howitzer

Ok, so now I'm back to really wanting this, as your description of the set makes me think why Technic is my favourite theme in all of Lego and how well the Cat would probably fit into there.

Yes, it was supposed to be first included with 42113 but as that set was cancelled, we're still without a proper buying source for the new dumb battery box.

Looks really nice, I thought about adding an engine as well, should fit nicely in there if you'd wanted to add an extra feature and the fenders indeed are a great way to use the piece. I'd love to see a real build, and also a bottom photo to see the mechanics inside.

For me it's genuine Lego only. Other brands are not as easily available here, except online but I don't see much reason to buy them, as I can afford basically any Lego I really want and while other brands might have useful bricks that TLG doesn't (yet) make, I like the constraint this creates, as it sparks creativity. The only exceptions I make are strings, hoses and rubber bands, as those are cheap, easy to obtain and needed in great variety. I might also be willing to (maybe, at some point) make exception for electronics, I've thought about investing in Buwizz unit and perhaps motors.

Yes, that's true as the mould is more complex, but I don't think that matters a lot in the bigger picture. Technic bricks would require similarly complex mould, and they also contain more ABS, though in comparison beams require more pins to connect, which make for an additional cost. On the other hand, flipflop beams probably save some parts as less connectors (and by extension, pins) are required for sturdy builds.

Very nice! I love these kind of machines! Could it also sort pins with bush? Though I imagine they might be problematic, as they come in enormous variety of colours, so they'd end up in every bin... -

Why would that be? Has someone actually already measured their resistance to bending? I know the normal beams have been studied extensively but it would surely be nice to know how the flipflops compare.

I didn't have much time to build during the holidays, until I got common cold and had to cancel all new year's eve plans. So I've been doing some more building in the last couple of days. Mostly I've been working on the geometry of the thing, trying to find places for linear actuators and their transmission so the thing is still very much kludged together with what parts I had laying around, with no regards for aesthetics or even structural soundness in some places. Anyway, here's my current progress, though it's not finished even in the sense of all the mechanical parts, as it appears that the current upgearing needed for the linear actuators to travel far enough, isn't big enough. So lots of work still ahead, and I haven't even started the programming yet, save for some very simple motor testing. Here's a photo of the current configuration:

Of course they won't but my guess is that the building styles will change to reflect the new beams, and less and less old beams are going being used as structural part. They are of course needed still for exteriors and sometimes in structural purposes, so it's not like they are going away. It's just that flipflops will mostly replace the traditional ones in chassis building and such.

I haven't been building much recently, but while making my TC21 entry I felt that the new flipflop beams could be useful, so I ordered a bunch from Bricklink. They arrived a couple of days ago, and I've gotta say, they are a game changer. So many connections made so much easier, which leads to stronger yet more lightweight structures. Now I only wish I had more of them and in more lengths. It feels that enough of them would make the traditional beams more like a specialized part only necessary in few places while the new beams will become the basic structural part.

I thought that too, at least I'm not aware of it being used as cam ever before. Which is pretty funny, considering it could be really useful as such, and is even called "cam".

Looks like you've jumped right to the deep end of Technic sets, as this set in particular seems to be problematic for many people. The differential orientation is where the vast majority of drive problems with this set occurs, so as others have said, check them out carefully against the instructions. If they really are correctly oriented (check again), there's probably something wrong with the gearbox, like it being stuck on a bed-lifting position for some reason.

You're right about the form factor difference between the Technic hub and PF battery box, but I believe you could put the Technic hub upside down in the middle, just above the axle powering front wheels, and then design an opening roof in order to access the batteries. The power button can be accessed from the bottom then, as long as you leave some clearance next to the axle. It's true though that it doesn't lend itself well for small cars with complex drivetrains. But as I said before, you could use the other 2-port hub if you're building a car with only 2 motors even if it has AWD. I also like the shape and mounting points of the RI hub, makes it really easy to integrate into builds. It also helps a lot that you don't have to design it to be removable, as it can be charged on the spot. I'm not that familiar with the hub from the Spike Essential set, looks like I've got to do some searching to find out it's specs...

The Technic hub isn't really any bigger than the PF battery box, just a different shape. And unlike the PF battery box, you can actually use the Technic hub as a structural part, as batteries can be changed without taking the whole unit out. If you need a smaller unit, there's the 88009 hub, which is the same size and shape as the old PF rechargeable battery box though it only has two ports which can support drive and steer with only single motor each. Granted, the PU lineup would really benefit from a small multi-port hub with rechargeable battery. RI hub is there of course, but it's also similar in size to the PF battery box, so it might be too large for small vehicles.

That must be one of the best GBC mechanisms in terms of how convoluted yet simple it can be made.

I actually managed to open one of those motors as a kid and got it back together too so it's possible. Still, it sounds like you're in for a replacement motor, fortunately at least used ones don't cost much in BL.

Garbage truck would be great, but there has never been a proper large-scale A-model garbage truck except maybe 8479, so I'm guessing TLG considers them too unglamorous vehicles to be put prominently on the shelf.

The electronics is very simple, indeed you can just connect the motors to battery box with wires. Those wires are notorious for their degradation over time, so your best chance is to buy some new ones as the original ones are not going to get any better. They might have been produced with better insulation material too, if BL sellers have those with affordable enough price, you're good to go. Newer wires from PF and C+ are not compatible (there was a conversion cable between PF and 9V but those are short and have different ends, so they won't work.) I have no idea if there is usable third party wires, unless you're willing to attempt to open the connector casings and do some soldering to replace the original cable with a new one. I don't think this would work, as I understand the wiring is routed through some very tight spaces, so the connector stacks might get in the way of other stuff.

The scale is the same though, and I think the main reason for the lowish part count is that the main function (=drum) was made of only a few parts, unlike other trucks in similar scale. So I'd say the part count isn't a great guide here.

So if you put 2 into a pin joiner, they're not going to come out? Anyway, gotta get a bunch of them, I was always annoyed by the looseness of the traditional half pin as a connector part between System and Technic pieces...

I love the simplicity of it, no fancy gear mechanisms, but simple ball lift and gravity-operated counting mechanism. The required fine-tuning would worry me though, at least if you wanted to take it to a show or something...

Yeah, I also don't have the parts as I'm severely deficient in the System department, and only have 4 of those rotor blades you used for wings... Hopefully there's someone who can realize it as a physical build too!

I don't look this forum much, but saw this linked in the Technic forum, and I've gotta say that you've nailed the looks! The mechanism is simple yet seems effective, hopefully you can make a physical build at some point too.

I also instantly though of this after seeing the movie. The one shown at Brothers Brick looks nice, but I want at least somewhat functional one, that is with moving wings and all. But I expect such a build to be very difficult one.

Yeah, I think a longer thin liftarms would be too fragile and TLG wouldn't manufacture such a part as it's easy to break it accidentally. Comparing to 1-wide plates, if you have an 1x12 one clutched to other pieces and you start separating it from one end, the rest of it tend to follow, rather than bend and break, while a liftarm would be attached with pins, which might get stuck so a careless pull would easily break it.