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aeh5040

Eurobricks Knights
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Everything posted by aeh5040

  1. aeh5040
    I'm really enjoying all the abstract geometry discussion recently. Keep it coming!
  2. aeh5040
    Woah - that looks awesome! Here is something I came up with a while ago that fits the description - I have not computed which is smaller. Actually, some of us were thinking along similar lines at the last convention I was at (Bricks Cascade). We came up with a related question: design a similar 3D structure that is very strong but at the same time very low density (and preferably not too expensive). Then the idea would be to make a huge slab of it (say a 1m x 1m x 1m cube for starters). That is the structure of graphite. I made a piece like this a while back... Can we find a way to do the crystal structure of diamond?
  3. aeh5040
    Here we go. Green exists, red doesn't. (Like I said, I'm only considering 1x1x2 here). By the way, I sometimes find it rather amazing that this part can exist: If you think about the two things that it joins in situ: an axle just abutting a pin hole without going in to it, it is amazing that there is enough space between them to make a connection, let alone a strong one in ABS, and, moreover, while keeping the bush part within the usual bush profile (so that a 24t gear two holes away does not foul it). Another related topic: a few years ago Lego Education had a "parts pack" advertised for which the picture on the website contained a version of this part:, except with axle holes for the two horizontal holes!! I eventually ordered it, and was disappointed to find I just got the part above. I guess they planned such a part but decided to make that one instead.
  4. aeh5040
    This is a fascinating question! I would say there are more than a few combinations missing, some of which would be very useful. Just restricting to a 1x1x2 piece containing two of your four connection types, I reckon there are 24 possibilities, leaving out symmetries and things that seem physically impossible, such as two parallel male pins. Of these, I believe 13 exist as parts. For a further 3 there is a part that is close, in the sense that it does achieve the correct placement, but sticks out further than 1x1x2. I'll add pictures to the table tomorrow.... Key: Yes/No/Close axial/axial pm/pm Y 2780 pm/pf N pm/am Y 43093 pm/af C 32054 pf/pf Y 62462 pf/am N pf/af N am/am Y 32062 am/af N af/af Y 6538c axial/transverse pm/pf Y 15100 pm/af N pf/pf N pf/af N am/pf Y 22961 am/af C 57585 af/pf Y 32013 af/af Y 32039 transverse/transverse parallel pf/pf Y 43857 pf/af Y 60483 af/af Y 41677 x2 transverse/transverse skew pf/pf C 44809 pf/af Y 6536 af/af N
  5. aeh5040
    Very interesting! I'm curious how much current it uses. How long would the battery last, and will it work with the IR receiver?
  6. aeh5040
    OMG, how did you manage to collect so many!? Hear hear to that! I don't really have a favorite, but I'm a fan of this guy (very useful for those awkward connections): I know what you mean...
  7. aeh5040
    Whatever the white clutch gear is used for, it is fouling the connector, which seems to be part of the drive train. You will definitely have grinding until you fix that (and it is very easy to do).
  8. aeh5040
    Awesome - I had not realized that!
  9. aeh5040
    Slip, yes. Grind, no!
  10. aeh5040
    Here is another consequence of the first observation above. Stack five 5x7 frames on top of each other, each time using the twisted diagonal-diagonal connection. Then the overall twist between the top and bottom frames is almost exactly 90 degrees. So you can join another 5x7 frame vertically to both of them (with a liftarm to space it one stud away at one side). Sorry I don't have access to a picture right now - it is an exercise for the reader! ------------------------------ That's very cool!
  11. aeh5040
    Nice find! It can be seen as another example of the "Lego proof" of Pythagoras that I gave before, with the following parameters: EG=9-4=5; GB=6+6=12; BE=9+4=13, giving a 5-12-13 triangle.
  12. aeh5040
    Awesome! Do let us know how it goes...
  13. aeh5040
    It's very hard to tell what the issues might be from one small picture, but it looks as if you have the 24t white clutch gear and the light bluish gray axle connector fouling each other at the extreme right of the picture. If they are at 2 stud spacing, they will contact. A bush instead of the connector will not.
  14. aeh5040
    It is possible to control 2 functions with 1 motor. It is possible for the two directions of motor rotation to power different functions. The only official set I know of that does this is 4895.
  15. aeh5040
    Here is an interesting little construction I stumbled upon. I post it in case it is useful to someone. The fit is not mathematically perfect, but very very close. The angle produced by the frames is 180 - 2 arctan(4/6) = 112.62 degrees, whereas the connectors are 112.5! What other constructions like this do you know?
  16. aeh5040
    Thanks everyone for the kind remarks. I guess I too have always been fascinated by things gradually going in and out or phase like this. Eric is correct (or should that be 90% correct?). They are X-Pod bottoms (in pairs). No special method for collecting them - several orders, patience, etc. It worked pretty well at the two consecutive shows I just did. On the positive side: it runs incredibly smoothly - no problems at all, and not even any detectable ABS dust after six solid days of running. The negative: it's not necessarily the easiest for spectators to appreciate. If they walk past during the more random phase, they may not notice that the pattern is changing, and thus quickly tune it out. On the last day I added a little sign saying "The pods synchronize about every 5 minutes", which helped. Quite a few people waited to see it and were happy! I'll probably make an LDraw file at some point... Here are some static pictures as requested (see bricksafe for more)
  17. aeh5040
    That's right. I was referring more to how the actual gearing works, which tends to baffle people. I'll take a few photos soon. My first attempt had the differentials arranged differently. One linking pods 1,2 and 3, the next linking 2,3,4, etc. Theoretically this gives exactly the same effect, but it did not work at all. A combination of friction and gear lash meant that it just locked up. The current version (with diffs between 1,5,9; 1,3,5; 5,7,9; 1,2,3; 3,4,5; 5,6,7; 7,8,9) works very smoothly. It's not so easy to explain the big difference. Yeah, diffs are awesome, and I would like to find more applications. Here's something else I used them for a while ago: http://www.brickshelf.com/cgi-bin/gallery.cgi?i=4756066
  18. aeh5040
    Thanks! You should be able to see the gear setup pretty clearly at 1:50. Let me know if any something is unclear. Understanding why it works is a different question. As I said, the two ends pods are geared directly from the motor, with 1:2 x 3:5 and 1:3 ratios, giving 9:10 or equivalently 72:80. Then the middle pod is driven by the cage of a differential connected to the ends, so its speed is the average of the ends, or 76. Then another differential averages the 72 and 76 to give 74, and so on.
  19. aeh5040
    Hi all, Here is my latest kinetic art piece: The nine pods all oscillate at slightly different speeds, so the pattern is always changing, and repeats about every 5 minutes. The two at the ends are directly geared in a 9:10 ratio. The others are driven by differentials which successively average the speeds. This means that the speeds are in the ratios 72:73:74:75:76:77:78:79:80. At various times, it produces 1 wave, 2 interlacing waves, and 3 synchronized color sets. Enjoy!
  20. aeh5040
    That's some amazing mechanical sequencing! (Not to mention very clean and compact structure). Please do share some pictures and video of the internal mechanisms... I think we are all wondering how it is done!
  21. aeh5040
    8043 was indeed a great set, but I'm not sure that's what you meant... If I really had to pick one I think it would be 8480. Partly this is nostalgia (it ended my dark age). But also I love the way form and function combine so flawlessly...
  22. aeh5040
    You need to make a pneumatic engine and attach it to the wheels. Below is a fairly minimal example (among many others). But it will not go far on the contents of a single air tank. For that you need to use a larger non Lego bottle, as below, or else many many air tanks.
  23. aeh5040
    I'm not sure there is much point in pursuing this further. As you say, it was your ultimately your mistake that you did not read the terms of service carefully enough (if I understood). That mistake resulted in a financial cost. You are basically asking them (bl) to pay that cost instead of you. I.e. you are asking them to subsidize you. That may be a reasonable request, and some businesses might do it in order to keep a valued customer happy. But it is also quite reasonable for them to refuse. I don't see how any of the language in the email can be construed as inappropriate, although the numerous spelling, grammatical, and factual errors (e.g. pretty sure amazon has amassed more sales!) do suggest this customer service representative is inexperienced. If you're determined to pursue it, I'd definitely insist on talking to a manager...
  24. aeh5040
    I've just made it in real life, and of course it works perfectly. Maybe it would be possible to make a "puzzle ring" along the lines of these: Edit: I think this could work... I just tried replacing every third connector along each strand with a #5 - the ones that go "over the top" of another strand. As I hope, this gives the whole thing a gentle curve. One could probably continue like that and join it up to form a (large) loop. Other just adjustments might allow a smaller radius loop...
  25. aeh5040
    I think I will have to try recreating this as well! Again, it's an awesome creation. If I understand correctly, the second double layer of of 2x8 technic plates from the top is not supported by anything from below - it is just "hanging" from the 1x1 round bricks and the "cross beam". Is that right? (Not a criticism - just making sure I know how to build it!)
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