aeh5040

Very nice! From now on, no supercar will be complete without a sausage steering wheel!

To avoid the slipping problem, I guess the barrier could have some regular holes, and the vehicle could have a rotating index wheel (like a gear but with few teeth) that fits into them. I don't know whether or not that is realistic in terms of the real machine.

Great progress!

They are very cheap!

Wow, what a fascinating project! Looks like good progress so far. It definitely sounds doable, although I'm sure there will be many unforeseen challenges along the way! Thanks for sharing... One thing you might want to bear in mind is this piece A wall built out of these can be curved into basically any shape, with no sharp corners. Moreover it can be secured firmly to technic parts with light sabre pieces through the holes.

That's beautiful!

The new joint: the modularity makes me think there may be plans to expand this system further.

Understood. As an alternative (for some future version) I wonder whether the actual contact with the bat could be made to trigger the bounce - not by torque detection but by a mechanical lever attached to the bat. Then when the player missed there would be no bounce at all. Anyway, very glad you got it working!

It looks like 60 deg to me.

Had to check it's not April 1! Very cool though.

Connector #7 in black. I hope it will eventually become more affordable.

Really nice use of the banana gear!

Wow, congratulations on getting this working!! The mechanism looks surprisingly simple, given what it is doing. I would like to see more details of how it works. Is there some mechanial difference between what is happening when the user hits the ball with the bat versus when they miss? So that in principle this could be used to trigger a scoring mechanism?

Here are just the mechanisms...

Good work! It's great to have another entry!

Not having anything else to do, I made a digital model, and instructions are in preparation... Also some better quality pictures below. Incidentally, the "perfect fit" geometry was used in various ways to position the red windows:

The Marvellous Mechanical Date Engine (automatic perpetual calendar) Determines the day of the week of any date in the time period 1601 - 2300 (in the modern Gregorian calendar) Automatic correct treatment of leap years, including the special 100- and 400-year rules. (This is in contrast with all other hand-calculation methods and physical perpetual calendars that I am aware of, all of which require some kind of manual adjustment for leap years) Simple intuitive operation Four hand-operated knobs to select date, month, century and year Positive, precise switching, with no ambiguity of results (achieved by a combination of spring and gravity detent mechanisms) Three differentials perform the calculation Modular construction, making for straightforward set-up and adjustment Dimensions: 35x20x20 cm Parts: approx 1300 Discussion thread:

[Also posted on LDraw forum - hope this is OK] Hi all, Some help/advice would be much appreciated. Making instructions using MLCad/LPub I am trying to do the following: 1. Early in the build, a part gets partially inserted (specifically a Technic pin with bush ) 2. Then many steps (and submodels) later, it gets pushed in all the way. I cannot be the first person to want to do this. It is very common in official Lego instructions. The only ways I can think of to achieve it are: Either A. Buffer exchange STORE just before it is partially inserted, then just before pushing it in, RETRIEVE, and then repeat all the parts and submodels that were added in the interim, but with all STEP commands and LPUB stuff removed, and then add the part in its final position. Or B. For every STEP between the initial and final insertion (including the first but not the last) add a new buffer excehange in which this part is redisplayed in its partially inserted position and then removed again after displaying the step. Either option seems horrendously messy, and requires tricky adjustment of the parts list, and even more so if there are multiple such partially inserted parts to deal with. My questions are: how do people do this? Which way is preferred? Is there some better way I am missing? Am I wanting something unreasonable? Apologies if this is already answered somewhere, but I have looked and not found...

Cool! I hope it doesn't shake itself to pieces...

Wow, fascinating!

Thanks! Glad I am not the only one to appreciate a satisfying clunk

This has been a really fun one for me. I hope there will be more contest themes like this.

Can't say I've ever used those hubs, but to me the sliding 8t gears are wonderful and totally irreplaceable. That odd 4L liftarm is sometimes useful. I have a particular soft spot for it because it is used so perfectly in the legendary 8480.

A few more details: The algorithm is basically like the tabular methods at https://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week and physical "perpetual calendars" like this one https://en.wikipedia.org/wiki/Perpetual_calendar#/media/File:50yearcalendar.JPG. However, so far as I am aware, all previous such methods and devices required some sort of manual adjustment for leap years. This device handles leap years automatically. As you can see, the year drum has 14 positions, alternating between leap years and non-leap years, and its motion controls the selector which uncovers different instances of Jan and Feb (other months are not affected). A second innovation is the way exact centuries (1900, 2000, ...) are handled. There is no "00" on the year drum. Instead, these years are formed using the "0" and "000". These are positioned so as to get it right (leap year for a multiple of 400, but not for other multiples of 100). More centuries beyond 1601-2300 could be handled by adding extra entries to the century dial, but I decided this was enough. The day, century and month drums also have 14 positions rather than 7. There is no fundamental need for this, but it simplifies the construction and allows for fewer entries sharing a position (in particular no sharing on the century drum). The output day drum moves by a full 1/7 turn, partly to make it more dramatic and partly to combat gear lash issues. It would be possible to add manual horizontal sliders to the drums so that a single entry could be selected, making it more like a calendar. There is no obstacle to this but I decided it would make it too fussy. Regarding mechanics, it is important that the signals are constantly geared UP, to minimize the effects of gear lash. Gear lash is always a constant fraction of a tooth for every gear meshing (even more for a differential), so each "click" needs to correspond to a big rotation of the shafts, so that the lash remains a small fraction of it. In fact each click corresponds to one rotation for most of the mechanism. Of course there is a balancing act, because gearing up too much would increase resistance. It is also important to minimize the gears. All this ensures that the lash in the final output is fairly small even without the final gravity detent, so then the gravity detent is enough to click it into place. The splat gears are very useful both for their large size (so that they can mesh with an axle that does not intersect the drum) and to get the necessary factor-of-7 gear ratios. The "stickers" are actually not stuck to the drums, but form a tight band around them held in place by friction. This makes adjustment much easier. There are lots of tight clearances everywhere - it feels rather miraculous that everything fits. The drums themselves are quite close to each other; the vertical axle for the leap year selector passes really close to the drums; the taller red window for the day involves some ridiculously small gaps as described above. I'm really happy with how it has turned out. Many of us know that with a model like this there is almost always something that never quite works as well as it should. For once I seem to have escaped that curse!

OK, video is finished!