Aurorasaurus

I've now done a bit of playing with my new brushless toys, and run into the same problem as everyone else: wheel hubs. I have a 3d printer and some small bearings that fit axles through, and I think I want to have metal U joints come out of the hubs. Currently I'm thinking 5.5m axle through the bearing so it cant slide out, then use pinholes to get ball joint pieces in the right places. What does everyone else think? what should I focus on? Metal parts initially seem like an acceptable option, but the price is too much, even if I had any money at the moment...

In a word, "no". Sorry about that. But you can use the powered up technic hub, if that helps.

Hear me out... I know it's inefficient, but it wont skip, and it fits a 3x3 space. https://www.bricklink.com/v2/catalog/catalogitem.page?P=32072#T=S&O={"iconly":0}

Well, I'm officially part of the club! My A2212 and geekservo finally arrived, and I have a fully working motor setup. I just have one problem. My geekservo wont turn full 180 turns, and the dial on my transmitter that controls its maximum is set to the highest amount of movement. Im using a dumborc x6 and x6fg, quicrun 16BL30 esc, and 1500mah 3s lipo that's charged correctly atm. I think I calibrated the transmitter correctly, but maybe I need to calibrate the receiver somehow too. Any tips? Edit: I should also say, I've tried toggling the gyro on the receiver. My specific receiver model is the x6fg v1.1, which seems to have no official information available online... Edit #2: I pushed the button on the receiver 4x and now its fine, apparently. Sorry for the fuss.

Wow! It looks stunning, especially those seats, I love them. Do you think you could add photos of the underside? Im curious to see the 4x4 in this model, given the high weight.

Nevermind, I solved my problem...

They will fall off, or the wheel hubs might melt. Unless you're keeping the speeds low. Check out the Buwizz modified supercars, they had to use 3d printed wheels attaching to turntables to keep the wheels on for the daytona mod.

It might have been this :> Thanks for the praise, I'm hoping to improve the sideways stability and steering play before the competition, but I think I've got time.

Thank you! In theory they do steer at different angles, but in reality the difference is negligible because of the slack in the steering axle and the steering racks.

28:20, 20:12. https://bricksafe.com/files/Aurorasaurus/tatra-8x8-first-edition/20241103_002720.mp4 Here's a video of it with that gearing.

Thank you, I appreciate the support :) The XL motors are geared 1:1 to planetary hubs, and with the Buwizz they get higher voltage thus higher rpm. I actually had it geared significantly faster before, but the motors were overheating after about 10 minutes of play.

Thank you very much! The requirements for next year are not out afaik, but I'm working on assumptions/a previous draft version. I have enough time on my hands on the weekends to build, and sometimes I get into that flow state where everything just works out. Music helps.

Thank you! The front 2 axles steer, so 4 wheels steer it.

It uh, seems to be missing doors... Otherwise, I'm shocked how quickly you made such a massive vehicle, it looks pretty good.

In preparation for next years Buwizz gathering, I thought I should start working on making a trial truck, among other things. I've never finished a trial truck build before, so I expected to run into some problems this time, but I suppose I got lucky and I didn't! As the title says, I also made this model in just 1 day on the weekend, which I'm proud of. I was inspired by a trial version the Tatra 813, from HT Group Racing. Here's a video of this truck. https://www.youtube.com/watch?v=uxFjTTEWORI Details The model has independent left and right side drivelines, each side is powered by 1 PF XL motor, geared 1:1 to planetary hubs. Steering is done by a C+/PU L motor, and has more slack than I'd like. The 1st and 2nd axles steer at different ratios, but due to the slack in the steering axle the difference is negligible. The model uses Tatra suspension pivoting off the drive axle. This is obviously not ideal, as it adds unnecessary load to the drive axle, but I was feeling lazy. The gears probably should skip, but I never heard them skip once when I was driving, so I guess its okay. Here's a mock up of the second axles swing arm, made especially to please the anti-color vomit crowd ;) And finally, a video of it in action! I recorded this on the weekend, with my phone hanging off my controller, so I apologize for the shakiness of it, and the wind noise. Thanks for reading, please feel free to ask any questions!

I also use 5mm to be a good size for the holes, and also use 6.2mm diameter for the counterbore. But I make my counterbore 1.05mm deep. Maybe this was only necessary for me because I typically print in high layer heights for speed.

Have you heard of PyBricks? Racingbrick has some good videos on it, and theres a thread here and a website with what seems like plentiful documentation. It allows you to pair an xbox controller straight to the hubs, but the downside is you need to recode it for every new creation.

Design a test piece with holes in multiple orientations, and test hole size in increments of .1mm. If its still hard to get a good fit, try increments of .05mm. If you don't have access to CAD software I could make one for you. Another thing could be you need to dry your filament and/or somehow temperature control the environment for your printer. Maybe external factors are impacting print accuracy.

I made a few 12t clutch gears from esun petg, and the teeth broke. I also tried a 28t clutch gear from pla and the internal clutch teeth broke, same with 24t and 2 module long clutch ring. So for gearboxes IMO there's no substitute for injection moulded ABS. But something that did work well for me was printing a 28t gear that slipped on top of a 16t clutch gear, using the strong clutch interface of ABS, and the good enough teeth of PLA, since at that distance from the axle the torque in my application was managable by the teeth. As for other things, I tried short reinforced cv joints, so I could make a 5l independent suspension system. Making those from PLA worked fine, but maybe wouldnt in a high wear environment like sand. Something that has worked great for me is 3d printing rims and body panels. For rims, I recommend printing in TPU so that the abrasive effect from the layer lines is mibimised. With PLA or other harder filaments, when you put the rim on and take it off many times you can wear down the pin and it will not hold the rim so well. Body panels from PLA have been fine for me. I just spend some time sanding and filling before painting and they come out just fine for my eyes. I've also made extremely specialised parts, but I'll talk about those another time.

Is there any reason you didn't attach the cv joints to the motor instead of attaching axle joiners to the motor and cv joints to the axle joiners? Was that because you originally planned to not use the planetary hub to gear down? I'm thinking about using the same method you used and was thinking I could save 4 studs this way.

I try to keep my parts out of the sun and dont have any problems with parts cracking. But my collection is definitely on the newer side. Also, how can we possibly not have even length liftarms by now!?

Would you be bothered by the layer lines? Or are you planning to use them just for mechanical parts, not bodywork? The only filament I've used that matches lego colors nicely is black :) Good luck anyhow, I'd be curious to see what you find. Maybe you can order filament samples instead of full spools?

I was looking for just that today, that motor size is 130. From my quick search, that size in brushless doesn't seem to exist. But I think it could be done somehow. As for the truggy, I love it, the climbing is amazing. I'd love to see some more footage of it at top speed on gravel/sand too though.

Its scary but really funny. Nice work making it move in such a fun way!

Just use brickcontroller, its so much more reliable. You just need to watch out and drive carefully because theres no current limits available in BC2 yet.