Stereo

A little hard to tell from the video but it doesn't look like you have the right timing advance on your switches. Around 45-90 degrees ahead of the piston works best, yours appears to be at 0 or 180. The design I've had success with puts them 60 degrees ahead, so when the piston is at bottom the switch is already opening, and 30 degrees later the switch is full open and the piston can expand. With a 2 piston engine you might be able to route the air to opposite pistons to get 90 degrees, that should be capable of moving itself but it might be more jerky than at the ideal spot.

Batmobile has temporarily lost its wheels in service to testing the steering, looks like I can just about clear the 5-wide frame and coincidentally get pretty good Ackermann as well. I did have to turn it 180 from how I thought it would work. The steering stop is the 3L beam behind the gear rack. Though on closer inspection the rack also hits the 3L axle with stud the wheel mounts to.

Thanks, that's good enough for me.

Basically this: The worm is on grid. The connection points are at the two black squares, and the space in between them is unavailable. The 3x5 opening is about the most I can afford it before it runs into other things. The closest holes available above/below the cube are spaced 5 apart (on the right, using plates with pinholes above/below). If it's turned sideways then the underside studs line up with a jumper plate, but that makes something 6 plates tall in a 3 stud (7.5 plate) gap so there's no space to do anything at the top. Like the simple solution is use the antistud pins, I'd be confident in the strength of this but they're 1/2 plate too thick to fit the 3 stud space. I do have room to continue outward from here, so maybe I can put a 3l bar through a Technic pin and into the 1x3 round plate... not sure that has anything to stop the 1x3 from sliding away from the worm though. Looks kinda janky but maybe this is all legal? If I repeat it for the higher row of studs even better. I much prefer this 'balanced' style where it's attached to all 4 corners, but maybe with 2 cubes, using 2 corners multiple times is good enough. The motion is applying mostly vertical force on the cube but with a small torque, so it's more a question of whether it could work loose from stud connections if only the top or bottom of the cube was attached. So thanks for that tip, I'll see if I can acquire 2 cubes.

For a while I've wanted to build a working 2-stage mast on a forklift, this scale is just about big enough to make it happen and only look a bit too bulky. Mostly so far I've been thinking about what parts to use, but the last couple days I began fitting it together in Studio. The tire size limitation led me to a heavy duty forklift; smaller ones usually run big front, small rear tires, at this size they use 6 tires with 4 on the front axle. So scale works out to about 1:24. Same as the Mack Anthem and car transporter. Might need battery counterweights, but one goal is to be able to lift the Anthem's container. From there I pulled the basic dimensions (20 stud wheelbase, 20 stud tall mast). 19 stud helicopter blades are a little long, but there's really not a lot of middle ground there, straight from 8 to 19, brick building would likely weigh too much. To help keep the design organized, the mast stages are colour coded, yellow ones attached to the chassis, red as the first stage, blue as the second stage that actually holds the forks. Very likely going to be all black in bricks (no blue 7 length liftarms with alternating holes, yet...). Yellow and blue slide in the red parts, which have an H shape. The forks also move 3 studs side to side, I've seen on real ones they have some mechanism to manage this but I don't have ideas to allow that, other than maybe winding string all over the place. I wanted front wheel drive with a differential, but also keeping the mast as far back as possible, so the diff couldn't go between the tires. It's going to be a fake engine, no motorization. I'm not happy with how prominent the small linear actuators are, hopefully once it has a body that'll be less of a problem. Planning to make them diagonally downward, but I haven't tested what triangle gives reasonable range of motion. The raising is done by the worm onto 20T gear at the back, through knob gears, and then the new city screws cause I've wanted an excuse to play with some. They're a bit annoying to convert into the Technic grid; this is a 5 stud deep setup to pinholes on the upper/lower studs. Which feels like a lot for a piece that's a 2 stud cube. Once I get some in hand I'll be able to try some more iffy options, like only attaching it from one side, and see if it's still able to run smoothly. Right now I'm just getting the basic mechanisms in place to make sure they'll fit. Once I'm fairly confident I have the functions packed into the space, I'll need to build something in bricks to test out the gear ratios. 1:20 on the worm gear is concerningly high, 5 full rotations per 2 studs the forks raise.

I wouldn't expect mold numbers to be completely unique; they start over any time they redesign the part. I expect they're for internal QC so they'd only be taking care that they don't run multiple with the same number simultaneously. I just looked at my headlight bricks cause I happened to have them sitting around for a MOC, and the early '90s to around 2000 ones have only a mold number (1, 5, 6, 13, 15). The more recent ones with a slot have the (C)LEGO, mold+position stamps (1-2, 4-29, 19-35, 29-35, 43-39, 25-2, 25-13, 10-24, 14-24) I did find one oddity though, the 10-24 and 14-24 ones are actually stamped in two locations - 24-14 in the spot the other ones have it, plus 14-24 on the bottom surface of the brick. I think they're probably mold 24 since 24-10 and 24-14 having the same weirdness makes more sense. "Old" style with only 15 is on a dark grey brick which actually puts it in a pretty narrow time window of 1999-2003, I know mine are from 7111 and 4489. Just to make sure I have a reference point, "new" style 61-40 and 62-46 are from a set 30435 that I'm confident has never been shuffled into my other lego. Same set has 07-68 on a 2x3 plate; if I continue reading numbers I'll probably go from those cause they're easier.

The layout's still operational pretty much unchanged, other than receiving some part orders to make the colours more consistent. The decouplers continue to work fine. I've noticed that the two cars using the most current plastic-on-plastic wheelsets pick up hair much faster than anything else, and don't roll well. The stubs are mostly on a 1 plate per 16 stud downhill once they leave the switches, and the metal axle cars coast to the end. The all-plastic ones don't move. Lesson learned, I won't buy more of them even at half the price. I added a boxcar because I wanted more variety of type and colours. Same 6x16 base as the other cars. It's closer to the medium azure stake car than I'd thought when buying the parts, so that one might get "repainted" to something more distinct, perhaps lavender or orange, since it gets its colour entirely from 1x2x1 panels anyway. More pictures on Bricksafe, instructions on Rebrickable. Through another channel, someone pointed out that the brake wheels overhang past the buffers on some of these cars, so there's potential for collisions in corners. The reason that doesn't happen is: When facing the end of the car, the wheel is always to the left hand side. So if two of the brake wheels happen to be coupled face to face, they miss each other. I built them that way by coincidence, but now that I'm aware of it I can continue that pattern.

Maybe also pushes sales to the official Lego store, as far as I know only one version goes to store shelves. Lime Lamborghini, yellow Bugatti, probably grey Jesko.

Is this a "legal" connection? It's certainly doable in real parts, but it looks like colliding in Studio. If not, my alternative idea is something like this, with flick missiles, but I'd rather get something more compact.

Probably gives it a softer touch as well, 42157 is a big sturdy tractor and using the manual pump flexes it quite a bit. Would need to have been mounted on the base, which makes that less removable (if it's intended to be at all)

70 studs (56cm) long to 23m in reality is about 1:40, so it's pretty much minifig scale. I don't see much sign of studs or bars for minifigs to attach though.

Lubrication/durability seems to be most of the answer, the worm gear is desirable for its high reduction ratio (remember this was invented well before power steering so 20:1, 30:1 ratios aren't uncommon) but because the teeth slide against each other, it uses ball bearings for the worm in a sealed compartment, and then the other rack acting on the Pitman arm is just a simple motion with much less sliding. Might be a bit of a factor of hand building vs. mass production as well, rack & pinion gears need a whole bunch of teeth cut into the rack, this seems to get by with fewer. Like a rack and pinion might have a 10 tooth pinion and 60 on the rack to get the same kind of ratio.

24 can't, but it's possible to use the space 2 studs away for parts shaped like axle/pin perpendicular connector's axle end (6536, 42003, 32068). Though interestingly that only applies to some 24T gears, I ran into a problem with a MOC once when I used the wrong variant of 3648b - some have flattened tips of teeth, some are rounded and can't do this. I'll have better 3d tools later in the week for measuring this stuff, I'm wondering if a 20t would work if you basically design it as slots in the outer housing of the diff that a non-bevel can dig into. Or if those teeth get all the way into the 12t bevels inside the diff.

I have thought about a smaller diff design, probably 24t ring, but never got to building a 3d model for it. It might work with the usual 'axle hole on an undersize bar' but probably 12t bevel with pinhole would be helpful to making it structurally sound. 1st piece is loose bar (or pinhole) sized stubs for mounting the planets, you'd put an axle with stop through from the middle into the 12t bevel on one side. 2nd piece is a 24t gear with a 1 stud wide crosspiece through the middle, with pinhole, and gaps for the bevel gears. So an axle with stop goes through it the other way into the other 12t bevel. The two fit together like lincoln logs and are fit in between beams so everything's captive. Wouldn't be as strong as a one-piece diff but for the kind of small construction that wants a narrow diff it'd be fine. It might be possible to have the bars for the planet gears overlong and clip into the ring gear, but I'd need a dimensionally accurate 3d model to decide about that.

Yes, it has 4 teeth and they're spaced 1 stud apart lengthwise, so one revolution is 4L (moves the black box from one end to the other, since it's 2 studs long). The other kind of gear rack is 5 teeth per 2 studs, so 4L is 10 gear teeth per revolution. So on a 20t gear it would turn 180 degrees. I imagine in that design you don't need more than 60 degrees on the red arm.

Yeah, the way parts like the 24t gear have been modified over the years (getting rid of its diagonal axle holes) makes me think they're more cautious of parts that can break into small pieces now. So maybe more viable is something like a 2.5 or 3.5 stud beam with axle holes at both ends and nothing in the middle.

A thin liftarm with half-offset axle holes at one end would be nice to have. Like the cam piece but not 2 studs wide. Maybe 5 long with 3 pinholes, then 3 axleholes overlapping.

I would probably turn the white L-brackets around so they connect the beams, but also in this situation it seems better to have the motors directly drive the tracks instead of using any gears.

It's kinda specialist info, cause tire sizes before ~1965 didn't work the same way as modern ones. 5 means the width of the tread, 15 is the diameter of wheel it fits onto. Unlike modern tires there's no measuring the height of the tire sidewall, it's just assumed to be a similar ratio to other wheels (about 75% the width). So in modern terms it should be a 125/75r15 tire on the front, 155/75r15 on the rear. But only approximately. If you have a properly scaled side view it's better to measure off of that.

The yellow plane on the right appears to be 60250 Mail Plane and the yellow-accented helicopter on the left 31029 Cargo Heli. The other yellow+red one is a B-model of 5866 Rotor Rescue. [edit to add] The other one in the Spaceships photo appears to be 70162 Infearno Inception. Fig with glowing eyes is Mr. E, seems to be from a couple sets.

I suppose I'm first curious about the wheel/tire, 5.00-15 should be about 57cm tall, 15cm wide, or 71x19mm in 1:8. And Lego Technic for the most part jumps from 62.4x20 (large truck/crane) at kinda reasonable size to the very wide (for something like this) medium wheels with 68/82mm tires. Maybe Vespa 75x20 tires work? Ignoring that they have motorcycle profile. I'd probably scale off of those (1:7.5) or the 'truck' tires (1:9).

You wouldn't be able to "drive them in" if they have doorhandles or wheel arches, but if you had the side fold open, you could load most 4 wide cars between these in windowframes https://rebrickable.com/parts/62113/bar-1-x-4-x-3-end-tabs/ https://rebrickable.com/parts/5032/chain-link-fence-4-x-6/ My train has this car in it cause anything larger doesn't really work with 6-wide trains https://rebrickable.com/sets/4544-1/car-transport-wagon-with-car/#parts

If you have some extra vertical space, you can use a double-sided 12T bevel on the vertical axle, and mesh it into a double sided 20T bevel behind it, so that one can go to the 12T for the third axle. Since it just goes 12-20-12 there's no gear reduction and both axles end up at the same speed. A bit annoying to fit the 20T though, it's wide enough you can't have it in between 4 stud wide beams. 12-12-12 technically possible but difficult to mount the middle one since it needs half stud offset vertical holes.

Maybe outside of trains as trains. Single axle is fine for a layout with no switches, so things like GBC constructions can use them for sure. And pretty often use multiple motors on the 'train', not just a train bogie motor.

I suppose the simple answer is plug one of these across 2 bogies https://www.bricklink.com/v2/catalog/catalogitem.page?P=4758#T=C and then run the wire from that. Or if they're directly adjacent, you can just put the 2x2 plug across the electric studs on both bogies. Or use the 2x4 electric plate to bridge from one bogie to 2 studs on the next, then have the wire connect to the other 2 studs. Not sure the exact parts that most easily replace the standard "2xN plate with buffer at one end, bogie plate on top of that", but 9V plugs are easy to integrate into regular structures. Or if they're really spread out (like opposite ends of a car with only 4 wheels) just have a separate wire to each.