2GodBDGlory

Very happy to see some progress on this! It would be very cool to have something like this more readily available.

Very interesting! I'm not sure how I feel about this specific instance, because it feels like it's a replacement for what could have been a traditional, multi-piece build, but I can see a place for it in low-production-number parts, like exclusive minifigure headgear that only needs to be in one set ever, where the higher per-part cost would still be cheaper than the big up-front cost of buying a mold. The only other real reason to print a part would be to have properties that injection molding can't create, like the internal mechanisms in this train. I don't really imagine we'll see much like this in Technic, since you have to remember that 3D printing is expensive at large scale, so it's really only going to be low-production specialty parts, and in Technic we don't have a ton of that. The only Technic part from the last several years that I can think might have been good to 3D print is the Mack bulldog part, since it didn't need structural strength, and it only had to be used in one set.

Super fun to watch the progress on this!

Unfortunately, most likely not. I talked about it more in the topic for the book, but I'm no longer at the stage of life where I have the level of free time I used to, and I think updating the book is something that's going to be dropped.

Sorry for the delay in updating my progress! I think I understand the theory now, and I made some more tweaks to the area with the 7L gear racks, so they're now able to rotate the full 360 degrees. This also required moving the small banana gears up one stud. Unfortunately, in its current form, it's not really working. There's some pretty major backlash problems with the 12T gears driving the gear racks, such that the racks can move freely about a stud, which is a pretty crucial difference. Getting rid of the backlash might be tricky, but I wonder if replacing the rack with a small linear actuator might work. It would be even bulkier, but the screw would prevent any backlash from causing issues. Beyond that, the actual ratcheting part at the top isn't really working. Part of the issue is that the eccentric moving the arms is so much lower (worse now that I moved the output ring up) than where the 12T gears engage with the banana gear, but it's just generally floppy and imprecise, at this point in development. I think solving these problems is going to require fairly significant re-engineering, so I think this is where I'm going to stop working on the project (at least for now, since I've got other projects waiting), but I hope you can put in the work to get it working! I do feel like the required precision and inherent complexity are right on the edge of what is possible with Lego, but I think it can be done! I'd recommend moving to a physical build at this point, though, since there is so much moving, and since so much depends on countering the slack in physical parts. I've updated the Studio file with my changes (mostly in green parts), and I've also uploaded a quick video of what operation looks like for me: https://bricksafe.com/files/2GodBDGlory/miscellaneous/Divitis CVT.io Good luck with the project, and thanks for sharing!

Huh, interesting. It doesn't look like a replacement for a full-on Technic motor system, so hopefully it won't be any worse than adding a few additional (and probably unwelcome) interactive features to some Technic models, rather than replacing something else.

Nice, looks like an ambitious project!

I do seem to remember that some of those old sets could come with different sizes of pumps. The interesting thing with that old system is that the pumps and cylinders are actually functionally the same! I would think having a pump with the integrated spring would make operation easier, but if you don't mind manually pulling it up to pump again, one without would work, I think

I got the gearbox built now! I think the main other things I had to change were adjusting the worm gear at the bottom, and changing the ratchets on the top, since those connectors didn't interlock with the 8T gears satisfactorily in real life. Also, I don't really understand the theory behind the gearbox, but I think something must be off with the 7L gear racks, because the way I see it, these blue gears can't actually rotate to move the rack, because doing so would mean moving the LBG 5L beam with which the gear is braced. That area in general feels like it's missing something--should there be some rubber bands to press the 3x7 bent beams against the sides of that ring gear? There also doesn't seem to be a whole lot to hold the rack in place, but again, I don't really understand the theory behind it. My one other question is how is the gearbox controlled? We've got the worm gear driving the 8T gear on the bottom, but is that the input shaft or is it controlling shifting? I assume the red Bohrok eye on the top is the output, but is there a third input/gearbox control somewhere else? I look forward to working through these things to get the concept working! Good job designing such a complex model digitally--that's a huge challenge!

I'm not sure what the theory around them would be, but yeah, they're too tight. If you look at the screenshot up there, you can kind of see that the spacing between the body of the gears is pretty small, and smaller than the height of a gear tooth. Fortunately, I figured out some bracing for my workaround gearing strategy, and it seems to be working, with all the gears rotating at the same speed in the same direction, with only relatively minor changes! I ran out of time last night to finish the build, but hopefully I can get it done today The only other issue I've found (I'm pretty sure it's not by design) is that the 1L liftarms on frictionless pins mounted on the DBL 7L alternating hole liftarms on top of the 15x11 frames interfere with the rotation of the large banana gear assembly, since the tan 4L axles interfere with them. I just removed them, and I expect it'll be fine like that?

The 12T gear is one layer up, on a fifth 36T gear, so we're not running into the issue of having gears trying to rotate different directions at once; it's just that the 36Ts on the same level don't quite fit that spacing

I picked up the last of the necessary parts today, and started building! However, I have ran into an issue: When building physically, it becomes apparent that these 4 36T gears interfere with each other, and just won't mesh in that configuration. I've came up with an alternate gearing option, which could work in theory, but it will require some adjustments to the frame:

Looks nice! It's impressive to see a vehicle that can drive at reasonable speeds, while still having an 8-speed on board! Also, it's fun to see Znap usage like that!

That is a clever tailgate lock design! It's also nice to see people making the best of the PU system in models like this

Looks nice! I look forward to seeing that in a model!

Nicely done! Looks are good, and it's cool to see those new panels being used so effectively already

Hmm, I'd think something like PETG would probably be technically strong enough for it to work, but it would take some very precise CAD work to make them functional, I think. These aren't parts I'd really imagine being a good fit for 3D printing

What do you mean by ratchet joints?

I mean, likely not, but they put real effort into the Bronco front suspension, and they've made lots of nice compact suspension parts lately, so I wouldn't rule it out entirely

Looks like some good progress!

Honestly, Technic is a CHEAP hobby, at least if you're into MOCing and reusing parts, instead of collecting sets. My Technic collection is probably worth under $2000 CAD, and I've probably gotten well over 4000 hours of enjoyment out of it over the last nine years! And, of course, I still have almost all of the Lego, which could theoretically be resold to recoup a lot of that money. I'm also a bit of a "car guy," and enjoy reading about people's project cars, but when you look at the cost of everything to do with cars, it becomes pretty clear that I can get way, way more enjoyment per dollar out of Lego than cars! Even a dirt-cheap beater project car would probably be at least $2000 (assuming it's rust free enough to ever pass inspection), and then you're looking at hundreds on tires, hundreds on fluids, and hundreds for parts, not even factoring in insurance, fuel, and any modifications! I think I'll keep my car interest at the level of daily-driving an interesting car, and maintaining it, thank you very much!

That sounds like a good way of doing it! A lot more precise than pneumatics!

Strangely enough, when I was a kid I built a (pretty terrible) MOC of a Ford GT, and it had what sounds like a similar mechanism! I used a pneumatic cylinder to slide the steering rack forwards and backwards to adjust toe. I'm not sure why I thought it was a good idea to include that, but it sure seems coincidental that I would put that same system on this same car!

Cool, thanks for sharing!

Nice job! That's an impressively complex mechanism, and it seems to work smoothly!