they get rid of it completely? I really hope a new version will be introduced, and not that they would be toning down RC stuff..

A question to @Krxlion and @janssnet or anybody having experience with AM32 ESCs. I have been looking at the Ali links provided here as well, and find that those AM32 ESCs do not have a switch to turn them on/off. I have been wondering how you guys solve this issue? Just unplug it from the battery? I have been looking at mini switches like the ones on other ESCs, but I don't quite get how they work. The problem is those mini switches can take very little amps (like 50 mA), while those ESCs can withstand 20-30 A as well. So I can just put the switch in between the battery and the ESC. How do those switches that work on other ESCs? Am I missing something here? @vergogneless I just saw your mini 3d printed axle here (I saw the post before but the pictures did not load back then), great work! I did not know those MTP U-joints are only 2L, is that right? Those MTP 3/4 liftarm connector screws are also neat, but outrageously expensive.. I have been wondering if I could just use something like M5 screws driven into the printed hole for similar purposes on the steering knuckle (frictionless connection).

I agree that the situation is far from ideal, but I also think that TLG mainly ended up here due to bad decisions and lazyness / short term thinking and not intentionally, so I would not say it's disgusting. I think all the smartphone thing sounded like a good idea because then they only need to write software for it, and so they could spare making physical remotes, and also they were assuming that smartphones are spreading anyways, so most children will have them regardless of Lego. Obviously, that's in a way counterintuitive for a toy whose strength is physical interaction and the way it can help child development, so that part is sad. At the same time, I guess they underestimated the complexities and management issues of the software component, so they kind of shot themselves in the foot with the whole idea. On the long run I think developing physical remotes would not only have been a better fitting product, but altogether it could also have ended up being cheaper to maintain the ecosystem. Maybe some firmware updates, but not maintaining several apps for multiple platforms that are ever changing (and fast). That's just my guess though, but hearing that the whole auto industry has underestimated the complexities of software and its maintenance, it's easy to imagine that Lego fell to the same trap.

Oh, I fully understand you :) Indeed, manual steering calibration is a really missing feature of the app..

I like the electronics layout on this, especially the placement of the buggy motor, one of those rare cases where the weird form factor fits the model nicely! Is there are specific reason to use a PF servo for the gear switching? Couldn't that be done with another PU L motor (easier to get nowadays)?

Nice axles, I knew someone would start using these parts for good :) And great that you cover multiple steering options.

I know PU L motors are about 15% more powerful than PF ones, but what other specs do you mean? For example, they are also slower by 25% which may be undesirable, especially when used in conjunction with planetary wheel hubs and/or high ratio diffs (red ones). The Zetros is a good counterexample here (too slow, unnecessary torque).

Hmm, why am I not surprised by this inconsistency.. this option would be more useful exactly for the larger builds..

Lego has an app for this - it's called the Lego Builder - 3D building instructions. It is available on App store, probably also for Android. You can just scan the QR code of the instructions booklet to find a set / probably also by set number. I'm not sure thoughif you can freely rotate or if it just gives you a 3d view from fixed angles..

No, only around the mounting points of the motors / Buwizz. I haven't tested it off-road yet, so I don't know. Not sure if it's worth it due to the weak steering.. I don't know, maybe I'll test with Bronco tires, but they seem hard and expect them to be slippery. This bodywork would probably not work with small tractor tires as they are wider and get caught up in the fenders easily.

Another batch of orders have arrived, so here is the next brushless motor I am making: the big brother of the Injora Purple Viper, the Fat Viper, which is 2200 kv. This is a 28 x 19 mm motor optimized for more torque, controlled by the same Injora ESC as the smaller one I previously posted. The overall construction is very similar, just the mounting face is a different shape due to the bigger size of the motor, this time it is 5x3x3, 5 units being its intended height. Due to the bigger size of the motor, its mounting holes are also further apart, so I had to change the mounting wall accordingly. Here are the steps for constructing the motor. First, the wall is mounted with M3 screws. Then, the planetary gearset is added, sliding into the horizontal sockets. Finally, the face is added and secured with two screws from the side. It can be taken apart by unscrewing and pulling the wall out, helping the process with a knife at the horizontal holes above and below the motor. Running is similar to the smaller one with the purple Viper, but a bit slower and more torquey. As for mounting and building in, the idea is that beams can be run above and below it, but not directly next to it, because of the width of the motor. Also, a driveshaft could not be run right under it, hence probably two stages of driveshaft lowering will be required. Thus, the housing is tall to create axle holes two studs below the output, where the driveshaft will drop. With this motor I will probably build something with 68 - 80mm tires.

So what you are essentially doing is turning off the sinusoidal startup :) Indeed, it could be an interesting setup to test. To go back on topic, I have made a PF/PU/Buwizz version of the chassis, just for the sake of seeing if it could be done and how it would behave. I used a PU angular small motor for steering instead of the GeekServo as it is almost the same size, so it fits. I have always wanted to test this motor for a steering alternative. It is somewhat weak, but it kind of works on not so sticky surface. For the drive I used a PF L motor, the PU version did not fit. The speed/torque ratio is quite okay actually, but of course slow speed control is not so much. Because of the mix of PF and PU motors, a Buwizz 3 had to be used for power, which fits into the bed.

Thanks for the info! I wanted to try 3d printing rims anyways :) It also looks like the steering arms are 3d printed? Anything else? :D

Looks really nice all around! Where is the buggy motor located? In the middle? Is the gearbox manual or RC? What kind of tires are those? And what size? They look really nice and thin. Do you have a link maybe? Which lego rims do they fit onto? Or are those RC rims? Not really visible on the images..

That is interesting to know - I did think that something like that might be the happening, because precise speed control and coasting (no speed control) sound like technically opposing things. However, I'd expect that free coasting would be happening when the trigger is released, hence, when speed control is not happening, so they might not be opposing after all. But then one thing could break this reasoning, namely that as I am releasing the trigger, the speed control might react so fast that it is continuously slowing down the motor already, and hence by the time I actually release it, it is too slow and does not coast. But even then, I think that the fact that it only cogs at brake level 1 is kind of an inconsistency with itself for all other levels, so whatever the phenomenon should be it should at least not behave very differently for this one value than all the others, hence I suspect it is a bug. Also, I think free coasting is something that is not actively done, it is something that only happens naturally, so by that, it could not be opposing some other process that is done actively (the speed control). So still weird..

Thanks, that worked!

Do you have a link for beams with pins in the end? I never managed to find those on AliExpress.