Davidz90

Now that is unusual! Amazing engineering with conveyor belts and their logic.

Wow, that's a lot of power! Extremely impressive.

Another update to the clock tower. Now it is over 2 metres high. The mechanism includes working calendar (day, month, day of the week), moon phase indicator, striking train (with actual bell tower), additional 24 hour time with sunrise/sunset indicators.

Amazing idea with the locking system!

If I recall correctly, ABS melting point is 105 degrees C, which didn't stop some people from making Lego steam engines with actual steam. However, they may be softened and/or discolored at much lower temperature. [edit] This topic has an excellent demonstration of brick warping under heat. Looks like that up to 95 degrees C is safe.

Amazing! I think that this may be a great setup to test various angles of attack of the blades.

Good point. It would have to be a long elastic band that goes around some pullley and back up.

I guess that the simplest solution would be to add a rubberband at the bottom that will pull the fork back down.

Haha amazing!

He meant the holes surrounding the elongated one. They are 2sqrt(2) apart.

Amazing work on the turret.

Wow, soo much nicer than the official Lego one!

Congratulations and good luck in getting to 10k supporters! Amazing job on shaping the hull.

Thank You very much! Yes, I had used several Lego dials in the past. The simplest one is probably circle gear rack (it has 12 evenly spaced holes). One can also use #3 connectors to form a 12-gon, although the axles are a little stressed in such configuration. Finally, recently I've made one with plates: 20220608_084527 by David_Z1, on Flickr Here, I could use Lego dial for hours, but there is no way to do the calendar so I decided to keep style consistent.

Another update. After several orders with unholy amount of black bricks, clock tower became even more massive. Now the mechanism is powered by four 1.5 kg weights, which keep it running for 240 hours (10 days) on a single rewind. Moreover, the clock will be equipped with a working 365 day calendar. Overview of progress is here: And here is the calendar mechanism: and instruction how to do a 1:365 gear reduction: Also, I figured out an easy way to make 1:12 reduction for clock hands that has very little gear backlash:

Indeed. There seems to be a second row of pistons in the engine image, but it's hard to tell. Interesting model, although I'd like it more in blue-black color scheme.

Sure! The system is in the image below. Differential (the new type) has one axle and casing locked. The amount of play in output is about 1/12 of rotation (marked by blue lines). With 8:40 reduction, the play is also reduced by almost 5 times. backlash by David_Z1, on Flickr Adding another 1:5 reduction reduces the play further by a factor of ~3.

Impressive accuracy! Magnetic core memory.

As I understand it, the play on any gear is about third to half of one tooth and accumulates when multiple gear ratios are used. If I lock one axle and the casing of the differential, then the third axle can move left/right by approximately 1/12 of a rotation (result of 2 gear ratios involving 12T gears). If I put a 8T gear on that axle, and couple it with 40T gear, then the play is almost 5x smaller (not exactly because 8T/40T ratio adds some play on its own). Overall, "big gear reduction immediately before input/output" seems like a valid strategy. But yes, the fact that clock works one way only solves many issues as well.

I see, yes that is an issue. I guess the input would need to be geared up, put through differential and then geared down. That works for my clocks. I wonder if this switch design can be used as a pressure sensor - the force produced by the hose as it tries straighten itself should depend on pressure. Maybe this, along with some Watt regulator for speed sensing, could be used for a fully automatic engine timing control?

Amazing! Your designs are always so neat and well thought out. Great demonstration of switchless pneumatic engine. Always wanted to make one - did several "regular" ones, but they tend to be extremely inefficient unless switches and pistons are modified (which I don't want to do). Also, interesting idea with the timing. An alternative approach would be to use a differential instead of tilting the whole mechanism.

Nice, compact mechansim (at least as compact as chain encoding allows). It's amazing how many things can be done with pins on chains, from all sorts of counters to music boxes.

Wow, that is absolutely amazing! Awesome piece of engineering, adjusting the tension of 128 strings must have taken a while. I'm actually surprised that the regulation was as much as 2 plates, is the string length that inconsistent?

I rebuilt my clock tower to look a bit like a cathedral. The mechanism features auto-rewinder and hours striking with a large pipe chime. overview by David_Z1, on Flickr

Yeah, that would totaly be case here. Metal axles? Gears will yield. Add metal gears? Liftarms holding everything together will yield. In the end you need more and more metal parts. Clever business strategy