ord

Nice! How is the performance of the bearings? It looks like you've kept a 2L space between both the inner and outer rings?

The year is selected first then the red carriage will move to one of two positions depending if it's a leap year or not, if I understand correctly? Maybe you could use the 14-tooth sprocket with treads with tiles attached:

Wow, another interesting entry. Curious to see how you handle leap years and the '400 year rule'.

I have a feeling that it can. The joints appear to be able to attach in series using 2x 2L axles, and a friction pin would make that connection even more robust. I was thinking that too. Interestingly, the joint that part is designed for has a very similar function to this joint - 2 articulations with 15 degree increments.

Fascinating and creative use of Lego. Following closely .

It is essentially the method that Glaysche mentioned of using two parallel gear trains. It is explained in this thread: I am looking forward to this!

There was some discussion recently in this topic: This is the smoothest ball bearing design I've seen:

In some sets they come in grey, I guess for aesthetics.

Have you considered this? Someone posted it in a MOC recently and I thought it was smart. Not sure about it's real world performance.

Wow, that's great! I especially like the conveyor design but there are lots of things to like here.

An almost perfect fit that is new for me: The width of three stacked beams (red dimension) is 8 x 3 = 24mm. According to The Unofficial Lego Technic Builder's Guide, beams are 7mm wide on the thin side, which would make the sides of the yellow triangle (2.5 x 8) - (7 / 2) = 16.5 and the hypotenuse sqrt(16.5² + 16.5²) = 23.33mm. 0.67mm undersize might seem like a lot, but in reality the three stacked beams are held rather snugly at 45°. This can be tested easily inside a 5x7 frame. Edit: like this...

Again, I learnt from the great Akiyuki: I was looking into this last night. The train wheels don't stand up on their own so I think they need a carrier ring connecting them together. Maybe only four wheels could fit on such a ring, which might compromise performance. Also, the 1x1 tiles do a surprisingly good job at providing radial support, but the train wheels not as much, so the bearing might require extra support if using the train wheels. I will build one and see...

I built a bearing based on Akiyuki's design but with the smaller banana gears and it works well: I even managed to pass two axles through it. I think I'll be incorporating this into my robot arm as it seems very rigid.

It's an interesting problem @sammypants and one I have been scratching my head at too. Having built Akiyuki's design (first video), I think it's possibly the best solution - it runs smoothly and is the most rigid design that I've built. The design in the second video is easier to build and remains in-grid, but doesn't have the upper gear form-locked below the lower gear, so is less rigid. I'm not sure how either design would go with the smaller banana gears, but would be interested to see!

Making a video is too much work so I don't plan to do that. Yes the subject is complicated but all of the information is available if you follow the installation instructions on the vpype github - this is how I learnt how to do it. The mechanics of my plotter are fundamentally pretty simple. It's the coding of complex plots, I would say, that make it a complex system.